United States
Environmental Protection
Agency
United States
Department Of
State
21P-3001
February 1991
Policy. Planning And Evaluation (PM-222)
U.S. Efforts To Address
Global Climate Change
Report To Congress
Appendices
Prepared jointly by the
U.S. Department of State
and the U.S. Environmental Protection Agency
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U.S. EFFORTS TO ADDRESS
GLOBAL CLIMATE CHANGE
A Report to Congress
Appendices
February, 1991
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APPENDIX A
WHITE HOUSE STATEMENTS
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THE WHITE HOUSE
Office of the Press Secretary
For Immediate Release November 7, 1989
UNITED STATES JOINS 70 NATIONS IN UNANIMOUS DECLARATION ON
CLIMATE CHANGE
President Bush announced today that the United States has agreed
with other industrialized nations that stabilization of carbon
dioxide (CO2) emissions should be achieved as soon as possible.
The U.S. also agreed that it is timely to investigate
quantitative targets to limit or reduce carbon dioxide emissions.
The U.S. was joined by over 70 countries attending the
Ministerial Conference on Atmospheric Pollution and Climate
Change in Noordwijk, The Netherlands.
In joining the Declaration at the Ministerial Conference, the
United States recommended that international funding be directed
towards funding a chlorofluorocarbons (CFCs) phase-out in
developing countries and promoting efficient use of energy. In
addition, the Declaration:
Urges all countries to take steps individually and
collectively to promote greater energy conservation and
efficiency;
Recognizes the need to stabilize the emissions of carbon
dioxide and some other greenhouse gases, while ensuring
sustainable development of the world economy;
Agrees that developing countries will need to be assisted
financially and technically;
Urges all countries to join and intensify the ongoing work
in the Intergovernmental Panel on Climate Change (IPCC) with
respect to a framework convention.
The President said, "I asked my EPA Administrator Bill Reilly and
my Science Advisor Allan Bromley to continue the leadership role
which the U.S. has performed since the Intergovernmental Panel on
Climate Change (IPCC) was formed in 1988."
The President also praised the Conference for providing the
United States an excellent opportunity for useful consultations,
both informally and formally, with many of the participating
countries, including many countries that have not previously been
active in the IPCC process. President Bush also noted that such
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conferences contribute substantially to the growing consensus
among policy makers with respect to global climate change.
William Reilly, the Administrator of the Environmental Protection
Agency, and Dr. Allan Bromley, Science and Technology Advisor to
President Bush, emphasized during the Conference that the United
States currently devotes $500 million to the study of issues
related to climate change and plans to increase this to about $1
billion in FY 1991. Additionally, through such measures as the
Clean Air Act, more stringent fuel efficiency standards for
automobiles, aggressive energy conservation, and reforestation
programs, among others, the United States is already playing a
leading role in reducing CO2 emissions. The President announced
in March that the United States was committed to total phase-out
of CFCs by the year 2000. CFCs account for about 25 percent of
United States greenhouse emissions.
The United States delegates emphasized their support for the IPCC
process in which it chairs the Strategies Working Group, one of
three such working groups. The IPCC will hold a plenary meeting
in Washington, D.C. in February, 1990. Special reports on the
Science, Effects and Responses to global warming will be
available later in 1990.
In parallel with this work, a Working Group of the Domestic
Policy Council, chaired by Dr. Allan Bromley, is undertaking an
intensive program examining the potential impacts of climate
change and their associated economic consequences.
With the results of these Working Groups and the IPCC report in
the fall of 1990, the United States expects to play a leading
role negotiating the framework convention anticipated to be
called for by the IPCC process. The United States is currently
developing policies based on sound analyses to guide national and
international actions directed toward eventual solutions to
greenhouse problems.
# # #
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REMARKS BY THE PRESIDENT
TO THE
INTERGOVERNMENTAL PANEL ON CLIMATE CHANGE (IPCC)
GEORGETOWN UNIVERSITY, WASHINGTON, D.C.
February 5, 1990
The recommendations that this distinguished organization
makes can have a profound effect on the world's environmental and
economic policy. By being here today, I hope to underscore
concern—my country's and my own personal concern about your
work, about environmental stewardship, and to reaffirm our
commitment to finding responsible solutions. It's both an honor
and a pleasure to be the first American President to speak to
this organization, as its work takes shape.
You're called upon to deliver recommendations which strike a
difficult and yet critical international bargain a convergence
between global environmental policy and global economic policy.
-A bargain where both perspectives benefit and neither is
compromised.
As experts, you understand that economic growth and
environmental integrity need not be contradictory priorities.
One reinforces and complements the other. Each, a partner. Both
are crucial.
A sound environment is the basis for the continuity and
quality of human life and enterprise. Clearly, strong economies
allow nations to fulfill the obligations of environmental
stewardship. Where there is economic strength, such protection
is possible. But where there is poverty, the competition for
resources gets much together. Stewardship suffers.
For all of these reasons, I sincerely believe we must do
everything in our power to promote global cooperation: for
environmental protection and economic growth; for intelligent
management of our natural resources and efficient use of our
industrial capacity. And for sustainable and environmentally
sensitive development—around the world.
The United States is strongly committed to the IPCC process
of international cooperation on global climate change. We
consider it vital that the community of nations be drawn together
in an orderly, disciplined, rational way to review the history of
our global environment, to assess, the potential for future
climate change and to develop effective programs.
The state of the science, the social and economic impacts,
and the appropriate strategies all are crucial components to a
global resolution. The stakes here are very high; the
consequences, very significant.
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The United States remains committed to aggressive and
thoughtful action on environmental issues. Last week, in my
State of the Union address, I spoke of stewardship, because I
believe it's something we owe ourselves, our children and their
children. So we are renewing the ethic of stewardship in our
domestic programs; in our work to forge international agreements;
in our assistance to developing and East bloc nations; and here
by chairing the Response Strategies Working Group.
I have just submitted a budget to our Congress for fiscal
1991. It includes more than $2 billion in new spending to
protect the environment. And underscoring our commitment to your
efforts, I am pleased to note that funding for the U.S. Global
Change Research Program will increase by nearly 60%, to more than
$billion.
That commitment, by far the largest ever made by any nation,
reflects our determination to improve our understanding of the
science of climate change. We are working with our neighbors
around the world to enhance global monitoring and data
management, improve analysis, reduce the uncertainty of
predictive models, and conduct regular reassessments of the state
of science.
Our program allows NASA (Nations Aeronautics and Space
Administration) and her sister agencies and all our inter-
national partners to move forward with the "Mission to Planet
Earth." That will initiate the U.S. Earth Observing System, in
cooperation with Europe and Japan, to advance the state of
knowledge about the planet we share.
Steps Already Taken
Furthermore, even as we wait for the benefits of this
research, the United States already has taken many steps in our
country that bring both economic and environmental benefits.
Steps that make sense on their own merits in terms of
responsibility and efficiency, which help reduce emissions of
CFCs and carbon dioxide and other pollutants now entering the
atmosphere. Let me outline them very briefly:
We are pursuing new technology development that will
increase the efficiency of our energy use and thus reduce total
emissions.
We're crafting a revised Clean Air Act with incentives for
our private sector to find creative, market-driven solutions to
enhance air quality.
We've launched a major reforestation initiative to plant a
billion tress a year on the private land across America.
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And we're working out a comprehensive review and revision of
our National Energy Strategy, with initiatives to increase energy
efficiency and the use of renewable resources. These efforts,
already underway, are the heart of a $336 million Department of
Energy program and are expected to produce energy savings through
the year 2000 of over $30 billion—while achieving significant
pollution reduction. Quite a return on investment.
We're also working, through diplomatic channels withour
colleagues in other countries and through innovative measures
like debt-for-nature swaps, to do more than simple reduce global
deforestation. We hope to reverse it, turn it around—not
unilaterally, but by working with our international neighbors.
The economics of our response strategies to climate change
are getting intensive study here in our country, in the United
States. We're developing real data on the costs of various
strategies, assessing new measures, and encouraging other nations
to follow suit. And we look forward to sharing this knowledge
and technical support with our international colleagues.
As we work to create policy and agreements on action, we
want to encouraging the most creative, effective approaches.
Wherever possible, we believe that market mechanisms should be
applied—and that our policies must be consistent with economic
growth and free market principles in all countries. Our
development efforts and our dialogue can help us reach effective
and acceptable solutions.
Last December at Malta, in my meeting with President
Gorbachev, I proposed that the United States offer a venue of the
first negotiating session for a framework convention, once the
IPCC completes its work. I reiterate that invitation here and
look forward to your cooperation in that agenda.
We all know that human activities are changing the
atmosphere in unexpected and in unprecedented ways. Much remains
to be done. Many questions remain to be answered, together, we
have a responsibility to ourselves and the generations to come to
fulfill our stewardship obligations. But that responsibility
demands that we do it right.
An Open Mind
We acknowledge a broad spectrum of views on these issues,
but our respect for a diversity of perspectives does not diminish
our recognition of our obligation—or soften our will to produce
policies that work. Some may be tempted to exploit legitimate
concerns for political positioning. Our responsibility is to
maintain the quality of our approach, our commitment to sound
science, and an open mind to policy options.
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So the United States will continue its efforts to improve
our understanding of climate change—to seek hard data, accurate
models, and new ways to improve the science—and determine how
best to meet these tremendous challenges. Where politics and
opinion have outpaced the science, we are accelerating our
support of the technology to bridge the gap. And we are
committed to coming together periodically, for international
assessments of where we stand.
Therefore, this spring, the United states will host a White
House conference on science and economic research on the
environment — convening top officials from a representative
group of nations, to bring together the three essential
disciplines: science, economics, and ecology. They will share
their knowledge, assumptions, and state-of-the-art research
models to outline our understanding and help focus our efforts.
I look forward personally to participating in this seminar and to
learning from its deliberations.
Our goal continues to be matching policy commitments to
emerging scientific knowledge — and a reconciling of
environmental protection with the continued benefits of economic
development. And as Secretary Baker observed a year ago,
whatever global solution to climate change are considered, they
should be as specific and as cost effective as they can possibly
be.
If we hope to promote environmental protection and economic
growth around the world, it will be important not to wok in
conflict, but with our industrial sectors. That will mean moving
beyond the practice of command, control, and compliance — toward
a new kind of environmental cooperation — and toward an emphasis
on pollution prevention, rather than mere mitigation and
litigation. Many of our industries, in fact, are already
providing crucial research and solution.
One corporation, for example — and there are others, but
I'll single out one of them — 3M started an inhouse program
called Pollution Prevention Pays — one company. And that has
saved the company will over half a billion dollars since 1975 —
prevented 112,000 tons of air pollutants, 15,000 tons of'water
pollutants, and almost 400,000 tons of sludge and solid waste
from being released into the environment. They've done it by
rewarding employees for coming up with ideas. And they have
clearly demonstrated the benefits of doing it right.
Where developing nations are.concerned, I know some argue
that we'll have to abandon the free market principles of
prosperous economies. In fact, we think it's all the more
crucial in the developing countries to harness incentives of the
free enterprise system in the service of the environment.
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I believe we should make use of what we know. We know that
the future of the earth must not be compromised. We bear a
sacred trust in our tenancy here — and a covenant with those
most precious to us: our children and theirs. We also understand
the efficiency of incentives — and that well-informed free
markets yield the most creative solutions. We must now apply the
wisdom of that system, the power of those forces, in defense of
the environment we cherish.
Working together, with good faith and earnest dialogue, I
believe we can reconcile vitality with environmental protection.
And so let me commend you on your outstanding work — and wish
you all deliberate speed in your efforts to address a very
difficult, but very important, human concern.
It is a great pleasure to be the first President to address
this distinguished group. Thank you very much.
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THE WHITE HOUSE
Office of the Press Secretary
For Immediate Release April 10, 1990
REMARKS BY THE PRESIDENT
IN THE CLOSING ADDRESS
TO THE WHITE HOUSE CONFERENCE
ON SCIENCE AND ECONOMICS RESEARCH
RELATED TO GLOBAL CHANGE
The J.W. Marriott
2:32 P.M. EDT
THE PRESIDENT: Thank you, ladies and gentlemen. Thank you,
Dr. Bromley, very much. Dr. Boskin, Mr. Deland and Secretaries
Watkins and Lujan of our Cabinet. Dr. Bolin, and distinguished
delegates to this truly unprecedented conference.
After all of the hard work that's taken place here — in
what I know was an atmosphere of lively debate — I would begin
with thanks, and a moment of perspective: for your purpose here
is profoundly important to the state of nature, and the fate of
mankind. Your presence has offered hope for a new era of
environmental cooperation around the world and the promise of a
quieter, more thoughtful, more careful tenancy of nature's legacy
to humanity.
You know, during these last two days we've listened and
learned — and I've been briefed thoroughly on some of the
committee's works — learned about Brazil's new initiatives to
protect the Amazon rain forest, about Nigeria's plans to remove
lead from gasoline, about Mexico's promising efforts to reduce
the Mexico City air pollution.
A year ago I participated in an American education summit,
and found the most productive sessions were those working groups.
This conference was structured with that lesson in mind. So my
thanks go to all the delegates who played such an integral role
in those working groups — particularly the foreign delegates who
served as co-chairmen.
A growing sense of global stewardship prompted us to host
this conference. It's a- sense of stewardship shared by all of
you and by the nations you represent. And it arises out of a
natural sense of obligation. An understanding that we owe our
existence, all that we know and are, to this miraculous sphere
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that sustains us. Somebody told me that the evening you had over
at the museum brought this into very, very clear perspective when
you heard from some of the NASA people.
Such stewardship finds expression in many ways — from
public demonstration in landmark legislation. But it is also
rewarded in many ways, in moments unexpected and unforgettable.
Nature's beauty has a special power — a resonance that at once
elevates the mind's eye, and yet humbles us as well.
Before nature, the works of humanity seem somehow small. We
may build cathedrals, temples, mosques, monuments and mausoleums
to great men and women and high ideals. And still we know we can
build no monuments to compare with nature. Our greatest
creations really can't equal God's smallest.
Yet as our tools and intellect advance, we've learned of our
power to alter the Earth. We understand that small actions,
taken together, can have profound global consequences for the
environment we share and the humanity we share it with. The
importance of global stewardship can be best understood in human
terms.
We also recognize that ours is an increasingly prosperous
planet with greater hopes now than ever before that more of our
people, in every nation, may come to know an enduring peace and
an unprecedented quality of life
So we're called upon to ensure that the Earth's integrity is
preserved and that mankind's prospects for prosperity, peace, and
in some regions, even survival, are not put at risk by the
unintended consequences of noble intentions.
That's the reason we've held this conference.
The minds at work here are among the very best we have and
they are the best insurance that our actions are sound. We've
gathered talent from around the world — scientists, economists,
environmentalists, energy ministers, policymakers — to address
the unprecedented cross-fertilization of disciplines and of
nations. That alone, I think, is reason for hope.
But if diversity of perspective is expected, unity of
purpose is crucial. In an atmosphere of uncertainty, we must
foster a climate of goodwill and a stubborn hope that we might
forge solutions without the excessive heat of politics.
Among all- the challenges in our tenancy of this plant,
climate change is, of course, foremost in your minds. We're
leading the search for response strategies and working through
the uncertainty of both the science and the economics of climate
change. But there is one area where we will allow for no
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uncertainty — and that is our commitment to action — to sound
analyses and sound policies.
To those who suggest we're only trying to balance economic
growth and environmental protection, I say they miss the point.
We are calling for an early new way of thinking to achieve both
while compromising neither. By applying the power of the
marketplace in the service of the environment.
And we cannot allow a question like climate change to be
characterized as a debate between economists versus
environmentalists. To say that this issue has sides is about as
productive as saying that the Earth is flat. It may simplify
things, but it just doesn't do justice to the facts or to our
future. The truth is, strong economies allow nations to fulfill
the obligations of stewardship. And environmental stewardship is
crucial to sustaining strong economies. If we lose sight of the
forest for the trees we risk losing both.
But above all, the climate change debate is not about
research versus action, for we've never considered research a
substitute for action. Over the last two days, you've heard
formally and informally, that the United States is already taking
action to stabilize and reduce emissions through our clean air
legislation, our use of market-based incentives to control
pollution, our search for alternative energy sources, our
emphasis on energy efficiency, our reforestation initiatives, and
our technical assistance programs to developing nations.
These policies were developed to address a broad range of
environmental concerns, in particular our phaseout of CFCs, the
impact of our Clean Air Act on emissions, our tree-planing
initiative, and other strategies will produce reductions in
greenhouse gas emissions that will reach 15 percent in 10 years -
- and considerably more later on.
We're also making a leading investment in climate change
research — absolutely essential because it will tell us what to
do next. But what bears emphasis is that we are committed to
domestic and international policies that are environmentally
aggressive, effective, and efficient.
And we are deeply committed to an international partnership,
through the IPCC process. We look forward to its interim
assessment. An we would encourage a framework convention as a
part of a comprehensive approach to address the system, sources,
and sinks as a whole if a decision is make that environmental
action is needed to reduce net emissions. We hope to provide a
venue for the first negotiating sessions here in the United
States.
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And finally, here in conference working groups, we've
offered four new ideas — a charter for cooperation in science
and economic research related to global change; possible creation
of international institutes for research on the science and
economics of global change; data and information transfers
through a global change communications network; and a statement
of principles for implementing international cooperation in
scientific and economic research related to global change.
I call on you to support these suggestions. All of you here
today understand climate change as one of many challenges in -he
call to global stewardship. Ozone depletion, water supply, c aan
pollution, wetlands, deforestation, biological diversity,
population change, hunger, energy demand — in short, all the
interrelated issues of the global environment. Each demands our
attention. Each will have great impact.
And some we can predict, and regrettably and frankly, some
can't be easily anticipated. But each has a human dimension we
must never forget. Understand the choices we are making. They
affect us all, but in profoundly different ways. We have many
paths to choose from, and some of them are fraught with risk to
precious and life-giving resources. Risk to geopolitical
stability. And certainly, man-made limits to prosperity — most
painfully reflected in the hollow eyes of hungry children and
their prospects for survival.
If developed nations ignore the growth needs of developing
nations it will imperil us all. We know that even small changes
in GNP growth rate often threaten adequate shelter, food, and
health care for millions and millions of people. And to bear
this in mind is no barrier to action. Those who have ascended
the economic hill must break down the barriers to progress and
assist other not making the climb. But this will only be
possible if the nations of the world are linked in partnerships
of every kind: scientific, economic, technical, agricultural,
environmental.
Pollution is not, as we once believed, the inevitable by-
product of progress. True global stewardship will be achieved
not by seeking limits to growth, which are contrary to human
nature, but by achieving environmental protection through more
informed, aore efficient, and cleaner growth.
Those who value environmental quality the most, should be
the most ardent supporters of strategies that tap the power of
free wills and free markets; strategies that turn human nature to
environmental'advantage.. Equally, those who value economic
development most highly should be the most ardent defenders of
the environment, which provides the basis for a healthy economy.
Efficient strategies are the only realistic hope for developing
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nations to save themselves from the mistakes that developed
nations have already made.
And we have made mistakes. But over the past century, we've
made tremendous progress in this country, especially in the last
20 years. In the United States, automotive emission controls
have brought about a new generation of cars that emit only four
percent as much pollution as the typical 1970 model. We've cut
airborne particulates by 60 percent, carbon monoxide by about 40
percent, cut sulfur emissions, and virtually eliminated lead from
the air — all during a period of population growth and economic
expansion. And now we want to share that knowledge — our
technologies, new processes, and pollution prevention
techniques — with the developing world.
Two decades ago, America — holding to its birthright of
free expression — was home to a movement symbolized by Earth
Day. It motivated President Nixon to sign into law a national
policy to encourage productive and enjoyable harmony between man
and the environment. And it set in motion an new sense of
conscience that a few idealists hoped would change the world.
And it did. What began as an isolated American movement 20
years ago is now shared by over 130 counties on seven continents.
And wile many thought his experiment in environmental protection
would prove impossible, that you couldn't maintain both a
productive economy and a health environment, we've learned that
economic prosperity and environmental protection go hand in hand.
And we've learned that worldwide, united action is essential and
possible, as the Montreal Protocol proved.
America and other nations must now extend an offered hand to
emerging democracies in Eastern Europe and to developing
societies around the world. In some, the raging fires of forests
and grasslands burned for compelling but devastating economic
reasons have been visible to astronauts in space. Other nations,
in the struggle to support life, have been virtually stripped of
the resources that sustain life.
And in Eastern Europe, whether through the tyranny of
neglect or the neglect of tyrants, pollution has been unveiled as
one of the Old World's cruellest dictators; an oppressor. Not
man, but man-made.
In the majestic city of Krakow, that I visited a couple of
years ago, monuments to great men, statues that survived
countless invasions by kings and emperors, by Hitler and by
Stalin, have been defaced by pollution; their medieval majesty
reduced to shapeless lumps of stone.
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If mankind's greatest creations cannot equal God's smallest,
some may grieve that our greatest destruction is turned at time
upon ourselves.
Let us neither grieve nor quarrel, but act on what we know
can help, and act in good faith. Our challenge is global
stewardship. To work together to find long-term strategies that
will meet the needs of the entire world, and all therein.
Our convictions, and my sincere belief, is that
environmental protection and economic growth, well-managed,
complement one another. And that we can serve this generation
while preserving the Earth for the next and all that follow. It
is an uncommon opportunity we share. And so let us seize the
moment. And together, we will succeed.
Thank you for what, I believe, is a significant contribution to
environmental progress in the world. Thank you for coming our
way. Thank you very much.
End 2:50 P.M. EOT
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APPENDIX B
IPCC FIRST ASSESSMENT REPORT OVERVIEW
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NOTE TO THE READER
THE FIRST ASSESSMENT REPORT OF THE
INTERGOVERNMENTAL PANEL ON CLIMATE CHANGE (IPCC)
The IPCC First Assessment Report consists of
* the Overview
* the policymakers summaries of the IPCC
Working Groups and Special Committee on the
Participation of Developing Countries
* the reports of the IPCC Working Groups.
This volume contains the IPCC Overview and the
policymakers summaries.
The report of Working Group I has already been
published commercially; there are plans to publish the
other two reports also, each separately, by the end of
the year. They are available, on request, from the IPCC
Secretariat, World Meteorological Organization, P.O.Box
2300, CH 1211 Geneva 2, Switzerland.
N. Sundararaman
IPCC Secretary
October 1990
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OVERVIEW JSCC
TABLE OF CONTENTS
Page
PREFACE iii
1. SCIENCE 1
2. IMPACTS 3
2.1 Agiculture and forestry 5
2.2 Natural terrestrial ecosystems 5
2.3 Hydrology and water resources 6
2.4 Human settlements, energy, transport, and
industrial sectors, human health and air quality... 7
2.5 Oceans and coastal zones 8
2.6 Seasonal snow cover, ice and permafrost 8
3. RESPONSES STRATEGIES 9
3.1 Roles of industrialized and developing countries... 9
3.2 Options 10
4 . PARTICIPATION OF DEVELOPING COUNTRIES 13
5 . INTERNATIONAL CO-OPERATION AND FUTURE WORK 15
APPENDIX Emissions scenarios developed by IPCC 17
ii
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OVESVUW IPOC
PREFACE
TO THE IPCC OVERVIEW
The IPCC First Assessment Report consists of
* this IPCC Overview,
* the Policymakers Summaries of the three IPCC Working Groups
(concerned with assessment respectively of the science, impacts
and response strategies) and the IPCC Special Committee on
the Participation of Developing Countries, and
* the three reports of the Working Groups.
The Overview brings together material from the four Policymakers Summaries.
It presents conclusions, proposes lines of possible action (including suggestions
as to the factors which might form the basis for negotiations) and outlines
further work which is required for a more complete understanding of the
problems of climate change resulting from human activities.
Because the Overview cannot reflect all aspects of the problem which
are presented in the three full reports of the Working Groups and the four
Policymakers Summaries, it should be read in conjunction with them.
The issues, options and strategies presented in the Report are intended
to assist policymakers and future negotiators in their respective tasks.
Further consideration of the Report should .be given by every government
as it cuts across different sectors in all countries. It should be noted
that the Report reflects the technical assessment of experts rather than
government positions, particularly those governments that could not participate
in all Working Groups of IPCC.
iii
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OVERVIEW LPOC
This Overview reflects the
conclusions of the reports of (i)
the three IPCC working Groups on
science, impacts, and response
strategies, and (ii) the Policymake-
rs Summaries of the IPCC Working
Groups and the IPCC Special
Committee on the Participation of
Developing Countries.
1 . SCIENCE
This section is structured
similarly to the Policymakers
Summary of Working Group I.
We are certain of the following:
* There is a natural greenhouse
effect which already keeps the
Earth warmer than it would
otherwise be.
* Emissions resulting from human
activities are substantially
increasing the atmospheric
concentrations of the greenhouse
gases: carbon dioxide, methane,
chlorofluorocarbons (CFCs) and
nitrous oxide. These increases
will enhance the greenhouse
effect, resulting on average in
an additional warming of the
Earth's surface. The main
greenhouse gas, water vapour,
will increase in response to
global warming and further
enhance it.
We calculate with confidence that:
* Some gases are potentially more
effective than others at
changing climate, and their
relative effectiveness can be
estimated. Carbon dioxide has
been responsible for over half
of the enhanced greenhouse
effect in the past, and is
likely to remain so in the
future.
* Atmospheric concentrations of
the long-lived gases (carbon
dioxide, nitrous oxide and the
CFCs) adjust only slowly to changes
of emissions. Continued emissions
of these gases at present rates
would commit us to increased
concentrations for centuries ahead.
The longer emissions continue
to increase at present-day rates,
the greater reductions would have
to be for c'lnoEntrat'' c"g to stabilize
at a given level.
For the four scenarios of future
emissions which IPCC has developed
as assumptions (ranging from one
where few or no steps are taken
to limit emissions, viz., Scenario
A or Business as Usual Scenario,
through others with increasing
levels of controls respectively
called Scenarios B, C and 0),
there will be a doubling of equivalent
carbon dioxide concentrations
from pre-industrial levels by
about 2025, 2040 and 2050 in Scenarios
A, B, and C respectively (see
the section "Which gases are the
most important?" in the Policymakers
Summary of Working Group I for
a description of the concept of
equivalent carbon dioxide}. See
the Appendix for a description
of the IPCC emissions scenarios.
Stabilization of equivalent carbon
dioxide concentrations at about
twice the pre-industrial level
would occur under Scenario D towards
the end of the next century.
Immediate reductions of over 60%
in the net (sources minus sinks)
emissions from human activities
of long-lived gases would achieve
stabilization of concentration
at today's levels; methane
concentrations would be stabilized
with a 15-20% reduction.
The human-caused emissions of
carbon dioxide are much smaller
than the natural exchange rates
of carbon dioxide between the
atmosphere and the oceans, and
between the atmosphere and the
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OVERVIEW EPOC
terrestrial system. The natural
exchange rates were, however,
in close balance before human-
induced emissions began; the
steady anthropogenic emissions
into the atmosphere represent
a significant disturbance of the
natural carbon cycle.
Based on current model results, we
predict:
* An average rate of increase of
global mean temperature during
the next century of about 0.3°C
per decade (with an uncertainty
range of 0.2 - 0.5°C per decade)
assuming the IPCC Scenario A
(Business as Usual) emissions
of greenhouse gases; this is
a more rapid increase than seen
over the past 10,000 years.
This will result in a likely
increase in the global mean
temperature of about 1°C above
the present value by 2025 (about
2°C above that in the pre-
industrial period), and 3°C
above today's value before the
end of the next century (about
4°C above pre-industrial).
The rise will not be steady
because of other factors.
* Under the other IFCC emissions
scenarios which assume
progressively increasing levels
of controls, rates of increase
in global mean temperature of
about 0.2°C per decade (Scenario
B), just above 0.1 °C per decade
(Scenario C) and about 0.1 °C per
decade (Scenario D). The rise
will not be steady because of
other factors.
* Land surfaces warm more rapidly
than the oceans, and higher
northern latitudes warm more
than the global mean in winter.
* The oceans act as a heat sink
and thus delay the full effect
of a greenhouse warming.
Therefore, we would be committed
to a further temperature ns<
which would progressively become.
apparent in the ensuing decades
and centuries. Models predict
that as greenhouse gases increase,
the realized temperature rise
at any given time is between 50
and 80% of the coonitted temperature
rise.
* Under the IPCC Scenario A (Business
as Usual) emissions, an average
rate of global mean sea-level
rise of about 6 cm per decade
over the next century (with an
uncertainty range of 3 - 10 cm
per decade), mainly due to thermal
expansion of the oceans and the
melting of some land ice. The
predicted rise is about 20 cm
in global mean sea level by 2030,
and 65 cm by the end of the next
century. There will be significant
regional variations.
With regard to uncertainties, we note
that:
* There are many uncertainties in
our predictions particularly with
regard to the timing, magnitude
and regional patterns of climate
change, especially changes in
precipitation.
These uncertainties are due
to
-------
OVERVIEW LKC
Our -Judgement is that:
* Global mean surface air
temperature has increased by
0.3 to 0.6°C over the last 100
years, with the five global-
average warmest years being in
the 1980's. Over the same
period global sea-level
increased by 10 to 20 cm.
These increases have not been
smooth in time, nor uniform
over the globe.
* The size of the warming over
the last century is broadly
consistent with the prediction
by climate models, but is also
of the same magnitude as natural
climate variability. If the
sole cause of the observed
warming were the human-made
greenhouse effect, then the
implied climate sensitivity
would be near the lower end of
the range inferred from models.
Thus the observed increase could
be largely due to this natural
variability; alternatively this
variability and other human
factors could have offset a
still larger human-induced
greenhouse warming. The
unequivocal detection of the
enhanced greenhouse effect from
observations is not likely- for
a decade or more.
* Measurements from ice cores
going back 160,000 years show
that the Earth's temperature
closely paralleled the amount
of carbon dioxide and methane
in the atmosphere. Although
we do not know the details of
cause and effect, calculations
indicate that changes in these
greenhouse gases were part,
but not all, of the reasons for
the large (5-7°C) global
temperature swings between ice
ages and interglac-ial periods.
* Natural sources and sinks of
greenhouse gases are sensitive
to a change in climate. Although
many of the response (feedback)
processes are poorly understood,
it appears that, as climate warms,
these feedbacks will lead to an
overall increase, rather than
a decrease, in natural greenhouse
gas abundances. For this reason,
climate change is likely to be
greater than the estimates given
above.
2. IMPACTS
The report on impacts of Working
Group II is based on the work of a
number of subgroups, using independent
studies which have used different
methodologies. Based on the existing
literature, the studies have used
several scenarios to assess the
potential impacts of climate change.
These have the features of:
i) an effective doubling of
C02 in the atmosphere between
now and 2025 to 2050;
ii) a consequent increase of
global mean temperature in
the range of 1.5°C to 4° -
5°C;
iii) an unequal global distribution
of this temperature increase,
namely a smaller increase
of half the global mean in
the tropical regions and a
larger increase of twice the
global mean in the polar
regions; and
iv) a sea-level rise of about
0.3 - 0.5 m by 2050 and about
1 m by 2100, together with
a rise in the temperature
of the surface ocean layer
of between 0.2° and 2.5°C.
These scenarios pre-date, but
are in line with, the assessment of
Working Group I which, for Scenario
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OVERVIEW HOC
A (Business as Usual) has estimated
the magnitude of sea-level rise at
about 20 cm by 2030 and about 65 cm
by the end of the next century.
working Group I has also predicted
the increase in global mean
temperatures to be about 1°C above
the present value by 2025 and 3°C
before the end of the next century.
Any predicted effects of climate
change must be viewed in the context
of our present dynamic and changing
world. Large-scale natural events
such as El Nino can cause
significant impacts on agriculture
and human settlement. The predicted
population explosion will produce
severe impacts on land use and on
the demands for energy, fresh water,
food and housing, which will vary
from region to region according to
national incomes and rates of
development. In many cases, the
impacts will be felt most severely
in regions already under stress,
mainly the developing countries.
Human-induced climate change due to
continued uncontrolled emissions
will accentuate these impacts. For
instance, climate change, pollution
and ultraviolet-B radiation from
ozone depletion can interact,
reinforcing their damaging effects
on materials and organisms.
Increases in atmospheric concentra-
tions of greenhouse gases may lead
to irreversible change in the
climate which could be detectable
by the end of this century.
Comprehensive estimates of the
physical and biological effects of
climate change at the regional level
are difficult. Confidence in
regional estimates of critical
climatic factors is low. This is
particularly true of precipitation
and soil moisture, where there is
considerable disagreement between
various general circulation model
and palaeoanalog results. Moreover,
there are • several scientific
uncertainties regarding the
relationship between climate change
and biological effects and betwee
these effects and socioeconomi.
consequences.
This impact study part of the
Overview does not attempt to
anticipate any adaptation, technological
innovation or any other measures to
diminish the adverse effects of climate
change that will take place in the
same time frame. This is especially
important for heavily managed sectors,
e.g., agriculture, forestry and public
health.
Finally, the issue of timing and
rates of change need to be considered;
there will be lags between:
i) emissions of greenhouse gases
and doubling of concentrations;
ii) doubling of greenhouse gas
concentrations and change
in climate;
iii)changes in climate and
resultant physical and biological
effects; and
iv) changes in physical and mnlngiral
rfPHiM art resultant **»•*'»-«i»»n.ir*
(including ecological)
consequences. The shorter
the lags, the less the
ability to cope and the greater
the socioeconomic impacts.
There is uncertainty related to
these time lags. • The changes will
not be steady and surprises cannot
be ruled out. The severity of the
impacts will depend to a large degree
on the rate of climate change.
Despite these uncertainties, Working
Group II has been able to reach some
major conclusions. These are presented
below.
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OVERVIEW HOC
2 .1 Agriculture and forestry
Sufficient evidence is now
available from a variety of
different studies to indicate that
changes of climate would have an
important effect on agriculture and
livestock. Studies have not yet
conclusively determined whether, on
average, global agricultural
potential will increase or decrease.
Negative impacts could be felt at
the regional level as a result of
changes in weather and pests
associated with climate change, and
changes in ground-level ozone
associated with pollutants,
necessitating innovations in
technology and agricultural
management practices. There may be
severe effects in some regions,
particularly decline in production
in regions of high present-day
vulnerability that are least able
to adjust. These include Brazil,
Peru, the Sahel Region of Africa,
Southeast Asia, and the Asian region
of the USSR and China. There is a
possibility that potential
productivity of high and mid
latitudes may increase because of
a prolonged growing season, but it
is not likely to open up large new
areas for production and it will be
mainly confined to the Northern
Hemisphere.
Patterns of agricultural trade
could be altered by decreased cereal
production in some of the currently
high-production areas, such as
western Europe, southern USA, parts
of South America and western
Australia. Horticultural production
in mid-latitude regions may be
reduced. On the other hand, cereal
production could increase in
northern Europe. Policy responses
directed to breeding new plant
cultivars, and agricultural
management designed to cope with
changed climate conditions, could
lessen the severity - of regional
impacts. On the balance, the
evidence suggests that in the face
of estimated changes of climate,
food production at the global level
can be maintained at essentially
the same level as would have occurred
without climate change; however,
the cost of achieving this is unclear.
Nonetheless, climate change may intensify
difficulties in coping with rapid
population growth. An increase or
change in UV-B radiation at ground
level resulting from the depletion
of stratospheric ozone will have a
negative impact on crops and livestock.
The rotation period of forests
is long and current forests will mature
and decline during a climate in which
they are increasingly more poorly
adapted. Actual impacts depend on
the physiological adaptability of
trees and the host-parasite
relationship. Large losses from both
factors in the form of forest declines
can occur. Losses from wildfire will
be increasingly extensive. The climate
zones which control species
distribution will move poleward and
to higher elevations. Managed forests
require large inputs in terms of choice
of seedlot and spacing, thinning and
protection. They provide a variety
of products from fuel to food.
The degree of dependency on products
varies among countries, as does the
ability to cope with and to withstand
loss. The most sensitive areas will
be where species are close to their
biological limits in terms of temperature
and moisture. This is likely to be,
for example, in semi-arid areas.
Social stresses can be expected to
increase and consequent anthropogenic
damage to forests may occur. These
increased and non-sustainable uses
will place more pressure on forest
investments, forest conservation and
sound forest management.
2.2 Natural terrestrial ecosystems
Natural terrestrial ecosystems
could face significant consequences
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CWEKVIZW IPOC
as a result of the global increases
in the atmospheric concentrations
of greenhouse gases and the
associated climatic changes.
Projected changes in temperature and
precipitation suggest that climatic
zones could shift several hundred
kilometres towards the poles over
the next fifty years. Flora and
fauna would lag behind these
climatic shifts, surviving in their
present location and, therefore,
could find themselves in a different
climatic regime. These regimes may
be more or less hospitable and,
therefore, could increase
productivity for some species and
decrease that of others. Ecosystems
are not expected to move as a single
unit, but would have a new structure
as a consequence of alterations in
distribution and abundance of
species.
The rate of projected climate
changes is the major factor
determining the type and degree of
climatic impacts on natural
terresv. \.al ecosystems. These rates
are lixaly to be faster than the
ability of some species to respond
and responses may be sudden or
gradual.
Some species could be lost owing
to increased stress leading to a
reduction of global biological
diversity. Increased incidence of
disturbances such as pest outbreaks
and fire are likely to occur in some
areas and these could enhance
projected ecosystem changes.
Consequences of C02 enrichment
and climate change for natural
terrestrial ecosystems could be
modified by other environmental
factors, both natural and man-
induced (e.g. by air pollution).
Most at risk are those
communities in which the options for
adaptability are limited (e.g.
montane, alpine, polar, island and
coastal communities, remnant
vegetation, and heritage sites and
reserves) and those communities where
climatic changes add to existing stresses.
The socioeconomic consequences of
these impacts will be significant,
especially for those regions of the
globe where societies and related
economies are dependent on natural
terrestrial ecosystems for their welfare.
Changes in the availability of food,
fuel, medicine, construction material
and income are possible as these ecosystems
are changed. Important fibre products
could also be affected in some regions.
2.3 Hydrology and water resources
Relatively small climate changes
can cause large water resource problems
in many areas, especially arid and
semi-arid regions and those humid
areas where demand or pollution has
led to water scarcity. Little is
known about regional details of
greenhouse-gas-induced hydroneteorolcgical
change. It appears that many areas
will have increased precipitation,
soil moisture and water storage, thus
altering patterns of agricultural,
ecosystem and other water use. Water
availability will decrease in other
areas, a most important factor for
already marginal situations, such
as the Sahelian zone in Africa. This
has significant implications for
agriculture, for water storage and
distribution, and for generation of
hydroelectric power. In some limited
areas, for example, under an assumed
scenario of a 1 °C to 2°C temperature
increase, coupled with a 10% reduction
in precipitation, a 40-70% reduction
in annual runoff could occur.
Regions such as southern Asia, that
are dependent on unregulated river
systems, are particularly vulnerable
to hydrometeorological change. On
the other hand, regions such as the
western USSR and western United States
that have large regulated water resource
systems are less sensitive to the
range of hydrometeorological changes
in the assumed scenario. In addition
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OVERVIEW IPCC
to changes in water supply, water
demand may also change through human
efforts to conserve, and through
improved growth efficiency of plants
in a higher C02 environment. Net
socioeconomic consequences must
consider both supply and demand for
water. Future design in water
resource engineering will need to
take possible impacts into account
when considering structures with a
life span to the end of the next
century. Where precipitation
increases, water management
practices, such as urban storm
drainage systems, may require
upgrading in capacity. Change in
drought risk represents potentially
the most serious impact of climate
change on agriculture at both
regional and global levels.
2.4 Human settlements. energy.
transport.
and
industrial
sectors, human health and air
quality
The most vulnerable human
settlements are those especially
exposed to natural hazards, e.g.
coastal or river flooding, severe
drought, landslides, severe wind
storms and tropical cyclones. The
most vulnerable populations are in
developing countries, in the lower-
income groups: residents of coastal
lowlands and islands, populations
in semi-arid grasslands, and the
urban poor in squatter settlements,
slums and shanty towns, especially
in megacities. In coastal lowlands
such as in Bangladesh, China and
Egypt, as well as in small island
nations, inundation due to sea-level
rise and storm surges could lead to
significant movements of people.
Major health impacts are possible,
especially in large urban areas,
owing to changes in availability of
water and food and increased health
problems due to heat stress
spreading .of infections. Changes
in precipitation and* temperature
could radically alter the patterns
of vector-borne and viral diseases
by shifting them to higher latitudes,
thus putting large populations at
risk. As similar events have in the
past, these changes could initiate
large migrations of people, leading
over a nuifaer of yuum to SENSES disruptions
of settlement patterns and social
instability in some areas.
Global warming can be expected
to affect the availability of water
resources and biomass, both major
sources of energy in many developing
countries. These effects are likely
to differ between and within regions
with some areas losing and others
gaining water and biomass. Such changes
in areas which lose water may jeopardize
energy supply and materials essential
for human habitation and energy.
Moreover, climate change itself is
also likely to have different effects
between regions on the availability
of other forms of renewable energy
such as wind and solar power. In
developed countries some of the greatest
impacts on the energy, transport and
industrial sectors may be determined
by policy responses to climate change
such as fuel regulations, emission
fees or policies promoting greater
use of mass transit. In developing
countries, climate-related changes
in the availability and price of
resources such as energy, water, food
and fibre may affect the competitive
position of many industries.
Global warming and increased
ultraviolet radiation resulting from
depletion of stratospheric ozone may
produce adverse impacts on air quality
such as increases in ground- level
ozone in some polluted urban areas .
An increase of ultraviolet-B radiation
intensity at the Earth's surface would
increase the risk of damage to the
eye and skin and may disrupt the marine
food chain.
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OVERVIEW EPOC
2.5 Oceans and coastal zones
Global warming will accelerate
sea-level rise, modify ocean
circulation and change marine
ecosystems, with considerable
socioeconomic consequences. These
effects will be added to present
trends of rising sea-level, and
other effects that have already
stressed coastal resources, such as
pollution and over-harvesting. A
30-50 cm sea-level rise (projected
by 2050) will threaten low islands
and coastal zones. Aim rise by
2100 would render some island
countries uninhabitable, displace
tens of millions of people,
seriously threaten low-lying urban
areas, flood productive land,
contaminate fresh water supplies and
change coastlines. All of these
impacts would be exacerbated if
droughts and storms become more
severe. Coastal protection would
involve very significant costs.
Rapid sea-level rise would change
coastal ecology and threaten many
important fisheries. Reductions in
sea ice will benefit shipping, but
seriously impact on ice-dependent
marine mammals and birds.
Impacts on the global oceans
will include changes in the heat
balance, shifts in ocean circulation
which will affect the capacity of
the ocean to absorb heat and C02and
changes in upwelling zones
associated with fisheries. Effects
will vary by geographic zones, with
changes in habitats, a decrease in
biological diversity and shifts in
marine organisms and productive
zones, including commercially
important species. Such regional
shifts in fisheries will have major
socioeconomic impacts.
2.6 Seasonal snow cover, ice and
permafrost
The global areal extent and
volume of elements of the
terrestrial cryosphere (seasonal
snow cover, near-surface layers oi
permafrost and some masses of ice)
will be substantially reduced.
ihese reductions, whan reflected regionally
could have significant impacts on
related ecosystems and social and
economic activities. Compounding
these impacts in some regions is that,
as a result of the associated climatic
warming positive feedbacks, the reductions
could be sudden rather than gradual.
The areal coverage of seasonal
snow and its duration are projected
to decrease in most regions, particularly
at mid latitudes, with some regions
at high latitudes possibly experiencing
increases in seasonal snow cover.
Changes in the volume of snow cover,
or the length of the snow cover season,
will have both positive and negative
impacts on regional water resources
(as a result of changes in the volume
and the timing of runoff from snowmelt),
on regional transportation (road,
marine, air and rail), and on recreation
sectors.
Globally, the ice contained in
glaciers and ice sheets is projected
to decrease, with regional responses
complicated by the effect of increased
snowfall in some areas which could
lead to accumulation of ice. Glacial
recession will have significant
implications for local and regional
water resources, and thus impact on
water availability and on hydroelectric
power potential. Glacial recession
and loss of ice from ice sheets
will also contribute to sea-level
rise. Permafrost, which currently
underlies 20-25% of the land mass
of the Northern Hemisphere, could
experience significant degradation
within the next 40-50 years. Projected
increases in the thickness of the
freeze-thaw (active) layer above the
permafrost and a recession of permafrost
to higher latitudes and altitudes
could lead to increases in terrain
instability, erosion and landslides
in those areas which currently contain
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OVERVIEW IPQC
permafrost. As a result, overlying
ecosystems could be significantly
altered and the integrity of man-
made structures and facilities
reduced, thereby influencing
existing human settlements and
development opportunities.
3. RESPONSE STRATEGIES
The consideration of climate
change response strategies presents
formidable difficulties for
policymakers. The information
available to make sound policy
analyses is inadequate because of:
(a) uncertainty with respect to how
effective specific response
options or groups of options
would be in actually averting
potential climate change;
(b) uncertainty with respect to the
costs, effects on economic
growth, and other economic and
social implications of specific
response options or groups of
options.
The IPCC recommends a programme
for the development and implementa-
tion of global, comprehensive and
phased action for the resolution of
the global warming problem under a
flexible and progressive approach.
* A major dilemma of the issue of
climate change due to increasing
emission of greenhouse gases in
the atmosphere is that actions
may be required well before many
of the specific issues that are
and will be raised can be
analyzed more thoroughly by
further research.
* The CFCs are being phased out
to protect the stratospheric
ozone layer. This action will
also effectively slow down the
rate of increase of radiative
forcing of greenhouse gases in
the atmosphere. Every effort
should be made to find replacements
that have little or no greenhouse
wanting po^epfr'iai or ozone depletion
potential rather than the HCFCs
and MFCs that are now being
considered.
* The single largest anthropogenic
source of radiative forcing is
energy production and use. The
energy sector accounts for an
estimated 46% (with an uncertainty
range of 38-54%) of the enhanced
radiative forcing resulting from
human activities.
* It is noted that emissions due
to fossil fuel combustion amounts
to about 70-90% of the total
anthropogenic emissions of C02
into the atmosphere, whereas the
remaining 10-30% is due to human
use of terrestrial ecosystems.
A major decrease of the rate of
deforestation as well as an increase
in afforestation would contribute
significantly to slowing the rate
of C02 concentrations increase
in the atmosphere; but it would
be well below that required to
stop it. This underlines that
when forestry measures have been
introduced, other measures to
limit or reduce greenhouse emissions
should not be neglected.
3.1 Roles of industrialized and
developing countries
* Industrialized and developing
countries have a common but varied
responsibility in dealing with
the problem of climate change
and its adverse effects. The
former should take the lead in
two ways:
i) A major part of emissions
affecting the atmosphere at
present originates in
industrialized countries where
the scope for change is greatest.
Industrialized countries should
adopt domestic measures to
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CVEKVTEW IPOC
limit climate change by
adapting their own
economies in line with
future agreements to limit
emissions.
ii) To co-operate with
developing countries in
international action,
without standing in the way
of the latter' s development
by contributing additional
financial resources, by
appropriate transfer of
technology, by engaging in
close co-operation in
scientific observation,
analysis and research, and
finally by means of
technical co-operation
geared to forestalling and
managing environmental
problems.
Sustainable development1 in
industrialized as well as
developing countries requires
proper concern for environmental
protection as the basis for
continued economic growth.
Environmental considerations
must be systematically
integrated into all plans for
development. The right balance
must be struck between economic
growth and environmental
objectives.
Emissions from developing
countries are growing in order
to meet their development
requirements and thus, over
time, are likely to represent
an increasingly significant
1. Sustainable development is development
that meets the needs of the present without
compromising the ability of future
generations to meet their own needs and does
not imply in any way encroachment upon
national sovereignty. (Annex II to decision
15/2 of the 15th session of the UNEP
Governing Council, Nairobi, May 1989)
percentage of global emissions.
As the greenhouse gas emissions
in developing Gantries are increasing
with their population and economic
growth, rapid transfer, on a
preferential basis, to developing
countries, of technologies which
help to monitor, limit or adapt
to clijnate change, without hindering
their economic development, is
an urgent requirement. Developing
countries should, within the limits
feasible, take measures to suitably
adapt their economies. Recognizing
the poverty that prevails among
the populations of developing
countries, it is natural that
achieving economic growth is given
priority by them. Narrowing the
gap between the industrialized
and developing world would provide
a basis for a full partnership
of all nations in the world and
would assist developing countries
in dealing with the climate change
issue.
3.2 Potions
The climate scenario studies of
Working Groups I and III outline
control policies on emissions
that would slow global warming
from the presently predicted value
of about 0.3°C per decade to about
0. 1 °C per decade (see Appendix) .
The potpn^ a^ i y serious
of climate change give sufficient
reasons to begin adopting response
strategies that can be justified
immediately even in the face of
significant uncertainties. The
response strategies include:
o phasing out of CFC emissions
and careful assessment of
the greenhouse gas potential
of proposed substitutes;
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OVERVIEW 3PCC
o efficiency improvements and
conservation in energy
supply, conversion and end
use, in particular through
improving diffusion of
energy-efficient tech-
nologies, improving the
efficiency of mass-produced
goods, reviewing energy-
related price and tariff
systems to better reflect
environmental costs;
o sustainable forest
management and afforesta-
tion;
o use of cleaner, more
efficient energy sources
with lower or no emissions
of greenhouse gases;
o review of agriculture
practices.
There is no single quick-fix
technological option for
limiting greenhouse gas
emissions. Phased and flexible
response strategies should be
designed to enhance relevant
technological research,
development and deployment,
including improvement and
reassessment of existing
technologies. Such strategies
should involve opportunities for
international co-operation. A
comprehensive strategy
addressing all aspects of the
problem and reflecting
environmental, economic and
social costs and benefits is
necessary.
Because a large, projected
increase in world population
will be a major factor in
causing the projected increase
in global greenhouse gases, it
is essential that global climate
change strategies take into
account the need.to deal with
the issue of the rate of growth
of the world population.
Subject to their particular
circumstances, individual
nations, or groups of nations,
may wish to consider taking
steps now to attempt to limit,
stabilize or reduce the emission
of greenhouse gases resulting
from human activities and prevent
the destruction and improve the
effectiveness of sinks. One option
that governments may wish to consider
is the setting of targets for
C02 and other greenhouse gases.
A large number of options were
preliminarily assessed by IPCC
Working Group III. It appears
that some of these options may
be eocncmically and socially feasible
for implementation in the near-
term while others, because they
are not yet technically or
economically viable, may be more
appropriate for implementation
in the longer term. In general,
the Working Group found that the
most effective response strategies,
especially in the short term,
are those which are:
o beneficial for reasons other
than climate change and
justifiable in their own right,
for example increased energy
efficiency and lower greenhouse
gas emission technologies,
better management of forests,
and other natural resources,
and reductions in emissions
Of ^fCS fflPCi OulQT O^?T¥1fr OBCufiCUlQ
substances that are also
radiatively important gases;
o economically efficient and
cost effective, in particular
those that use market-based
mechanisms;
o able to serve multiple
social, economic and
environmental purposes;
11
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OVERVIEW XPQC
o flexible and phased, so
that they can be easily
modified to respond to
increased understanding of
scientific, technological
and economic aspects of
climate change;
o compatible with economic
growth and the concept of
sustainable development;
o administratively practical
and effective in terms of
application, monitoring and
enforcement;
o reflecting obligations of
both industrialized and
developing countries in
addressing this issue,
while recognizing the
special needs of developing
countries, in particular
in the areas of financing
and technology.
The degree to which options are
viable will also vary considerably
depending on the region or country
involved. For each country, the
implications of specific options
will depend on its social,
environmental and economic context.
Only through careful analysis of all
available options will it be
possible to determine which are best
suited to the circumstances of a
particular country or region.
Initially, the highest priority
should be to review existing
policies with a view to minimizing
conflicts with the goals of climate
change strategies. New policies
will be required.
* In the long-term perspective,
work should begin on defining
criteria for selection of ap-
propriate options which would
reflect the impacts of climate
change and its costs and
benefits on the one hand, and
social and economic costs and
benefits of the options on th<
other.
Consideration of measures for
reducing the impacts of global
climate change should begin as
soon as possible, particularly
with regard to disaster
preparedness policies, coastal
zone management and control
measures for desertification,
many of these being justified
in their own right. Measures
to limit or adapt to climate
change should be as cost-effective
as possible while taking into
account important a-n-iai implications.
Limitation and adaptation should
be considered as an integrated
package.
Assessing areas at risk from sea-
level rise and developing
comprehensive management plans
to reduce future vulnerability
of populations and coastal
developments and ecosystems as
part of coastal zone management
plans should begin as soon as
possible.
Environmental objectives can be
pursued through regulations and/or
through market based economic
instruments. The latter, through
their encouragement of flexible
selection of abatement measures,
tend to encourage innovation and
the development of improved
technologies and practices for
reducing emissions and therefore
frequently offer the possibility
of achieving environmental
improvements at lower costs than
through regulatory mechanisms.
It is not likely, however, that
economic instruments will be
applicable to all circumstances.
Three factors are considered as
potential barriers to the operation
of markets and/or the achievement
of environmental objectives through
12
-------
OVERVIEW EPOC
market mechanisms. These are:
i) information problems, which
can often cause markets to
produce less effective or
unfavourable environmental
outcomes;
ii) existing measures and
institutions, which can
encourage individuals to
behave in environmentally
damaging ways; and
iii) balancing competing
objectives (social,
environmental and
economic).
An initial response strategy may
therefore be to address information
problems directly and to review
existing measures which may be
barriers. For example, prior to
possible adoption of a system of
emission charges, countries should
examine existing subsidies and tax
incentives on energy and other
relevant greenhouse gas producing
sectors.
* With respect to institutional
mechanisms for providing
financial co-operation and
assistance to developing
countries, a two track approach
was considered:
i) one track built on work
underway or planned in
existing institutions.
Bilateral donors could
further integrate and
reinforce the environmental
components of their
assistance programmes and
develop cofinancing
arrangements with
multilateral institutions
while ensuring that this
does not impose inap-
propriate environmental
conditions.
ii) parallel to this track the
possibility of new mechanisms
and facilities was considered.
Seme developing and industrial-
ized countries suggested
that new mechanisms directly
related to a future climate
convention and protocols that
might be agreed upon, such
as a new international fund,
were required.
Governments should undertake
now:
o accelerated and co-ordinated
research programmes to reduce
scientific and socioeconom-
ic uncertainties with a view
towards improving the basis
for response strategies
and measures;
o review of planning in the
fields of energy, industry,
transportation, urban areas,
coastal zones and resource
use and management;
o encouragement of beneficial
behavioral and structural
(e.g. transportation and housing
infrastructure) changes;
o expansion of the global ocean
observing and monitoring
systems.
It should be noted that no detailed
assessments have been made as of yet
of the economic costs and benefits,
technological feasibility or market
potential of the underlying policy
assumptions.
4. EAKFIOPXnQf GP O3JEL(FIN5
It is obvious that the impact
on and the participation by the
developing countries in the further
13
-------
OVERVIEW IFCC
development of a future strategy is
essential. The IPCC has attempted
to address this specific issue by
establishing a Special Committee on
the Participation of Developing
Countries and requested it to
identify factors inhibiting the full
participation of the developing
countries in IPCC and recommend
remedial measures where possible.
The Committee stressed that full
participation includes not only the
physical presence at meetings but
also the development of national
competence to address all issues of
concern such as the appreciation of
the scientific basis of climate
change, the potential impacts on
society of such change and
evaluations of practical response
strategies for national/regional
applications.
The factors that kept developing
countries from fully
participating were identified by the
Special Committee as:
o insufficient information;
o insufficient communication;
o limited human resources;
o institutional difficulties;
o limited financial
resources.
On some of these factors, the
IPCC Working Groups have
developed policy options which are
to be found in their
respective reports.
* Developing countries will, in
some cases, need additional
financial resources for
supporting their efforts to
promote activities which
contribute both to limiting
greenhouse gas emissions and/or
adapting to the adverse effects
of climate change, while at the
same time promote economic
development. Areas of co-
operation could include, inter
alia;
efficient use of energ
resources, the use of fossil
fuels with lower greenhouse
gas emission rates or non-
fossil sources, the development
of clean and renewable
energy sources, such as:
biomass, windpower, wave-
power, hydroelectric and
solar, wherever applicable;
increased rational utilization
of forest products, sound
forest management practices
and agricultural techniques
which reduce the negative
effects on climate;
facilitating the develop-
ment and transfer of clean
and safe technologies in
areas which could include:
the building and
manufacturing industries;
public transport systems;
industry;
measures which enhance the
capacity of developing
countries to develop programmes
to address climate change,
including research and
development activities and
public awareness and education
programmes, such as:
the development of the
human resources necessary
to tackle the problem
of climate change and
its adverse effects;
the provision of study
and training programmes
in subjects and techniques
related to climate change;
the provision of skilled
personnel and the
material necessary to
organize education
programmes to develop
14
-------
OVERVIEW IPOC
locally the skills
necessary to assess
climate change and
combat its adverse
effects;
the development of
climate-related
research programmes
organized on a
regional basis;
o facilitating the participa-
tion of developing
countries in fora and
organizations such as: the
International Geosphere-
Biosphere Programme, the
Land-Ocean Inter-actions
in the Coastal Zone, the
Biosphere Aspects of the
Hydrological Cycle, the
Global Change Impact on
Agriculture and Society,
the World Climate Programm-
e, the Man and the
Biosphere Programme;
o facilitating participation
by developing countries in
international fora on
global climate change such
as the IPCC;
o strengthening existing
education and research
institutions and the
development of new ones at
national and regional
levels.
Further, co-operation and
assistance for adaptive measures
would be required, noting that
for some regions and countries,
adaptation rather than limita-
tion activities are potentially
most important.
The IPCC concludes that the
recommendations of the Special
Committee need not and should
not await the outcome of future
negotiations on a climate
convention. It appeals to the
multilateral and bilateral
funding organizations to implement
its recommendations. It further
to goveanents far cantiruing
and increased contributions to
the IPCC Trust Fund on an urgent
basis.
5. INTERNATIONAL CO-OPERATION AND
FUTURE WORK
* The measures noted above require
a high degree of interna-tional
co-operation with due respect
for national sovereignty of
states. The international
negotiations on a framework
convention should start as
quickly as possible after
presentation of this Report in
line with Resolution SS II/3
Climate.C. (August 1990) of the
UNEP Governing Council and Resolution
8 (EC-XLII, June 1990) of the
WMO Executive Council. Many,
essentially develop-ing, countries
stressed that the negotiations
must be conducted in the forum,
manner and with the timing to
be <¥rirtRri by the UM General Assembly.
This convention, and any additional
protocols that might be agreed upon,
would provide a firm basis for effective
co-operation to act on greenhouse
gas emissions and adapt to any
adverse effects of climate change.
The convention should recognize climate
change as a common concern of mankind
and, at a minimum, contain general
principles and obligations. It should
be framed in such a way as to gain
the adherence of the largest possible
number and most suitably balanced
range of countries while permitting
timely action to be taken.
Key issues for negotiations will
include the criteria, timing, legal
form and incidence of any obligations
to control the net emissions of greenhouse
15
-------
gases, how to address equitably the
consequences for all, any
institutional mechanisms including
research and monitoring that may be
required, and in particular, the
requests of the developing countries
for additional financial resources
and for the transfer of technology
on a preferential basis. The
possible elements of a framework
convention on climate change were
identified and discussed by Working
Group III in its legal measures
topic paper, appended to its
Policymakers Summary.
* The IPCC recommends that
CKEPNTEN IPOC
research regarding the science of
climate change in general, technologica
development and the international
economic implications, be intensified.
* Because climate change would
affect, either directly or
indirectly, almost every sector
of society, broad global
understanding of the issue will
facilitate the adoption and the
implementation of such response
options as deemed necessary and
appropriate. Further efforts
to achieve such global understand-
ing are urgently needed.
16
-------
OVERVIEW IPGC
APPENDIX
Emissions scenarios developed bv IPCC
The IPCC used two methods to develop scenarios of future emissions:
* One method used global models to develop four scenarios which were
subsequently used by Working Group I to develop scenarios of future
warming. All of these four scenarios assumed the same global economic
growth rates taken from the World Bank projections and the same population
growth estimates taken from the United Nations studies. The anthropogenic
emissions of carbon dioxide and methane from these scenarios are
shown in Figures 1 and 2 below.
* The second method used studies of the energy and agriculture sectors
submitted by over 21 countries and international organizations to estimate
C02 emissions.
Both scenario approaches indicate that C02 emissions will grow from
about 7 BtC (billion or 1000 million tonnes carbon) per year now to 12-
15 BtC per year by the year 2025. Scenario A (Business as Usual) includes
a partial phase-out of CFCs under the Montreal Protocol and lower CO? and
CH4 emissions than the Reference Scenario. The Reference Scenario developed
through country and international studies of the energy and agriculture
groups, includes higher C02 emissions and assumed a total CFC phase-out.
The results indicate that the C02 equivalent concentrations and their effects
on global climate are similar.
Figure 1. Projected Man-Made C02 Emissions
(Billion or 1000 million tonnes carbon per year)
BUSINESS
AS.U3UAL
(SCENARIO A)
SCENAAOB
SC€K*WOC
SCCNAAOO
10
1980 2000 2020 2040 2080 2080 2100
YEAR
17
-------
OVERVIEW IPOC
Figure 2. Projected Man-Made Methane Emissions
(Million tonnes per year)
BUSINESS
A*.USUAL
(SCENARIO A)
SCENAPOB
3CC
:9fO 2000 2520 2C«0 2:60 2CIO 2100
TEAM
Method I
Scenario A (Business as Usual) assumes that few or no steps are taken
to limit greenhouse gas emissions. Energy use and clearing of tropical
forests continue and fossil fuels, in particular coal, remain the world's
primary energy source. The Montreal Protocol comes into effect but without
strengthening and with less than 100 percent compliance. Under this scenario,
the equivalent of a doubling of pre-industrial CO2 levels occurs, according
to Working Group I, by around 2025.
Scenario B (Low Emissions Scenario) assumes that the energy supply
mix of fossil fuels shifts towards natural gas, large efficiency increases
All of the scenarios assumed some level of compliance with
the Montreal Protocol but not with all of the (June 1990)
amendments agreed to in London. The London amendments to the
Montreal Protocol, when fully implemented, would result in a
virtually complete elimination of production of fully halogenated
CFCs, halons, carbon tetrachloride and methyl chloroform early
in the 21st century. The Parties of the Protocol also call for
later elimination of HCFCs. Thus, the assumptions of Scenarios
A and B overestimate the radiative forcing potential of CFCs and
halons. Additionally, the UN has provided recent population
projections that estimate higher population than used in the
global model scenarios (Scenarios A through D); use of these
newer projections would increase future C02 emissions. Additionally,
the Reference Scenario CO2 emissions are higher than Scenario A
(Business as Usual), suggesting Scenario A (Business as Usual)
may be an underestimate.
18
-------
OVERVIEW IPOC
are achieved, deforestation is reversed and emissions of CFCs are reduced
by 50% from their 1986 levels. This results in an equivalent doubling
of pre-industrial carbon dioxide by about 2040.
Scenario C (Control Policies Scenario) assumes that a shift towards
renewable energies and safe nuclear energy takes place in the latter part
of the next century, CFG gases are phased out and agricultural emissions
(methane and nitrous oxide) are limited; an equivalent doubling of pre-
industrial carbon dioxide will occur in about 2050.
Scenario D (Accelerated Policies Scenario) assumes that a rapid shift
to renewable energies and safe nuclear energy takes place early in the
next century, stringent emission controls in industrial countries and moderate
growth of emissions in developing countries. This scenario, which assumes
carbon dioxide emissions are reduced to 50% of 1985 levels, stabilizes
equivalent carbon dioxide concentrations at about twice the pre-industrial
levels towards the end of the next century.
Method 2 (see footnote 2 on previous page)
Using the second method, the so-called Reference Scenario was developed
by the Energy and Industry Subgroup and Agriculture and Forestry Subgroup
of Working Group III. Under the Reference Scenario, global C02 emissions
from all sectors grow from approximately 7.0 BtC (per year) in 1985 to
over 15 BtC (per year) in 2025. The energy contribution grows from about
5 BtC (per year) to over 12 BtC (per year). Primary energy demand more
than doubles between 1985 and 2025 with an average growth rate of 2.1%.
The per capita energy emissions in the industrialized countries increase
from 3.1 tonnes carbon (TC) in 1985 to 4.7 TC in 2025; for the developing
countries, they rise from 0.4 TC in 1985 to 0.8 TC in 2025.
Summary
All of the above scenarios provide a conceptual basis for considering
possible future patterns of emissions and the broad responses that might
affect those patterns. No full assessment was made of the total economic
costs and benefits, technological feasibility, or market potential of the
underlying policy assumptions. Because of the inherent limitations in
our ability to estimate future rates of population and economic growth,
individual behaviour, technological innovation, and other factors which
are crucial for determining emission rates over the course of the next
century, there is some uncertainty in the projections of greenhouse gas
emissions. Reflecting these inherent difficulties, the IPCC's work on
emissions scenarios are the best estimates at this time covering emissions
over the next century, but continued work to develop improved assumptions
and methods for scenario estimates will be useful to guide the development
of response strategies.
19
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WMO
INTERGOVERNMENTAL PANEL ON
CLIMATE CHANGE
POLICYMAKERS
SUMMARY
OF THE
SCIENTIFIC ASSESSMENT OF
CLIMATE CHANGE
Report Prepared for IPCC
by Working Group I
June 1990
-------
POLICYMAKERS SUMMARY WGI
TABLE OF CONTENTS
PAGE
Executive Summary 1
Introduction: what is the issue? 3
What factors determine global climate? 3
What natural factors are important? 3
How do we know that the natural greenhouse effect is real? 4
How can man change global climate? 5
What are the greenhouse gases and why are they increasing? 5
Concentrations, lifetimes and stabilisation of the gases 7
How will the greenhouse gases increase in future? 9
Greenhouse gas feedbacks 9
Which gases are the most important? 10
How can we evaluate the effect of different greenhouse gases? 11
How much dp we expect climate to change? 13
How quickly will global climate change? 13
a. If emissions follow a Business-as-Usual pattern 13
b. If emissions are subject to controls 14
What will be the patterns of climate change by 2030? 16
How will climate extremes and extreme events change? 17
Will storms increase in a warmer world? 17
Climate change in the longer term 19
Other factors which could influence future climate 19
How much confidence do we have in our predictions? 19
Will the climate of the future be very different? 20
Has man already begun to change the global climate? 21
How much will sea level rise? 22
What will be the effect of climate change on ecosystems? 23
What should be done to reduce uncertainties, and how long
will this take? 25
Annex 27
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POLICYMAKERS SUMMARY WGI
EXECUTIVE SUMMARY
We are certain of the following:
• there is a natural greenhouse effect which
already keeps the Eanh wanner than it
would otherwise be.
• emissions resulting from human activities
are substantially increasing ihe atmospheric
concentrations of the greenhouse gases:
carbon dioxide, methane,
chlorofluorocarbons (CFCs) and nitrous
oxide. These increases will enhance the
greenhouse effect, resulting on average in
an additional warming of the Earth's
surface. The main greenhouse gas, water
vapour, will increase in response to global
warming and further enhance it
We calculate with confidence that:
• some gases are potentially more effective
than others at changing climate, and their
relative effectiveness can be estimated.
Carbon dioxide has been responsible for
over half the enhanced greenhouse effect in
the past, and is likely to remain so in the
future.
• atmospheric concentrations of the long-
lived gases (carbon dioxide, nitrous oxide
and the CFCs) adjust only slowly to
changes in emissions. Continued emissions
of these gases at present rates would
commit us to increased concentrations for
centuries ahead. The longer emissions
continue to increase at present day rates, the
greater reductions would have to be for
concentrations to stabilise at a given level.
• the long-lived gases would require
immediate reductions in emissions from
human activities of over 60% to stabilise
their concentrations at today's levels;
methane would require a 15-20%
reduction.
Based on current model results,
we predict:
• under the IPCC Business-as-Usual
(Scenario A) emissions of greenhouse
gases, a rate of increase of global mean
temperature during the next century of
about 0.3'C per decade (with an uncertainty
range of 0.2'C to 0.5'C per decade); this is
greater than that seen over the past 10,000
years. This will result in a likely increase in
global mean temperature of about 1'C
above the present value by 202S and 3'C
before the end of the next century. The rise
will not be steady because of the influence
of other factors.
• under the other IPCC emission scenarios
which assume progressively increasing
levels of controls, rates of increase in
global mean temperature of about 0.2'C per
decade (Scenario B), just above 0.1'C per
decade (Scenario C) and about 0.1'C per
decade (Scenario D).
• that land surfaces warm more rapidly than
the ocean, and high northern latitudes warm
more than the global mean in winter.
• regional climate changes different from the
global mean, although our confidence in the
prediction of the detail of regional changes
is low. For example, temperature increases
in' Southern Europe and central North
America are predicted to be higher than the
global mean, accompanied on average by
reduced summer precipitation and soil
moisture. There are less consistent
predictions for the tropics and the southern
hemisphere.
• under the IPCC Business as Usual
emissions scenario, an average rate of
global mean sea level rise of about 6cm per
decade over the next century (with an
uncertainty range of 3 - 10cm per decade),
mainly due to thermal expansion of the
oceans and the melting of some land ice.
The predicted rise is about 20cm in global
mean sea level by 2030. and 65cm by the
end of the next century. There will be
significant regional variations.
-------
WGI POLICYMAKERS SUMMARY
There are many uncertainties in
our predictions particularly with
regard to the timing, magnitude
and regional patterns of climate
change, due to our incomplete
understanding of:
• sources and sinks of greenhouse gases,
which affect predictions of future
concentrations
• clouds, which strongly influence the
magnitude of climate change
• oceans, which influence the timing and
patterns of climate change
• polar ice sheets which affect predictions of
sea level rise
These processes are already partially understood,
and we are confident that the uncertainties can be
reduced by further research. However, the
complexity of the system means that we cannot
rule out surprises.
Our judgement is that:
• Global - mean surface air temperature has
increased by 0.3'C to 0.6*C over the last
100 years, with the five global-average
wannest years being in the 1980s. Over the
same period global sea level has increased
by 10-20cm. These increases have not
been smooth with time, nor uniform over
the globe.
• The size of this wanning is broadly
consistent with predictions of climate
models, but it is also of the same magnitude
as natural climate variability. Thus the
observed increase could be largely due to
this natural variability; alternatively this
variability and other human factors could
have offset a still larger human-induced
greenhouse wanning. The unequivocal
detection of the enhanced greenhouse effect
bom observations is not likely for a decade
or more.
• There is no firm evidence that climate has
become more variable over the last few
decades.' However, with an increase in the
mean temperature, episodes of high
temperatures will most likely become more
frequent in the future, and cold episodes
less frequent
Ecosystems affect climate, and will be
affected by a changing climate and by
increasing carbon dioxide concentrations.
Rapid changes in climate will change the
composition of ecosystems; some species
will benefit while others will be unable to
migrate or adapt fast enough and may
become extinct. Enhanced levels of carbon
dioxide may increase productivity and
efficiency of water use of vegetation. The
effect of warming on biological processes,
although poorly understood, may increase
the atmospheric concentrations of natural
greenhouse gases.
To improve our predictive
capability, we need:
• to understand better the various climate-
related processes, particularly those
associated with clouds, oceans and the
carbon cycle
• to improve the systematic observation of
climate-related variables on a global basis,
and further investigate changes which took
place in die past
• to develop improved models of the
Earth's climate system.
• to increase support for national and
international climate research activities,
especially in developing countries
• to facilitate international exchange of
ciuDatedatt
-------
POLICYMAKERS SUMMARY WGI
Introduction: what is the
issue ?
There is concern that human activities may be
inadvertently changing the climate of the globe
through the enhanced greenhouse effect, by past
and continuing emissions of carbon dioxide and
other gases which will cause the temperature of
the Earth's surface to increase - popularly termed
the "global warming". If this occurs, consequent
changes may have a significant impact on
society.
The purpose of the Working Group I report, as
determined by the first meeting of IPCC, is to
provide a scientific assessment of:
1) the factors which may affect climate change
during the next century especially those
which are due to human activity.
2) the responses of the atmosphere - ocean -
land - ice system.
3) current capabilities of modelling global and
regional climate changes and their
predictability.
4) the past climate record and presently
observed climate anomalies.
On the basis of this assessment, the report
presents current knowledge regarding predictions
of climate change (including sea level rise and the
effects on ecosystems) over the next century, the
timing of changes together with an assessment of
the uncertainties associated with these
predictions.
This Policymakers Summary aims to bring out
those elements of the main report which have the
greatest relevance to policy formulation, in
answering the following questions:
• What factors determine global climate?
• What are the greenhouse gases, and how
and why are they increasing?
• Which gases are the most important?
• How much do we expect the climate to
change?
• How much confidence do we have in our
predictions?
• Will the climate of the future be very
different ?
• Have human activities already begun to
change global climate?
• How much will sea level rise?
• What will be the effects on ecosystems?
• What should be done to reduce
uncertainties, and how long will this take?
This report is intended to respond to the practical
needs of the policymaker. It is neither an
academic review, nor a plan for a new research
programme. Uncertainties attach to almost every
aspect of the issue, yet policymakers are looking
for clear guidance from scientists; hence
authors have been asked to provide their
best-estimates wherever possible, together
with an assessment of the uncertainties.
This report is a summary of our understanding in
1990. Although continuing research will deepen
this understanding and require the report to be
updated at frequent intervals, basic conclusions
concerning the reality of the enhanced
greenhouse effect and its potential to alter global
climate are unlikely to change significantly.
Nevertheless, the complexity of the system may
give rise to surprises.
What factors determine
global climate ?
There are many factors, both natural and of
human origin, that determine the climate of the
earth. We look first at those which are natural,
and then see how human activities might
contribute.
What natural factors are
important?
The driving energy for weather and climate
comes from the sun. The Earth intercepts solar
radiation (including that in the short-wave,
visible, part of the spectrum); about a third of it is
reflected, the rest is absorbed by the different
components (atmosphere, ocean, ice, land and
biota) of the climate system. The energy
absorbed from solar radiation is balanced (in the
long term) by outgoing radiation from the Earth
and atmosphere; this terrestrial radiation takes the
form of long-wave invisible infra-red energy,
and its magnitude is determined by the
temperature of the Earth-atmosphere system.
-------
V> »jl POLICYMAKERS SUMMARY
There are several natural factors which can
change the balance between the energy absorbed
by the Earth and that emitted by it in the form of
longwave infra-red radiation; these factors cause
the radiative forcing on climate. The most
obvious of these is a change in the output of
energy from the Sun. There is direct evidence of
such variability over the 11-year solar cycle, and
longer period changes may also occur. Slow
variations in the Earth's orbit affect the seasonal
and latitudinal distribution of solar radiation;
these were probably responsible for initiating the
ice ages.
One of the most important factors is the
greenhouse effect; a simplified explanation of
which is as follows. Shortwave solar radiation
can pass through the clear atmosphere relatively
unimpeded. But long-wave terrestrial radiation
emitted by the warm surface of the Earth is
partially absorbed and then re-emitted by a
number of trace gases in the cooler atmosphere
above. Since, on average, the outgoing long
wave radiation balances the incoming solar
radiation, both the atmosphere and the surface
will be warmer than they would be without the
greenhouse gases.
The main natural greenhouse gases are not the
major constituents, nitrogen and oxygen, but
water vapour (the biggest contributor), carbon
dioxide, methane, nitrous oxide, and ozone in the
troposphere (the lowest 10-15km of the
atmosphere) and stratosphere.
Aerosols (small panicles) in the atmosphere can
also affect climate because they can reflect and
absorb radiation. The most important natural
perturbations result from explosive volcanic
eruptions which affect concentrations in the
lower stratosphere. Lastly, the climate has its
own natural variability on all timescales and
changes occur without any external influence.
How do we know that the natural
greenhouse effect is real?
The greenhouse effect is real; it is a well
understood effect, based on established scientific
principles. We know that the greenhouse effect
works in practice, for several reasons.
Firstly, the mean temperature of the Earth's
surface is already warmer by about 33'C
(assuming the same reflectivity of the earth) than
it would be if the natural greenhouse gases were
not present. Satellite observations of the radiation
emitted from the earth's surface and through the
atmosphere demonstrate the effect of the
greenhouse gases.
some solar radiation
is reflected by the earm
and the atmosphere
|solar
'radiation
of the infra-red
radiation is absorbed
and re-emitted by the
reenhouse gases.
The effect of this is to
warm the surface and
!|trie lower atmosphere
passes
through
the clear
atmosphere
ATMOSPHERE
most solar
radiation is absorbed
by me earth's surface and
warms it
infra-red
radiation is
omitted from
the earth's
surface
A simplified diagram illustrating the greenhouse effect.
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POLICYMAKERS SUMMARY VV G I
Secondly, we know the composition of the
atmospheres of Venus, Earth and Mars are very
different, and their surface temperatures are in
general agreement with greenhouse theory.
Thirdly, measurements from ice cores going back
160,000 years show that the earth's temperature
closely paralleled the amount of carbon dioxide
and methane in the atmosphere. Although we do
not know the details of cause and effect,
calculations indicate that changes in these
greenhouse gases were pan. but not ail, of the
reason for the large (5-7*C) global temperature
swings between ice ages and imerglacial periods.
How might human activities change
global climate ?
Naturally occurring greenhouse gases keep the
Earth warm enough to be habitable. By
increasing their concentrations, and by adding
new greenhouse gases like chlorofluorpcarbons
(CFCs), humankind is capable of raising the
global-average annual-mean surface-air
temperature (which, for simplicity, is referred to
as the "global temperature"), although we are
uncertain about the rate at which this will occur.
Strictly, this is an enhanced greenhouse effect -
above that occurring due to natural greenhouse
gas concentrations; the word "enhanced" is
usually omitted, but it should not be forgotten.
Other changes in climate are expected to result.
for example changes in precipitation, and a global
warming will cause sea levels to rise; these are
discussed in more detail later.
2
0
-2
-4
-10
1990
leva)
or C02 -»
o
" I
a
eao a
*"!!
400 9
300
280
260
240
220
200
180
0 40 80 120 160
Age (thousand years before present)
Analysis of air trapped in Antarctic ice cores
shows that methane and carbon dioxide
concentrations were closely correlated with the
local temperature over the last 160,000 years.
Present day concentrations of carbon dioxide
are indicated
There are other human activities which have the
potential to affect climate. A change in the albedo
(reflectivity) of the land, brought about by
desertification or deforestation affects the
amount of solar energy absorbed at the Earth's
surface. Human-made aerosols, from sulphur
emitted largely in fossil fuel combustion, can
modify clouds and this may act to lower
temperatures. Lastly, changes in ozone in the
stratosphere due to CFCs may also influence
climate.
What are the greenhouse
gases and why are they
increasing?
We are certain that the concentrations of
greenhouse gases in the atmosphere have
changed naturally on ice-age time-scales, and
have been increasing since pre-industrial. times
due to human activities. The table below
summarizes the present and pre-industrial
abundances, current rates of change and present
atmospheric lifetimes of greenhouse gases
influenced by human activities. Carbon dioxide,
methane, and nitrous oxide all have significant
natural and human sources, while the
chlorpfluorocarbons are only produced
industrially.
-------
WGI POLICYMAKERS SUMMARY
SUMMARY OF KEY GREENHOUSE GASES AFFECTED BY HUMAN AdTVmES
Atmospheric
concentration
Pre-industrial
(1750-1800)
Present day (1990)
Current rate of
change per year
Atmospheric lifetime
(years)
Carbon
Dioxide
ppmv
280
353
1.8
(0.5%)
(50-200)t
Methane
ppmv
0.8
1.72
0.015
(0.9%)
10
CFC-11
PPtv
0
280
9.5
(4%)
65
CFC-12
pptv
0
484
17
(4%)
130
Nitrous
Oxide
ppbv
288
310
0.8
(0.25%)
150
ppmv • pans per million by volume;
ppbv • pans per trillion (thousand milliOD) by volume;
pptv • pans per trillion (minimi million) by volume.
t The way in which CO] is absorbed by me oceans and biosphere is rax simple and a single value
given; refer to the Bam report for fuiiuu ducuuiOD.
Two important greenhouse gases, water vapour
and ozone, are not included in the table above.
Water vapour has the largest greenhouse effect,
but its concentration in the troposphere is
determined internally within the climate system,
and, on a global scale, is not affected by human
sources and sinks. Water vapour will increase in
response to global warming and further enhance
it; this process is included in climate models. The
concentration of ozone is changing both in the
stratosphere and the troposphere due to human
activities, but it is difficult to quantify the
changes from present observations.
For a thousand years prior to the industrial
revolution, abundances of the greenhouse gases
were relatively constant. However, as the
world's population increased, as the world
became more industrialized and as agriculture
developed, the abundances of the greenhouse
gases increased markedly. The figures below
illustrate this- for carbon dioxide, methane,
nitrous oxide and CFC-11.
Since the industrial revolution the combustion of
fossil fuels and deforestation have led to an
increase of 26% in carbon dioxide concentration
in the atmosphere. We know the magnitude of
jspbj
[day
the present day fossil-fuel source, but the input
from deforestation cannot be estimated
accurately. In addition, although about half of
the emitted carbon dioxide stays in the
atmosphere, we do not know well how much of
the remainder is absorbed by the oceans and how
much by terrestrial biota. Emissions of
chlorofluorocarbons, used as aerosol propellants,
solvents, refrigerants and foam blowing agents,
are also well known; they were not present in the
atmosphere before their invention in the 1930s.
The sources of methane and nitrous oxide are
less well known. Methane concentrations have
more than doubled because of rice production,
cattle rearing, biomass burning, coal mining and
ventilation of natural gas; also, fossil fuel
combustion may have also contributed through
chemical reactions in the atmosphere which
reduce the rate of removal of methane. Nitrous
oxide has increased by about 8% since pre-
industrial times, presumably due to human
activities; we are unable to specify the sources,
but it is likely that agriculture plays a part.
-------
POLICYMAKERS SUMMARY WGI
a
5
u
5
o
360
340
320
300
280
, CARBON DIOXIDE
260
1750
1800
1850 1900
YEAR
19SO 2000
1800
1850 1900
YEAR
1950 2000
i
c
IU
o
310
300
290
280
NITROUS OXIDE
0.3
i
<
X
2
0.1
CFC11
1750 1800
1850 1900
YEAH
1950 2000
0.0
1750 1800
1850 1900
YEAR
1950 2000
Concentrations of carbon dioxide and methane after remaining relatively constant up to the 18th
century, have risen sharply since then due to man's activities. Concentrations of nitrous oxide
have increased since the mid-18th century, especially in the last few decades. CFCs were not
present in the atmosphere before the 1930s
The effect of ozone on climate is strongest in the
upper troposphere and lower stratosphere.
Model calculations indicate that ozone in the
upper troposphere should have increased due to
human-made emissions of nitrogen oxides,
hydrocarbons and carbon monoxide. While at
ground level ozone has increased in the northern
hemisphere in response to these emissions,
observations are insufficient to confirm the
expected increase in the upper troposphere. The
lack of adequate observations prevents us from
accurately quantifying the climatic effect of
changes in tropospheric ozone.
In the lower stratosphere at high southern
latitudes ozone has decreased considerably due .to
the effects of CFCs, and there are indications of a
global-scale decrease which, while not
understood, may also be due to CFCs. These
observed decreases should act to cool the earth's
surface, ihus providing a small offset to the
predicted warming produced by the other
greenhouse gases. Further reductions in lower
stratospheric ozone are possible during the next
few decades as the atmospheric abundances of
CFCs continue to increase.
Concentrations, lifetimes and
stabilisation of the gases
In order to calculate the atmospheric
concentrations of carbon dioxide which will
result from human-made emissions we use
computer models which incorporate details of the
emissions and which include representations of
the transfer of carbon dioxide between the
atmosphere, oceans and terrestrial biosphere.
For the other greenhouse gases, models which
incorporate the effects of chemical reactions in
the atmosphere are employed.
-------
WGI POLICYMAKERS SUMMARY
S 500
5400
o
o
u
8 300
100% 1990
EMISSONS
50% of 1090
EMISSIONS
500
400
8 300
2% pa DECREASE
FROM 2010
2%plOECflEAS6
FROM 1930
(C)
1980 2000 2020 2040 2060 2080 2100
YEAR
1980 2000 2020 2040 2080 2080 2100
YEAR
The relationship between hypothetical fossil fuel emissions of carbon dioxide and its
concentration in the atmosphere is shown in the case where (a) emissions continue at 1990
levels, (b) emissions are reduced by 50% in 1990 and continue at that level, (c) emissions are
reduced by 2% pa from 1990, and (d) emissions, after increasing by 2% pa until 2010, are then
reduced by 2% pa thereafter.
The atmospheric lifetimes of the gases are
determined by their sources and sinks in the
oceans, atmosphere and biosphere. Carbon
dioxide, chlorofluorocarbons and nitrous oxide
are removed only slowly from the atmosphere
and hence, following a change in emissions, their
atmospheric concentrations take decades to
centuries to adjust fully. Even if all human-made
emissions of carbon dioxide were halted in the
year 1990. about half of the increase in carbon
dioxide concentration caused by human activities
would sail be evident by the year 2100.
In contrast, some of the CFC substitutes and
methane have relatively short atmospheric
lifetimes so that their atmospheric concentrations
respond fully to emission changes within a few
decades.
To illustrate the emission-concentration
relationship clearly, the effect of hypothetical
changes in carbon dioxide fossil fuel emissions is
shown below: (a) continuing global emissions at
1990 levels; (b) halving of emissions in 1990;
(c) reductions in emissions of 2% per year (pa)
from 1990 and (d) a 2% pa increase from 1990-
2010 followed by a 2% pa decrease from 2010.
Continuation of present day emissions are
committing us to increased future concentrations,
and the longer emissions continue to increase, the
greater would reductions have to be to stabilise at
a given leveL If there are critical concentration
levels that should not be exceeded, then the
earlier emission reductions are made the more
effective they are.
STABILISATION OF ATMOSPHERIC CONCENTRATIONS
Reductions is the human-made emissions of greenhouse gases required to stabilise concentrations at
present day levels:
Carbon Dioxide
Methane
Nitrous Oxide
CFC-11
CFC-12
HCFC-22
IS - 20%
70- 80%
70 - 75%
75 - 85%
40- 50%
Note that toe-stabilisation of each of these gases would have different effects on climate.
as explained in the next section.
-------
POLICYMAKERS SUMMARY YVGI
The term "atmospheric stabilisation" is often
used to describe the limiting of the concentration
of the greenhouse gases at a certain level. The
amount by which human-made emissions of a
greenhouse gas must be reduced in order to
stabilise at present day concentrations, for
example, is shown in the box opposite. For
most gases the reductions would have to be
substantial.
How will greenhouse gas abundances
change in the future?
We need to know future greenhouse gas
concentrations in order to estimate future climate
change. As already mentioned, these
concentrations depend upon the magnitude of
human-made emissions and on how changes in
climate and other environmental conditions may
influence the biospheric processes that control the
exchange of natural greenhouse gases, including
carbon dioxide and methane, between the
atmosphere, oceans and terrestrial biosphere - the
greenhouse gas "feedbacks".
Four scenarios of future human-made emissions
were developed by Working Group HI. The first
of these assumes that few or no steps are taken to
limit greenhouse gas emissions, and this is
therefore termed Business-as-Usual (Ball). (It
should be noted that an aggregation of national
forecasts of emissions of carbon dioxide and
methane to the year 2025 undertaken by Working
Group in resulted in global emissions 10-20%
higher than in the BaU scenario.) The other three
scenarios assume that progressively increasing
levels of controls reduce the growth of
emissions; these are referred to as scenarios B,
C, and D. They are briefly described in the
Annex. Future concentrations of some of die
greenhouse gases which would arise from these
emissions are shown opposite.
Greenhouse gas feedbacks
Some of the possible feedbacks which could
significantly modify future greenhouse gas
concentrations in a wanner world are discussed
in the following paragraphs.
The net emissions of carbon dioxide from
terrestrial ecosystems will be -elevated if higher
temperatures increase respiration at a faster rate
than photosynthesis, or if plant populations.
particularly large forests, cannot adjust rapidly
enough to changes in climate.
2000 2020 2040 2060 2080 2100
YEAR
2000 2020 2040 2060 2080 2100
YEAR
2000 2020 2040 2060 2080 2100
YEAR
Atmospheric concentrations of carbon dioxide,
methane and CFC-11 resulting from the four
IPCC emissions scenarios
A net flux of carbon dioxide to die atmosphere
may be particularly evident in warmer conditions
in tundra and boreal regions where there are large
stores of carbon. The opposite is true if higher
abundances of carbon dioxide in the atmosphere
enhance the productivity of natural ecosystems.
or if there is an increase in soil moisture which
can be expected to stimulate plant growth in dry
ecosystems and to increase the storage of carbon
in tundra peat. The extent to which ecosystems
-------
YVGI POLICYMAKERS SUMMARY
can sequester increasing atmospheric carbon
dioxide remains to be quantified.
If the oceans become warmer, their net uptake of
carbon dioxide may decrease because of changes
in (i) me chemistry of carbon dioxide in seawater
(Li) biological activity in surface waters and (iii)
the rate of exchange of carbon dioxide between
the surface layers and the deep ocean. This last
depends upon the rate of formation of deep water
in the ocean which, in the North Atlantic for
example,, might decrease if the salinity decreases
as a result of a change in climate.
Methane emissions from natural wetlands and
rice paddies are particularly sensitive to
temperature and soil moisture. Emissions are
significantly larger at higher temperatures and
with increased soil moisture; conversely, a
decrease in soil moisture would result in smaller
emissions. Higher temperatures could increase
the emissions of methane at high northern
latitudes from decomposable organic matter
trapped in permafrost and methane hydrates.
As illustrated earlier, ice core records show that
methane and carbon dioxide concentrations
changed in a similar sense to temperature
between ice ages and interglacials.
Although many of these feedback processes are
poorly understood, it seems likely that, overall,
they will act to increase, rather than decrease,
greenhouse gas concentrations in a wanner
world.
Which gases are the most
important?
We are certain that increased greenhouse gas
concentrations increase radiative forcing. We can
calculate the forcing with much more confidence
than the climate change that results because the
former avoids the need to evaluate a number of
poorly understood atmospheric responses. We
then have a base from which to calculate the
relative effect on climate of an increase in
concentration of each gas in the present-day
atmosphere, both in absolute terms and relative to
carbon dioxide. These relative effects span a
wide range; methane is about 21 times more
effective, molecule-for-molec'-ie. than carbon
dioxide, and CFG-11 about 12,000 times more
effective. On a kilogram-per-kilogram basis, the
equivalent values are 58 for methane and about
4,000 for CFC-11, both relative to carbon
dioxide, yalues for other greenhouse gases are to
be found in the full report.
The total radiative forcing at any time is the sum
of those from the individual greenhouse gases.
We show in the figure below how this quantity
has changed in the past (based on observations of
greenhouse gases) and how it might change in
the future (based on the four IPCC emissions
scenarios). For simplicity, we can express total
forcing in terms of the amount of carbon dioxide
which would give that forcing; this is termed die
equivalent carbon dioxide concentration.
Greenhouse gases have increased since pre-
industrial titim* (the mid-18th century) by an
10
F 8
t.
i 4
o
B
2 2
BUSINESS
AS USUAL
SCBIARIOO
1120
560
280
1900
1950
2000
YEAH
2050
2100
Increase in radiative forcing since the mid-18th century, and predicted to result from the four
IPCC emissions scenarios, also expressed as equivalent carbon dioxide concentrations
10
-------
POLICYMAKERS SUMMARY W G I
CARBON
DIOXIDE
CFCs
11 and 12
OTHER
CFCs
NITROUS
OXIDE
METHANE
The contribution from each of the human-made
greenhouse gases to the change in radiative
forcing from 1980 to 1990. The contribution
from ozone may also be significant, but
cannot be quantified at present.
amount that is radiatively equivalent to about a
50% increase in carbon dioxide, although carbon
dioxide itself has risen by only 26%; other gases
have marift up the rest.
The contributions of the various gases to the total
increase in climate forcing during the 1980s is
shown above as a pie diagram; carbon dioxide is
responsible for about half the decadal increase.
(Ozone, the effects of which may be significant,
is not included)
How can we evaluate the effect of
different greenhouse gases?
To evaluate possible policy options, it is useful to
know the relative radiative effect (and, hence,
potential climate effect) of equal emissions of
each of the greenhouse gases. The concept of
relative Global Warming Potentials (GWP)
has been developed to take into account the
differing times that gases remain in the
atmosphere.
This index defines the time-integrated wanning
effect due to an instantaneous release of unit
mass (1 kg) of a given greenhouse gas in today's
atmosphere, relative to that of carbon dioxide.
The relative importances will change in the future
as atmospheric composition changes because,
although radiative forcing increases in direct
proportion to the concentration of CFCs, changes
in the other greenhouse gases (particularly carbon
dioxide) have an effect on forcing which is much
less than proportional.
The GWPs in the following table are shown for
three time horizons, reflecting the need to
consider the cumulative effects on climate over
various time scales. The longer time horizon is
appropriate for the cumulative effect; the shorter
timescale will indicate the response to emission
changes in the short term. There are a number of
practical difficulties in devising and calculating
the values of the GWPs, and the values given
here should be considered as preliminary. In
addition to these direct effects, mere are indirect
effects of human-marie emissions arising from
chemical reactions between the various
GLOBAL WARMING POTENTIALS
The warming effect of an emission of 1kg of each gas relative to that of CCh
These figures are best estimates calculated on the basis of the present day atmospheric composition
Carbon dioxide
Methane (including indirect)
Nitrous oxide
CFC-11
CFC-12
HCFC-22
Global Wanning Potentials for a
20 yr
1
63
270
4500
7100
4100
Time Horizon
100 yr
1
21
290
3500
7300
1500
500 yr
1
9
190
1500
4500
510
range of CFCs and potential replacements are given in the full text
11
-------
WGI POLICYMAKERS SUMMARY
THE RELATIVE CUMULATIVE CLIMATE EFFECT OF
1990 MAN-MADE EMISSIONS
Carbon dioxide
Methane*
Nitrous oxide
CFCs
HCFC-22
Others*
GWP
(lOOyr
horizon)
1
21
290
Various
1500
Various
1990
emissions
(Tg)
26000t
300
6
0.9
0.1
*These values include the indirect effect of these emissions on <
rgreenhi
Relative
contribution
over lOOyr
61%
15%
4%
11%
0.5%
8.5%
i via chemical reactions in the
:ga
tmosphere. Such estimates are highly model dependent and should be considered preliminaiy and subject 10 change.
The estimated effect of ozone is included under "others". The gases included under 'omen" arc given in the full report.
t 26 000 Tg (leragrams) of carbon dioxide = TOOOTg (=7 Gt) of carbon
constituents. The indirect effects on stratospheric
water vapour, carbon dioxide and tropospheric
ozone have been included in these estimates.
The table indicates, for example, that the
effectiveness of methane in influencing climate
will be greater in the first few decades after
release, whereas emission of the longer-lived
nitrous oxide will affect climate for a much
longer time. The lifetimes of the proposed CFC
replacements range from 1 to 40 years; the longer
lived replacements are still potentially effective as
agents of climate change. One example of this,
HCFC-22 (with a 15 year lifetime), has a similar
effect (when released in the same amount) as
CFC-11 on a 20 year timescale; but less over a
500 year timescale.
The table shows carbon dioxide to be the least
effective greenhouse gas per kilogramme emitted.
but its contribution to global wanning, which
depends on the product of the GWP and the
amount emitted, is largest. In the example in the
box below, the effect over 100 years of
emissions of greenhouse gases in 1990 are
shown relative to carbon dioxide. This is
illustrative; to compare the effect of different
emission projections we have to sum the effect of
emissions made in future years
MAJOR
GAS CONTRIBUTOR?
Carbon dioxide
Methane
Nitrous oxide
CFCs
HCFCs, etc
Ozone
yes
yes
not at
present
yes
not at
present
possibly
LONG
LIFETIME?
yes
no
yes
yes
mainly no
no
SOURCES
KNOWN?
yes
semi-quantitatively
qualitatively
yes
yes
qualitatively
12
-------
POLICYMAKERS SUMMARY W G I
There are other technical criteria which may help
policymakers to decide, in the event of emissions
reductions being deemed necessary, which gases
should be considered. Does the gas contribute in
a major way to current, and future, climate
forcing? Does it have a long lifetime, so earlier
reductions in emissions would be more effective
than those made later? And are its sources and
sinks well enough known to decide which could
be controlled in practice? The table opposite
illustrates these factors.
How much do we expect
climate to change?
It is relatively easy to determine the direct effect
of the increased radiative forcing due to increases
in greenhouse gases. However, as climate begins
to warm, various processes act to amplify
(through positive feedbacks) or reduce (through
negative feedbacks) the wanning. The main
feedbacks which have been identified are due to
changes in water vapour, sea-ice, clouds and the
oceans.
The best tools we have which take the above
feedbacks into account (but do not include
greenhouse gas feedbacks) are three-dimensional
mathematical models of the climate system
(atmosphere-ocean-ice-land), known as General
Circulation Models (GCMs). They synthesise
our knowledge of the physical and dynamical
processes in the overall system and allow for the
complex interactions between the various
components. However, in their current state of
development, the descriptions of many of the
processes involved are comparatively crude.
Because of this, considerable uncertainty is
attached to these predictions of climate change.
which is reflected in the range of values given;
further details are given in a later section.
The estimates of climate change presented here
are based on
i) the "best estimate" of equilibrium climate
sensitivity (i.e the equilibrium temperature
change due to a doubling of carbon dioxide
in the atmosphere) obtained from model
simulations, feedback analyses and1
observational considerations (see later box:
"What tools do we use?")
ii) a "box diffusion upwelling" ocean-
atmosphere climate model which translates
the greenhouse forcing into the evolution of
the temperature response for the prescribed
climate sensitivity. (This simple model has
been calibrated against more complex
atmosphere-ocean coupled GCMs for
situations where the more complex models
have been run).
How quickly will global climate change?
a. If emissions follow a Business-as-
Usual pattern
Under the IPCC Business-as-Usual (Scenario A)
emissions of greenhouse gases, the average rate
of increase of global mean temperature during the
next century is estimated to be about 0.3'C per
decade (with an uncertainty range of 0.2*C to
0.5'C). This will result in a likely increase in
global mean temperature of about 1*C above the
present value (about 2'C above that in the pre-
industrial period) by 2025 and 3'C above today's
(about 4"C above pre-industrial) before the end
of the next century.
The projected temperature rise out to the year
2100. with high, low and best-estimate climate
responses, is shown in the diagram below.
Because of other factors which influence climate,
we would not expect the rise to be a steady one.
The temperature rises shown above are realised
temperatures; at any time we would also be
committed to a further temperature rise toward
the equilibrium temperature (see box:
"Equilibrium and Realised Climate Change").
For the Ball "best estimate" case in the year
2030, for example, a further 0.9'C rise would be
expected, about 0.2*C of which would be
realised by 2050 (in addition to changes due to
further greenhouse gas increases); the rest would
become apparent in decades or centuries.
Even if we were able to stabilise emissions of
each of the greenhouse gases at present day
levels from now on, the temperature is predicted
to rise by about 0.2'C per decade for the first few
decades.
The global warming will also lead to increased
global average precipitation and evaporation of a
few percent by 2030. Areas of sea-ice and snow
are expected to diminish.
13
-------
WGI POLICYMAKERS SUMMARY
HIGH ESTIMATE
BEST ESTIMATE
LOW ESTIMATE
1900
1950 2000
YEAR
2050 2100
Simulation of the increase in global mean temperature from 1850-1990 due to observed increases
in greenhouse gases, and predictions of the rise between 1990 and 2100 resulting from the
Business-as-Usual emissions.
b. If emissions are subject to controls
Under the other IFCC emission scenarios which
assume progressively increasing levels of
controls, average rates of increase in global mean
temperature over the next century are estimated to
be about 0.2*C per decade (Scenario B), just
above 0.1'C per decade (Scenario C) and about
0.1'C per decade (Scenario D). The results are
illustrated opposite with the Business-as-usual
case for comparison. Only the best-estimate of
the temperature rise is shown in each i
The indicated range of uncertainty in global
temperature rise given above reflects a subjective
assessment of uncertainties in the calculation of
climate response, but does not include those due
to the transformation of emissions to
concentrations, nor the effects of greenhouse gas
feedbacks.
BUSINESS
AS-USUAL
SCENARIO B
SCENARIO C
SCENARIO 0
1900
1950 2000
YEAR
2050 2100
Simulations of the increase in global mean temperature from 1850-1990 due to observed increases
in greenhouse gases, and predictions or the rise between 1990 and 2100 resulting from the IPCC
Scenario B.C and D emissions, with the Business-as-Usual case for comparison.
14
-------
POLICYMAKERS SUMMARY WGI
What tools do we use to predict future climate, and how do we use them?
The most highly developed tool which we have to predict future climate is known as a general circulation
model or GCM. These models are based on the laws of physics and use descriptions in simplified physical
terms (called parameterisaiions) of the smaller-scale processes such as those due to clouds and deep mixing in
the ocean. In a climate model an atmospheric component, essentially the same as a weather prediction model.
is coupled to a model of the ocean, which can be equally complex.
Climate forecasts are derived in a different way from weather forecasts. A weather prediction model gives a
description of the atmosphere's state up to 10 days or so ahead, starting from a detailed description of an
initial state of the atmosphere at a given lime. Such forecasts describe the movement and development of
large weather systems, though they cannot represent very small scale phenomena; for example, individual
shower clouds.
To make a climate forecast, the climate model is first run for a few (simulated) decades. The statistics of the
model's output is a description of the model's simulated climate which, if the model is a good one, will bear
a close resemblance to the climate of the real atmosphere and ocean. The above exercise is then repealed wiih
increasing concentrations of the greenhouse gases in the model. The differences between the statistics of the
two simulations (for example in mean temperature and interannual variability) provide an estimate of the
accompanying climate change.
The long term change in surface air temperature following a doubling of carbon dioxide (referred to as
the climate sensitivity) is generally used as a benchmark to compare models. The range of results from
model studies is 1.9 to 5.2'C. Most results are close to 4.0'C but recent studies using a more detailed but
not necessarily more accurate representation of cloud processes give results in the lower half of this range.
Hence the models results do not justify altering the previously accepted range of l.S to 4.5'C.
Although scientists are reluctant to give a single best estimate in this range, it is necessary for the
presentation of climate predictions for a choice of best estimate to be made. Taking into account the model
results, together with observational evidence over the last century which is suggestive of the climate
sensitivity being in the lower half of the range, (see section: "Has man already begun to change global
climate?") a value of climate sensitivity of 2.5'C has been chosen as the best esamate. Further details are
given in Section 5 of the report.
In this Assessment, we have also used much simpler models, which simulate the behaviour of GCMs, to
make predictions of the evolution with time of global temperature from a number of emission scenarios.
These so-called box-diffusion models contain highly simplified physics but give similar results to GCMs
when globally averaged.
A completely different, and potentially useful, way of predicting patterns of future climate is to search for
periods in the past when the global mean temperatures were similar to those we expect in future, and then
use the past spatial patterns as analogues of those which will arise in the future. For a good analogue, it
is also necessary for the forcing factors (for example, greenhouse gases, orbital variaoons) and other
conditions (for example, ice cover, topography, etc.) to be similar, direct comparisons with climate
situations for which these conditions do not apply cannot be easily interpreted. Analogues of future
greenhouse-gas-changed climates have not been found.
We cannot therefore advocate the use of palaeo-cliinates as predictions of regional climate change due to
future increases in greenhouse gases. However, palaeo-climatologtcal information can provide useful
insights into climate processes, and can assist in the validation of climate models.
15
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VVGI POLICYMAKERS SUMMARY
Equilibrium and realised climate change
When the radiative forcing on the earth-atmosphere system is changed, for example by increasing greenhouse
gas concentrations, the atmosphere will try to respond (by warming) immediately. But the atmosphere is
closely coupled to the oceans, so in order for the air to be wanned by the greenhouse effect, the oceans also
have to be warmed: because of their thermal capacity this takes decadea or centuries. This exchange of heat
between atmosphere and ocean will act to slow down the temperature rise forced by the greenhouse effect
In a hypothetical example where the concentration of greenhouse gases in the atmosphere, following a period
of constancy, rises suddenly to a new level and remains there, the radiative forcing would also rise rapidly to
a new level. This increased radiative forcing would cause the atmosphere and oceans to warm, and eventually
come to a new, stable, temperature. A commitment to this equilibrium temperature rise is incurred as
soon as the greenhouse gas concentration changes. But at any time before equilibrium is reached, the actual
temperature will have risen by only pan of the equilibrium temperature change, known as the realised
temperature change.
Models predict that, for the present day case of an increase in radiative forcing which is approximately steady.
the realised temperature rise at any time is about 50% of the committed temperature nse if the climate
sensitivity (the response to a doubling of carbon dioxide) is 4.5°C and about 80% if the climate sensitivity
isl.5°C. If the forcing were then held constant, temperatures would continue to nse slowly, but it is not
certain whether it would take decades or centuries for most of the remaining rise to equilibrium 10 occur
•3
*
Forcing
SO 100 ISO
Years
Eqrfbrium
tempvuur*
100 200 300
Years
Equation
SO 100
Years
150
100 200 300
Years
What will be the patterns of climate
change by 2030?
Knowledge of the global mean wanning and
change in precipitation is of limited use in
determining the impacts of climate change, for
instance on agriculture. For this we need to
know changes regionally and seasonally.
Models predict that surface air will warm faster
over land than over oceans, and a minimum of
warming will occur around Antarctica and in the
northern North Atlantic region.
There are some continental-scale changes which
are consistently predicted by the highest
resolution models and for which we understand
16
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POLICYMAKERS SUMMARY WGI
the physical reasons. The wanning is predicted
to be 50-100% greater than the global mean in
high northern latitudes in winter, and
substantially smaller than the global mean in
regions of sea ice in summer. Precipitation is
predicted to increase on average in middle and
high latitude continents in winter (by some 5 -
10% over 35-55'N).
Five regions, each a few million square
kilometres in area and representative of different
climatological regimes, were selected by IPCC
for particular study (see map below). In the box
below are given the changes in temperature,
precipitation and soil moisture, which are
predicted to occur by 2030 on the Business-as-
Usual scenario, as an average over each of the
five regions. There may be considerable
variations within the regions. In general,
confidence in these regional estimates is low,
especially for the changes in precipitation and soil
moisture, but they are examples of our best
estimates. We cannot yet give reliable regional
predictions at the smaller scales demanded for
impacts assessments.
How will climate extremes and extreme
events change?
Changes in the variability of weather and the
frequency of extremes will generally have more
impact than changes in the mean climate at a
particular location. With the possible exception
of an increase in the number of intense showers.
there is no clear evidence that weather variability
will change in the future. In the case of
temperatures, assuming no change in variability,
but with a modest increase in the mean, the
number of days with temperatures above a given
value at the high end of the distribution will
increase substantially. On the same assumptions,
there will be a decrease in days with temperatures
at the low end of the distribution. So the number
of very hot days or frosty nights can be
substantially changed without any change in the
variability of the weather. The number of days
with a minimum threshold amount of soil
moisture (for viability of a certain crop, for
example) would be even more sensitive to
changes in average precipitation and evaporation.
If the large scale weather regimes, for instance
depression tracks or anticyclones, shift their
position, this would effect the variability and
extremes of weather at a particular location, and
could have a major effect However, we do not
know if, or in what way, this will happen.
Will storms increase in a warmer world?
Storms can have a major impact on sociery. Will
their frequency, intensity or location increase in a
wanner world?
Tropical storms, such as typhoons and
hurricanes, only develop at present over seas that
are warmer than about 26'C. Although the area
of sea having temperatures over this critical value
Map showing the locations and extents of the five areas selected by IPCC
17
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WGI POLICYMAKERS SUMMARY
ESTIMATES FOR CHANGES BY 2030
(IPCC Business-as-Usual scenario; changes from pre-industrial)
The numbers given below are based on high resolution models, scaled to be consistent with our best estimate
of global mean wanning of 1.8'C by 2030. For values consistent with other estimates of global temperature
rise, the numbers below should be reduced by 30% for the low estimate or increased by 50% for the high
estimate. Precipitation estimates are also scaled in a similar way.
Confidence in these regional estimates is low
Central North America (35'-50'N 85M05'W)
The warming varies from 2 to 4*C in winter and 2 to 3"C in summer. Precipitation
increases range from 0 to 15% in winter whereas there are decreases of 5 to 10% in
summer. Soil moisture decreases in summer by IS to 20%.
Southern Asia (5*-30'N 70'-105*E)
The wanning varies from 1 to 2'C throughout the year. Precipitation changes little in
winter and generally increases throughout the region by 5 to 15% in summer. Summer
soil moisture increases by 5 to 10%.
Sahel (10'-20'N 2
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POLICYMAKERS SUMMARY WGI
Climate change in the longer term
The foregoing calculations have focussed on the
period up to the year 2100; it is clearly more
difficult to make calculations for years beyond
2100. However, while the timing of a predicted
increase in global temperatures has substantial
uncertainties, the prediction that an increase will
eventually occur is more certain. Furthermore,
some model calculations that have been extended
beyond 100 years suggest that, with continued
increases in greenhouse climate forcing, there
could be significant changes in the ocean
circulation, including a decrease in North Atlantic
deep water formation.
Other factors which could influence
future climate
Variations in the output of solar energy may
also affect climate. On a decadal time-scale solar
variability and changes in greenhouse gas
concentration could give changes of similar
magnitudes. However the variation in solar
intensity changes sign so that over longer
timescales the increases in greenhouse gases are
likely to be more important. Aerosols as a
result of volcanic eruptions can lead to a cooling
at the surface which may oppose the greenhouse
warming for a few years following an eruption.
Again, over longer periods the greenhouse
wanning is likely to dominate.
Human activity is leading to an increase in
aerosols in the lower atmosphere, mainly from
sulphur emissions. These have two effects, both
of which are difficult to quantify but which may
be significant particularly at the regional level.
The first is the direct effect of the aerosols on the
radiation scattered and absorbed by the
atmosphere. The second is an indirect effect
whereby the aerosols affect the microphysics of
clouds leading to an increased cloud reflectivity.
Both these effects might lead to a significant
regional cooling; a decrease in emissions of
sulphur might be expected to increase global
temperatures.
Because of long-period couplings between
different components of the climate system, for
example between ocean and atmosphere, the
earth's climate would still vary without being
perturbed by any external influences. This
natural variability could act to add to, or
subtract from', any human-made wanning; on a
century timescale this would be less than changes
expected from greenhouse gas increases.
How much confidence do
we have in our predictions?
Uncertainties in the above climate predictions
arise from our imperfect knowledge of:
• future rates of human-made emissions
• how these will change the atmospheric
concentrations of greenhouse gases
• the response of climate to these changed
concentrations
Firstly, it is obvious that the extent to which
climate will change depends on the rate at which
greenhouse gases (and other gases which affect
their concentrations) are emitted. This in turn
will be determined by various complex economic
and sociological factors. Scenarios of future
emissions were generated within IPCC WGIII
and are described in the annex.
Secondly, because we do not fully understand
the sources and sinks of the greenhouse gases,
there are uncertainties in our calculations of
future concentrations arising from a given
emissions scenario. We have used a number of
models to calculate concentrations and chosen a
best estimate for each gas. In the case of carbon
dioxide, for example, the concentration increase
between 1990 and 2070 due to the Business-as-
Usual emissions scenario spanned almost a factor
of two between the highest and lowest model
result (corresponding to a range in radiative
forcing change of about 50%)
Furthermore, because natural sources and sinks
of greenhouse gases are sensitive to a change in
climate, they may substantially modify future
concentrations (see earlier section: "Greenhouse
gas feedbacks"). It appears that, as climate
warms, these feedbacks will lead to an overall
increase, rather than decrease, in natural
greenhouse gas abundances. For this reason,
climate change is likely to be greater than the
estimates we have given.
Thirdly, climate models are only as good as our
understanding of the processes which they
describe, and this is far from perfect. The ranges
in the climate predictions given above reflect the
uncertainties due to model imperfections; the
largest of these is cloud feedback (those factors
affecting the cloud amount and distribution and
the interaction of clouds with solar and terrestrial
radiation), which leads to a factor of two
uncertainty in the size of the wanning. Others
arise from the transfer of energy between the
atmosphere and ocean, the atmosphere and land
19
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WGI POLICYMAKERS SUMMARY
surfaces, and between the upper and deep layers
of the ocean. The treatment of sea-ice and
convection in the models is also crude.
Nevertheless, for reasons given in the box
below, we have substantial confidence that
models can predict at least the broad-scale
features of climate change.
Furthermore, we must recognise that our
imperfect understanding of climate processes
(and corresponding ability to model them) could
make us vulnerable to surprises; just as the
human-made ozone hole over Antarctica was
entirely unpredicted. In particular, the ocean
circulation, changes in which are thought to have
led to pehods of comparatively rapid climate
change at the end of the last ice age, is not well
observed, understood or modelled.
Will the climate of the
future be very different?
When considering future climate change, it is
clearly essential to look at the record of climate
variation in the past. From it we can learn about
the range of natural climate variability, to see
how it compares with what we expect in the
future, and also look for evidence of recent
climate change due to man's activities.
Climate varies naturally on all time scales from
hundreds of millions of years down to the year to
year. Prominent in the Earth's history have been
the 100,000 year glacial-interglacial cycles when
climate was mostly cooler than at present.
Global surface temperatures have typically varied
by 5-7*C through these cycles, with large
changes in ice volume and sea level, and
temperature changes as great as 10-1S'C in some
Confidence in predictions from climate models
What confidence can we have that climate change due to increasing greenhouse gases will look anything like
the model predictions? Weather forecasts can be compared with the actual weather the next day and their skill
assessed: we cannot do that with climate predictions. However, there are several indicators that give us some
confidence in the predictions from climate models.
When the latest atmospheric models are run with the present atmospheric concentrations of greenhouse gases
and observed boundary conditions their simulation of present climate is generally realistic on large scales.
capturing the major features such as the wet tropical convergence zones and mid-latitude depression belts, as
well as the contrasts between summer and winter circulations. The models also simulate the observed
variability; for example, the large day-to-day pressure variations in the middle latitude depression belts and
the maxima in imerannual variability responsible for the very different chancier of one winter bom another
both being represented. However, on regional scales (2,000km or less), there are significant errors in
all models.
Overall confidence is increased by atmospheric models' generally satisfactory portrayal of aspects of
variability of the atmosphere, for instance those associated with variations in sea surface temperature. There
has been some success in simulating the general circulation of the ocean, including the patterns (though not
always the intensities) of the principal currents, and the distributions of tracers added to the ocean.
Atmospheric models have been coupled with simple models of the ocean to predict the equilibrium response
to greenhouse gases, under the assumption that the model errors are the same in a changed climate. The
ability of such models to simulate important aspects of the climate of the last ice age generates confidence
in their usefulness. Atmospheric models have also been coupled with multilayer ocean models (to give
coupled ocean-atmosphere GCMs) which predict the gradual response to increasing greenhouse gases.
Although the models so far are of relatively coarse resolution, the large scale structures of the ocean and the
atmosphere can be simulated with some skill. However, the coupling of ocean and atmosphere models
reveals a strong sensitivity to small scale errors which leads to a drift away from the observed climate. As
yet. these errors must be removed by adjustments to the exchange of heat between ocean and atmosphere.
There are similarities between results from the coupled models using simple representations of the ocean and
those using more sophisticated descriptions, and our understanding of such differences as do occur gives us
some confidence in the results.
20
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POLICYMAKERS SUMMARY WGI
middle and high latitude regions of the northern
hemisphere. Since the end of the last ice age,
about 10.000 years ago, global surface
temperatures have probably fluctuated by little
more than 1*C. Some fluctuations have lasted
several centuries, including the Little Ice Age
which ended in the nineteenth century and which
appears to have been global in extent.
The changes predicted to occur by about the
middle of the next century due to increases in
greenhouse gas concentrations from the
Business-as-Usual emissions will make global
mean temperatures higher than they have been in
the last 130,000 years.
The rate of change of global temperatures
predicted for Business-as-usual emissions will
be greater than those which have occured
naturally on earth over the last 10,000 years, and
the rise in sea level will be about three to six
rimes faster than that seen over the last 100 years
or so.
Has man already begun to
change the global climate?
The instrumental record of surface
temperature is fragmentary until the mid-
nineteenth century, after which it slowly
improves. Because of different methods of
measurement, historical records have to be
harmonised with modern observations,
introducing some uncertainty. Despite
these problems we believe that a real warming
of the globe of 0.3*C - 0.6"C has taken place
over the last century; any bias due to urbanisation
is Likely to be less than 0.03'C.
Moreover since 1900 similar temperature
increases are seen in three independent data sets:
one collected over land and two over the oceans.
The figure below shows current estimates of
smoothed global mean surface temperature over
land and ocean since 1860. Confidence in the
record has been increased by their similarity to
recent satellite measurements of mid-tropospheric
temperatures.
Although the overall temperature rise has been
broadly similar in both hemispheres, it has not
been steady, and differences in their rates of
wanning have sometimes persisted for decades.
Much of the wanning since 1900 has been
concentrated in two periods, the first between
about 1910 and 1940 and the other since 1975;
the five wannest years on record have ail been in
the 1980s. The nonhem hemisphere cooled
between the 1940s and the early 1970s when
southern hemisphere temperatures stayed nearly
constant. The pattern of global warming since
1975 has been uneven with some regions, mainly
in the northern hemisphere, continuing to cool
undl recently. This regional diversity indicates
that future regional temperature changes are likely
to differ considerably from a global average.
The conclusion that global temperature has been
rising is strongly supponed by the retreat of most
mountain glaciers of the world since the end
of the nineteenth century and the fact that global
sea level has risen over the same period by an
average of 1 to 2mm per year. Estimates of
thermal expansion of the oceans, and of
O 0.4
1990
Global mean combined land-air and sea-surface temperatures, 1861 • 1989, relative to the average
for 1951-80.
21
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WGI POLICYMAKERS SUMMARY
increased melting of mountain glaciers and the ice
margin in West Greenland over the last century,
show that the major pan of the sea level rise
appears to be related to the observed global
warming. This apparent connection between
observed sea level rise and global warming
provides grounds for believing that future
warming will lead to an acceleration in sea level
rise.
The size of the warming over the last century is
broadly consistent with the predictions of climate
models, but is also of the same magnitude as
natural climate variability. If the sole cause of the
observed warming were the human-made
greenhouse effect, then the implied climate
sensitivity would be near the lower end of the
range inferred from the models. The observed
increase could be largely due to natural
variability; alternatively this variability and other
man-made factors could have offset a still larger
man-made greenhouse warming. The
unequivocal detection of the enhanced
greenhouse effect from observations is not likely
for a decade or more, when the committment to
future climate change will then be considerably
larger than it is today.
Global-mean temperature alone is an inadequate
indicator of greenhouse-gas-induced climatic
change. Identifying the causes of any global-
mean temperature change requires examination of
other aspects of the changing climate, particularly
its spatial and temporal characteristics - the man-
made climate change "signal". Patterns of
climate change from models such as the northern
hemisphere warming faster than the southern
hemisphere, and surface air warming faster over
land than over oceans, are not apparent in
observations to date. However, we do not yet
know what the detailed "signal" looks like
because we have limited confidence in our
predictions of climate change patterns.
Furthermore, any changes to date could be
masked by natural variability and other (possibly
man-made) factors, and we do not have a clear
picture of these.
How much will sea level
rise ?
Simple models were used to calculate the rise in
sea level to the year 2100; the results are
illustrated below. The calculations necessarily
ignore any long-term changes, unrelated to
greenhouse forcing, that may be occurring but
cannot be detected from the present data on land
ice and the ocean. The sea-level rise expected
from 1990-2100 under the IPCC Business as
Usual emissions scenario is shown below. An
average rate of global mean sea level rise of about
6cm per decade over the next century (with an
uncertainty range of 3 - 10 cm per decade). The
predicted rise is about 20cm in global mean sea
level by 2030, and 65cm by the end of the next
century. There will be significant regional
variations.
The best estimate in each case is made up mainly
of positive contributions from thermal expansion
of the oceans and the melting of glaciers.
Although, over the next 100 years, the effect of
the Antarctic and Greenland ice sheets is expected
to be small, they make a major contribution to the
uncertainty in predictions.
HIGH ESTIMATE
BEST ESTIMATE
LOW ESTIMATE
1980 2000 2020 2040 2060 2080 2100
YEAR
Sea level rise predicted to result from Business-as-L'sual emissions, showing the best-estimate
and range
22
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POLICYMAKERS SUMMARY WGI
Even if greenhouse forcing increased no further,
there would still be a commitment to a continuing
.sea level rise for many decades and even
centuries, due to delays in climate, ocean and ice
mass responses. As an illustration, if the
increases in greenhouse gas concentrations were
to suddenly stop in 2030, sea level would go on
rising from 2030 to 2100. by as much again as
from 1990-2030, as shown in the diagram
below.
2 10
in
FORCING STABILISED
IN 2030
1980 2000 2020 2040 2060 2080 2100
YEAR
Commitment to sea level rise in the year
2030. The curve shows the sea level rise due
to Business-as-Usual emissions to 2030, with
the additional rise that would occur in the
remainder of the century even if climate
forcing was stabilised in 2030.
Predicted sea level rises due to the other three
emissions scenarios are shown below, with the
Business-as-usual case for comparison; only
best-estimate <^ilc*i^af'nfi5 are shown.
80
Ul
M
60
Ul
Ul
-1 40
Ul
M
0 20
ui
3
SCENARIO 0
1980 2000 2020 2040 2060 2080 2100
YEAR
Model estimates of sea-level rise from 1990-
2100 due to all Tour emissions scenarios.
The West Antarctic Ice Sheet is of special
concern. A large portion of it, containing an
amount of ice equivalent to about 5m of global
sea level, is grounded far below sea level. There
have been suggestions that a sudden outflow of
ice might result from global wanning and raise
sea level quickly and substantially. Recent
studies have shown that individual ice streams
are changing rapidly on a decade-to- century
timescale; however this is not necessarily related
to climate change. Within the next century, it is
not likely that there will be a major outflow of ice
from West Antarctica due directly to global
warming.
Any rise in sea level is not expected to be
uniform over the globe. Thermal expansion,
changes in ocean circulation, and surface air
pressure will vary from region to region as the
world warms, but in an as yet unknown way.
Such regional details await further development
of more realistic coupled ocean atmosphere
models. In addition, vertical land movements can
be as large or even larger than changes in global
mean sea level; these movements have to be taken
into account when predicting local change in sea
level relative to land.
The most severe effects of sea-level rise are likely
to result from extreme events (for example, storm
surges) the incidence of which may be affected
by climatic change.
What will be the effect of
climate change on
ecosystems?
Ecosystem processes such as photosynthesis and
respiration are dependent on climatic factors and
carbon dioxide concentration in the short term.
In the longer term, climate and carbon dioxide are
among the factors which control ecosystem
structure, i.e., species composition, either
directly by increasing mortality in poorly adapted
species, or indirectly by mediating the
competition between species. Ecosystems will
respond to local changes in temperature
(including its rate of change), precipitation, soil
moisture and extreme events. Current models are
unable to make reliable estimates of changes in
these parameters on the required local scales.
Photosynthesis captures atmospheric carbon
dioxide, water and solar energy and stores them
in organic compounds which are then used for
subsequent plant growth, the growth of animals
or the growth of microbes in the soil. All of
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YVGI POLICYMAKERS SUMMARY
these organisms release carbon dioxide via
respiration into the atmosphere. Most land plants
have a system of photosynthesis which will
respond positively to increased atmospheric
carbon dioxide ("the carbon dioxide fertilization
effect") but the response varies with species.
The effect may decrease with time when
restricted by other ecological limitations, for
example, nutrient availability. It should be
emphasized that the carbon content of the
terrestrial biosphere will increase only if the
forest ecosystems in a state of maturity will be
able to store more carbon in a wanner climate and
at higher concentrations of carbon dioxide. We
do not yet know if this is the case.
The response to increased carbon dioxide results
in greater efficiencies of water, light and nitrogen
use. These increased efficiencies may be
particularly important during drought and in
arid/semi-arid and infertile areas.
Because species respond differently to climatic
change, some will increase in abundance and/or
range while others will decrease. Ecosystems
will therefore change in structure and
composition. Some species may be displaced to
higher latitudes and altitudes, and may be more
prone to local, and possibly even global,
extinction; other species may thrive.
As stated above, ecosystem structure and species
distribution are particularly sensitive to the rate of
change of climate. We can deduce something
about how quickly global temperature has
changed in the past from paleoclimatological
records. As an example, at the end of the last
glaciation, within about a century, temperature
increased by up to 5'C in the North Atlantic
region, mainly in Western Europe. Although
during the increase from the glacial to the current
interglacial temperature simple tundra ecosystems
responded positively, a similar rapid temperature
increase applied to more developed ecosystems
could result in their instability.
Deforestation and Reforestation
Man has been deforesting the Earth for millennia. Until the early pan of the century, this was mainly in
temperate regions, more recently it has been concentrated in the tropics. Deforestation has several potential
impacts on climate: through the carbon and nitrogen cycles (where it can lead to changes in atmospheric
carbon dioxide concentrations), through the change in reflectivity of terrain when forests are cleared, through
its effect on the hydndogical cycle (precipitation, evaporation and runoff) and surface roughness and thus
atmospheric circulation which can produce remote effects on climate.
It is estimated that each year about 2 Gt of carbon (GtC) is released to the atmosphere due to tropical
deforestation. The rate of forest clearing is difficult to estimate; probably until the mid-20th century.
temperate deforestation and the loss of organic matter from soils was a more important contributor to
atmospheric carbon dioxide than was the burning of fossil fuels. Since then, fossil fuels have become
dominant; one estimate is that around 1980.1.6 GtC was being released annually from the clearing of
tropical forests, compared with about 5 GtC from the burning of fossil fuels. If all the tropical forests were
removed, the input is variously estimated at from ISO to 240 GtC; this would increase atmospheric carbon
dioxide by 35 to 60 ppmv.
To analyse the effect of reforestation we assume that 10 million hectares of forests are planted each year
for a period of 40 years, ie 4 million km2 would men have been planted by 2030. at which lime IGtC
would be absorbed annually until these forests reach maturity. This would happen in 40-100 years for most
forests. The above scenario implies an accumulated uptake of about 20GtC by the year 2030 and up to
SOGlC after 100 years. This accumulation of carbon in forests is equivalent to some 5-10% of the emission
due to fossil fuel burning in the Business-as-Usual scenario.
Deforestation can also alter climate directly by increasing reflectivity and decreasing evapptranspiration.
Experiments with climate models predict (hat replacing all the forests of (he Amazon Basin by grassland
would reduce the rainfall over the basin by about 20%. and increase mean temperature by several degrees.
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POLICYMAKERS SUMMARY WGI
What should be done to
reduce uncertainties, and
how long will this take?
Although we can say that some climate change is
unavoidable, much uncertainty exists in the
prediction of global climate properties such as the
temperature and rainfall. Even greater uncertainty
exists in predictions of regional climate change,
and the subsequent consequences for sea level
and ecosystems. The key areas of scientific
uncertainty are:
• clouds: primarily cloud formation,
dissipation, and radiative properties, which
influence the response of the atmosphere to
greenhouse forcing;
• oceans: the exchange of energy between
the ocean and the atmosphere, between the
upper layers of the ocean and the deep
ocean, and transport within the ocean, all of
which control the rate of global climate
change and the patterns of regional change;
• greenhouse gases: quantification of the
uptake and release of the greenhouse gases,
their chemical reactions in the atmosphere,
and how these may be influenced by
climate change.
• polar ice sheets: which affect
predictions of sea level rise
Studies of land surface hydrology, and of impact
on ecosystems, are also important.
To reduce the current scientific uncertainties in
each of these areas will require internationally
coordinated research, the goal of which is to
improve our capability to observe, model and
understand the global climate system. Such a
program of research will reduce the scientific
uncertainties and assist in the formulation of
sound national and international response
strategies.
Systematic long-term observations of the
system are of vital importance for understanding
the natural variability of the Earth's climate
system, detecting whether man's activities are
changing it, parametrising key processes for
models, and verifying model simulations.
Increased accuracy and coverage in many
observations are required. Associated with
expanded observations is the need to develop
appropriate comprehensive global information
bases for the rapid and efficient dissemination
and utilization of data. The main observational
requirements are:
i) the maintenance and improvement of
observations (such as those from satellites)
provided by the World Weather Watch
Programme of WMO
ii) the maintenance and enhancement of a
programme of monitoring, both from
satellite-based and surface-based
instruments, of key climate elements for
which accurate observations on a
continuous basis are required, such as the
distribution of imponant atmospheric
constituents, clouds, the earth's radiation
budget, precipitation, winds, sea surface
temperatures and terrestrial ecosystem
extent, type and productivity.
iii) the establishment of a global ocean
observing system to measure changes in
such variables as ocean surface
topography, circulation, transport of heat
and chemicals, and sea-ice extent and
thickness.
iv) the development of major new systems to
obtain data on the oceans, atmosphere and
terrestrial ecosystems using both satellite-
based instruments and instruments based
on the surface, on automated instrumented
vehicles in the ocean, on floating and deep
sea buoys, and on aircraft and balloons.
v) the use of paleoclimatological and historical
instrumental records to document natural
variability and changes in the climate
system, and subsequent environmental
response.
The modelling of climate change requires the
development of global models which couple
together atmosphere, land, ocean and ice models
and which incorporate more realistic formulations
of the relevant processes and the interactions
between the different components. Processes in
the biosphere (both on land and in the ocean) also
need to be included. Higher spatial resolution
than is currently generally used is required if
regional patterns are to be predicted. These
models will require the largest computers which
are planned to be available during the next
decades.
Understanding of the climate system will be
developed from analyses of observations and of
the results from model simulations. In addition,
25
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WGI POLICYMAKERS SUMMARY
detailed studies of particular processes will be
required through targetted observational
campaigns. Examples of such field campaigns
include combined observational and small scale
modelling studies for different regions, of the
formation, dissipation, radiative, dynamical and
microphysicaJ properties of clouds, and ground-
based (ocean and land) and aircraft measurements
of the fluxes of greenhouse gases from specific
ecosystems. In particular, emphasis must be
placed on Held experiments that will assist in the
development and improvement of sub-grid-scale
parametrizarions for models.
The required program of research will require
unprecedented international cooperation, with the
World Climate Research Programme (WCRP) of
the World Meteorological Organization and
International Council of Scientific Unions
(ICSU), and the International Geosphere-
Biosphere Programme (IGBP) of ICSU both
playing vital roles. These are large and complex
endeavours that will require the involvement of
all nations, particularly the developing countries.
Implementation of existing and planned projects
will require increased financial and human
resources; the latter requirement has immediate
implications at all levels of education, and the
international community of scientists needs to be
widened to include more members from
developing countries.
The WCRP and IGBP have a number of ongoing
or planned research programs, that address each
of the three key areas of scientific uncertainty.
Examples include:
• clouds:
International Satellite Cloud Climatology
Project (ISCCP);
Global Energy and Water Cycle Experiment
(GEWEX).
• oceans:
World Ocean Circulation Experiment
(WOCE);
Tropical Oceans and Global Atmosphere
(TOGA).
• trace gases:
Joint Global Ocean Flux Study (JGOFS);
International Global Atmospheric Chemistry
(IGAQ;
Past Global Changes (PAGES).
As research advances, increased understanding
and improved observations will lead to
progressively more reliable climate predictions.
However considering the complex nature of the
problem and the scale of the scientific
programmes to be undertaken we know that rapid
results cannot be expected. Indeed further
scientific advances may expose unforeseen
problems and areas of ignorance.
Timescales for narrowing the uncertainties will
be dictated by progress over the next 10-15 years
in two main areas:
• Use of the fastest possible computers, to
take into account coupling of the
atmosphere and the oceans in models, and
to provide sufficient resolution for regional
predictions.
• Development of improved representation of
small scale processes within climate
models, as a result of the analysis of data
from observational programmes tn be
conducted on a continuing basis well into
the next century.
26
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POLICYMAKERS SUMMARY WGl
Annex
EMISSIONS SCENARIOS FROM WORKING GROUP IH OF
THE INTERGOVERNMENTAL PANEL ON CLIMATE CHANGE
The Steering Group of the Response Strategies
Working Group requested the USA and the
Netherlands to develop emissions scenarios for
evaluation by the EPCC Working Group I. The
scenarios cover the emissions of carbon dioxide
(COj), methane (CH4), nitrous oxide (N29)>
chlorofluorocarbons (CFCs), carbon monoxide
(CO) and nitrogen oxides (NO*) from the present
up to the year 2100. Growth of the economy and
population was taken common for all scenarios.
Population was assumed to approach 10.S billion
in the second half of the next century. Economic
growth was assumed to be 2-3% annually in the
coming decade in the OECD countries and 3-5 %
in the Eastern European and developing
countries. The economic growth levels were
assumed to decrease thereafter. In order to reach
the required targets, levels of technological
development and environmental controls were
varied.
In the Business-as-Usual scenario
(Scenario A) the energy supply is coal intensive
and on the demand side only modest efficiency
increases are achieved. Carbon monoxide
controls are modest, deforestation continues until
the tropical forests are depleted and agricultural
emissions of methane and nitrous oxide are
uncontrolled. For CFCs the Montreal Protocol is
implemented albeit with only partial participation.
Note that the aggregation of national projections
by EPCC Working Group III gives higher
emissions (10 - 20%) of carbon dioxide and
methane by 202S.
In Scenario B the energy supply mix shifts
towards lower carbon fuels, notably natural gas.
Large efficiency increases are achieved. Carbon
monoxide controls are stringent, deforestation is
reversed and the Montreal Protocol implemented
with full participation.
In Scenario C a shift towards renewables and
nuclear energy takes place in the second half of
next century.. CFCs are now phased out and
agricultural emissions limimH
For Scenario D a shift to renewables and
nuclear in the first half of the next century
reduces the emissions of carbon dioxide, initially
more or less stabilizing emissions in the
industrialized countries. The scenario shows that
stringent controls in industrialized countries
combined with moderated growth of emissions in
developing countries could stabilize atmospheric
concentrations. Carbon dioxide emissions are
reduced to 50% of 1985 levels by the middle of
the next century.
1980 2000 2020 2040 2060 2080 2100
YEAR
900
300
1980 2000 2020 2040 2060 2080 2100
YEAR
Emissions of carbon dioxide and methane (as
examples) to the year 2100, in the four
scenarios developed by IPCC Working Group
III.
27
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WGII POLICYMAKERS SUMMARY
Contents
Executive summary 1
Agriculture and forestry 2
Natural terrestrial ecosystems 3
Hydrology and water resources 4
Human settlements, energy, transport, and industrial sectors, human health and
air quality 4
Oceans and coastal zones 5
Seasonal snow cover, ice and permafrost 5
Future action 6
Scenarios 8
Summary of findings 12
Potential impacts of climate change on agriculture, land use and forestry ... 12
Potential impacts on agriculture 12
Major findings 12
Principal issues 12
Magnitudes of possible dislocation 12
Most vulnerable regions and sectors 12
Effect of altered climate extremes 13
Effects on crop growth potential, land degradation, pests and
diseases 13
Regional impacts 14
Adaptation in agriculture 14
Recommendations for action 14
Potential impacts on managed forests and the forest sector 15
Biophysical effects on forest ecosystems 16
Socioeconomic implications 17
Adaptation 17
Recommendations for action 18
Potential impacts of climate change on natural terrestrial ecosystems and the
socioeconomic consequences 19
Major findings 19
Principal issues 20
Particularly sensitive species 20
Changes in the boundaries of vegetation zones 20
Changes within ecosystems 21
Recommendations for action 23
Potential impacts of climate change on hydrology and water resources 23
Major findings 23
Principal issues 24
Regional impacts 24
Continental/national 24
River basins and critical environments 25
Large lakes/seas 26
ii
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Recommendations for action 26
Potential impacts of climate change on human settlement, the energy, transport
and industrial sectors, human health and air quality 27
Major findings 27
Principal issues 27
Human settlement 28
Energy 29
Transport 30
Industry 30
Human health 31
Air pollution 32
Ultraviolet-B radiation 32
Recommendations for action 32
Potential impacts of climate change on the world ocean and coastal zones . . 33
Major findings 33
Impacts of jea-level rise on coastal zones 34
Threatened populations in low-lying areas and island nations ... 34
Alteration of the biophysical properties of estuaries and wetlands 35
Inundation and recession of barrier islands, coral atolls and other
shorelines 36
Impacts on the World Ocean 37
Recommendations for action 38
Impacts of climate change on seasonal snow cover, ice and permafrost, and
socioeconomic consequences 38
Major findings 39
Principal issues 40
Seasonal snow cover 40
Ice sheets and glaciers 41
Permafrost 42
Recommendations for action 44
Summary of major future actions 45
Concluding remarks 46
Tables
Table 1. Palaeoclimate analogs used by Soviet scientists 10
Table 2. Estimates for regional changes by Working Group I 10
111
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Executive summary
The IPCC Working Groups on scientific
analysis (Working Group I), impacts
(Working Group II) and response
strategies (Working Group III) were
established in November 1988 and
proceeded to work in parallel under
instructions from IPCC. The respon-
sibility of Working Group II is to
describe the environmental and socio-
economic implications of possible
climate changes over the next decades
caused by increasing concentrations of
greenhouse gases.
The report of Working Group II is based
on the work of a number of subgroups,
using independent studies which have
used different methodologies. Based on
the existing literature, the studies have
used several scenarios to assess the
potential impacts of climate change.
These have the features of:
(i) an effective doubling of CO2 in the
atmosphere between now and 2025 to
2050 for a 'business-as-usual' scenario;
(ii) a consequent increase of global
mean temperature in the range of 1.5° C
to 4°-5°C;
(iii) an unequal global distribution of
this temperature increase, namely a
smaller increase of half the global mean
in the tropical regions and a larger
increase of twice the global mean in the
polar regions; and
(iv) a sea-level rise of about 0.3-0.5 m
by 2050 and about 1 m by 2100, together
with a rise in the temperature of the
surface ocean layer of between 0.2° and
2.5° C.
These scenarios pre-date, but are in line
with, the recent assessment of Working
Group I which, for a 'business-as-usual'
scenario (scenario A in Working Group
I Report) has estimated the magnitude
of sea-level rise at about 20 cm by 2030
and about 65 cm by the end of the next
century. Working Group I has also
predicted the increase in global mean
temperatures to be about 1°C above the
present value by 2025 and 3°C before
the end of the next century.
Any predicted effects of climate change
must be viewed in the context of our
present dynamic and changing world.
Large-scale natural events such as El
Nino can cause significant impacts on
agriculture and human settlement. The
predicted population explosion will
produce severe impacts on land use and
on the demands for energy, fresh water,
food and housing, which will vary from
region to region according to national
incomes and rates of development. In
many cases, the impacts will be felt most
severely in regions already under stress,
mainly the developing countries.
Human-induced climate change due to
continued uncontrolled emissions will
accentuate these impacts. For instance,
climate change, pollution and ultra-
violet-B radiation from ozone depletion
can interact, reinforcing their damaging
effects on materials and organisms.
Increases in atmospheric concentrations
of greenhouse gases may lead to irrever-
sible change in the climate which could
be detectable by the end of this century.
Comprehensive estimates of the physical
and biological effects of climate change
at the regional level are difficult.
Confidence in regional estimates of
critical climatic factors is low. This is
particularly true of precipitation and soil
moisture, where there is considerable
disagreement between various general
circulation model and palaeoanalog
results. Moreover, there are several
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scientific uncertainties regarding the
relationship between climate change and
biological .effects and between these
effects and socioeconomic consequences.
This report does not attempt to antici-
pate any adaptation, technological
innovation or any other measures to
diminish the adverse effects of climate
change that will take place in the same
time frame. This is especially important
for heavily managed sectors, eg agri-
culture, forestry and public health. This
is one of the responsibilities of Working
Group III.
Finally, the issue of timing and rates of
change need to be considered; there will
be lags between:
i) emissions of greenhouse gases and
doubling of concentrations;
ii) doubling of greenhouse gas concen-
trations and changes in climate;
iii) changes in climate and resultant
physical and biological effects; and
iv) changes in physical and ecological
effects and resultant socioeconomic
(including ecological) consequences.
The shorter the lags, the less the ability
to cope and the greater the socio-
economic impacts.
There is uncertainty related to these
time lags. The changes will not be
steady and surprises cannot be ruled out.
The severity of the impacts will depend
to a large degree on the rate of climate
change.
Despite these uncertainties, Working
Group II has been able to reach some
major conclusions, which are;
Agriculture and forestry
Sufficient evidence is now available from
a variety of different studies to indicate
that changes of climate would have an
important effect on agriculture and live-
stock. Studies have not yet conclusively
determined whether, on average, global
agricultural potential will increase or
decrease. Negative impacts could be felt
at the regional level as a result of
changes in weather and pests associated
with climate change, and changes in
ground-level ozone associated with
pollutants, necessitating innovations in
technology and agricultural management
practices. There may be severe effects
in some regions, particularly decline in
production in regions of high present-day
vulnerability that are least able to adjust.
These include Brazil, Peru, the Sahel
Region of Africa, Southeast Asia, the
Asian region of the USSR and China.
There is a possibility that potential
productivity of high and mid latitudes
may increase because of a prolonged
growing season, but it is not likely to
open up large new areas for production
and it will be mainly confined to the
Northern Hemisphere.
Patterns of agricultural trade could be
altered by decreased cereal production
in some of the currently high-production
areas, such as Western Europe, southern
US, parts of South America and western
Australia. Horticultural production in
mid-latitude regions may be reduced.
On the other hand, cereal production
could increase in northern Europe.
Policy responses directed to breeding
new plant cultivars, and agricultural
management designed to cope with
changed climate conditions, could lessen
the severity of regional impacts. On
balance, the evidence suggests that in
the face of estimated changes of climate,
food production at the global level can
be maintained at essentially the same
-------
level as would have occurred without
climate change; however, the cost of
achieving this is unclear. Nonetheless,
climate change may intensify difficulties
in coping with rapid population growth.
An increase or change in UV-B radia-
tion at ground level resulting from the
depletion of stratospheric ozone will
have a negative impact on crops and
livestock.
The rotation period of forests is long
and current forests will mature and
decline during a climate in which they
are increasingly more poorly adapted.
Actual impacts depend on the physio-
logical adaptability of trees and the host-
parasite relationship. Large losses from
both factors in the form of forest
declines can occur. Losses from wildfire
will be increasingly extensive. The
climate zones which control species
distribution will move poleward and to
higher elevations. Managed forests
require large inputs in terms of choice of
seedlot and spacing, thinning and
protection. They provide a variety of
products from fuel to food. The degree
of dependency on products varies among
countries, as does the ability to cope
with and to withstand loss. The most
sensitive areas will be where species are
close to their biological limits in terms of
temperature and moisture. This is likely
to be, for example, in semi-arid areas.
Social stresses can be expected to
increase and consequent anthropogenic
damage to forests may occur. These
increased and non-sustainable uses will
place more pressure on forest invest-
ments, forest conservation and sound
forest management.
Natural terrestrial ecosystems
Natural terrestrial ecosystems could face
significant consequences as a result of
the global increases in the atmospheric
concentrations of greenhouse gases and
the associated climatic changes. Pro-
jected changes in temperature and pre-
cipitation suggest that climatic zones
could shift several hundred kilometres
towards the poles over the next fifty
years. Flora and fauna would lag behind
these climatic shifts, surviving in their
present location and, therefore, could
find themselves in a different climatic
regime. These regimes may be more or
less hospitable and, therefore, could
increase productivity for some species
and decrease that of others. Ecosystems
are not expected to move as a single
unit, but would have a new structure as
a consequence of alterations in distri-
bution and abundance of species.
The rate of projected climate changes is
the major factor determining the type
and degree of climatic impacts on
natural terrestrial ecosystems. These
rates are likely to be faster than the
ability of some species to respond and
responses may be sudden or gradual.
Some species could be lost owing to
increased stress leading to a reduction in
global biological diversity. Increased
incidence of disturbances such as pest
outbreaks and fire are likely to occur in
some areas and these could enhance
projected ecosystem changes.
Consequences of CO2 enrichment and
climate change for natural terrestrial
ecosystems could be modified by other
environmental factors, both natural and
man-induced (eg by air pollution).
Most at risk are those communities in
which the options for adaptability are
limited (eg montane, alpine, polar, island
and coastal communities, remnant vege-
tation, and heritage sites and reserves)
and those communities where climatic
changes add to existing stresses.
-------
The socioeconomic consequences of
these impacts will be significant,
especially for those regions of the globe
where societies and related economies
are dependent on natural terrestrial
ecosystems for their welfare. Changes in
the availability of food, fuel, medicine,
construction materials and income are
possible as these ecosystems are
changed. Important fibre products could
also be affected in some regions.
Hydrology and water resources
Relatively small climate changes can
cause large water resource problems in
many areas, especially arid and semi-arid
regions and those humid areas where
demand or pollution has led to water
scarcity. Little is known about regional
details of greenhouse-gas-induced hydro-
meteorological change. It appears that
many areas will have increased precipi-
tation, soil moisture and water storage,
thus altering patterns of agricultural,
ecosystem and other water use. Water
availability will decrease in other areas,
a most important factor for already
marginal situations, such as the Sahelian
zone in Africa. This has significant
implications for agriculture, for water
storage and distribution, and for
generation of hydroelectric power. In
some limited areas, for example, under
the assumed scenario of a 1°C to 2°C
temperature increase, coupled with a
10% reduction in precipitation, a 40-70%
reduction in annual runoff could occur.
Regions such as Southeast Asia, that are
dependent on unregulated river systems,
are particularly vulnerable to hydro-
meteorological change. On the other
hand, regions such as the western USSR
and western United States that have
large regulated water resource systems
are less sensitive to the range of
hydrometeorological changes in the
assumed greenhouse scenario.
In addition to changes in water supply,
water demand may also change through
human efforts to conserve, and through
improved growth efficiency of plants in
a higher COZ environment. Net socio-
economic consequences must consider
both supply and demand for water.
Future design in water resource
engineering will need to take possible
impacts into account when considering
structures with a life span to the end of
the next century. Where precipitation
increases, water management practices,
such as urban storm drainage systems,
may require upgrading in capacity.
Change in drought risk represents
potentially the most serious impact of
climate change on agriculture at both
regional and global levels.
Human settlements, energy,
transport, and industrial sectors,
human health and air quality
The most vulnerable human settlements
are those especially exposed to natural
hazards, eg coastal or river flooding,
severe drought, landslides, severe wind
storms and tropical cyclones. The most
vulnerable populations are in developing
countries, in the lower income groups,
residents of coastal lowlands and islands,
populations in semi-arid grasslands, and
the urban poor in squatter settlements,
slums and shanty towns, especially in
megacities. In coastal lowlands such as
in Bangladesh, China and Egypt, as well
as in small island nations, inundation
due to sea-level rise and storm surges
could lead to significant movements of
people. Major health impacts are
possible, especially in large urban areas,
owing to changes in availability of water
and food and increased health problems
due to heat stress spreading of infec-
tions. Changes in precipitation and
temperature could radically alter the
patterns of vector-borne and viral
diseases by shifting them to higher
-------
latitudes, thus putting large populations
at risk. As similar events have in the
past, these changes could initiate large
migrations of people, leading over a
number of years to severe disruptions of
settlement patterns and social instability
in some areas.
Global wanning can be expected to
affect the availability of water resources
and biomass, both major sources of
energy in many developing countries.
These effects are likely to differ between
and within regions with some areas
losing and others gaining water and
biomass. Such changes in areas which
lose water may jeopardise energy supply
and materials essential for human
habitation and energy. Moreover,
climate change itself is also likely to
have different effects between regions on
the availability of other forms of
renewable energy such as wind and solar
power. In developed countries some of
the greatest impacts on the energy,
transport and industrial sectors may be
determined by policy responses to
climate change such as fuel regulations,
emission fees or policies promoting
greater use of mass transit. In
developing countries, climate-related
changes in the availability and price of
production resources such as energy,
water, food and fibre may affect the
competitive position of many industries.
Global warming and increased ultra-
violet radiation resulting from depletion
of stratosphere ozone may produce
adverse impacts on air quality such as
increases in ground-level ozone in some
polluted urban areas. An increase of
UV-B radiation intensity at the earth's
surface would increase the risk of
damage to the eye and skin and may
disrupt the marine food chain.
Oceans and coastal zones
Global warming will accelerate sea-level
rise, modify ocean circulation and
change marine ecosystems, with con-
siderable socioeconomic consequences.
These effects will be added to present
trends of rising sea-level, and other
effects that have already stressed coastal
resources, such as pollution and over-
harvesting. A 30-50 cm sea-level rise
(projected by 2050) will threaten low
islands and coastal zones. Aim rise
by 2100 would render some island
countries uninhabitable, displace tens of
millions of people, seriously threaten
low-lying urban areas, flood productive
land, contaminate fresh water supplies
and change coastlines. All of these
impacts would be exacerbated if
droughts and storms become more
severe. Coastal protection would involve
very significant costs. Rapid sea-level
rise would change coastal ecology and
threaten many important fisheries.
Reductions in sea ice will benefit
shipping, but seriously impact on ice-
dependent marine mammals and birds.
Impacts on the global oceans will include
changes in the heat balance, shifts in
ocean circulation which will affect the
capacity of the ocean to absorb heat and
CO2, and changes in upwelling zones
associated with fisheries. Effects will
vary by geographic zones, with changes
in habitats, a decrease in biological
diversity and shifts in marine organisms
and productive zones, including commer-
cially important species. Such regional
shifts in fisheries will have major
socioeconomic impacts.
Seasonal snow cover, ice and
permafrost
The global areal extent and volume of
elements of the terrestrial cryosphere
(seasonal snow cover, near-surface layers
-------
of permafrost and some masses of ice)
will be substantially reduced. These
reductions, when reflected regionally,
could have significant impacts on related
ecosystems and social and economic
activities. Compounding these impacts
in some regions is that, as a result of the
associated climatic warming positive
feedbacks, the reductions could be
sudden rather than gradual.
The areal coverage of seasonal snow and
its duration are projected to decrease in
most regions, particularly at mid-
latitudes, with some regions at high
latitudes possibly experiencing increases
in seasonal snow cover. Changes in the
volume of snow cover, or the length of
the snow cover season, will have both
positive and negative impacts on
regional water resources (as a result of
changes in the volume and the timing of
runoff from snowmelt); on regional
transportation (road, marine, air and
rail); and on recreation sectors.
Globally, the ice contained in glaciers
and ice sheets is projected to decrease,
with regional responses complicated by
the effect of increased snowfall in some
areas which could lead to accumulation
of ice. Glacial recession will have
significant implications for local and
regional water resources, and thus
impact on water availability and on
hydroelectric power potential. Glacial
recession and loss of ice from ice sheets
will also contribute to sea-level rise.
Permafrost, which currently underlies
20-25% of the land mass of the Northern
Hemisphere, could experience significant
degradation within the next 40-50 years.
Projected increases in the thickness of
the freeze-thaw (active) layer above the
permafrost and a recession of permafrost
to higher latitudes and altitudes could
lead to increases in terrain instability,
erosion and landslides in those areas
which currently contain permafrost. As
a result, overlying ecosystems could be
significantly altered and the integrity of
man-made structures and facilities
reduced, thereby influencing existing
human settlements and development
opportunities.
Future action
The results of the Working Group II
studies highlight our lack of knowledge,
particularly at the regional level and in
areas most vulnerable to climate change.
Further national and international
research is needed on:
• regional effects of climate change on
crop yields, livestock productivity and
production costs;
• identification of agricultural
management practices and tech-
nology appropriate for changed
climate;
• factors influencing distribution of
species and their sensitivity to climate
change;
• initiation and maintenance of
integrated monitoring systems for
terrestrial and marine ecosystems;
• intensive assessment of water
resources and water quality, especially
in arid and semi-arid developing
countries and their sensitivity to
climate change;
• regional predictions of changes in soil
moisture, precipitation, surface and
subsurface runoff regimes and their
interannual distributions as a result of
climate change;
• assessment of vulnerability of
countries to gain or loss of energy
resources, particularly biomass and
-------
hydroelectric power in developing
countries;
• adaptability of vulnerable human
populations to heat stress and vector-
borne and viral diseases;
• global monitoring of sea-level
changes, particularly for island
countries;
• identification of populations and
agricultural and industrial production
at risk in coastal areas and islands;
• better understanding of the nature
and dynamics of ice masses and their
sensitivity to climate change;
• integration of climate change impact
information into the general planning
process, particularly in developing
countries; and
• development of methodology to assess
sensitivity of environments and
socioeconomic systems to climate
change.
• Some of these topics are already
being covered by existing and
proposed programs and these will
need continuing support. In
particular, there are three core
projects of the International
Geosphere-Biosphere Program,
namely:
Land-Ocean Interactions in the
Coastal Zone
Biosphere Aspects of the
Hydrological Cycle
Glob.al Change Impact on
Agriculture and Society
that will provide valuable data in the
coming years.
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Scenarios
Any changes which take place as the
results of increasing emissions must be
viewed against a background of changes
which are already occurring and which
will continue to occur as a result of
other factors such as:
• Natural changes - these include long-
term changes which are driven by
solar and tectonic factors, and short-
to-medium term changes which are
driven by ocean and atmospheric
circulation patterns.
• Population increase - the predicted
world population is expected to be
above 10 billion by the middle of the
next century; this growth will be
unevenly distributed on a regional
basis and will impact on already
vulnerable areas.
• Land use changes - the clearing of
forests for new agricultural
production, together with more
intensive use of existing agricultural
land, will contribute to land
degradation and increase demands for
water resources.
In an ideal world, Working Group I
would have had the time to produce
scenarios for emission-induced climate
change which could have been used as a
basis for the analyses of this Working
Group. However, this was precluded
because work proceeded in parallel. As
a result, and in order to complete its
work in time, Working Group II has
used a number of scenarios based on
existing models in the literature.
The scenarios generally have the
following features:
(i) an effective doubling of CO2 in the
atmosphere over pre-industrial levels
between now and 2025 to 2050 for a
'business-as-usual' scenario, with no
changes to present policy;
(ii) an increase of mean global
temperature in the range 1.5°C to 4.5°C
corresponding to the effective doubling
of CO2;
(iii) an unequal global distribution of
this temperature increase, namely half
the global mean in the tropical regions
and twice the global mean in the polar
regions;
(iv) a sea-level rise of about 0.3 to 0.5
m by 2050 and about 1 m by 2100,
together with a rise in temperature of
the surface ocean layer of between 0.2°
and 2.5°.
These scenarios can be compared with
the recent assessment of Working
Group I which, for a 'business as usual*
scenario, has predicted the increase in
global temperatures to be about 1°C
above the present value by 2025 and
3°C before the end of next century.
However, it has also estimated the
magnitude of sea-level rise to be about
20 cm by 2030 and about 65 cm by the
end of next century. Nevertheless, the
impacts based on 1-2 m rise serve as a
warning of the consequences of
continued uncontrolled emissions.
The smaller rise does not lessen the
anxiety, for their continued existence, of
the small island countries, particularly
the Pacific and Indian Oceans and the
Caribbean, or of the larger populations
in low-lying coastal areas such as
Bangladesh. It is difficult to predict the
regional effects of sea-level rise with any
certainty. Significant variations of sea-
level already occur for a variety of
reasons, while there are considerable
8
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shifts in land levels associated with
tectonic plate movements which can also
lead to rises and falls.
The scenarios of Working Group II are
derived both from General Circulation
Models and from palaeoanalog tech-
niques. Palaeoclimate analogs are
proposed by Soviet scientists as a means
by which climate changes can be
assessed. The methodology assumes that
past warm geologic intervals provide
insight into possible future climate
conditions. The General Circulation
Models, developed by Western scientists,
are based on three-dimensional
mathematical representations of the
physical processes in the atmosphere and
the interactions of the atmosphere with
the earth's surface and the oceans.
There is considerable scientific debate
about the merits and demerits of each of
these, as discussed in the report of
Working Group I.
The palaeoclimate scenarios used by
Soviet scientists are based on three
warm geological periods with estimated
future levels of concentration of CO2
applied to them. The details of these
are shown in Table 1. While these are
superficially similar to the predictions of
the general circulation model approach
for different CO2 concentrations, the
factors which caused the climate changes
in geologic times are not clear. Never-
theless, they have been used to make
predictions of climate change of regions
in the USSR.
The General Circulation Models are, in
their current state of development,
comparatively crude in their description
of many of the processes involved.
However they can be used to simulate
regional changes resulting' from a range
of concentrations of CO2 in the atmo-
sphere. Working Group I has favoured
the general circulation model approach
in producing its predictions of temper-
ature rise and precipitation changes. In
its report, estimates for 2030 have been
given for central North America,
southern Asia, Sahel, southern Europe
and Australia. These are reproduced in
Table 2 and are broadly similar to those
used by Working Group II.
Despite the current uncertainties, both
techniques have been used by Working
Group II in the development of regional
impacts to assist policy makers. There
are problems with prediction of regional
precipitation since there is disagreement
between various general circulation
model outputs as a result of simplifi-
cations to the representation of complex
physical processes. Current research is
seeking to improve the general circu-
lation model approach and to increase
resolution to enable better regional
predictions. There are also problems
with the palaeoanalog approach which
yields differing scenarios for precipi-
tation from the general circulation
model approach. This leads to different
assessments of impact on water
resources and agriculture. Soviet
scientists are working to validate their
techniques and improve regional
scenarios.
It should be noted that, in many
situations, the overall impact is
determined more by the changes in the
magnitude and frequency of extreme
events than by changes in the average.
This is especially the case for tropical
storms and droughts. The assessment of
Working Group I of possible climate
changes suggests a low probability of
increased frequency of extreme events.
However, it is entirely possible that shifts
in climate regimes will result in changes
in frequency in certain regions.
-------
Table 1 Palaeodimate analogs used by Soviet scientists
Period Analogue Temperature Past CO2 concn. Assumed CO2
(year) (difference from (ppm) concn. (ppm)
present)
Holocene 2000 +1 280 380
Optimum
Eemian 2025 +2 280 420
Interglacial
Pliocene 2050 +4 500-600 560
Table 2 Estimates for regional changes by Working Group I
(IPCC Business-as-Usual scenario; changes from pre-industrial)
The estimates are based on high resolution models, scaled to give a global mean warming of 1.8" C
consistent with the best estimate (2.5 °C) of climate response to greenhouse gases. With the low
estimate value of 1.5* C, these values should be reduced by 30%; with a high estimate of 4.5°C, they
should be increased by 50%. Confidence on these estimates is low.
Central North America (35<-50>N 85° -105" W)
The warming varies from 2* to 4° C in winter and 2" to 3"C in summer. Precipitation increase range
from 0% to 15% in winter, whereas there are decreases of 5% to 10% in summer. Soil moisture
decreases in summer by 15% to 20%.
Southern Asia (5°-30°N 70" -105° E)
The warming varies from 1° to 2°C throughout the year. Precipitation changes little in winter and
generally increases throughout the region by 5% to 15% in summer. Summer soil moisture increases
by 5% to 10%.
Sahel (10"-20*N 20°W^O'E)
The wanning ranges from 1" to 3° C. Area mean precipitation increases and area mean soil moisture
decreases marginally in summer. However, there are areas of both increase and decrease in both
parameters throughout the region, which differ from model to model.
Southern Europe <30'-50'N 10°W-45°E)
The wanning is about 2" C in winter and varies from 2° to 3° C in summer. There is some indication
of increased precipitation in winter, but summer precipitation decreases by 5% to 15%, and summer
soil moisture by 15% to 25%.
Australia (12°-45°S 110e-15S°"E)
The wanning ranges from 1° to 2° in summer and is about 2°C in winter. Summer precipitation
increases by around 10%, but the models do not produce consistent estimates of the changes in soil
moisture. The area averages hide large variations at the subcontinental level.
10
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An issue of importance not considered in
any detail is the impact of possible
response strategies (developed by
Working Group IE) on the scenarios
used here. Thus, a major change in
energy production from fossil fuel to
nuclear or renewable energy sources
could drastically alter our assessments.
Further, changes in agricultural practice
could dramatically alter yields of
particular crops in certain regions.
These impacts of response strategies
require much additional work.
Despite all these uncertainties, it is
possible to make assessments of
potential impacts of climate change by
considering the sensitivity of natural
systems to significant variations. These
are summarised in the following sections
under: agriculture and forestry;
terrestrial ecosystems; hydrology and
water resources; human settlement,
energy, transport, industry, human health
and air quality; world ocean and coastal
zones; seasonal snow cover, ice and
permafrost.
11
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Summary of findings
Potential impacts of climate
change on agriculture, land use
and forestry
Potential impacts on agriculture
Major findings
• Sufficient evidence is now available
from a variety of different studies to
indicate that changes of climate would
have an important effect on agri-
culture, including livestock. Yet the
fact that there are major uncer-
tainties regarding likely effects in
specific regions should be a cause for
concern. Studies have not yet
conclusively determined whether, on
average, global agricultural potential
will increase or decrease.
• Negative impacts could be felt at the
regional level as a result of changes in
weather, diseases, pests and weeds
associated with climate change,
necessitating innovation in technology
and agriculture management
practices. There may be severe
effects in some regions, particularly in
regions of high present-day vulner-
ability that are least able to adjust
technologically to such effects.
• There is a possibility that potential
productivity of high and mid-latitudes
may increase because of a prolonged
growing season, but it is not likely to
open up large new areas for
production, and will be largely
confined to the Northern Hemi-
sphere.
• On balance, the evidence is that in
the face of estimated changes of
climate, food production at the global
level can be maintained at essentially
the same level as would have
occurred without climate change; but
the cost of achieving this is unclear.
Nonetheless, climate changes may
intensify difficulties in coping with
rapid population growth.
Principal issues
Magnitudes of possible dislocation
Under the estimate of changes in pro-
ductive potential for the changes of
climate outlined in this report, the cost
of producing some mid-latitude crops,
such as maize and soybean, could
increase, reflecting a small net decrease
in the global food production capability
of these crops. Rice production could,
however, increase if available moisture
increased in Southeast Asia, but these
effects may be limited by increased
cloudiness and temperature. The
average global increase in overall pro-
duction costs due to climate change
could thus be small.
Much depends on the possible benefits
of the so-called 'direct* effects of
increased CO2 on crop yield. If plant
productivity were substantially enhanced
and more moisture were available in
some major production areas, then world
production of staple cereals could
increase relative to demand. If, on the
contrary, there is little beneficial direct
CO2 effect and climate changes are
negative for agricultural potential in all
or most of the major food-exporting
areas, then the average costs of world
agricultural production due to climate
change could increase significantly.
Most vulnerable regions and sectors
On the basis of both limited resource
capacity in relation to present-day
population and possible future
diminution of the agricultural resource
12
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base as a consequence of reduced crop-
water availability, two broad sets of
regions appear most vulnerable to
climate change: (i) some semi-arid,
tropical and subtropical regions (such as
western Arabia, the Maghreb, western
West Africa, Horn of Africa and
southern Africa, eastern Brazil), and (ii)
some humid tropical and equatorial
regions (such as Southeast Asia and
Central America).
In addition, certain regions that are
currently net exporters of cereals could
also be characterised by reduced produc-
tive potential as a result of climate
changes. Any decrease in production in
these regions could markedly affect
future global food prices and patterns of
trade. These regions might include, for
example, Western Europe, southern US,
parts of South America, and Western
Australia.
Effect of altered climate extremes
Relatively small changes in the mean
values of rainfall and temperature can
have a marked effect on the frequency
of extreme levels of available warmth
and moisture. For example, the number
of very hot days which can cause
damaging heat stress to temperate crops
and livestock could increase significantly
in some regions as a result of a 1°C to
2°C increase in mean annual temper-
atures. Similarly, reduction in average
levels of soil moisture as a result of
higher rates of evapotranspiration could
increase substantially the number of days
below a minimum threshold of water
availability for given crops.
Although at present we know little about
how the frequency of extreme events
may alter as a result of climate change,
the potential impact of concurrent
drought or heat stress in the major
food-exporting regions of the world
could be severe. In addition, relatively
small decreases in rainfall, changes in
rainfall distribution or increases in
evapotranspiration could markedly
increase the probability, intensity and
duration of drought in currently drought-
prone (and often food-deficient) regions.
Increase in drought risk represents
potentially the most serious impact of
climate change on agriculture at both
the regional and global level.
Effects on crop growth potential, land
degradation, pests and diseases
Higher levels of atmospheric CO2 are
expected to enhance the growth rate of
some staple cereal crops, such as wheat
and rice, but not of others such as millet,
sorghum and maize. The use of water
by crop plants may also be more
efficient under higher CO2 levels. How-
ever, it is not clear how far the poten-
tially beneficial 'direct' effects of
enhanced atmospheric CO2 will be mani-
fested in the farmer's field.
Warming is likely to result in a poleward
shift of thermal limits of agriculture,
which may increase productive potential
in high-latitude regions. But soils and
terrain may not enable much of this
potential to be realised. Moreover,
shifts of moisture limits in some semi-
arid and sub-humid regions could lead to
significant reductions of potential with
serious implications for regional food
supplies in some developing countries.
Horticultural production in mid-latitude
regions may be reduced owing to insuf-
ficient accumulated winter chilling. The
impact of climate change will be far
greater for long-lived horticultural fruit
crops, with long establishment periods,
than for annual crops where new
cultivars can quickly replace others.
Temperature increases may extend the
geographic range of some insect pests,
13
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diseases and weeds, allowing their
expansion to new regions as they warm
and become suitable habitats. Changes
in temperature and precipitation may
also influence soil characteristics.
Regional impacts
Impacts on potential yields are likely to
vary greatly according to types of climate
change and types of agriculture.
In the northern mid-latitude regions,
where summer drying may reduce pro-
ductive potential (eg in the south and
central US and in southern Europe),
yield potential is estimated to fall by
10-30% under an equilibrium 2 x CO2
climate by the middle of the next
century. Towards the northern edge of
current core producing regions, however,
wanning may enhance productive
potential in climatic terms. When
combined with direct CO2 effects,
increased climatic potential could be
substantial • though in actuality it may
be limited by soils, terrain and land use.
There are indications that wanning could
lead to an overall reduction of cereal
production potential in North America
and to southern Europe, but increased
potential in northern Europe. Warming
could allow increased agricultural output
in regions near the northern limit of
current production in the USSR and
North America, but output in the
southern areas of these regions could
only increase if corresponding increases
in soil moisture were to occur; this is at
present uncertain.
Little is known about likely impacts in
semi-arid and humid tropical regions,
because production potential here
largely depends on crop-water avail-
ability, and the regional pattern of
possible changes in precipitation is
unclear at present. It is prudent,
however, to assume that qrop-water
availability could decrease in some
regions. Under these circumstances
there could be substantial regional
dislocation of access to food.
Adaptation in agriculture
In some parts of the world, climatic
limits to agriculture are estimated to
shift poleward by 200-300 km per degree
of warming. The warming-induced
upwards shift in thermal zones above
mountain slopes could be in the order of
150-200 m.
Agriculture has an ability to adjust,
within given economic and technological
constraints, to a limited rate and range
of climate change. This capability varies
greatly between regions and sectors, but
no thorough analysis of adaptive capacity
has yet been conducted for the
agriculture sector.
In some currently highly variable
climates, farmers may be more adaptable
than those in regions of more equable
climate. But in developing economies,
and particularly in some marginal types
of agriculture, this intrinsic adaptive
capability may be much lower. It is
important to establish in more detail the
nature of this adaptability and thus help
to determine critical rates and ranges of
climatic change that would exceed those
that could be accommodated by adjust-
ments within the system.
Recommendations for action
This study has emphasised the
inadequacy of our present knowledge. It
is clear that more information on
potential impacts would help to identify
the full range of potentially useful
responses and assist in determining
which of these may be most valuable.
14
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Some priorities for future research may
be summarised as follows:
• Improved knowledge is needed of
effects of changes in climate on crop
yields and livestock productivity in
different regions and under varying
types of management To date, less
than a dozen detailed regional studies
have been completed, and these are
insufficient as a basis for generalising
about effects on food production at
the regional or world scale. Further
research in vulnerable regions in
particular should be encouraged.
• Improved understanding of the effects
of changes in climate on other
physical processes is needed: for
example on rates of soil erosion and
salinisation; on soil nutrient
depletion; on pests, diseases and soil
microbes, and their vectors; on
hydrological conditions as they affect
irrigation water availability.
• An improved ability is required to
'scale-up' our understanding of effects
on crops and livestock, effects on
farm production, on village
production, and on national and
global food supply. This is parti-
cularly important because policies
must be designed to respond to
impacts at the national and global
levels. Further information is needed
on the effects of changes in climate
on social and economic conditions in
rural areas (eg employment and
income, equity considerations, farm
infrastructure, and support services).
• Further information is needed on the
range of potentially effective technical
adjustments at the farm and village
level (eg irrigation, crop selection,
fertilising etc) and on the economic
and political constraints on such
adjustments. In particular, it is
recommended that national and inter-
national centres of agricultural
research consider the potential value
of new research programs aimed at
identifying or developing cultivars and
management practices appropriate for
altered climates.
• Further information is needed on the
range of potentially effective policy
responses at regional, national and
international levels (eg reallocation of
land use, plant breeding, improved
agricultural extension schemes, large-
scale water transfers etc).
Potential impacts on managed
forests and the forest sector
All impacts referred to in this section
reflect the current uncertainty in the
extent of warming, and levels and
distribution of precipitation. They
reflect the consensus that anthropogenic
change is occurring; the direction is
towards higher temperatures, with the
extent affected by latitude and
continentality.
The distinction between managed and
unmanaged forests is often unclear, but
it is taken here to be one of degree in
the intensity of human intervention. In
managed forests, harvesting takes place
and the forests are renewed, replaced or
restructured in such a way that actual
physical inputs are needed to achieve
goals.
Managed forests are quite distinct from
the unmanaged forests. They supply a
wide variety of products and are found
in a wide variety of countries with
different social, physical and political
environments. The intensity of forest
management may not necessarily parallel
the degree of economic development;
different countries depend to different
degrees on the products from forests.
15
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Therefore the severity of the impacts will
vary among countries as will the ability
to respond.. In tropical countries the
managed forests characteristically
employ exotic species, whereas in the
northern countries greater reliance is
placed on indigenous species.
Biophysical effects on forest ecosystems
Impacts on forest ecosystems will be at
the tree and microsite levels, at the
stand/watershed level and at the
regional level. Impacts on individual
trees include tolerance of drought and
winds, the possible effects of altered
seasonality (active vs dormant stages),
altered photosyntheiic rates and
increased water use efficiency. At the
microsite level, moisture may be limited
and biological soil processes may be
enhanced. Forest renewal will be
adversely affected if there is a shortage
of moisture at the critical establishment
phase.
On stand levels, insects and diseases can
be expected to cause significant losses to
forests and these losses can be expected
to increase with increasing change. Fire
severity will increase, and while managed
forests may have less fuel available than
unmanaged ecosystems, this will not
lessen the incidence of fire, nor will it
affect the weather conditions giving rise
to the rates of spread or the extent of
the areas burned. Developed countries
can barely cope with the current state
and the extent of areas burned seem to
be rising. The incidence of fire may be
less in the tropics as the climate there
changes less, but many plantations are in
semi-arid zones and will be suffer
adverse impacts. Costs associated with
flooding, resulting from rising sea-levels
and disruption of weather patterns, can
be expected. There will be problems in
using the lower quality wood grown
under stress and large costs associated
with moving processing facilities and
infrastructure as the wood supply zones
move northward. The most important
feature of these costs and disruptions
from a global point of view is that the
changes will differ among countries and
that some countries are better able than
others to cope with the impacts.
Major forest-type zones and species
ranges could shift significantly as a result
of climate change. Results of several
Northern Hemisphere studies show that
both high-latitude and low-latitude
boundaries of temperate and northern
forests (and tree species) may shift
hundreds of kilometres poleward. In
contrast, studies in the Southern Hemi-
sphere suggest that Australian species
could adapt and grow at temperatures
much warmer than those of their natural
distribution.
At the stand level, the following effects
of climate change on forests are likely:
increased mortality owing to physical
stress; increased susceptibility to and
infestations of insects and diseases;
increased susceptibility to and incidences
of fire; changed stand growth rates, both
increases and decreases; more difficult
stand establishment by both natural and
artificial regeneration; and changed
composition of species.
Two broad types of forests are likely to
be sensitive to a changing climate: (i)
boreal forests, where stands are mainly
even-aged and often temperature-
limited, and where temperature changes
are expected to be large; and (ii) forests
in arid and semi-arid regions where
increased temperatures and stable or
decreasing precipitation could render
sites inhospitable to the continued
existence of current forest stands.
However, there could be compensating
effects of faster growth owing to higher
ambient CO2.
16
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Socioeconomic implications
All countries use forests for heating,
cooking and food. The degree to which
people are dependent on these, however,
varies widely. Forest ecosystem changes
and tree distribution have no regard for
political or administrative boundaries.
Managed forests have, by definition, high
levels of investment in them; some
countries are better able than others to
tolerate the risk to, and possible loss, of
these investments.
Intensively managed forests have high
inputs from choice of species, sites,
spacing, tending, thinning, fertilisation
and protection. These interventions are
costly and some countries may not be
able to supply the inputs necessary to
establish, maintain and protect the
investments.
Increased protection costs will be
unevenly borne and could encourage
poorer countries to accelerate harvesting,
reduce rotation periods and engage in
other practices, which may not be
sustainable. More data are needed on
these secondary and insidious effects of
climate change. Associated disruptions
in the social fabric of many countries
may impact adversely on forests, as
instances of arson or other damage as do
now.
The socioeconomic implications of shifts
in the ranges of tree species will be
influenced by the fact that climate will
probably change much faster than tree
species can naturally respond (eg
through migration).
Moreover, new sites may not be
hospitable, having evolved over
thousands of years under other climatic
and vegetative regimes. The suitability
of new ranges and the actual compo-
sition and growth patterns of forests
under new climates will have no regard
for non-ecological boundaries such as
watersheds, ownerships, parks, nature
reserves and recreation areas.
It is concluded that climate change could
more likely exacerbate most current and
near-term issues and tensions rather than
relieve them. This finding is very
dependent on the assumption that during
the next 30-50 years, in response to
climate change, forests everywhere in the
world will be prone to some measure
and form of decline. These changes will
be taking place at the same time as a
substantial increase in population with
increased demands. If, on the other
hand, forests in some regions are largely
unaffected by climate change, or actually
experience increased growth rates, then
perhaps most of the issues and tensions
could be at least partly relieved.
Adaptation
Much can be done to reduce the suscep-
tibility of socioeconomic systems to
climate-induced forest declines.
Appropriate measures include the whole
array of forest-management tools, to be
chosen and implemented as local con-
ditions warrant, but some may be
detrimental to other indicators, for
example, wildlife or recreation.
For wood supply, the forest-products
industry can move processing technology
towards new kinds and qualities of fibre,
and plan new mills in areas improving in
wood-supply potential. Governments
can support efforts in economic
diversification in forest-based
communities, and engage in improved
long-range planning for future changes in
land potential for forestry. The
provision of recreational facilities is
another example of an important forest-
based economic sector. Governments
and private firms must anticipate how
17
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forested landscapes might change, and
plan accordingly to divest themselves of
the old facilities and invest in the new.
Recommendations for action
The ability to deal with climate change
and the forest sector is related to the
amount of knowledge available. There
are uncertainties 10 be considered: for
instance, in the future, will the same
tensions and issues have similar high
priority? Studies of the socioeconomic
impacts must be global in scope, inter-
national in organisation, institutional in
focus and historical in breadth. We
need regional climate scenarios and
better information on stand-level
responses, the biological relationship
between species and sites and the
inherent variability of species. Changing
climates demonstrate the need for
strategies in active management in the
forest sector. Even better knowledge is
needed of the potential role of forest
management in mitigating impacts and
exploiting opportunities from climate
change.
A major impact, of which there is
evidence now, will be considerable
apprehension on the part of the general
public, particularly those dependent on
the forest sector for their livelihood.
Public cooperation in the implemen-
tation of decisions will be required for
dealing with a problem which has
biological rather than ideological
solutions.
Research on the socioeconomic impacts
of climate change must focus on the
transitional climates occurring over the
next several decades, not only at specific
points in time. This reflects the way
people live - in specific localities and in
real time. It makes sense to prepare for
serious irr .lacts by implementing policies
which are biologically sustainable, even
if the eventual changes are minimal.
Examining biogeochemical changes on a
global scale is complex enough; adding
humans as a variable factor complicates
the issue even more. Nevertheless,
humans are the critical element in the
study of ecological systems. We must
consider the institutional imperatives and
the economic and political influences on
people in different nations, together with
the cultural diversity that distinguishes
and may dominate our actions.
The nature and temporal/spatial distri-
bution of climate change itself is highly
uncertain, as are the various ways by
which a changing climate could influence
forests and their growing sites, and the
various repercussions this might have on
our uses of forests. Moreover, the
means by which society might cope with
the changing environmental and socio-
economic conditions, in a context in
which those conditions are rapidly
changing quite independently of climate
change, are largely unexplored so far.
The following major research and assess-
ment initiatives should be developed and
pursued in the near future (early 1990s)
to begin to shed light on the impacts
discussed in this section: (i) more secure
regional climate scenarios; (ii)
simulation of impacts of climate change
on managed forest stands; (ill) modelling
studies for better understanding of
matches between species and sites; (iv)
analyses of the potential role of forest
management in mitigating undesirable
impacts and capitalising on desirable
impacts of climate change; (v) regional
analyses of potential disruption of
wildlife habitat and the recreational
potential of forests due to forest-
structure changes brought on by climate
change; (vi) regional analyses of
potential socioeconomic repercussions of
18
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fluctuations in timber supply due to
climate change on rural communities,
industrial concerns, markets and trade in
forest products, and governments, (vii)
synthesis studies of the policy
possibilities for the forest sector to
prepare for climate change; and (viii)
periodical assessment of the destruction
of tropical forests using remote sensing.
Potential impacts of climate
change on natural terrestrial
ecosystems and the socioeconomic
consequences
Major findings
• Global increases in the atmospheric
concentration of greenhouse gases
and related climatic changes will have
significant consequences for natural
terrestrial ecosystems and related
socioeconomic systems.
• Climatic zones could shift several
hundred kilometres towards the poles.
Flora and fauna would lag behind
these climatic shifts, surviving in their
present location; they would therefore
find themselves in a different climatic
regime.
• The rate of projected climatic changes
is the major factor determining the
type and degree of climatic impacts
on natural terrestrial ecosystems.
These rates are likely to be faster
than the ability of some species to
respond and these responses may be
sudden or gradual.
• New climatic regimes may be less
hospitable under some circumstances
(eg towards lower latitudes and lower
altitudes) and may. be more
hospitable under others (eg towards
higher latitudes). Vegetation zone
changes are projected to be greatest
where the land is classified as polar
desert, tundra and boreal forest.
• Ecosystems are not expected to move
as a single unit, but would have a new
structure as a consequence of
alterations in species distributions and
abundance.
• Some species could be lost owing to
increased stresses leading to a
reduction in global biological
diversity, whereas other species may
thrive as stresses decrease.
• Most sensitive are those communities
in which the options for adaptability
are limited (eg montane, alpine,
polar, island and coastal com-
munities, remnant vegetation, and
heritage sites and reserves) and those
communities where climatic change
add to existing stresses.
• Increased incidents of disturbances
such as pest outbreaks and fire are
likely to occur in some areas and
these could enhance projected
ecosystem changes.
• The direct effects of increased
atmospheric concentrations of CO2
may increase plant growth, water use
efficiency and tolerance to salinity,
though this positive effect could be
reduced over time by ecosystem feed-
backs. Enhanced levels of air
pollution could also reduce this
positive effect.
• Socioeconomic consequences of these
impacts will be significant, especially
for those regions of the globe where
societies and related economies are
dependent on natural terrestrial
ecosystems for their welfare. Changes
in the availability of food, fuel,
medicine, construction materials and
income are possible as these
19
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ecosystems are affected. Important
fibre products, recreation and tourism
industries could also be affected in
some regions.
Principal issues
The projected changes in climate will
present these ecosystems with a climate
warmer than that experienced during
their recent evolution and there will be
warming at a rate 15-40 times faster than
past glacial-interglacial transitions. This
combination of relatively large and fast
changes in climate will cause disruption
of ecosystems, allowing some species to
expand their ranges while others will
become less viable and, in some cases,
may disappear.
Current knowledge does not allow a
comprehensive and detailed analysis of
all aspects of the impacts of climate
change on natural terrestrial ecosystems.
It is possible, however, to make some
plausible implications. All estimates
presented below are based on scenarios
of enhanced atmospheric concentrations
of greenhouse gases and related changes
in global climate. It is impossible to
evaluate the consequences of change in
climatic variability since the required
climatic analyses are not available.
Particularly sensitive species
The species which are particularly
sensitive to climatic changes are:
• species at the edge of (or beyond)
their optimal range;
• geographically localised species (eg
those found on islands, on mountain
peaks, in remnant vegetation patches
in rural areas, and in parks and
reserves);
• genetically impoverished species;
• specialised organisms with specific
niches;
• poor dispersers;
• more slowly reproducing species; and
• localised populations of annual
species.
This would suggest that montane and
alpine, polar, island and coastal
communities, and heritage sites and
reserves are particularly at risk, since
their component species may not be able
to survive or adapt to climate change
because of the limited number of
adaptive options available to them.
Changes in the boundaries of vegetation
zones
Projected changes in global temperature
of 1.5°-4.5°C and changes in precipi-
tation will result in the movement of the
boundaries of vegetation zones, and will
impact on their floristic composition and
associated animal species. Boundaries
(eg boreal-tundra, temperate forests,
grasslands etc) are expected to shift
several hundreds of kilometres over the
next SO years. Real rates of the move-
ment of species, however, will be
restricted by limits on their ability to
disperse and the presence of barriers to
dispersion; they will, therefore, average
approximately 10-100 m/year.
Both coniferous and broad-leaved
thermophilic tree species will find
favourable environments much further
poleward than their current limits, la
the northern parts of the Asian USSR,
the boundary of the zone will move
northward 40° -50° of latitude (500-600
km). The tundra zone is expected to
disappear from the north of Eurasia.
20
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Expected changes in precipitation will
allow species to extend their boundaries
equatorward. As a result, broad-leaved
species range will expand and these
ecosystems will be more maritime in
terms of species composition. The forest
steppe subzone in the European USSR
will change while in southern portions of
western Siberia the forest-steppe
boundary could move up to 200 km.
In the semi-arid, arid and hyper-arid
ecoclimatic zones of the Mediterranean,
greenhouse-gas-induced climate change
will reduce plant productivity and result
in desertification of the North African
and Near Eastern steppes owing to
increased evapotranspiration. The upper
limit of the deserts would migrate under
the influence of climate change and most
likely extend into the area that currently
corresponds to the lower limits of the
Semi-Arid Zone (ie foothills of the high,
Mid and Tell Adas and Tunisian Dorsal
in Northern Africa, and of the main
mountain ranges of the Near-Middle
East: Taurus, Lebanon, Alaoui,
Kurdistan, Zagros and Alborz).
The impact of climate changes on the
present tropical and temperate rainforest
is uncertain. For example, almost all of
Tasmania is expected to become, at best,
climatically 'marginal* in terms of
temperate rainforests, largely owing to a
rise in winter temperatures suggested by
climate scenarios. This increase in
temperature is unlikely to have a direct
effect on the forest, but may facilitate
the invasion of less frost-tolerant species.
Changes within ecosystems
Projected greenhouse-gas-induced
climate changes will profoundly affect
hydrologic • relationships in natural
terrestrial ecosystems, both directly by
altering inputs of precipitation, runoff,
soil moisture, snow cover and melt, and
evapotranspiration, as well as indirectly
by altering sea and lake levels which
influence water levels in coastal and
shoreline ecosystems.
The seasonality of rainfall also affects its
impact. A lengthening of the dry season
or, conversely, an increase in ground-
water table levels could both accentuate
salinisation problems. In Mediterranean
and semi-arid climates, where evapotran-
spiration exceeds precipitation for long
periods and increased percolation from
vegetation clearing or excessive irrigation
may have raised the water table, surface
soil salinisation can be a major problem.
Such salinisation can kill all but the most
halophytic vegetation, increase soil
erosion and reduce water quality.
Salinisation is already a problem in
many Mediterranean and semi-arid
regions (eg coastal Western Australia,
the Mediterranean, subtropical Africa)
and is a major cause of increased
desertification.
Greenhouse-gas-induced climatic
changes will affect the structure and
composition of natural terrestrial
ecosystems as a result of altered
relationships within these ecosystems,
perhaps leading to the introduction of
new species.
Given the new associations of species
that could occur as climate changes,
many species will face 'exotic'
competitors for the first time. Local
extinctions may occur as climate change
causes increased frequencies of droughts
and fires, and invasion of species. One
species that might spread, given such
conditions, is Melaleuca quinquenervia, a
bamboo-like Australian plant. This
species has already invaded the Florida
Everglades, forming dense monotypic
stands where drainage and frequent fires
have dried the natural marsh community.
21
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Pests and pathogens, in some cases, are
expected to increase their ranges as a
result of climate change and, in the case
of insects, their population densities.
This could place at risk the health of
ecosystems, and thereby play an
important role in determining future
vegetation and animal distributions
Pest outbreaks can also be expected as a
result of the increased stress and
mortality of standing vegetation resulting
from a combination of climate-driven
stressors. An example from New
Zealand concerns hard beech
(Nothofagus tntncata). A 3°C rise in
temperature would increase annual
respiratory carbon losses by 30%; such a
loss exceeds the total annual amount
allocated to stem and branch growth for
this species. With insufficient reserves
to replace current tissue, the tree is
weakened, and becomes more suscep-
tible to pathogens and insects.
Following repeated drought episodes,
several (Nothofagus) species succumbed
to defoliation insects. This would be
exacerbated by non-induced climate
change.
Since wetlands, particularly seasonal
wetlands in warmer regions, provide
habitat for the breeding and growth of
vectors of a number of serious diseases
such as malaria, filariasis and schisto-
somiasis, an increase in average temper-
ature and any change in the distribution
of seasonal wetlands will alter the
temporal and spatial distribution of these
diseases.
Higher temperatures and changed
precipitation may well lead to increased
drought frequency and fire risk in many
forested areas. Coupled with probably
increased fuel density because of the
direct effects of increased ambient CO2
on forest understorey, this could lead to
increased exposure of forests to fire.
which would tend to accelerate changes
in ecosystem composition under con-
ditions of changing climate.
In areas with a distinct wet and dry
season (parts of the tropic, and all of the
Mediterranean-climate regions), change
in the amount of precipitation in rainy
months could alter fuel loads by
influencing growth. The altered fuel
loads, along with changes in precipi-
tation, could affect fire intensities during
the dry season. A shift towards a slightly
wetter climate during the summer rainy
season could increase fuel loadings in
most of the subtropical and temperate
woodlands of Mexico, which would
suggest increased fire frequencies.
Global biological diversity is expected to
decrease with possible socioeconomic
consequences as a result of climate
change; however, some local increases
may also result, especially over the
longer term. The resulting impacts on
biological diversity are dependent on the
balance between changes in species
interactions and adaptation through
migration.
Warming could set off a chain of
extinctions by eliminating keystone
herbivores or their functional
counterparts in other ecosystems. For
example, in the 100 years following the
disappearance of elephants in the
Hluhluwe Game reserve in Natal,
several species of antelope have been
extirpated and populations of open
country grazers, such as wildebeest and
waterbuck, have been greatly reduced.
The direct effects of increased
atmospheric concentrations of CO2 may
increase the rate of plant growth;
however, man-induced changes in the
chemical composition of the atmosphere
(eg ozone) and ecosystem feedbacks
22
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could reduce this positive effect over
time.
Recommendations for action
While the specific impacts of global
warming on any one region or a single
species are to some degree matters of
conjecture, there are some clear
conclusions that can be made. Natural
terrestrial ecosystems will change in
make-up and shift in location, and those
species which can adapt and shift will
survive. The sensitive species, especially
those for which options are limited, will
dwindle and disappear.
Examination of the environmental
impacts of climate change on natural
terrestrial ecosystems and the associated
socioeconomic consequences is in its
infancy. The studies that have been
carried out are limited; only specific
regions and sectors have been examined.
Further limiting this work is that, for the
most part, existing studies have taken a
narrow view of the problem and not
looked at it from a multi-disciplinary
perspective. In addition, most of the
studies have examined the effects of
climate change on current social,
economic and environmental systems
and have not considered social and
economic adjustments nor impacts and
consequences during ecosystem
transitional periods.
These limitations can be addressed by:
• assembling relevant inventories of
species and ecosystems;
integrated
initiating and
monitoring programs;
• gathering • information on relative
species and ecosystems sensitivities to
climate change;
• initiating and supporting regional
national and international research
and impacts programs; and
• educating resource managers and the
public about the potential
consequences of climatic change for
natural terrestrial ecosystems.
Potential impacts of climate
change on hydrology and water
resources
Major findings
• For many watersheds worldwide,
especially those in arid and semi-arid
regions, runoff is very sensitive to
small changes and variations in
climate. For example, 1°C to 2°C
temperature increase coupled with a
10% reduction in precipitation could
conceivably produce a 40-70%
reduction in annual runoff.
• Based on empirical data and
hydrological models, annual runoff
appears to be more sensitive to
changes in precipitation than to
changes in temperature. However, in
regions where seasonal snowfall and
snowmelt are a major part of the total
water supply, the monthly distribution
of runoff and soil moisture is more
sensitive to temperature than to
precipitation.
• The construction of hypothetical
scenarios provides a range of runoff
responses and the characteristics of
those responses for particular areas.
However, credible forecasts for any
specific region, sufficient to designate
either direction or magnitude of
change, are not yet available. We can
conduct warm sensitivity analysis
using General Circulation Models
while the scientific basis slowly
improves.
23
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• Vulnerabilities in present water uses
(ie where demand exceeds firm yield)
and conflicts among current uses are
likely to be exacerbated by global
warming in most arid and semi-arid
regions.
• The regions that appear to be at
greatest risk, in terms of serious
threats to sustaining the population
are: Africa - Maghreb, Sahel, the
north of Africa, southern Africa; Asia
- western Arabia, Southeast Asia, the
Indian subcontinent; North America -
Mexico, Central America, southwest
US; South America - parts of eastern
Brazil; Europe - Mediterranean zone.
• The relative degree of water
management (storage versus mean
annual flow) is a primary determinant
in adapting to changes in the mean
annual variability.
• It is essential that future design of
water resource engineering take into
account that climate is a
non-stationary process, and that
structures with a design life of SO to
more than 100 years should be
designed to accommodate climatic
and hydrometeorological conditions
which may exist over the entire life of
the structure.
Principal issues
If worthwhile estimates of water
resources conditions, appropriate for
planning and policy formulation, are to
be produced, then studies must include
estimates on the frequency, intensity and
duration of potential future hydrologic
events. This is especially critical for
evaluating effects on agriculture, the
design of water resource management
systems, and for producing reasonably
accurate water supply estimates.
In many instances it can be expected
that changes in hydrologic extremes in
response to global warming will be more
significant than changes in hydrologic
mean conditions. Thus, attention must
be focused on changes in the frequency
and magnitude of floods and droughts in
evaluating the societal ramifications of
water resource changes.
Initial water resource planning and
policy making will continue to be
implemented even in the face of
uncertainty about global change.
Clarification and specification of the
useful information about the various
methods for estimating future change
must be made available to the
management community.
Regional impacts
Continental/national
Based on palaeoclimatic analogs coupled
with physically based water-balance
models, annual runoff over the whole of
the USSR is projected to rise, although
runoff is expected to decrease slightly in
the forest steppe and southern forest
zones. In any case, winter runoff is
expected to increase in the regions with
snowfall and snowmelt. Serious flooding
problems could arise in many northern
rivers of the USSR,
An assessment of all the river basins in
the US shows that the arid and semi-arid
regions of the US would be most
severely affected by global warming,
even though there is a high degree of
water control. The competing uses of
agricultural irrigation, municipal water
supply, and generation of hydroelectric
power, have stressed even the present
system. All other regions in the US will
probably suffer adverse water-resource
impacts to some degree, whether for
generation of hydroelectric power,
24
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municipal water supply shortages, or
agricultural irrigation.
An assessment of the general circulation
model studies for the nations of the
European Economic Community (EEC)
indicates that precipitation and runoff
may increase in the northern nations,
possibly causing flooding problems in
low-lying countries. The Mediterranean
countries of the EEC may experience a
decline in runoff, thereby increasing the
already serious and frequent water
supply shortages occurring in that region.
It is most probable that agriculture will
suffer the most adverse effects.
In Japan, prolonged periods of droughts
and shorter periods of intense precipi-
tation may be likely. Current storage
capacity is limited and a large proportion
of the population is located on flood-
plains. Water demand can be expected
to increase, which will seriously stress
the existing water management system.
An increase in precipitation and
consequent flooding, along with
overloads of stormwater/sewerage
systems leading to degradation of surface
water quality, is possible in New
Zealand.
The UK can expect an increase in mean
annual runoff over most of the country,
but with a stronger seasonal variation in
peak flows, imposing the need for
redesigning existing water management
systems.
River basins and critical environments
Runoff in the Volga River basin, after
undergoing an initial decrease through
the year 2000, is expected to increase
after that year.
Studies indicate that hydrological
conditions in the Sahelian zone are very
sensitive to climatic conditions, especially
precipitation. Research suggests, for
example, that a 20% to 30% decrease in
precipitation could lead to a 15% to
59% reduction in runoff. As for
potential changes in water resources in
the future, it can be said that the
situation is very uncertain. Therefore,
additional comprehensive studies of this
problem, which is very important for the
region, are required.
A study of the Sacramento-San Joaquin
River basin showed how a highly
managed water resource system,
dependent on snowmelt-generated
runoff, would be affected by global
warming. Air temperature increases
changed the timing and increased the
magnitude of snowmelt-generated runoff
by 16% to 81%, severely stressing the
flood-control capabilities of existing
reservoirs. However, summer runoff
decreases of 30% to 68%, coupled with
soil moisture decreases of 14% to 36%
and a doubling of water demand by the
year 2020, suggest that serious water use
conflicts and periodic shortages are a
distinct possibility for this system.
In the Murray-Darling basin of Australia,
the use of spatial analogs indicates that
precipitation could decrease by 40% to
50%. However, based on general
circulation model outputs, the
summer-dominant rainfall area of
Australia will possibly expand to
encompass 75% of the continent by
2035. Runoff could double on the
Darling River.
A water supply-demand stochastically-
based sensitivity analysis was conducted
for the Delaware River basin, a highly
urbanised watershed in the northeastern
US. Basin-wide estimates of annual
runoff indicate a possible decrease of
9% to 25%. Also, the probability of
drought increases substantially
25
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throughout the basin. The Delaware
River supplies a large percentage of New
York City's water supply, which is
already operating below its safe yield.
Reduced flows in the Delaware River
would threaten the city of Philadelphia's
water supply intakes in the estuarine
portion of the river through upstream
movement of the freshwater-saltwater
interface.
Large lakes/seas
The Caspian Sea is the largest closed
water body in the world. It receives
nearly 80% of its runoff from the Volga
River and will respond to the initial
decrease in projected Volga River flows
to the year 2000, but will increase
thereafter. This will greatly improve the
severely degraded water quality and
ecological conditions in the Sea.
Based on general circulation model
results, the Great Lakes are expected to
incur net basin runoff decreases of 23%
to 51% under an effective doubling of
CO2 scenario. Generation of hydro-
electric power, the very important
commercial navigational uses, and lake
water quality which is due to thermal
stratification, are expected to be
adversely affected.
The Aral Sea would continue to
experience water-quality degradation by
polluted irrigation return flows, as the
precipitation-runoff increases projected
for the area would not be enough to
compensate for increased expansion of
irrigated agriculture.
Recommendations for action
The most essential need is for more
reliable and detailed (both in space and
time) estimates of future climatic
conditions. These estimates must be
regionally specific and provide infor-
mation on both the frequency and
magnitude of events. Increased
understanding of relations between
climatic variability and hydrologic
response must be developed. Such work
should include the development of
methods for translating climate model
information into a form that provides
meaningful input data to watershed and
water resource system models.
Areas particularly vulnerable to even
small changes in climate must be
identified worldwide. Vulnerabilities
must be ascertained considering both
natural and anthropogenic conditions
and potential changes.
Intensive assessments of water resource
sensitivities are necessary in developing
countries, especially those located in
environmentally sensitive arid and
semi-arid regions, where the potential
for conflicts associated with low water
resource system development and rapidly
increasing water demands is high.
Studies are needed that produce
improved procedures for operating water
management systems in consideration of
climate uncertainty. A related aspect of
this work is the development of design
criteria for engineered structures that
specifically incorporate estimates of
climatic variability and change.
Very little is currently known about the
effects of climate change on water
quality. Although concerns about water
quality are becoming increasingly
important, the separation of human-
induced versus climate-induced changes
in water quality is a very difficult
problem. Specifically, there is an
immediate need to identify those aspects
of this problem that hold the most
promise for yielding credible evaluations
of climatic effects on water quality.
26
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Potential impacts of climate
change on human settlement, the
energy, transport and industrial
sectors, human health and air
quality
Major findings
• Throughout the world the most
vulnerable populations are fanners
engaged in subsistence agriculture,
residents of coastal lowlands and
islands, populations in semi-arid
grasslands and the urban poor in
slums in shanty towns, especially in
megacities - those with several
millions of inhabitants,
• Climate change and even a modest
global sea-level rise can be expected
to prove disruptive to human
settlement in many vulnerable coastal
areas of some island nations and
communities where drought, floods
and changed agricultural growing
conditions have affected water
resources, energy, public health and
sanitation, and industrial or
agricultural production.
• Global warming can be expected to
cause a significant shift in the
permafrost zone; such rapid change
will prove quite disruptive to roads,
railways, buildings, oil and gas
pipelines, mining facilities and
infrastructure in the permafrost
region.
• Global warming can be expected to
affect the availability of water
resources and biomass, both major
energy sources in a large number of
developing countries. Such changes
in areas which lose water may
jeopardise energy supply and
materials essential for human
habitation and energy. Climate
change will also affects the regional
distribution of other renewable energy
resources such as wind and solar
power.
• Vector-borne and viral diseases such
as malaria, schistosotniasis and
dengue can be expected under
warmer climatic conditions to shift to
higher latitudes.
• Should severe weather, such as
tropical cyclones, occur more
frequently or become more intense as
a result of climate changes, human
settlement and industry may be
seriously affected, with large loss of
human life.
Principal issues
The impact on developing countries,
many of which lack resources for
adaptation, may be particularly
disruptive. Understanding likely impacts
of climate change on human settlement,
energy, transport, industry and human
health in such countries should be a high
priority, together with reinforcing
indigenous capability to design and
implement strategies to reduce adverse
impacts of climate change.
The impacts of climate change on
human settlement and related
socioeconomic activity, including the
energy, transport and industry sectors,
will differ regionally, depending on
regional distribution of changes in
temperature, precipitation, soil moisture,
patterns of severe storm, and other
possible manifestations of climate
change. As the general circulation
model scenarios provided by Working
Group I have indicated, changes in some
of these climatic characteristics may
differ considerably among regions. In
addition, the vulnerability to change in
climate of human settlement and related
27
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economic activity varies considerably
among regions and within regions. For
example, coastal areas may generally be
more vulnerable to climate change than
inland areas within the same region.
Development of effective strategies to
respond to climate change will require
much better capability to predict and
detect regional climate change and
occurrence of severe meteorological
phenomena. A major issue is that of
timing. For example, a sea-level rise of
0.5 m over 50 years would have substan-
tially different impacts than the same
rise over 100 years. Not only are
present-value costs for adaptation
measures vastly different, but also much
of the present-day infrastructure would
have undergone replacement in the
longer time period.
Human settlement
A principal difficulty in determining the
impact of climate change on human
habitat is the fact that many other
factors, largely independent of climate
change, are also important One can
reliably predict that certain developing
countries will be extremely vulnerable to
climate changes because they are already
at the limits of their capacity to cope
with climatic events. These include
populations in low-lying coastal regions
and islands, subsistence fanners,
populations in semi-arid grasslands, and
the urban poor.
The largest impacts on humanity of
climate change may be on human settle-
ment, with the existence of entire
countries such as the Maldives, Tuvalu,
and Kiribati imperilled by a rise of only
a few metres in sea-levels and populous
river delta and coastal areas of such
countries as Egypt, Bangladesh, India,
China and Indonesia, threatened by
inundation from even a moderate global
sea-level rise. Coastal areas of such
industrialised nations as the United
States and Japan will also be threatened,
although these nations are expected to
have the requisite resources to cope with
this challenge. The Netherlands has
demonstrated how a small country can
effectively marshall resources to deal
with such a threat.
Besides flooding of coastal areas, human
settlement may be jeopardised by
drought, which could impair food
supplies and the availability of water
resources. Water shortages caused by
irregular rainfall may especially affect
developing countries, as seen in the case
of the Zambezi river basin. Biomass is
the principal source of energy for most
of the countries of sub-Saharan Africa,
and changed moisture conditions in
some areas, reducing this biomass, could
pose grave problems for domestic energy
production and construction of shelter.
Although there has been only a handful
of city-specific studies, they suggest that
climate change could prove costly to
major urban areas in developed nations.
A study has projected that an effective
CO2 doubling could produce a major
water shortfall for New York City equal
to 28% to 42% of the planned supply in
the Hudson River Basin, requiring a $3
billion project to skim Hudson River
flood waters into additional reservoirs.
Although in the permafrost region global
warming may result in expansion of
human settlement poleward, thawing of
the permafrost may also disrupt
infrastructure and transport and
adversely affect stability of existing
buildings and conditions for future
construction.
The gravest effects of climate change
may be those on human migration as
millions are displaced by shoreline
28
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erosion, coastal flooding and severe
drought. Many areas to which they flee
are likely to have insufficient health and
other support services to accommodate
the new arrivals. Epidemics may sweep
through refugee camps and settlements,
spilling over into surrounding
communities. In addition, resettlement
often causes psychological and social
strains, and this may affect the health
and welfare of displaced populations.
Energy
Among the largest potential impacts of
climate change on the developing world
are the threats in many areas to biomass,
a principal source of energy in most
sub-Saharan African nations and many
other developing countries. More than
90% of the energy in some African
countries depends on biomass energy
(fuelwood). Owing to uncertainties in
water resource projections derived from
current climate models, it is very difficult
to provide reliable regional projections
of future moisture conditions in these
countries. Drier conditions could be
expected in some countries or regions,
and in those situations energy resources
could be severely impaired. There could
be possible compensating effects of
faster growth of fuelwood due to higher
ambient CO2. Analysis of this situation
should be a top priority for energy
planners.
In addition to affecting the regional
distribution of water and biomass,
climate-related changes in cloud cover,
precipitation and wind circulation
intensity will affect the distribution of
other forms of potential renewable
energy such as solar and wind power.
Understanding these impacts on hydro,.
biomass, solar and wind energy is
particularly important because renewable
energy sources are playing a significant
role in the energy planning of many
countries. This could become an
increasingly important concern in
developing countries, many of which are
facing serious economic pressures from
the need to import conventional energy
resources.
Developing countries, including many in
Africa, depend significantly on
hydroelectric power. By changing water
resource availability, climate change may
make some present hydroelectric power
facilities obsolete and future energy
planning more troubled, although others
may benefit from increased runoff.
Major studies to date of the likely
impact of global warming on the energy
sector in developed countries are
confined largely to six countries: Canada,
the Federal Republic of Germany,
Japan, the UK, the USSR and the US.
Generally, they show differing overall
aggregate impacts, depending on how
much energy use is related to residential
and office heating and cooling. Climate
warming will increase energy consump-
tion for air-conditioning and, conversely,
lower it for heating.
In addition, the energy sector may be
affected by response strategies against
global warming, such as a policy on
emission stabilisation. This may be
among the most significant energy sector
impacts in many developed countries,
enhancing opportunities for technologies
that produce low quantities of green-
house gases. Controversy on the way to
obtain CCyfree energy has already risen,
particularly the options of increased
reliance on nuclear power or hydro-
electric power, weighed against related
safety and environmental concerns.
Energy sector changes in both
developing and developed countries may
have broad economic impacts affecting
regional employment, migration and
patterns of living.
29
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Transport
Generally, the impacts of climate change
on the transport sector appear likely to
be quite modest, with two exceptions.
Ultimately, the greatest impact of
climate change on the transport sector in
developed countries would appear to be
changes produced by regulatory policies
or consumer shifts designed to reduce
transport-related emissions of green-
house gases. Because of the importance
of the transport sector as a source of
greenhouse gases, it is already being
targeted as a major source of potential
reductions in greenhouse gas emissions,
with potentially added constraints on
private automobile traffic, automotive
fuel and emissions, and increased use of
efficient public transport.
A second large impact on the transport
sector concerns inland shipping, where
changes in water levels of lakes and
rivers may seriously affect navigation and
the costs of barge and other transport.
Studies to date, focused entirely on the
Great Lakes region of Canada and the
US, have shown quite large potential
impacts. Climate scenarios have shown
a likely drop of lake levels of as much as
2.5 m resulting from an effective CO2
doubling. Such changes could increase
shipping costs, but the shipping season
could be longer than at present due to
decreased ice. Lake and river levels
may rise in some other regions with
potentially enhanced opportunities for
shipping.
Generally, impacts on roads appear
likely to be quite modest, except in
coastal areas where highways or bridges
may be endangered by sea-level rise or
in mountainous regions where potentially
increased intensity in rainfall-might pose
the risk of mudslides. Studies in
Atlantic Canada and Greater Miami,
US, indicate that highway infrastructure
costs could prove very costly in such
exposed coastal areas. Reduced snow
and ice and lessened threat of frost
heaves should generally produce highway
maintenance savings as suggested by a
study of Cleveland, Ohio, US.
Impacts on railways appear likely to be
modest, although heat stress on tracks
could increase summertime safety
concerns on some railways and reduce
operational capability during unusually
hot periods. Dislocations due to
flooding may increase.
There has been little analysis of likely
impacts on ocean transport The
greatest effect would appear likely to be
some jeopardy to shipping infrastructure
such as ports and docking facilities,
threatened both by sea-level rise and
storm surge. Some climate projections
indicate the possibility that tropical
cyclone intensity may increase. This
could have adverse implications for
ocean shipping and infrastructure. On
the other hand, decreased sea ice could
provide greater access to northern ports
and even enable regular use of the
Arctic Ocean for shipping. Moderate
sea-level rise could also increase the
allowable draught for ships using shallow
channels.
There is a strong need for analysis of
likely impacts of climate change for the
transport sector in developing countries,
as efficiency of the transport sector is
likely to be an essential element in the
ability of countries to respond to climate
change.
Industry
Studies of likely impacts of climate
change on the industrial sector tend to
be concentrated heavily on certain
sectors such as recreation and only on a
handful of developed countries,
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principally Australia, Canada, Japan, the
UK and the US. There is very little
analysis of the likely impacts of climate
change on industry in developing
countries, although there is some
evidence to suggest that industry of
developing countries may be particularly
vulnerable to climate change. An
especially important factor is the likely
change in the production map of primary
products as a result of climate change.
Changes in the regional and global
availability and cost of food and fibre
may significantly affect the competi-
tiveness and viability of such derivative
industries as food processing, forest and
paper products, textiles and clothing.
Climate change may be expected to have
impacts on the availability and cost of
food, fibre, water and energy which
would differ markedly from region to
region.
Just as the motor vehicle and the energy
sectors are likely to be influenced by
regulatory decisions and shifts in
consumer patterns emanating from
concerns about limiting greenhouse gas
emissions, heavy manufacturing may face
readjustment to new situations such as
transboundary siting constraints and
international mechanisms for develop-
ment and transfer of new technology.
Efficiency in the use of energy may
become an even more significant com-
petitive factor in steel, aluminium and
other metal industries, and automotive
manufacturing. Public concerns about
limiting greenhouse gas emissions may
also create opportunities for energy
conservation or for industries based on
'clean technology'. Studies of likely
impacts of climate change on industry
tend to be clustered in the recreational
sector, where direct impacts of climate
change are more ascertainable.
With sufficient lead time, industry may
be able to adjust to many of the changes
accompanying global warming.
Shortages of capital in developing
countries which may be vulnerable to
flood, drought or coastal inundation may,
however, constrain such industry's ability
to design effective response strategies.
Human health
Humans have a great capacity to adapt
to climatic conditions. However,
adaptations have occurred over many
thousands of years. The rate of
projected climatic changes suggest that
the cost of future adaptation may be
significant.
A greater number of heatwaves could
increase the risk of excess mortality.
Increased heat stress in summer is likely
to increase heat-related deaths and
illnesses. Generally, the increase in
heat-related deaths would be likely to
exceed the number of deaths avoided by
reduced severe cold in winter. Global
warming and stratospheric ozone
depletion appear likely to worsen air
pollution conditions, especially in many
heavily populated and polluted urban
areas. Climate change-induced
alterations in photochemical reaction
rates among chemical pollutants in the
atmosphere may increase oxidant levels,
adversely affecting human health.
There is a risk that increased
ultraviolet-B radiation resulting from
depletion of the stratospheric ozone
layer could raise the incidence of skin
cancer, cataracts and snow blindness.
The increased skin cancer risks are
expected to rise most among fair-skinned
Caucasians in high-latitude zones.
Another major effect of global warming
may be the movement poleward in both
hemispheres of vector-borne diseases
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carried by mosquitoes and other
parasites. Parasitic and viral diseases
have the potential for increase and
reintroduction in many countries.
Changes in water quality and availability
may also affect human health. Drought-
induced famine and malnutrition have
enormous consequences for human
health and survival.
The potential scarcity in some regions of
biomass used for cooking, and the
growing difficulty in securing safe
drinking water because of drought, may
increase malnutrition in some developing
countries.
Air pollution
NO, and auto-exhaust controls are
already being implemented to improve
air quality in urban areas in some
developed countries. Concerns about
possible energy penalties and overall
implications of such control measures for
greenhouse gas emissions will need to be
incorporated in future planning.
Moreover, global warming and strato-
spheric ozone depletion appear likely to
aggravate tropospheric ozone problems
in polluted urban areas. The tropo-
spheric temperature rise induced by the
enhanced greenhouse effect could
change homogeneous and heterogeneous
reaction rates, solubility to cloud water,
emission from marine, soil and vege-
tative surfaces, and deposition to plant
surfaces of various atmospheric gases,
including water vapour and methane. A
change in water vapour concentration
will lead to changes in the concentration
of HOZ radicals and H2O2, which are
important for the oxidation of SO2 and
NO, in the atmosphere. The predicted
change of the patterns of cloud cover,
stability in the lower atmosphere,
circulation and precipitation, could
concentrate or dilute pollutants, and
change their distribution patterns and
transformation rates in regional or local
sectors. A change in aerosol formation
by atmospheric conversion from NO,,
and SO2 and windblown dust from arid
land could lead to changes in visibility
and albedo. Material damage caused by
acidic and other types of air pollutants
may be aggravated by higher levels of
humidity.
Ultraviolet-B radiation
Besides the human health implications of
increased ultraviolet-B radiation already
discussed, such radiation may also signi-
ficantly affect terrestrial vegetation,
marine organisms, air quality and
materials. Increased ultraviolet-B
radiation may adversely affect crop
yields. There are some indications that
increased solar ultraviolet-B radiation
which penetrates into the ocean surface
zone where some marine organisms live,
may adversely affect marine phyto-
plankton, potentially reducing marine
productivity and affecting the global food
supply. Increased ultraviolet-B radiation
can also be expected to accelerate
degradation of plastic and other coating
used outdoors. The enhanced green-
house effect is expected to decrease
stratospheric temperatures and this may
affect the state of the stratospheric
ozone layer.
Recommendations for action
• Assessment of the vulnerability of
countries, especially in the developing
world, to gain or loss of energy
resources such as hydroelectric power,
biomass, wind and solar, and an
examination of available substitutes
under new climate conditions, should
be a high priority.
• Research is critically needed into the
adaptability of vulnerable human
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populations, especially the elderly and
the sick, to the occurrence of
increased heat stress as well as the
potential for vector-borne and viral
diseases to shift geographically.
• Policy makers should give priority to
the identification of population and
agricultural and industrial production
at risk in coastal areas subject to
inundation from sea-level rise of
various magnitudes and to storm
surge.
• It is important that developing
countries have the capability to assess
climate change impacts and to
integrate this information into their
planning. The world community
should assist countries in conducting
such assessments and work to create
indigenous climate-change impact
assessment capabilities in such
countries.
Potential impacts of climate
change on the world ocean and
coastal zones
Major findings
The projected global wanning will cause
sea-level rise, modify ocean circulation,
and cause fundamental changes to
marine ecosystems, with considerable
socioeconomic consequences.
Sea-level is already rising on average of
over 6 cm per SO years, with important
regional variations because of local
geological movements. The Greenland
and perhaps the Antarctic ice sheets may
still be responding to changes since the
last glaciation. Fisheries and various
coastal resources are presently under
growing stress from pollution, exploita-
tion and development, creating serious
problems for populations dependent on
them. Impacts from the enhanced
greenhouse effect, which have been
considered by the IPCC, will be added to
these present trends.
A 20-30 cm sea-level rise (projected by
the year 2050) poses problems for the
low-lying island countries and coastal
zones, destroying productive land and
the freshwater lens. Protecting these
areas entails considerable cost.
Aim sea-level rise (the maximum
projected by the year 2100) would
eliminate several sovereign states,
displace populations, destroy low-lying
urban infrastructure, inundate productive
lands, contaminate freshwater supplies
and alter coastlines. These effects could
not be prevented except at enormous
cost. The severity would vary among
coastal regions and would depend on the
actual rate of rise.
Coastal ecology is affected by the rate of
sea-level rise. Too rapid a rise could
reduce or eliminate many coastal eco-
systems, drown coral reefs, reduce
biological diversity and disrupt the life
cycles of many economically and
culturally important species.
Erosion of wetlands and increasing
availability of organic matter from
sea-level rise can increase estuarine and
near-shore productivity for some
decades.
Global warming will change the thermal
budget of the World Ocean and shift the
global ocean circulation. Changes in
ocean circulation, including high-latitude
deep water formation, will affect the
capacity of the ocean as a sink of
atmospheric heat and CO2. Upwellings
of nutrient-rich waters associated with
major fisheries are also expected to
change, causing a decrease in primary
production in open ocean upwelling
zones and an increase in primary
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production in coastal upwelling zones.
The expected impacts will include
chemical changes in biogeochemical
cycles such as the global carbon cycle
which affects the rate of accumulation of
atmospheric CO2.
Adverse ecological and biological
consequences will vary by geographic
zones of the world's oceans. The loss of
habitat will cause changes in biological
diversity, redistribution of marine
organisms and a shift in the ocean
production zones.
A simultaneous rise in both water
temperature and sea-level may lead to
the redistribution of commercially
important species and benthic organisms.
Changes in fisheries production may well
balance globally in the long term, but
there could be important regional shifts
in areas of fisheries, with major
socioeconomic impacts.
Shipping and ocean transportation will
benefit from less sea ice and small
increases in depth in harbours, but some
ice-dependent marine mammals and
birds will lose migratory and hunting
routes and the essential habitats.
Increase in ultraviolet-B radiation can
have widespread effects on biological
and chemical processes, on life in the
upper layer of the open ocean, on corals,
and on wetlands. These impacts are of
concern but not well understood.
Impacts of sea-level rise on coastal
zones
The magnitude and rate of sea-level rise
will determine the ability of social and
natural ecosystems to adapt to the rise.
Direct effects of the rise are straight-
forward: inundation of low-lying coastal
areas; erosion and recession of sandy
shorelines and wetlands; increased tidal
range and estuarine salt-front intrusion;
increases in sedimentation in the zone of
tidal excursion; and increase in the
potential for salt water contamination of
coastal freshwater acquifers. The
predicted changes in climate may also
affect the frequency and intensity of
coastal storms and hurricanes, which are
the major determinants of coastal
geomorphic features and extreme high
sea-level events.
The socioeconomic impacts of these
direct physical effects are uncertain and
more difficult to assess, and are region-
and site-specific. There are three
general impact categories that
encompass the physical effects:
• threatened populations in low-lying
areas and island nations.
• alteration and degradation of the
biophysical properties of beaches,
estuaries and wetlands.
• inundation, erosion and recession of
barrier beaches and shoreline.
Threatened populations in low-lying
areas and island nations
The most important socioeconomic
impact of sea-level rise is the inundation
of intensely utilised and densely
populated coastal plains. A 1 m rise
would produce a coastline recession of
several kilometres in a number of
countries. Other countries have a
substantial proportion of land area
between 1 m and 5 m above sea-level,
with high density coastal populations.
For example, aim sea-level rise could
inundate 12-15% of Egypt's arable land
and 14% of Bangladesh's net cropped
area, displacing millions of inhabitants.
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Sea-level rise would also expose a
greater proportion of low-lying areas to
coastal storm flooding from storm
surges. Densely populated urban areas
could be protected at great cost, but less
densely populated areas stretched out
along the coastline could not be
protected. In these situations, large-
scale resettlement might be necessary.
Another consequence of sea-level rise is
greater incursion of salt water into
freshwater estuarine areas, along with
larger tidal excursion. This would
reduce the freshwater portion of
estuarine rivers, especially during
drought periods, adversely affecting
municipal and industrial reshwater
supplies, and could contaminate coastal
groundwater acquifers, which also supply
water for municipal purposes in many
areas. Many estuarine areas across the
world, with large population centres,
would be affected, particularly those
where a decrease in net freshwater
runoff is also projected as a consequence
of global warming.
Finally, as sea-level rises, much of the
infrastructure in low-lying urban areas
would be affected, requiring major
engineering design adjustments and
investments. In particular, stormwater
drainage and sewerage systems of many
cities will be affected. Coastal pro-
tection structures, highways, power plants
and bridges may require redesign and
reinforcement to withstand increased
flooding, erosion, storm surges, wave
attack and sea-water intrusion.
Alteration of the biophysical properties
of estuaries and wetlands
An accelerated rise in sea-level could
severely redistribute coastal wetlands-
Salt, brackish and fresh marshes as well
as mangrove and other swamps would be
lost to inundation and erosion; others
would transform and adapt to the new
hydrologic and hydraulic regime or
would migrate inland through adjacent
lowlands not impeded by protective
structures. The value of these wetlands
as habitat for wildlife would be impaired
during the transitional period and their
biodiversity may decrease. Although
many wetlands have kept pace or have
increased in area under the historic rate
of sea-level rise owing to sediment
entrapment and peat formation, vertical
accretion of wetlands has not been
observed to occur at rates comparable to
those projected for sea-level rise in the
next century.
Wetlands are vital to the ecology and
economy of coastal areas. Their
biological productivity is equal to or
exceeds that of any other natural or
agricultural system, although little of that
productivity may be available to marsh
animals and coastal fisheries. Over half
the species of commercially important
fishes in the southeastern US use salt
marshes as nursery grounds. Wetlands
also serve as sinks for pollutants and
provide a degree of protection from
floods, storms and high tides. Based on
these functions, marshes can provide a
present value to society of as much as
$US5500/acre or over $US10,000/ha.
Coastal wetlands and estuaries are
important to many species. If sea-level
rise is too rapid, natural succession of
the coastal ecology will not take place
and will lead to great disruption in life
cycles. In the short term, production of
fisheries could rise as marshes flood, die
and decompose, thus improving fisheries
habitat in some cases and providing
more nutrients. Further nutrients will
become available from the leaching of
soils and peat which become more
frequently flooded. This temporary
increase in productivity appears to be
happening now in the southeast US
where sea-level rise is compounded by
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land subsidence. However, this
temporary benefit for fisheries may be
balanced by negative impacts on birds
and other wildlife as the habitat area is
decreased. In the longer term, by 2050
the overall impact on fisheries and
wildlife is likely to be negative.
While considering potential changes in
the biogeochemical cycles of chemicals
from sea-level rise, it should be noted
that (i) growth of nitrogen and
phosphorus concentrations on a regional
scale (in subpolar and mid latitudes, in
the Bering Sea in particular) would
result from flooding of coastal areas and
from soil erosion; and (ii) many
pesticides which are presently held in
sediments could be released into the
marine environment by coastal flooding.
The combination of climatic changes will
cause coastal ecosystems to move inland,
unless humankind intervenes, and
poleward. Also, if sea-level rise is rapid,
as predicted, productivity will probably
fall, but there may be some decades
during which wetlands-based productivity
increases before it falls. Once the ocean
begins to stabilise at its new level (if this
were to occur in the foreseeable future),
productivity will begin to decrease.
Inundation and recession of barrier
islands, coral atolls and other shorelines
Sea-level rise would cause inundation
and recession of all types of shorelines,
especially low-lying coastal areas. Many
beaches have very small gradients of
1:100 or less. Aim rise in sea-level
would inundate 100 m of beach.
Additional shoreline recession would
result from normal erosive processes
including storm surges and wave attack.
The potential destruction of coral atolls
is perhaps most significant, because
these island areas serve both as
contained human habitats as well as
important ecological habitats with high
biodiversity. Unlike continental areas
with receding coastlines, where areas for
resettlement are available landward of
the coasts, coral islands have very
limited possibilities. If the rate of
sea-level rise exceeds the maximum rate
of vertical coral growth (8 mm/yr), then
inundation and erosive processes begin
to dominate, leading to the demise of
the coral atoll. However, if the rate of
sea-level rise is small, then coral growth
may be able to keep pace. Although
there are engineering solutions for
retarding erosion and protecting against
storm damage of continental coasts,
coral atolls cannot be effectively
protected.
Barrier beaches are important for human
use, both for subsistence and recreation,
and as protection for lagoons and
mainland areas from coastal storms.
Coastal areas have always been
hazardous. Societies have adapted to or
sought to control the most extreme
conditions resulting from natural climate
variability. The loss of habitable coastal
areas, which are typically densely
populated will undoubtedly lead to
large-scale resettlement. Since most
commercial and subsistence fisheries are
de facto located in the very same
vulnerable areas, the impacts are
twofold: reduction in ecological
(wetlands) habitat that sustains fish
populations, coupled with increased
threats to habitable coastal areas. Many
areas around the globe, comprising
thousands of kilometres of shoreline and
affecting millions of people would be
adversely affected by a rise of 1 m, or
even 0.5 m. For the most part,
prevention of the primary physical
effects is not economical for most of the
threatened coastline. Therefore, the
prospect for adverse impacts should be
considered to be extremely important
and virtually irreversible.
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Impacts on the World Ocean
Global climate wanning can change the
physical, chemical and biological
processes in the oceans, and affect
productivity of the oceans and fisheries.
Effective CO2 doubling could lead to an
increase of sea-surface temperature by
0.2° -2° C and to changed heat balance
components. Impacts will differ among
geographic zones.
In addition, an increase in atmospheric
CO2 could cause an increase in sea-
water acidity up to 0.3 pH and elevation
of the lysocline (because of solution of
additional amounts of CaCO3). These
processes might be accompanied by a
decrease in the stability of the complexes
of trace metals with aquatic humus,
strengthening the toxic impacts of these
substances on marine organisms as well
as a change in the conditions of
accumulation of deposits.
Coastal ecosystems will be exposed to
the most severe impact owing to a water
temperature increase and, especially, to
sea-level rise. Disturbances by hydro-
logical and hydrochemical conditions in
these regions will be accompanied by a
shift of feeding zones of many commer-
cial fish species and benthic organisms,
a change in the trophic structure of
coastal communities and, as a conse-
quence, a decrease in their productivity.
At the first stage, as the flux of nutrient
increases, in the process of land flooding,
a certain increase in the productivity of
coastal areas might be observed.
A change in heat balance and the circu-
lation system in the oceans will produce
a direct effect on the productivity of
marine ecosystems. Taking into consi-
deration the fact that 45% of the total
annual production is in the zones of
oceanic and coastal upwellings and
subpolar regions, a change in these
regions would determine the future
productivity of the oceans.
According to the results of numerical
experiments with the use of General
Circulation Models of the atmosphere-
ocean system, as well as palaeo-
oceanographical data, the global
warming would be accompanied by a
weakening of the intensity of oceanic
upwellings because of a decrease in the
meridional temperature gradient. This
process will involve a decrease in the
productivity of these ecosystems.
However, some increase in the intensity
of coastal upwellings as a result of
increasing temperature difference
between land and water surface, would
partially compensate for the reduction of
oceanic upwellings. Besides, an increase
in the temperature at high latitudes will
be accompanied by an increase in their
productivity. As a result of the above
changes, a redistribution of productive
zones will probably occur. This could
lead to disturbances in the trophic
structure of marine ecosystems and to a
change in the conditions of the
formation of the stocks of commercial
fishes.
An increase in the zone of the area of
warm equatorial and tropical waters
would cause the movement of pelagic
and benthic communities of these areas
to the boreal and temperate regions.
This circumstance might significantly
affect the structure of world fisheries.
Under conditions of climate warming,
the intensification of biodegradation
processes will occur by up to 30-50% in
the zone of high latitudes. This factor,
along with the expected increase of
ultraviolet-B radiation, resulting from the
depletion of the ozone layer, could
accelerate bacterial and photochemical
degradation of pollutants and reduction
of their 'residence time' in the marine
environment. Ecological and biological
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consequences of climate changes will
vary among geographic zones. A
regional approach is needed to study the
biogeochemical carbon cycle, especially
in the most productive and vulnerable
ecosystems of the ocean.
The highly productive subpolar and
polar ecosystems of the Bering Sea,
Arctic Seas and Southern Ocean are
important to study because the
high-latitude areas will see the greatest
changes. These areas are important to
the total global carbon cycle in the
ocean, in climate-forming processes, in
fisheries, and in marine mammal and
bird production.
International investigations, for example
those planned for the region of the
Bering Sea, will contribute to the
determination of the role of subpolar
ecosystems in the formation of earth's
climate, as well as to a more compre-
hensive study of possible ecological
impacts of global warming on the ocean,
in particular on fisheries.
Many fisheries and marine mammal
populations are heavily stressed from
fishing pressure. Climate changes will
increase stress and the chance of
collapse. However, for some species, the
new climate may be more advantageous
to their well-being.
One benefit of warming will be the
reduction of sea ice and thus improved
access for shipping. However, there are
ecological concerns. Land animals use
sea ice for migratory and hunting routes,
while for many species of marine
mammals (eg seals, polar bears,
penguins) sea ice is an essential part of
their habitat. Thus, reduction of the
amount or duration of ice can cause
difficulties for such animals. Moderate
rises in sea-level, provided they are
insufficient to threaten port installations,
may prove to be beneficial by increasing
the allowable draught of ships in shallow
ports and channels.
Recommendations for action
• Identification and assessment of the
risks to coastal areas and islands and
living resources of a 0.3-0.5 m rise in
sea-level.
• Assessment of potential leaching of
toxic chemicals with sea-level rise.
• Improvement of the methods for
analysing the major components of
oceanic branch of carbon cycle (the
carbonate system and organic
carbon).
• Assessment of the possible impacts of
increased UV-B radiation from strato-
spheric ozone depletion on oceanic
and estuarine ecosystems.
• Determination of ecological impacts
of Arctic and Antarctic sea ice
reductions.
• Development of methodologies to
assess the impacts on living marine
resources, and socioeconomic impacts,
of changes in the ocean and coastal
zone.
• Development and implementation of
multinational systems to detect and
monitor expected environmental and
socioeconomic impacts of ocean and
coastal zone changes.
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Impacts of climate change on
seasonal snow cover, ice and
permafrost, and socioeconomic
consequences
Major findings
• The global areal extent and volume of
the terrestrial ciyosphere (seasonal
snow cover, near-surface layers of
permafrost and some masses of ice)
will be substantially reduced. These
reductions, when reflected regionally,
could have significant impacts on
related ecosystems and social and
economic activities.
• Thawing and reduction in the areal
extent of the terrestrial ciyosphere
can enhance global warming (positive
feedback on climate wanning)
through changes in the global and
local radiation and heat balances, and
the release of greenhouse gases. This
positive feedback could increase the
rate of global warming and, in some
regions, could result in changes that
are sudden rather than gradual. The
possibility of relatively rapid changes,
increases the potential significance of
the associated impacts.
• The areal coverage of seasonal snow
and its duration are projected to
decrease in most regions, particularly
at mid latitudes, with some regions at
high latitudes in the Arctic and
Antarctic possibly experiencing
increases in seasonal snow cover.
• Decreases in seasonal snow cover can
have both positive and negative socio-
economic consequences owing to
impacts on regional water resources,
winter transportation and winter
recreation.
• Globally, the ice contained in glaciers
and ice sheets is projected to
decrease. Regional responses,
however, are complicated by the
effect of increased snowfall in some
areas which could lead to accumu-
lation of ice. Glacial recession will
have significant implications for local
and regional water resources and thus
impact on water availability and on
hydroelectric power potential.
Enhanced melt rates of glaciers may
initially increase the flow of melt-
waters; however, flows will decrease
and eventually be lost as glacial ice
mass decreases. Glacial recession
and loss of ice from ice sheets will
also contribute to sea-level rise.
Degradation of permafrost is expected
with an increase in the thickness of
the seasonal freeze-thaw (active) layer
and a recession of permafrost to
higher latitudes and higher altitudes.
The thickness of the active layer is
expected to increase by 1 m over the
next 40-50 years. Although major
shifts are expected in climatic zones,
recession of permafrost will signi-
ficantly lag behind, receding only
25-50 km during the next 40-50 years.
These changes could lead to increases
in terrain instability, erosion and
landslides in those areas which are
currently underlaid by permafrost.
The socioeconomic consequences of
these changes in permafrost could be
significant. Ecosystems which are
underlaid by permafrost could be
substantially altered owing to terrain
disturbances and changes in the
availability of water. The integrity of
existing and planned structures and
associated facilities and infrastructure
could be reduced by changes in the
underlying permafrost. Retrofitting
or redesigning would be required at a
minimum; however, in some situations
the associated terrain disruptions
and/or costs (environmental, social
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and economic) may be too large,
necessitating abandonment. Develop-
ment opportunities could also be
affected in areas where the risks
associated with developing in an area
susceptible to permafrost degradation
are assessed as too high.
• The terrestrial cryosphere, because of
its relative responsiveness to climate
and climatic changes, provides an
effective means of monitoring and
detecting climatic change.
• Lack of sufficient data and gaps in
the understanding of associated
processes limits more quantitative
assessments at this time.
Principal issues
The terrestrial component of the cryo-
sphere consists of seasonal snow cover,
mountain glaciers, ice sheets, and frozen
ground, including permafrost and
seasonally frozen ground. These
elements of the terrestrial cryosphere
currently cover approximately 41 million
km2' with seasonal snow cover covering
as much as 62% of the Eurasian
continent and virtually all of North
America north of 35° latitude.
Projected changes in climate will
dramatically reduce the areal extent and
volume of these elements of the terres-
trial cryosphere. This has implications
not only with respect to changes in the
availability of fresh water, changes in
sea-level and in terrain characteristics,
but also for societies and related
economic systems which have come to
depend on, or are limited by, the
existence of a terrestrial cryosphere.
Feedback mechanisms are an important
factor in understanding the impacts of
climatic change on the terrestrial
cryosphere. Reduced areal coverage of
these elements and degradation of
permafrost as a result of climatic
warming can enhance warming through
changes in surface characteristics and
release of greenhouse gases.
The impacts of socioeconomic conse-
quences of changes in the terrestrial
cryosphere will depend to a large extent
on the rate at which the changes occur.
Where the rate of change is quick or
sudden, environment and associated
social and economic systems will have
little time to adapt. Under these
circumstances the impacts and socio-
economic consequences could be large.
Seasonal snow cover
General Circulation Models indicate that
in most parts of the Northern and
Southern Hemispheres the area of snow
cover is expected to decrease as a result
of increased temperature and, in most
regions, a corresponding decrease in
total mass of the snow. Areas where
snow cover is projected to increase
include latitudes south of 60° S and
higher elevations of inland Greenland
and Antarctica (though the latter is, and
will remain, largely a cold desert).
A reduction in the areal snow coverage
and in the length of the snow cover
season will result in a positive climatic
feedback, increasing global wanning as a
result of the greater amount of solar
radiation that a snow-free surface can
absorb relative to one that is snow-
covered.
Loss of snow cover has both negative
and positive socioeconomic conse-
quences. Decreases in snow cover will
result in increased risks of damages and
losses for those systems which rely on
snow as protection (ie insulation) from
cold winter climates. Included are
agricultural crops such as winter wheat.
40
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trees and shrubs, hibernating animals,
and construction and maintenance of
municipal infrastructures.
Reductions in both the temporal and
spatial coverage of seasonal snow cover
will have significant ramifications for
water resources as the amount of water
available for consumptive (eg potable
and irrigation water) and non-
consumptive (eg hydroelectric power and
waste management) uses decreases.
Particularly sensitive are those areas
such as the Alps and Carpathians, the
Altai mountains of Central Asia, the Syr
Dar'ya and Amu Dar'ya region of the
USSR, the Rocky Mountains and the
North American Great Plains, all of
which are dependent on snowmelt for
the majority of their spring and summer
water resources.
Changes in snow cover will also affect
tourism and recreation-based industries
and societies, particularly winter
recreation sports such as skiing.
Projected climate change could eliminate
a $50 million per annum ski industry in
Ontario, Canada.
From a positive impacts perspective,
reductions of seasonal snow cover will
reduce expenditures on snow removal
and will increase access opportunities
and ease transportation problems. A
reduction in snow cover, however, will
also have adverse impacts for transpor-
tation in those areas which rely on snow
roads in winter. Inability to use snow
roads will result in the necessity of using
other more costly methods of
transportation.
Ice sheets and glaciers
The relationships between climate and
ice sheets and glaciers are complex, and
because of relatively limited monitoring
and research, not fully understood at this
time. Increased temperatures generally
result in increased ablation and, hence,
a decrease in ice mass. Conversely,
increased snowfall usually increases ice
mass. Since projected changes in
climate for some ice-covered regions
include both increases in temperature
and snowfall, understanding the impact
of climatic changes on glaciers and ice
sheets must consider the combined
impact.
The bulk of the earth's ice mass is stored
in the Antarctic ice sheet, divided
between an eastern portion resting on
continental crust and a large western
portion which is underlaid both by
continental crust and ocean. Much of
the remaining ice mass is contained in
the Greenland ice sheet, with smaller
quantities stored in glaciers throughout
the world.
Although observed data are limited, it is
estimated that both Antarctic and
Greenland ice sheets are at present
roughly in equilibrium, with annual gains
close to annual losses. There is some
evidence that suggests that the Green-
land ice sheet has been thickening since
the late 1970s, which has been attributed
to new snow accumulations on the ice
sheet
Greenhouse-gas-induced climatic change
will tend gradually to warm these sheets
and bring them out of balance with the
new climate regime. Change in ice-sheet
volume is likely to be slow, however,
with significant loss unlikely to occur
until after 2100. Calculations for
Greenland suggest that a 3% loss of ice
volume in the next 250 years is possible,
based on the projected changes in
climate. In the case of the Antarctic ice
sheet the situation is more complex.
The mass of the eastern ice sheet is
expected to remain virtually the same or
increase slowly as a result of expected
41
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increases in precipitation and temper-
atures. In contrast, the western ice
sheet, like other marine ice sheets is
inherently unstable. Climatic wanning
could cause groundline retreat and rapid
dispersal of ice into the surrounding
ocean by way of relatively fast-flowing
ice streams. These changes in behaviour
could lead to collapse of a portion of the
western Antarctic ice sheet which,
depending on the amount of ice
involved, could have a dramatic impact
on sea-level and the surrounding
environment.
The response of glaciers to climatic
change will depend on their type and
geographic location. In general,
however, they have been shrinking for
the last 100 years and are expected to
continue to do so in response to pro-
jected changes in climate. In Austria a
3°C warming by 2050 is projected to
cause a reduction by about one-half in
the extent of alpine glaciers. Melting of
glaciers in the Soviet arctic archipelagoes
may result in their disappearance in
150-250 years. In contrast, an assess-
ment of mountain glaciers in the
temperate zone of Eurasia indicates that
up to 2020 these glaciers will, in general,
remain essentially unchanged, with
increased precipitation compensating for
increased melt.
Ice sheet and glacier melting will result
in higher sea-levels. Observations over
the last century indicate that levels have
been rising between 1-3 mm/year
primarily as a result of mass loss from
alpine glaciers. Current projections
suggest an accelerated rise with green-
house gas wanning to a most probable
rise of 65 cm by the end of the next
century.
Glacial melting can act as a negative
feedback to regional and global
warming, with heat extracted from the
air to melt glacial ice and snow, thereby
reducing the degree of warming.
The melting of glaciers will also alter
regional hydrologic cycles. In New
Zealand it has been estimated that a
3°C increase in temperature would, in
the short term, increase glacier-fed river
flow in some western rivers, increasing
hydroelectric power generation by 10%.
Another effect of glacier retreat is
possible increased debris flows. Large
amounts of debris masses on steep
slopes will become exposed as a result of
glacial retreat and, therefore, would be
unstable and vulnerable to the effects of
erosion. Landslides would result,
leading to burial of structures, traffic
routes and vegetation. Obstructions of
river flows and increased sediment loads
resulting in changes in water quantity (eg
local floods and reduced flows down-
stream) and water quality would also be
likely to occur as a result of debris flows.
Permafrost
Permafrost is the part of the terrestrial
cryosphere consisting of ground (soil and
rock) that remains at or below freezing
throughout the year. It usually contains
ice which can take a variety of forms
from ice held in soil pores to massive
bodies of more or less pure ice many
metres thick. The presence of this ice in
the ground makes it behave uniquely as
an earth material, and makes its
properties vulnerable to climatic
wanning.
At present about 20-25% of the land
surface of the earth contains permafrost,
primarily in the polar regions but also in
the alpine areas at lower latitudes. It
occupies approximately 10.7 million km2
in the USSR, 5 million km2 in Canada, 2
million km2 in China and 1.5 million km2
in Alaska. Present and past climate is
the major determinant of permafrost
-------
occurrence and characteristics; however,
a variety of other factors is also
important, for example, the properties of
the soil, and overlying terrain, vegetation
and snow cover.
Permafrost is usually present where the
mean annual air temperature is less than
-1°C At temperatures near this value it
is discontinuous in extent (discontinuous
permafrost zone). Both its extent and
thickness increase at progressively higher
latitudes where temperatures are lower.
It has been found to extend to depths of
approximately 1000 m or more in parts
of Canada, approximately 1500 m in the
USSR and 100-250 m in China.
Permafrost can also exist in seabeds.
There is extensive ice-bound material in
the continental shelf beneath the Arctic
Ocean; however, this permafrost is
commonly relict (ie it formed under past
conditions and would not form under
current ones).
Permafrost is to a large extent inherently
unstable since it exists so close to its
melting point. Most responsive to
changes in climate would be those
portions nearest the surface. Climate
warming would thicken the active layer,
leading to a decrease in soil stability.
This permafrost degradation would lead
to thaw settlement of the surface
(thennokarst), ponding of surface water,
slope failures (landslides) and increased
soil creep. This terrain instability would
result in major concerns for the integrity
and stability of roads, pipelines, airfields,
dams, reservoirs and other facilities in
areas which contain permafrost. Terrain
instability of the surface layer can also
occur as a result of permafrost degra-
dation in alpine areas, such as the Alps.
This instability could result in dangerous
debris falls from thawed rocks and
mudflows.
Slope failures, thermokarst and loss of
near-surface moisture, as the increased
depth of the active layer moved limited
water supplies further from the surface,
would have detrimental effects on vege-
tation and could lead to significant
decreases in plant populations. In the
longer term, permafrost degradation
would allow the growth of deeper
rooted, broadleaved species and the
establishment of denser forest of coni-
ferous species. Wildlife could also be
affected through changes in terrain,
surface hydrology and food availability.
Loss of species and habitats can be
expected, especially where wetlands dry
out or areas are flooded as a result of
melt.
Assessment of the effects of climate
change on permafrost in any particular
location must consider factors other than
temperature, eg changes in summer
rainfall and snow cover. In general,
however, the projected warming during
the next several decades would signi-
ficantly deepen the active layer and
initiate a northward retreat of perma-
frost. It is expected that a 2°C global
warming would shift the southern
boundary of the climatic zone currently
associated with permafrost over most of
Siberia north and northeast by at least
500-700 km. The southern extent of
permafrost will lag behind this, moving
only 25-50 km in the next 40-50 years
(up to 10% reduction in an area
underlaid by continuous permafrost).
The depth of the active layer is expected
to increase by 1 m during the next 40-50
years. Projected changes in permafrost
in Canada are of similar magnitude.
The melting of permafrost would result
in the release of methane and, to a
lesser extent, CO2 from previously frozen
biological material and from gas
hydrates. The extent to which this will
enhance the greenhouse effect is
43
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uncertain, but could be about 1°C by
the middle of the next century.
The socioeconomic impacts of perma-
frost degradation will be mixed.
Maintenance costs of existing northern
facilities such as buildings, roads and
pipelines will tend to rise with abandon-
ment and relocation needed in some
cases. Change in current construction
practices will be necessary, as may be
changes in sanitary waste disposal.
Benefits from climate wanning and
permafrost melt are likely for agri-
culture, forestry, and hunting and
trapping.
Recommendations for action
Projected greenhouse-gas-induced
changes in climate will lead to ablation
of global ice masses. Uncertainty exists,
however, regarding how this global
response will be reflected at the
regional/local level and how the
individual ice masses and seasonal ice
and snow will respond. The most impor-
tant effects of climatic change at high
latitudes and elevated regions will be on
and through changes in the terrestrial
cryosphere. Furthermore, the terrestrial
cryosphere is particularly suited for early
detection of the effects of climate
change. These two points necessitate a
better understanding of the nature and
dynamics of these ice masses and the
factors that control them. This will
require:
• establishment or enhancement of
integrated, systematic observation
programs commensurate with
research on the use of more efficient
ground-based systems and remote
sensing technologies designed to
provide baseline information and
trends;
• concurrent monitoring of those
facilities, structures and natural
resources that are at risk owing to
projected changes in the terrestrial
cryosphere;
• establishment of new guidelines and
procedures for design and construc-
tion practices that consider the
impacts of climatic changes on
permafrost;
• research, including international
cooperative efforts, on the relation-
ships between components of the
terrestrial cryosphere and climate in
conjunction with other determining
factors, including feedback
mechanisms;
• refinement of existing climate-
terrestrial cryosphere models;
• impacts assessments nationally and
regionally that will provide data and
information on the impacts of climate
change on areas in which components
of the terrestrial cryosphere occur and
the resulting socioeconomic conse-
quences;
• assessment of the needs for protected
areas (natural reserves) for affected
species and habitats; and
• development and distribution of
relevant educational material and
information on climatic changes, their
impacts on the terrestrial cryosphere
and socioeconomic consequences, as
well as a wider distribution of
research results.
44
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Summary of major future
actions
The results of the Working Group II
studies highlight our lack of knowledge,
particularly at the regional level and in
areas most vulnerable to climate change.
Further national and international
research is needed on:
• regional effects of climate change on
crop yields, livestock productivity and
production costs;
• identification of agricultural manage-
ment practices and technology
appropriate for changed climate;
• factors influencing distribution of
species and their sensitivity to climate
change;
• initiation and maintenance of
integrated monitoring systems for
terrestrial and marine ecosystems;
• intensive assessment of water
resources and water quality, especially
in arid and semi-arid developing
countries and their sensitivity to
climate change;
• regional predictions of changes in soil
moisture, precipitation, surface and
subsurface runoff regimes and their
interannual distributions as a result of
climate change;
• assessment of vulnerability of
countries to gain or loss of energy
resources, particularly biomass and
hydroelectric power in developing
countries;
• adaptability of vulnerable human
populations to heat stress and vector-
borne and viral diseases;
• a global
changes,
countries;
monitoring
particularly
of sea-level
for island
• identification of populations and
agricultural and industrial production
at risk in coastal areas and islands;
• better understanding of the nature
and dynamics of ice masses and their
sensitivity to climate change;
• integration of climate change impact
information into the general planning
process, particularly in developing
countries; and
• development of methodology to assess
sensitivity of environments and
socioeconomic systems to climate
change.
• Some of these topics are already
being covered by existing and
proposed programs and these will
need continuing support. In
particular, there are three core
projects of the International
Geosphere-Biosphere Program,
namely:
Land-Ocean Interactions in the
Coastal Zone
Biosphere Aspects
Hydrological Cycle
of the
Global Change Impact on
Agriculture and Society
that will provide valuable data in the
coming years.
45
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Concluding remarks
Human-induced climate change can have
profound consequences for the world's
social, economic and natural systems.
Each country should take steps to
understand the impacts on its population
and land resources resulting from such a
change, and the consequences of sea-
level rise, the changed character of
atmospheric circulation and the resulting
changes in typical weather patterns,
reduction of freshwater resources,
increased ultraviolet-B radiation and
spreading of pests and diseases. These
can affect the potential of food and
agricultural production and adversely
affect human health and well-being.
Too rapid a change in climate may not
allow species to adapt and, thus,
biodiversity could be reduced. This
reduction could occur equally as well in
the cryosphere regions, where melting of
sea ice could accelerate, and in the
equatorial regions where sea surface
temperatures could increase. Traditional
cost-benefit analyses do not allow for
assessment of these risks. Although
substantial scientific uncertainty remains
concerning the precise time, location and
nature of particular impacts, it is
inevitable, under the scenario developed
by Working Group I, that in the absence
of major preventive and adaptive actions
by humanity, significant and potentially
disruptive changes in the earth's
environment will occur.
The world community recognises the
need to undertake certain actions to
reduce and mitigate the impact of
climate change. Specific measures
should follow the assessments of poten-
tial impact on the biosphere and on
human activity, and a comparison of the
net costs of adaptation and mitigation
measures. Some of these impacts, such
as sea-level rise, are likely to proceed
slowly but steadily while others such as
shifts in climate zones - which will affect
the occurrence of such events as floods,
droughts and severe storms - may occur
unpredictably. Regions and nations
differ considerably in their vulnerability
to such changes and subsequent impacts.
Generally human activity in developing
countries is more vulnerable than that in
developed countries to the disruption
associated with climate change. Global
warming and its impact must not widen
the gap between developed and
developing countries.
The capacity of developing nations to
adapt to likely climate changes and to
minimise their own contributions to it
through greenhouse gas emissions, is
constrained by their limited resources, by
their debt problems and by their
difficulties in developing their economies
on a sustainable and equitable basis.
These countries will need assistance in
developing and implementing
appropriate response options (including
consideration of technological
development and transfer, additional
financial assistance, public education and
information). As they possess greater
resources to cope with climate change,
developed countries must recognise the
need to assist developing countries to
assess and deal with the potential
impacts of climate change.
46
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WMO UNEP
INTERGOVERNMENTAL PANEL ON
CLIMATE CHANGE
POLICYMAKERS
SUMMARY
OF THE
FORMULATION OF RESPONSE STRATEGIES
Report Prepared for IPCC
by Working Group III
June 1990
-------
POLICYMAKERS SUMMARY WG III
POLICYMAKERS SUMMARY OF THE
REPORT OP WORKING GROUP III OF THE
INTERGOVERNMENTAL PANEL ON CLIMATE CHANGE
(RESPONSE STRATEGIES WORKING GROUP)
TABLE OF CONTENTS
Page
CHAIRMAN1S INTRODUCTION iii
EXECUTIVE SUMMARY vi
1. SOURCES OF ANTHROPOGENIC GREENHOUSE GASES 1
2. FUTURE EMISSIONS OF GREENHOUSE GASES 3
2.1 Emissions scenarios 3
2.2 Reference scenario 4
3. RESPONSE STRATEGIES FOR ADDRESSING GLOBAL CLIMATE CHANGE ... 7
4. OPTIONS FOR LIMITING GREENHOUSE GAS EMISSIONS 9
4.1 Limitation of net emissions from the energy sector .... 10
4.2 Limitation of net emissions from the industry sector .. 18
4.3 Limitation of net emissions from the agriculture sector 18
4.4 Limitation of net emissions from forestry
and other activities 19
5. FURTHER WORK ON GREENHOUSE GAS EMISSION LIMITATION GOALS ... 21
6. MEASURES FOR ADAPTING TO GLOBAL CLIMATE CHANGE 22
6.1 Coastal zone management 22
6.2 Resource use and management 25
7. MECHANISMS FOR IMPLEMENTING RESPONSE STRATEGIES 27
7.1 Public information and education 28
7.2 Technology development and transfer 29
7.3 Economic measures 30
7.4 Financial mechanisms 32
7.5 Legal and institutional mechanisms 34
ANNEX I LEGAL MEASURES: REPORT OF TOPIC CO-ORDINATORS 37
LIST OF ACRONYMS AND CHEMICAL SYMBOLS 46
ii
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CHAIRMAN'S INTRODUCTION
POLICYMAKERS SUMMARY WG III
The First Plenary Meeting of
Working Group III of the IPCC, the
Response Strategies working Group
(RSWG), was held in Washington, 30
January - 2 February 1989. This
meeting was largely organizational
(see Figure 1), and it was not
until after a subsequent RSWG
Officers Meeting in Geneva, 8-12
May 1989, that the real work by the
four RSWG subgroups, the Emissions
Scenarios Task Force (Task A), and
"Implementation Measures" Topic
Coordinators (Task B) began.
The Second RSWG Plenary Session
was held in Geneva, from 2 to 6
October 1989, to discuss the
implementation measures: 1) public
education and information;
2) technology development and
transfer; 3) financial measures;
4) economic measures; and 5) legal
measures, including elements of a
framework climate convention. A
consensus was reached on five
topical papers dealing with these
measures, with the understanding
that they would be "living
documents" subject to further
modification as new information and
developments might require.
The Third Plenary Meeting of
RSWG, held in Geneva, 5-9 June
1990, achieved three objectives:
1) It reached consensus on the
attached "policy summary", the
first interim report of the RSWG.
2) It completed final editing and
accepted the reports of the four
RSWG subgroups, of the
coordinators of Task A, and of
the coordinators of the five Task
B topical papers. These
documents comprise the underlying
material for the consensus report
of this meeting, the policymakers
summary; they are not themselves
the product of a RSWG plenary
consensus although many governments
participated in their formulation.
Finally,
3) The Working Group agreed to
submit comments on its suggested
future work programme to the RSWG
Chairman by 1 July 1990, for
transmission to the Chair of the
IPCC. There was general agreement
that the work of the RSWG should
continue.
The primary task of the RSWG was,
in the broad sense, technical, not
political. The charge of IFCC to
RSWG was to lay out as fully and
fairly as possible a set of response
policy options and the factual basis
for those options.
Consistent with that charge, it
was not the purpose of the RSWG
to select or recommend political
actions, much less to carry out a
negotiation on the many difficult
policy questions that attach to
the climate change issue, although
clearly the information might tend
to suggest one or another option.
Selection of options for implementation
is appropriately left to the
policymakers of governments and/or
negotiation of a convention.
The work of RSWG continues. The
Energy and Industry Subgroup has,
since the June RSWG Plenary Meeting,
held another very productive meeting
in London, the results of which are
not reflected in this report.
It should be noted that quantitative
estimates provided in the report
regarding CFCs, including those in
Scenario A (Business as Usual), generally
do not reflect decisions made in
June 1990 by the Parties to the
Montreal Protocol. Those decisions
iii
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Task A':
Emissions
Scenarios
IPCC
RESPONSE STRATEGIES
WORKING GROUP
STEERING
COMMITTEE
Task B":
Implementation
Mechanisms:
Legal Measures (U.K. Canada. Malta)
Financial Measures (France. Netti.)
Economic Measures (Australia. N.Z.)
Technology Measures (Japan, India)
Public Education Measures (U.S.. PRC)
Energy and
Industry
Subgroup
(Japan and
China)
Agriculture
and Forestry
Subgroup
(FRGand
Zimbabwe)
Coastal
Manage
Subgrc
(N. Zeal
Nether
Zone
men!
tup
and &
lands)
Resource Use
Management
Subgroup
(France. India.
and Canada)
s
r
re 1.
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POLICYMAKERS SUMMARY WG III
accelerate the timetable to phase
out production and consumption of
CFCs, halons, carbon tetrachloride
and methyl chloroform.
It should further be noted that
quantitative estimates of forestry
activities (e.g., deforestation,
biomass burning, including fuel
wood, and other changes in land-
use practices), as well as
agricultural and other activities,
provided in the Report continue
to be reviewed by experts.
Two specific items of unfinished
business submitted to RSWG by
the Ministers at the November 1989
meeting in Noordwijk are the
consideration of the feasibility
of achieving: (1) targets to limit
or reduce C02 emissions, including
e.g. a 20 percent reduction of C02
emission levels by the year 2005;
(2) a world net forest growth of
12 million hectares a year in the
beginning of the next century.
The RSWG hopes to complete this
analysis before the Second World
Climate Conference in November of
this year.
The subgroup chairs and topic
coordinators took the responsibility
for completing their individual reports
and, along with their respective
governments, contributed generously
of their time and resources to that
end.
The RSWG Policymakers Summary
is the culmination of the first
year of effort by this body. The
RSWG has gone to considerable
lengths to insure that the summary
accurately reflects the work of the
various subgroups and tasks. Given
the very strict time schedule under
which the RSWG was asked to work,
this first report can only be a
beginning.
Frederick M. Bernthal
Chairman,
Response Strategies Working Group
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POLICYMAKERS SUMMARY WG III
EXECUTIVE SUMMARY
Working Grcup III (Response
Strategies Working Group) was
tasked to formulate appropriate
response strategies to global
climate change. This was to be
done in the context of the work of
Working Group I (Science) and
Working Group II (Impacts) which
concluded that:
"We are certain emissions
resulting from human activities are
substantially increasing the
atmospheric concentrations of the
greenhouse gases: carbon dioxide,
methane, chlorofluoro-carbons
(CFCs) and nitrous oxide. These
increases will enhance the
greenhouse effect, resulting on
average in an additional warming
of the Earth's surface.
"The longer emissions continue
at present day rates, the greater
reductions would have to be for
concentrations to stabilize at a
given level.
"The long-lived gases would
require immediate reductions in
emissions from human activities
of over 60% to stabilize their
concentrations at today's levels.
"Based on current model results,
we predict under the IPCC Business-
as-Usual emissions of greenhouse
gases, a rate of increase of global
mean temperature during the next
century of about 0.3°C per decade
(with an uncertainty range of 0.2°C
to 0.5°C per decade), greater than
that seen over the past 10,000
years; under the same scenario,
we also predict an average rate of
global mean sea level rise'of about
6 cm per decade over the next
century (with an uncertainty range
of 3 - 10 cm per decade).
"There are many uncertainties
in our predictions particularly with
regard to the timing, magnitude and
regional patterns of climate change.
"Ecosystems affect climate, and
will be affected by a changing
climate and by increasing carbon
dioxide concentrations. Rapid changes
in climate will change the composition
of ecosystems; some species will
benefit while others will be unable
to migrate or adapt fast enough
and may become extinct. Enhanced
levels of carbon dioxide may
increase productivity and efficiency
of water use of vegetation.
"In many cases, the impacts will
be felt most severely in regions
already under stress, mainly the
developing countries.
"The most vulnerable human
settlements are those especially
exposed to natural hazards, e.g.,
coastal or river flooding, severe
drought, landslides, severe storms
and tropical cyclones".
Any responses will have to
take into account the great diversity
of different countries' situations
and their responsibility for and
negative impacts on different countries
and consequently would require a
wide variety of responses. Developing
countries for example are at widely
varying levels of development and
face a broad range of different
problems. They account for 75% of
the world population and their
primary resource bases differ
widely. Nevertheless, they are
most vulnerable to the adverse
consequences of climate change
because of limited access to the
necessary information, infrastructure,
vi
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POLICYMAKERS SUMMARY NG III
and human and financial resources.
Main findings
1) Climate change is a global issue;
effective responses would require
a global effort which may have
a considerable impact on
humankind and individual
societies.
2) Industrialized countries and
developing countries have a
common responsibility in dealing
with problems arising from
climate change.
3) Industrialized countries have
specific responsibilities on two
levels:
a) major part of emissions
affecting the atmosphere at
present originates in
industrialized countries
where the scope for change
is greatest. Industrialized
countries should adopt
domestic measures to limit
climate change by adapting
their own economies in line
with future agreements to
limit emissions;
b) to co-operate with
developing countries in
international action, without
standing in the way of the
latter's development, by
contributing additional
financial resources, by
appropriate transfer of
technology, by engaging in
close co-operation concerning
scientific observation, by
analysis and research, and
finally by means of technical
co-operation geared to
forestalling and managing
environmental problems.
4) Emissions from developing
countries are growing and may
need to grow in order to meet
their development requirements
and thus, over time, are likely
to represent an increasingly
significant percentage of global
emissions. Developing countries
have the responsibility, within
the limits feasible, to take measures
to suitably adapt their economies.
5) Sustainable development requires
the proper concern for
environmental protection as
the necessary basis for continuing
economic growth. Continuing
economic development will
increasingly have to take into
account the issue of climate
change. It is imperative that
the right balance between
economic and environmental
objectives be struck.
6) Limitation and adaptation
strategies must be considered
as an integrated package and
should complement each other
to minimize net costs. Strategies
that limit greenhouse gases emissions
also make it easier to adapt
to climate change.
7) The potentially serious
consequences of climate change
on the global environment give
sufficient reasons to begin by
adopting response strategies
that can be justified immediately
even in the face of significant
uncertainties.
8) A well-informed population is
essential to promote awareness
of the issues and provide
guidance on positive practices.
The social, economic and cultural
diversity of nations will require
tailored approaches.
A flexible and progressive approach
Greenhouse gas emissions from
most sources are likely to increase
significantly in the future if no
response measures are taken.
vii
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POLICYMAKERS SUMMARY WG III
Although some controls have been
put in place under the Montreal
Protocol for CFCs and halons,
emissions of C02, CH4, N20 and other
gases such as several CFC-
substitutes will grow. Under these
scenarios, it is estimated that C02
emissions will increase from
approximately 7 billion (or 1000
million) tonnes carbon (BtC)in
1985 to between 11-15 BtC by 2025.
Similarly, man-made methane
emissions are estimated to increase
from about 300 teragrams (Tg) to
over 500 Tg by the year 2025.
Based on these projections, Working
Group I estimated that global
warming of 0.3°C/decade could
occur.
The climate scenario studies of
Working Group I further suggest
that control policies on emissions
can indeed slow global warming,
perhaps from 0.3°C/decade to
0.1°C/decade. The social, economic
and environmental costs and
benefits of these control policies
have not been fully assessed. It
must be emphasized that
implementation of measures to
reduce global emissions are very
difficult as energy use, forestry,
and land use patterns are primary
factors in the global economy. To
take maximum advantage of our
increasing understanding of
scientific and socio-economic
aspects of the issue, a flexible
and progressive approach is
required. Subject to their
particular circumstances,
individual nations may wish to
consider taking steps now to
attempt to limit, stabilize or
reduce the emission of greenhouse
gases resulting from human
activities and prevent the
destruction and improve the
effectiveness .of sinks. One option
that governments may wish to
consider is the setting of targets
for C02 and other greenhouse gases.
Because large, projected increas
in world population will be a ma jo
factor in causing the projected increase
in global greenhouse gases, it is
essential that global climate change
strategies include strategies and
measures to deal with the rate of
growth of the world population.
Shorter-term
The Working Group has identified
measures at the national, regional
and international levels as applicable
which, while helping to tackle
climate change, can yield other
benefits.
Limitation
- Improved energy efficiency reduces
emissions of carbon dioxide, the
most significant greenhouse gas,
while improving overall economic
performance and reducing other
pollutant emissions and increasing
energy security.
- Use of cleaner energy sources
and technologies reduces carbon
dioxide emissions, while reducing
other pollutant emissions that
give rise to acid rain and other
damaging effects.
- Improved forest management and,
where feasible, expansion of forest
areas as possible reservoirs of
carbon.
- Phasing out of CFCs under the
Montreal Protocol, thus removing
some of the most powerful and
long-lived greenhouse gases, while
also protecting the stratospheric
ozone layer.
- Agriculture, forestry and other
lunan activities are also responsible
for substantial quantities of
greenhouse gas emissions. In
the short term, reductions can
be achieved through improved
livestock waste management,
viii
-------
altered use and formulation of
fertilizers, and other changes
to agricultural land use, without
affecting food security, as well
as through improved management
in landfill and wastewater
treatment.
Adaptation
Developing emergency and
disaster preparedness policies
and programmes.
- Assessing areas at risk from
sea-level rise and developing
comprehensive management plans
to reduce future vulnerability
of populations and coastal
developments and ecosystems as
part of coastal zone management
plans.
- Improving the efficiency of
natural resource use, research
on control measures for
desertification and enhancing
adaptability of crops to saline
regimes.
Longer-term
Governments should prepare for
more intensive action which is
detailed in the report. To do so,
they should undertake now:
- Accelerated and coordinated
research programmes to reduce
scientific and socio-economic
uncertainties with a view towards
improving the basis for response
strategies and measures.
- Development of new technologies
in the fields of energy, industry
and agriculture.
- Review planning in the fields
of energy, industry, transporta.-
tion, urban areas, coastal zones
and resource use and management.
- Encourage beneficial behavioral
POLICYMAKERS SUMMARY WG III
and structural (e.g., tranporta-
tion and housing infrastructure)
changes.
Expand the global ocear.
observing and monitoring systems.
It should be noted that no
detailed assessments have been made
as of yet of the economic costs and
benefits, technological feasibility
or market potential of the underlying
policy assumptions.
International cooperation
The measures noted above require
a high degree of international
cooperation with due respect for
national sovereignty of states.
The international negotiation on
a framework convention should start
as quickly as possible after the
completion of the IPCC First
Assessment Report. This, together
with any additional protocols that
might be agreed upon, would provide
a firm basis for effective cooperation
to act on greenhouse gas emissions
and adapt to any adverse effects
of climate change. The convention
should, at a minimum, contain general
principles and obligations. It should
be framed in such a way as to gain
the adherence of the largest
possible number and most suitably
balanced range of countries while
permitting timely action to be
taken.
Key issues for negotiation will
include the criteria, timing, legal
form and incidence of any obligations
to control the net emissions of tjtuMnhnigp
gases, how to address equitably the
consequences for all, any institutional
mechanisms that may be required,
the need for research and monitoring,
and in particular, the request of
the developing countries for additional
financial resources and for the transfer
of technology on a preferential basis.
ix
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POLICYMAKERS SUMMARY WG III
Further consideration
The issues, options and
strategies presented in this
document are intended to assist
policymakers and future negotiators
in their respective tasks. Further
consideration of the summary and
the underlying reports of Working
Group III should be given by every
government as they cut across
different sectors in all countries.
It should be noted that the
scientific and technical information
contained in the policymakers summary
and the underlying reports of Working
Group III do not necessarily represent
the official views of all governments,
particularly those that could not
participate fully in all Working
Groups.
-------
POLICYMAKERS SUMMARY WG III
FORMULATION OF RESPONSE STRATEGIES
by Working Group III
1 . SOURCES OF ANTHROPOGENIC
GREENHOUSE GASES
A wide range of human activities
result in the release of greenhouse
gases, particularly C02, CH4/ CFCs
and N2O, into the atmosphere.
Anthropogenic emissions can be
categorized as arising from energy
production and use, non-energy
industrial activities (primarily
the production and use of CFCs),
agricultural systems, and changes
in land-use patterns (including
deforestation and biomass burning).
The relative contributions of these
activities to radiative forcing
during the 1980s are discussed in
the text and shown below in Figure
2 (see Working Group I report for
further explanation of the
radiative forcing of the various
greenhouse gases; see also the
Chairman's introduction regarding
these activities for the
quantitative estimates of their
contributions to radiative
forcing).
IPCC Working Group I calculated
that the observed increases in the
atmospheric concentrations of C02,
CH4, CFCs and N20 during the 1980s,
which resulted from human
activities, contributed to the
enhanced radiative forcing by 56%,
15%, 24% and 5%, respectively.
Energy
The single largest anthropogenic
source of radiative forcing is
energy production and use. The
consumption of energy from fossil
fuels (coal, petroleum and natural
gas excluding fuel wood) for
industrial commercial, residential,
transportation and other purposes
1
results in large emissions of C02
accompanied by much smaller emissions
of CH* from coal mining and the venting
of natural gas; the energy sector
accounts for an estimated 46% (with
an uncertainty range of 38-54%) of
the enhanced radiative farcing resulting
from human activities.
Natural fluxes of C02 into the
atmosphere are large (200 Bt/yr1),
but inputs of man made sources are
large enough to significantly disturb
the atmospheric balance.
Industry
The production and use of CFCs
and other halocarbons in various
industrial processes comprise about
24% of the enhanced radiative forcing.
Forestry
Deforestation, biomass burning
including fuel wood, and other changes
in land-use practices, release C02,
CH4, and N20 into the atmosphere and
together comprise about 18% (with
an uncertainty range of 9-26%) of
the. enhanced radiative forcing.
Agriculture
Methane releases from rice
cultivation and from livestock
systems, and nitrous oxide released
during the use of nitrogenous
fertilizers together comprise about
9% (with an uncertainty range of
4-13%) of the enhanced radiative
forcing.
Other sources
Carbon dioxide from cement
manufacturing and methane from
1 . Billion (or 1000 million) tonnes
per year.
-------
POLXCmNOJlS SUMMARY WG III
ESTIMATED CONTRIBUTION OF DIFFERENT HUMAN ACTIVITIES
TO THE CHANGE IN RADIATIVE FORCING DURING
THE DECADE FROM 1980 TO 1990*
Other (3%)
Agriculture (9%)
Forestry (18%)
Energy (46%)
CFCs (24%)
Figure 2
Percentage* derived from estimated greenhouse gas concentrations
in the atmosphere and the Global Warming Poteo ils of these
greenhouse gases given in the Policymakers Sum* y of Working
Group I on Pages 11 and 12.
-------
POLICYMAKERS SUMMARY WG III
land-fills together comprise about
3% (with an uncertainty range of
1-4%) of the enhanced radiative
forcing.
Estimates of current greenhouse
gas emissions are not precise
because of uncertainties regarding
both total emissions and emissions
from individual sources. Global
emissions from certain sources are
particularly difficult to
determine, e.g., C02 emission from
deforestation, CH4 emission from
rice cultivation, livestock
systems, biomass burning, coal
mining and venting of natural gas,
and N20 emissions from all sources.
The range of such estimates can be
quite large, typically, a factor
of 1.5 for methane from livestock,
a factor of 4 for C02 from
deforestation, and upto a factor
of 7 for rice.
2. FUTURE EMISSIONS OF GREENHOUSE
GASES
Greenhouse gas emissions from
most sources are likely to increase
significantly in the future if no
policy measures are taken. As
economic and population growth
continue, in particular in the
developing countries, there is
expected to be an increase in
energy use, industrial and
agricultural activity,
deforestation, and other activities
which result in a net increase of
greenhouse gas emissions. Although
some controls have been put in
place under the Montreal Protocol
for certain CFCs and halons,
emissions of C02, methane, nitrous
oxide, and other greenhouse gases
are likely to increase under
current patterns of economic
activity and growth.
However, because of-the inherent
limitations in our ability to
estimate future rates of population
and economic growth, etc, there is
some uncertainty in the projections
of greenhouse gas emissions,
individual behaviour, technological
innovation, and other factors whici.
are crucial for determining emission.
rates over the course of the next
century. This lends uncertainty
to projections of greenhouse gas
emissions over several decades or
longer. Reflecting these inherent
difficulties, the RSWG's work o..
emissions scenarios are the best
estimates at this time covering
emissions over the next century but
further work needs to be done.
The RSWG used two methods tc
develop scenarios of future emissions
as discussed in Sections 3.1. ar.c
3.2. One method used global models
to develop four scenarios which were
subsequently used by Working Group
I to develop estimates of future
warming. The second method used
studies of the energy and agriculture
sectors submitted by over 21 countries
and international organizations to
estimate emissions. These latter
studies were aggregated into a
reference scenario. Both approaches
show that emissions of CO2 and CH4
will increase in the future. Both
approaches indicate that OOg emissions
will grow from approximately 7 BtC
to between 11-15 BtC by the year
2025.
2.1 Emissions scenarios
One of the RSWG's first tasks
was to prepare some initial scenarios
of possible future greenhouse gas
emissions for the use of the three
IPCC Working Groups. An experts'
group was formed which looked at
four hypothetical future patterns
of greenhouse gas emissions and their
effect on the atmosphere. The
cumulative effect of these emissions
was calculated using the concept
of equivalent C02 concentrations (e.g.
the contributions of all greenhouse
gases to radiative forcing are
converted into their equivalent in
-------
POLICYMAKERS SUMMARY WG III
terms of C02 concentrations).
Global economic growth rates were
taken from World Bank projections
and population estimates were taken
from UN studies and assumed equal
for all scenarios.
The first of the scenarios,
called the Business-as-Usual or the
2030 High Emissions Scenario,
assumes that few or no steps are
taken to limit greenhouse gas
emissions. Energy use and clearing
of tropical forests continue and
fossil fuels, in particular coal,
remain the world's primary energy
source. The Montreal Protocol
comes into effect but without
strengthening and with less than
100 percent compliance. Under this
scenario, the equivalent of a
doubling of pre-industrial C02
levels occurs, according to Working
Group I, by around 2025.
The predicted anthropogenic
contributions to greenhouse gas
emissions in 2025 are shown in
Table 1. The RSWG attempted to
synthesize and compare the results
of the AFOS/EIS Reference Scenario
and the Task A "Business-as-usual"
(or "2030 High Emissions") Scenario
(see Figure 3). The figure shows
the equivalent C02 concentrations
for the Task A "Business-as-usual"
Scenario and the AFOS/EIS Reference
Scenario with its higher C02
emissions and the CFC phaseout
agreed to by the Parties to the
Montreal Protocol. The results
indicate that the C02 equivalent
concentrations and thus the effect
on the global climate are similar
for both scenarios.
The second of the scenarios, the
2060 Low Emissions Scenario,
assumes that a number of
environmental and economic concerns
result in steps to reduce the
growth of greenhouse gas emissions.
Energy efficiency measures, which
might only be possible with
government intervention, arr
implemented, emissions controls art
adopted globally, and the share of
the world's primary energy provided
by natural gas increases. Full
compliance with the Montreal
Protocol is achieved and tropical
deforestation is halted and reversed.
Under this scenario, the cumulative
effect of such measures is a CDfe equivalent
doubling around 2060.
The remaining two scenarios reflect
futures where steps in addition to
those in the 2060 Low Emissions Scenario
are taken to reduce greenhouse gas
emissions. These steps include rapid
utilization of renewable energy sources,
strengthening of the Montreal Protocol,
and adoption of agricultural policies
to reduce emissions from livestock
systems, rice paddies, and fertilizers.
All of the above scenarios provide
a conceptual basis for considering
possible future patterns of emissions
and the broad responses that might
affect those patterns. However,
they represent assumptions rather
than cases derived from specific
studies. In addition, no full assessment
was made as yet of the total economic
costs and benefits, technological
feasibility, or market potential
of the underlying policy assumptions.
2.2 Reference scenario
Table 2 shows the results of the
EIS Reference Scenario (for CO2
emissions from the energy sector
only) divided by region. The table
is incomplete and does not include
C02 emissions from non-energy
sources nor other greenhouse gases
and sinks. While it is not directly
a measure of a region's climate forcing
contribution, this table does portray
a future where, in the absence of
specific policy measures, global
emissions of one major gas, C02, grow
from 5.15 BtC in 1985, to 7.30 BtC
in 2000 and 12.43 BtC in 2025. Primary
energy demand more than doubles between
-------
POLICYMAKERS SUMMARY NG III
TABLE 1; Anthropogenic Greenhouse Gas Emissions From Working Group III Scenarios
AFOS/EIS Reference Scenario Task A "Business as Usual"
Lfied to include CFC phaseout Scenario
1985 2025 1985 2025
C02 Emissions (BtC)
Energy 5.1 12.4 5.1 9.9
Deforestation 1.73 2.6 0.74 1.4
Cement 0.1 0.2 0.1 0.2
Total 6.9 15.2 5.9 11.5
CH4 Emission (TgCH4)5
Coal Mining 44 126 35 85
Natural Gas 22 59 45 74
Rice 110 149 110 149
Enteric Perm. 75 125 74 125
Animal Wastes 37 59
Landfills 30 60 40 71
Biomass Burning 53 73 53 73
Total 371 651 357 577
N20 (TgN)5 4.6 8.7 4.4 8.3
CO (TgC)% 473 820 443 682
NOR (TgN)5 38 69 29 47
CFCs (Gg)
CFC-11 278 11 278 245
CFC-12 362 10 362 303
HCFC-22 97 1572 97 1340
CFC-113 151 0 151 122
CFC-114 15 0 15 9
CFC-115 50 55
CC14 87 110 87 300
CH3CC13 814 664 814 1841
Halon 1301 2.1 1.8 2.1 7.4
The estimates for emissions of CFCs in 1985 and 2025 reflect
the decisions taken at the meeting of the Parties to the Montreal
Protocol in London in June 1990. At that meeting, the parties
agreed to accelerate the phase out of the production and consumption
of CFCs, halons, carbon tetrachloride and methyl chloroform.
3 Midrange estimates for deforestation and biomass consistent
with preferred value from Working Group I.
4 Assuming low biomass per hectare and deforestation rates.
5 Differences in the 1985 emissions figures are due to differences
in definitions and qualifying the emissions from these particular
sources.
-------
EIS/AFOS Reference Scenario-Task A: Business as Usual
CO2 Equivalent Concentrations
(ppm)
1.400
1.200
1.000
800
600
400
200
EJS/Af OS 1 teleieiice Scenaiio
TASK A: BUSINESS AS USUAL SCENARIO
I
2000
2020
I
2O40
Figure 3.
I
206O
201)0
2100
o
i/i
ui
I
H
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POLICYMAKERS SUMMARY NG III
1985 and 2025, an average annual
growth rate of 2.1%.
The annual rate of growth in
CO2 emissions varies between 0.7%
in Western Europe, 1.3% in North
America and the Pacific OECD
Countries, and 3.6% in developing
countries. The share of emissions
between regions varies over time.
Under this scenario, the per
capita emissions in the
industrialized countries increase
from 3.1 tonnes carbon (TC) per
capita in 1985 to 4.7 TC per capita
in 2025. For the developing
countries, the per capita emissions
rise from 0.4 TC per capita in 1985
to 0.8 TC per capita in 2025.
The Reference Scenario sets out
an example of the scope of the
reductions in total global
emissions which might be necessary
to stabilize or reduce C02
emissions. The stabilization of
global emissions at 1985 levels
would require reductions of 29% by
2000 and 59% by 2025. A reduction
of global emissions to 20% below
1985 levels would require
reductions of 44% in 2000 and 67%
by 2025.
The carbon intensity figures
show, for each region, the amount
of carbon emitted per unit of
energy consumed. The contribution
of energy consumption in a region
to global wanning is largely a
function of its carbon intensity,
total fuel use, and of the
efficiency with which it consumes
fossil fuels. Carbon intensity for
industrialized countries changes
from 16.3 tonnes carbon per
gigajoule (TC-GJ) in 1985 to 15.5
in 2025. In the developing world
the change .is from 14.2 TC-GJ to
15.6.
3. RESPONSE STRATEGIES FOR ADDRESSING
GLOBAL CLIMATE CHANGE
Because climate change could
potentially result in significant
impacts on the global environment
and human activities, it is important
to begin considering now what measures
might be taken in response. Working
Group 1 found that under a "Business-
as-Usual" scenario global average
temperature could rise by 0.3 degrees
centigrade per decade; it also found
that under the Accelerated Control
Policies Scenario (scenario D) with
extremely stringent emissions reductions
the temperature rise could perhaps
be reduced to 0.1 degree centigrade
per decade. The RSWG identified
a wide range of options for the
international community to consider.
These include measures both to limit
net greenhouse gas emissions and
to increase the ability of society
and managed ecosystems to adapt to
a changing climate.
Strategies which focus only on
one group of emission sources, one
type of abatement option or one particular
greenhouse gas will not achieve this.
Policy responses should, therefore,
be balanced against alternative abatement
options among the energy, industry,
forestry and agricultural sectors,
and adaptation options and other
policy goals where applicable at
both national and international levels.
Ways should be sought to account
foe oth&x1 oountxi.es, and intergenerational
issues, when making policy decisions.
The consideration of climate
change response strategies, however,
presents formidable difficulties
for policymakers. On the one hand,
the information available to make
sound policy analyses is inadequate
because of: (a) remaining scientific
uncertainties regarding the magnitude,
timing, rate, and regional consequences
of potential climate change; (b)
uncertainty with respect to how effective
specific response options or groups
-------
POLICYMAKERS SUMMARY NG III
TABLE 2
GROSS C02 EMISSIONS FROM THE ENERGY SECTOR*
(From the Reference Scenario)
C02 Emissions in the Reference Scenario (billion tonnes carbon/year)
Global Totals
Industrialized
North America
Western Europe
OECD Pacific
Centrally Planned Europe
Developing
Africa
Centrally Planned Asia
Latin America
Middle East
South and East Asia
1985
5.15
3.83
1 .34
0.85
0.31
1 .33
%
(100)
(74)
(26)
(16)
(6)
(26)
2000
7.30
4.95
1 .71
0.98
0.48
1 .78
%
(100)
(68)
(23)
(13)
(7)
(24)
1.33 (26) 2.35
0.17
0.54
0.22
0.13
0.27
(3)
(10)
(4)
(3)
(5)
0.28
0.88
0.31
0.31
0.56
(32)
(4)
(12)
(4)
(4)
(8)
Global Totals
Industrialized
North America
Western Europe
OECD Pacific
Non OECD Europe
Developing
Africa
Centrally Planned Asia
Latin America
Middle East
South and East Asia
1985
PC** CI***
1.06 15.7
3.12 16.3
5.08 15.7
2.14 15.6
2.14 16.1
3.19 17.5
0.36 14.2
2000
PC. SI
1.22 15.8
3.65 16.1
5.75
2.29
3.01
3.78
15.8
15.1
16.1
16.9
0.51 15.2
0,
0,
0,
1 ,
29
47
55
20
12.
17.
11 .
16.
0,
0,
0,
1,
32
68
61
79
13.
18.
11.
16.
0.19 12.3
0.32 14.3
2025
12.43
6.95
2.37
1.19
0.62
2.77
%
(100)
(56)
(19)
(10)
(5)
(22)
5.48 (44)
0.80
1 .80
0.65
0.67
1 .55
(6)
(14)
(5)
(5)
(12)
2025
££ CI
1.56 16.0
4.65 16.0
7.12 16.6
2.69 14.6
3.68 14.8
5.02 16.4
0.84 16.0
0,
1,
0.
2,
54
15
91
41
15.
19.
11.
15,
0.64 15.6
**
***
This table presents regional CO2 emissions and does not include
CFCs, CH4, 03, N20, or sinks. Climate change critically depends
on all GHG from all economic sectors. This table should be interpreted
with care.
PC - Per capita carbon emissions in tonnes \rbon per person.
CI - Carbon Intensity in kilograms carbon p,-,.: gigajoule.
8
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POLICYMAKERS SUMMARY WG III
of options would be in actually
averting potential climate change;
and (c) uncertainty with respect
to the costs, effects on economic
growth, and other economic and
social implications of specific
response options or groupsof
options. The potentially serious
consequences of climate change on
the global environment, however,
give sufficient reasons to begin
by adopting response strategies
that can be justified immediately
even in the face of such
significant uncertainties.
Recognizing these factors, a
large number of options were
preliminarily assessed. It appears
that some of these options may be
economically and socially feasible
for implementation in the near-term
while others, because they are not
yet technically or economically
viable, may be more appropriate for
implementation in the longer-term.
In general, the RSWG found that the
most effective response strategies,
especially in the short-term, are
those which are:
- beneficial for reasons other
than climate change and
justifiable in their own right,
for example increased energy
efficiency and lower greenhouse
gas emission technologies, better
management of forests and other
natural resources, and reductions
in emissions of CFCs and other
ozone depleting substances that
are also radiatively important
gases;
- economically efficient and cost
effective, in particular those
that use market-based mechanisms;
- able to serve multiple social,
economic, and environmental
purposes;
- flexible and phased, so that
they can be easily modified to
respond to increased understanding
of scientific, technological and
economic aspects of climate change;
economic growth and the concept
of sustainable development;
administratively practical and
effective in terms of application,
monitoring, and enforcement; and
reflecting obligations of both
industrialized and developing
countries in addressing this issue,
while recognizing the special
needs of developing countries,
in particular in the areas of
financing and technology.
The degree to which options are
viable will also vary considerably
depending on the region or country
involved. For each country, the
implications of specific options
will depend on its social,
environmental, and economic context.
Only through careful analysis of
all available options will it be
possible to determine which are best
suited to the circumstances of a
particular country or region.
Initially, the highest priority should
be to review existing policies with
a view to minimizing conflicts with
the goals of climate change strategies.
New policies will be required.
4. OPTIONS FOR LIMITING GREENHOUSE
GAS EMISSIONS
The RSWG reviewed potential
measures for mitigating climate
change by limiting net emissions
of greenhouse gases from the energy,
industry, transportation, housing
and building, forestry, agriculture,
and other sectors. These measures
include those which limit emissions
from greenhouse gas sources (such
as energy production and use), those
which increase the use of natural
sinks (such as immature forests and
other biomass) for sequestering
greenhouse gases, as well as those
measures aimed at protecting reservoirs
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POLICYMAKERS SUMMARY NG III
such as existing forests. While
RSWG was not mandated to consider
the role of the oceans, Working
Group I noted that oceans also play
an equally important role as sinks
and reservoirs for carbon dioxide.
A discussion of both short and
long-term options for each major
emissions sector is provided below.
It also should be recognized
that the large, projected increase
in the world population, to as much
as ten billion people during the
next century, will be a major
factor in causing the projected
increase in global greenhouse
gases. This is because larger
populations will be accompanied by
increased consumption of energy and
of food, more land clearing, and
other activities, all of which will
cause an increase in net greenhouse
gas emission. It is essential,
therefore, that policies designed
to deal effectively with the issue
of potential global climate change
include strategies and measures to
reduce the rate of growth of the
world population.
4.1
Limitation of net
from the energy sector
The energy sector plays a vitally
important role in economic
well-being and development for all
nations. At the same time, because
energy production and use accounts
for approximately one half of the
radiative forcing from human
activities, energy policies need
to ensure that continued economic
growth occurs in a manner that,
globally, conserves the environment
for future generations. However,
there is no single, quick-fix
technological option for limiting
greenhouse gas emissions from
energy sources. A comprehensive
strategy is necessary which deals
with improving efficiency on both
the demand and supply sides as a
priority and emphasizes
technological research, development,
and deployment.
The RSWG recognizes the particular
difficulties which will be faced
by countries, particularly developing
countries, whose economy is heavily
dependent on the production and/or
export of fossil fuels, as a consequence
of actions taken by other countries
to limit or reduce energy related
greenhouse gas emissions. These
difficulties should be taken into
account when elaborating international
strategies.
Various potential options have
been identified for reducing
greenhouse gas emissions from energy
systems. The most relevant
categories of options appear to be:
efficiency improvements and
conservation in energy supply,
conversion, and end use;
fuel substitution by energy sources
which have lower or no greenhouse
gas emissions;
reduction of greenhouse gas
emissions by removal, T»*riTT*ii.aHffn
or fixation;
management and behavioral changes
(e.g. increased work in homes
through information technology)
and structural changes (e.g. modal
shift in transport).
Fran an analysis of the technologies
in these categories, it appears that
some technologies are available now
or in the short-term while others
need further development to lower
costs or to improve their environmental
characteristics.
Tables 3 and 4 provide various
examples of technological options
within each of the broad categories
defined above, and their possible
application in the short, medium,
and longer-term. This distinction
10
-------
TABLE 3
Examples of Shorl-Term Options
I. IMPROVE EFFICIENCY IN THE PRODUCTION. CONVERSION AND USE OF ENERGY
Electricity Generation
Industry Sector
Transport Sector
Building Sector
Improved efficiency in
spowering of existing
racifities With high
efficiency systems;
Introduction of
integrated gasification
combined cycle systems!
Introduction of
atmospheric fluidised
bful combustion;
Introduction of
pressurised fluidised bed
combustion with
combined cycle power
systems;
Improvement of boiler
efficiency.
Improved system for co-
generation of electricity and
operation and
Introduction of pbMovoliaics.
especially for local electricity
generation.
Introduction of fuel cells.
Promotion of further
efficiency improvements in
production pcoccssi
Materials recycling
(particularly energy-
intensive materials);
Substitution with lower
energy intensity materials;
Improved electromechanical
drives and motors;
Thermal process
optimisation, including
energy cascading and co-
nation.
I operation and
generaiiof
Improved
Improved fuel efficiency of
road vehicles;
Electronic engine
management and
transmission control
systems;
advanced vehicle
design; reduced size
and weight, with use
of lightweight
composite materials
and suuctural
ceramics; improved
aerodynamics,
combustion chamber
components, better
lubricants and lyre
design, etc.).
regular vehicle
maintenance*
higher capacity
trucks;
improved efficiency
in transport facilities;
regenerating units;
Technology development in
public transportation;
Intra-ciiy modal shift
(e.g. car to bus or
metro);
advanced train
control system to
increase traffic
density on urban rail
lines;
High-speed inter-city
trains;
Better intermodal
integration.
Driver behaviour, traffic
management, and vehicle
maintenance.
Improved healing and cooling
equipment and systems;
Improvement of energy
efficiency of air
conditioning;
Promotion of
introduction of area
heating and cooling
including use of heat
punipsi
Improved burner
efficiency;
Use of neat pumps in
buildings;
Use of advanced
electronic energy
management control
systems.
Improved space conditioning
efficiency in house/building;
Improved heal efficiency
through highly efficient
insulating materials;
Better building design
(orientation, window,
building, envelope, etc.);
Improved air-to-air heal
exchangers.
Improved lighting efficiency.
Improved appliance efficiency.
Improved operation and
maintenance.
Improved efficiency of cook
stoves (in developing
countries).
-------
TABLE 3 (CONTINUED)
II. NON FOSSIL AND LOW EMISSION ENERGY SOURCES
Electricity Generation
Other Sectors
Construction of small-scale and large-scale hydro projects;
Expansion of conventional nuclear power plants;
Consiniciion of gas-fired power plants;
Standardised design of nuclear power plants to improve economics
and safely;
Development of geothermal energy projects;
Introduction of wind turbines;
Expansion of sustainable biomass combustion.
Replacement of scrubbers and other energy consuming control technology
with more energy efficient emission control.
Substitution of natural gas and biomass for healing oil and coal;
Solar healing.
Technologies for producing and utilising alternative fuels;
Improved storage and combustion systems for natural gas;
introduction of flexible-fuel and alcohol fuel vehicles.
III. REMOVAL. RECIRCULATION OR FIXATION
Energy/Industry
Landfills
Recovery and use of leaked or released CH4 from fossil fuel storage, coal
mining;
Improved maintenance of oil and natural gas and oil production and
distribution systems to reduce CH4 leakage;
Improved emission control of CO. SO,. NO. and VOCs to protect sinks of
greenhouse gases.
Recycle and incineration of waste materials to reduce CH4 emissions;
Use or flaring of CH4 emissions;
Improved maintenance of landfill to decrease CH4 emissions
-------
TABLE 4
Examples of Medium-/Long-Tcrm Options
I. IMPROVE EFFICIENCY IN THE PRODUCTION. CONVERSION AND HIE USE OF ENERGY
Electricity Generation
Industry Sector
Transport Sector
Building Sector
Advanced technologies for
storage of intermittent energy;
Advanced batteries;
Compressed air energy storage;
Superconducting energy storage;
Increased use of less
energy-intensive materials;
Advanced process
technologies:
Use of biological
i in
! process energy
conversion;
Use of fuel cells for co-
generation.
Improved fuel efficiency of
road vehicles;
Improvements in aircraft
and ship design:
Advanced propulsion
concepts;
Ultra high bypass
aircraft engines;
Contra-routing ship
propulsion.
Improved energy storage
systems;
Use of information
technology to anticipate
and satisfy energy
needs;
Use of hydrogen to
store energy for use in
buildings.
Improved building systems;
New Building materials
for belter insulation at
reduced cost;
Windows which adjust
opacity to maximise
solar gain.
New food storage systems
which eliminate refrigeration
requirements.
H
-------
TABLE 4 (CONTINUED)
III NON FOSSIL AND LOW EMISSION ENERGY SOURCES
Electricity Generation
Other Sectors
Nuclear power plants:
Passive safely features to improve reliability and acceptability.
Solar power technologies:
Solar thermal;
Solar photovoltaic (especially lor local electricity generation).
Advanced fuel cell technologies.
Other technologies for producing and utilising alternative fuels;
Improved storage and combustion systems for hydrogen;
Control of gases boiled off from cryogenic fuels;
Improvements in performance of metal hydrides:
High-yield processes to convert lingp-ceUulosic btomass into
alcohol fuels;
Introduction of electric and hybrid vehicles:
Reduced re-charging lime for advanced batteries.
III. REMOVAL. RECIRCULATION OR FIXATION
Improved combustion conditions to reduce N2O emissions.
Treatment of exhaust gas to reduce NjO emissions.
CO, separation and geological and marine disposal.
-------
POLICYMAKERS SUMMARY WG III
among time frames is used in order
to reflect the remaining
technological needs in each
category and to assist in
formulating technological
strategies. Short-term
technologies are those which
apparently are orwill be both
technically and economically ready
for introduction and/or
demonstration up to the year 2005
and beyond. Mid-term technologies
are those which, while technically
available now, are not yet economic
and thus may not be implemented
until the period from 2005 to 2030.
Longer-term technologies are not
yet available but may emerge after
2030 as a result of research and
development. Such time frames
could be influenced by such factors
as the pace of the technological
changes and economic conditions.
The technical, economic, and
market potential of technological
options will vary depending upon
the sector in which they are to be
applied. The technical potential
of an energy technology is its
capacity to reduce potential
emissions, irrespective of the
costs involved, and is largely a
function of technical feasibility
and resource availability.
Economic potential refers to
whether the application of the
options is economically efficient
and cost-effective - it may be
significantly less than technical
potential where there are positive
resource costs. Market potential
refers to whether the consumer or
user is likely to adopt the option
- it might be even less than
economic potential due to market
imperfections, attitudes to risk,
and the presence of non-monetary
costs.
There is, in general, extensive
information available on the
technical potential of the many
technological options listed. For
example:
in the Transportation sector,
vehicle efficiency improvements
have very high technical
potential (e.g. 50 percent
improvement from the average
vehicle on the road in some
countries);
in the Electricity Generation
sector, efficiency improvements
of 15 to 20 percent could be
achieved for retrofits of coal
plants and up to 65 percent for
new generation versus average
existing coal plants; fuel
substitution could achieve 30
percent (for oil to natural gas)
to 40 percent (for coal to
natural gas) reduction in
emissions of C02;
in the Buildings sector, new
homes could be roughly twice as
energy efficient and new
commercial buildings up to 75
percent as energy efficient as
existing buildings; retrofitting
existing homes could average 25
percent improvement and existing
commercial buildings around fifty
percent;
in the Industry sector, the
technical potential for efficiency
improvements ranges from around
15 percent in some sub-sectors
to over 40 percent in others (i.e.
the best available technology
versus the stock average).
The constraints to achieving the
technical potential in these sectors
can be generally categorized as:
capital costs of more efficient
technologies vis-a-vis the cost
of energy;
relative prices of fuels (for
fuel substitution);
lack of infrastructure;
15
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POLICYMAKERS SUMMARY WG III
- remaining performance drawbacks
of alternative technologies;
- replacement rates;
- reaching the large number of
individual decision-makers
involved.
Each of these constraints may
be more or less significant
depending on the sector in
question. While not a constraint,
behavioral changes (e.g., improved
driver behaviour, better vehicle
maintenance and turning off unused
lights) can make significant
contributions to emissions
reduction in all sectors.
Achieving such changes requires the
engagement of both the energy
supplier and the consumer.
Likewise, improvements in
operational practices on the part
of industry and government (e.g.
better traffic management or boiler
operation) offer significant
potential but require increased
attention. Transport and housing
policies (e.g. promotion of public
transport, home insulation) could
also reduce greenhouse gas
emissions. A more comprehensive
assessment of the measures to
overcome these constraints is
contained in section 8 of this
report.
Factors external to the energy
sector also significantly constrain
potential. These include the
difficulty of:
- making basic changes in the
structure of economies (e.g.
development of new transportation
and housing infrastructure);
- making fundamental changes in
attitudinal and social factors
(e.g. preferences for smaller
and higher efficiency vehicles).
The challenge to policymakers
is to enhance the market uptake
of technological options and behavioral
and operational changes as well as
to address the broader issues outside
the energy sector in order to capture
more of the potential that exists.
Options and strategies
Tables 3 and 4 summarize the
technological, regulatory, and
institutional approaches which
could form elements of strategies
to control greenhouse gases.
A list of options recommended
by EIS as measures for addressing
greenhouse gas emissions is given
below. Countries are encouraged
to evaluate the social, economic
and environmental consequences of
these options.
taking steps now6 to attempt to
limit, stabilize or reduce the
emission of energy related
greenhouse gases and prevent ~ le
destruction and improve tiie
effectiveness of sinks. One
option that governments may wish
to consider is the setting of
targets for CO2 and other
greenhouse gases;
adopting a flexible progressive
approach, based on the best
available scientific, economic
and technological knowledge, to
action needed to respond to
climate change;
drawing up specific policies and
implementing wide-ranging
comprehensive programmes which
cover all energy-related
greenhouse gases;
6. There was significant concern expressed
at the RStiG meeting about the immediacy
implied by the word now in option one,
uhen implementation could only be considered
at a rate consistent with countries' level
of knowledge and particular circumstances.
16
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POLICYMAKERS SUMMARY WG III
- starting with implementing
strategies which have multiple
social, economic and environmen-
tal benefits, are cost effective,
are compatible with sustainable
development and make use of ma-
rket forces in the best way po-
ssible;
- intensifying international,
multilateral and bilateral co-
operation in developing new
energy strategies to cope with
climate change. In this context,
industrialized countries are
encouraged to promote the
development and the transfer of
energy efficient and clean
technologies to other countries;
- increasing public awareness of
the need for external
environmental costs to be
reflected in energy prices,
markets and policy decisions to
the extent that they can be
determined;
- increasing public awareness of
energy efficiency technologies
and products and alternatives,
through public education and
information (e.g. labelling);
- strengthening research and
development and international
collaboration in energy
technologies, and economic and
energy policy analysis, which
are relevant for climate change;
- encouraging the participation
of industry, the general public,
and NGOs in the development and
implementation of strategies to
limit greenhouse gas emissions.
Short-term strategy options
Short-term strategies for all
individual nations include:
- improving diffusion of energy
efficient and alternate energy
technologies which are technically
and commercially proven;
improving energy efficiency of
mass produced goods including
motor vehicles and electrical
appliances and equipment and
buildings (e.g., through improved
standards);
developing, diffusing and
transferring technologies to
limit energy related greenhouse
gas emissions;
reviewing energy-related price
and tariff systems and policy
decisions on energy planning to
better reflect environmental
costs.
Long-term strategy options
Over the longer term, sustainable
development will remain a central
theme of policies and strategies.
Specific approaches within a
sustainable development policy
framework will evolve as our
understanding of climate change and
its implications improves.
Long-term strategies for all
individual nations include:
accelerating work to improve the
long-term potential of efficiency
in the production and use of
energy; encouraging a relatively
greater reliance on no or lower
greenhouse gas emissions energy
sources and technologies; and
enhancing natural and man-made
means to sequester greenhouse
gases;
further reviewing, developing
and deploying policy instruments,
which may include public
information, standards, taxes
and incentives, tradeable
permits, and environmental impact
assessments, which will induce
sustainable energy choices by
17
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POLICYMAKERS SUMMARY WG III
producers and consumers without
jeopardizing energy security and
economic growth;
- developing methodologies "O
evaluate the trade off betwe;n
limitation and adaptation
strategies and establishing
changes in infrastructure (e.g.
pipelines, electrical grids,
dams) needed to limit or adapt
to climate change.
4.2 Limitation of net emissions
from the industry sector
The most significant source of
greenhouse gases associated with
industrial activity not related to
energy use is the production and
use of CFCs and other halocarbons.
CFCs represent a very important
source of greenhouse gas emissions
and account for about 24% of the
total contributions to the enhanced
radiative forcing for the period
of the 1980s. While the RSWG did
not consider control strategies for
these gases since the -ssue is
already addressed c ir the
Montreal Protocol on .. .stances
that Deplete the Ozone Layer, it
noted that the review of the
Montreal Protocol now underway
should take into account the global
warming potential of potential CFC
substitutes.
The RSWG did develop future
emission scenarios for CFCs and
HCFC-22 (HCFC-22 was used as a
surrogate for a potential mix of
HCFCs and MFCs substitutes). T..e
potential impact of such
substitutes on radiative forcing
was assessed by Working Group I.
For a given emission rate, HCFCs
and MFCs are less effective
greenhouse gases than the CFCs
because of their shorter lifetimes.
The growth rates assumed in the
ZPCC scenarios will result in the
atmospheric concentrations of HFCs
and HCFCs becoming comparable to
the CFCs during the next several
decades assuming that the CFCs had
continued to be used at current
rates. Assuming the IPCC scenarios
for HFCs and HCFCs, Working Group
I calculated that these gases would
contribute up to 10% of the total
additional radiative forcing for
the period 2000-2050.
4.3 Limitation of net emissions
from the agriculture sector
About 9 percent of anthropogenic
greenhouse gas emissions can be
attributed to the agricultural
sector, in particular livestock
systems, rice cultivation, and the
use of nitrogenous fertilizers.
Limitation of emissions from this
sector presents a challenge because
the processes by which greenhouse
gases, in particular methane and
nitrous oxide, are released in
agricultural activities are not
well understood. In addition,
response options in the agricultural
sector must be designed to ensure
maintenance of food supply. There
appear, however, to be a number of
short-term response options, some
economically beneficial in their
own right, which could contribute
to a limitation of net emissions
from agricultural sources. Where
appropriate the removal of subsidies,
incentives and regulatory barriers
that encourage greenhouse gas emissions
from the agricultural sector would
be both environmentally and economically
beneficial. In addition, there are
a number of promising technologies
and practices which, in the longer
term, could significantly reduce
greenhouse gas emissions.
Short-term options;
Livestock systems; Methane
emissions could be reduced
through improved management of
livestock wastes, expansion of
supplemental feeding practices,
and increased use of production
18
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POLICYMAKERS SUMMARY WG III
and growth enhancing agents with
safeguards for human health.
Fertilizer use; Nitrous oxide
emissions may be reduced by using
existing improved fertilizer
formulations, judicious use of
animal manures and compost/ and
improved application technology
and practices.
Marginal lands: Areas marginally
suitable for annual cropping
systems may be shifted to
perennial cover crops for fodder,
pastoral land uses or forests
if soils are suitable. Such
actions would increase carbon
uptake, both in the vegetation
and soil, and would yield other
benefits.
Sustainable
agricultural
practices; where possible,
minimum or no-till systems should
be introduced for those countries
currently using tillage as part
of the annual cropping sequence,
thus maintaining and increasing
soil organic matter.
Longer-term options;
Rice cultivation; A comprehensive
approach, including management
of water regimes, improvement
of cultivars, efficient use of
fertilizers, and other management
practices, could lead to a 10
to 30 percent reduction in
methane emissions from flooded
rice cultivation although
substantial research is necessary
to develop and demonstrate these
practices. It is estimated that
at least 20 years would be needed
to introduce such practices.
Adaptable alternative crops
research is needed to provide
a more diverse crop base for rice
growing regions.
Livestock; Through a number of
technologies it appears that
methane emissions may be reduced
from livestock systems by up to
25 - 75 percent per unit of
product in dairy and meat
production, although many
uncertainties exist.
Fertilizers: Fertilizer-derived
emissions of nitrous oxide
potentially can be reduced
(although to what extent is
uncertain) through changes in
practices such as using
fertilizers with controlled
nitrogen conversion rates,
improving fertilizer-use
efficiency, and adopting
alternative agricultural systems
where possible.
Desertification; Enhanced
research on control measures.
4.4 Limitation of net emissions
from for*»
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POLICYMAKERS SUMMARY NG III
from these sectors have been
identified.
Short-term options;
1 . Improvement of forest-management
and reduction of deforestation and
forest degradation which should be
supported by:
- reduction of air pollution which
contributes to forest
degradation;
- elimination of inappropriate
economic incentives and subsidies
that contribute to forest loss,
where appropriate;
- integration of forest
conservation requirements and
sustainable development in all
relevant sectors of national
development planning and policy
taking account of the interests
of local communities;
- co-ordinated remote sensing,
data collection and analyses to
provide the required data;
- a meeting of interested countries
from the developing and the
industrialized worlds and of
appropriate international
agencies to identify possible
key elements of a world forest
conservation protocol in the
context of a climate convention
process that also addresses
energy supply and use, and
practical means of implementing
it. Such a meeting should also
develop a framework and
methodology for analysing the
feasibility of the Noordwijk
remit including alternative
targets, as well as the full
range of costs and benefits;
- strengthening Tropical Forestry
Action Plan (TFAP) and in the
light of the independent review
which is being undertaken, the
International Tropical Timbe-
Organization (ITTO), and othei
international organizations whose
objective is to help developing
countries in achieving
conservation, and sustainable
development and management of
forests;
an assessment of incentives and
disincentives for sustainable
forest management, for example,
the feasibility of labelling;
introduction of sustainable
forest harvesting and management;
development of enhanced
regeneration methods;
development and implementation
of (large-scale) national
afforestation and forest
conservation plans, where
feasible.
2. Where appropriate expand forest-
areas, especially by afforestation.
agroforestry and regreening of
available surplus agricultural,
urban and marginal lands.
3. Where appropriate strengthen and
improve the use of forest products
and wood through measures such as
substituting a portion of fossil
energy sources by wood or other
sustainable managed biomass; partial
replacement of high energy input
materials by wood; further recycling
of forest products; and, improved
efficiency of use of fuel wood.
4. Development of methane recovery
systems for landfill and waste
water treatment facilities and
their use, in particular, in
industrialized countries.
Longer-term options;
1. Maintain the health and the
continuance of existing forests as
major natural carbon reservoirs,
20
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POLICYMAKERS SUMMARY WG III
especially through the development
and implementation of
- silvicultural adjustment and
stress management strategies;
- special forest protection
strategies (developed under
climate change scenarios);
- environmentally sound treatment
practices for peatlands;
- standardisation of methods of
forest inventory and bio-
monitoring to facilitate global
forest management.
2. Expand forest biomass, especially
of intensively managed temperate
forests, by silviculture measures
and genetically improved trees.
3. With regard to waste management,
use of gas collection and flaring
to reduce methane emissions from
landfills and development of biogas
plants to reduce methane emissions
from wastewater treatment.
Demonstration, training and
technology transfer are necessary
to realise these potentials, which
may range from 30 to 90 percent for
landfills and up to 100 percent for
wastewater treatment.
5. FURTHER WORK ON GREENHOUSE GAS
EMISSION LIMITATION GOALS
There has been considerable
international discussion of targets
for specific greenhouse gas
emissions, in particular, C02, which
is the most abundant of the
greenhouse gases. The final
declaration at the November 1989
Noordwijk Conference on Atmospheric
Pollution and Climate Change
encouraged -the IPCC to include in
its First Assessment Report an
analysis of quantitative targets
to limit or reduce C02 emissions,
and urged all industrialized
countries to investigate the
feasibility of achieving such
targets, including, for example,
a 20 percent reduction of C02
emissions by the year 2005. The
Conference also called for assessing
the feasibility of increasing net
global forest growth by 12 million
hectares per year. During its
Third Plenary, the IPCC accepted
the mandate.
Although the feasibility of
quantitative targets on greenhouse
gas emissions fell within the
RSWG's original mandate through its
Energy and Industry Subgroup (EIS),
it was agreed that these new,
specific tasks would require more
time, data and analyses in order
to be dealt with properly. It was
decided, therefore, that the results
of the deliberations of the EIS on
these remits could not be fully included
in its report, but only treated in
an incomplete and preliminary way.
A progress report is to be presented
to the Fourth IPCC Plenary following
an international workshop to be hosted
by the United Kingdom in June 1990.
As for the Noordwijk remit on
global forest growth, the RSWG
through its Agriculture, Forestry
and Other Human Activities Subgroup
(AFOS) noted that a framework and
methodology for analyzing its
feasibility should be developed.
While the technical potential
of a number of options has been
demonstrated, there is very little
information available on the actual
economic and social feasibility
associated with implementation of
such options. An adequate
understanding of the benefits, in
terms of changes in climate variables
that are avoided, is also seriously
lacking. It is imperative that further
work on the cost and benefit implications
of response strategies be undertaken.
These issues have been identified
as one of the most important areas
for future research by the RSWG,
21
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POLICYMAKERS SUMMARY WG III
concerned international
organizations, and individual
countries.
The material available to the
EIS demonstrates the important role
emissions of industrialized
countries play in total global
emissions in the near term. The
material also indicates that the
technical potential for reduction
is large, and differs greatly
between regions and countries.
Therefore, in the near term, no
significant progress in limiting
global emissions will occur without
actions by the industrialized
countries. Some countries have
already decided to stabilize or
reduce their emissions.
6. MEASURES FOR ADAPTING TO GLOBAL
CLIMATE CHANGE
In addition to the limitation
options discussed above, the RSWG
reviewed measures for adapting to
potential climate change. The
consideration of adaptation options
is critical for a number of
reasons. First, because it is
believed that there is likely to
be a lag time between emissions and
subsequent climate change, the
climate may already be committed
to a certain degree of change.
Implementation of adaptation
measures may thus be necessary
regardless of any limitation
actions which may be taken.
Secondly, natural climatic
variability itself necessitates
adaptation.
Furthermore, should significant
adverse climate change occur, it
would be necessary to consider
limitation and adaptation
strategies as part of an integrated
package in which policies adopted
in the two areas complement each
other so as to minimize costs.
Limitation and adaptation options
should be developed and analyzed
recognizing the relationship betweer
the timing and costs of limitation
and adaptation. For example, the
more net emissions are reduced and
the rate of climate change potentially
slowed, the easier it would be to
adapt. A truly comprehensive approach
should recognize that controlling
the different gases might have different
effects on the adaptive capacity
of natural resources.
The RSWG explored two broad
categories of adaptation options:
o Coastal zone management, or
options which maximize the
ability of coastal regions to
adapt to the projected sea level
rise and to reduce vulnerability
to storms; and
o Resource use and management, or
options which address the
potential impacts of global
climate change on food security,
water availability, natural and
managed ecosystems, land, and
biodiversity.
6.1 Coastal zone management
Under the 2030 high emissions
scenario, global climate change
is predicted to raise global mean
sea level 65 cm (with an uncertainty
range of 30 to 100 cm) by the year
2100. If sea level rises by 1 metre,
hundreds of thousands of square lei 1< imLms
of coastal wetlands and other lowlands
could be inundated, while ocean
beaches could erode as much as a
few hundred metres over the next
century. Flooding would threaten
lives, agriculture, livestock, and
structures, while saltwater would
advance inland into aquifers,
estuaries, and soils, thus threatening
water supplies and agriculture in
some areas. Loss of coastal ecosystems
would threaten fishery resources.
Seme nations would be particularly
vulnerable to such changes. Eight
22
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POLICYMAKERS SUMMARY WG III
to ten million people live within
one metre of high tide in each of
the unprotected river deltas of
Bangladesh, Egypt, and Vietnam.
Half a million people live in coral
atoll nations that lie almost
entirely within three metres of sea
level, such as the Maldives, the
Marshall Islands, Tuvalu, Kiribati,
and Tokelau. Other states with
coastal areas, archipelagos and
island nations in the Pacific and
Indian Oceans and the Caribbean
could lose much of their beaches
and arable lands, which would cause
severe economic and social
disruption.
Available responses to sea level
rise fall broadly into three
categories:
o Retreat; Under this option no
actions would be taken to protect
the land from the sea - the focus
would instead be on providing
for people and ecosystems to
shift landward in an optimal
fashion. This choice could be
motivated by either excessive
costs of protection or by a
desire to maintain ecosystems.
o Accommodation; Under this
strategy, while no attempt would
be made to protect the land at
risk, measures would be taken
to allow for continued habitation
of the area. Specific responses
under this options would include
erecting flood shelters,
elevating buildings on pilings,
converting agriculture to fish
farming, or growing flood- or
salt-tolerant species.
o Protection: A protection
strategy uses site-specific
features such as sea walls,
dikes, dunes, and vegetation to
protect the land from the sea
so that existing land uses can
be retained.
There are various environmental,
economic, social, cultural, legal,
institutional and technological
implications for each of these
options. Retreat could lead to a
loss of property, potentially
costly resettlement of populations,
and, in some notable cases, refugee
problems. Accommodation could
result in declining property values,
and costs for modifying infrastructure.
Protecting existing development from
a one metre sea level rise would
require about 360,000 kilometres
of coastal defences at a total cost
of US$ 500 billion, over the next
100 years. The annual cost of protection
represents, on average, 0.04 percent
of total gross national product (GNP),
and ranges from zero to 20 percent
for individual countries. The estimate
is not discounted and does not reflect
present coastal defence needs or
impacts of salt water intrusion or
flooding of unprotected lands.
Further, the protection could have
negative impacts on fisheries,
wildlife and recreation. The loss
of traditional environments could
potentially disrupt family life and
create social instability.
Actions to prepare for possible sea
level rise
A number of response options are
available which not only enhance
the ability of coastal nations to
adapt to sea level rise, but are
also beneficial in their own right.
Implementation of such options
would be most effective if undertaken
in the short-term, not because there
is an impending catastrophe, but
because there are opportunities to
avoid adverse impacts by acting now
- opportunities which may not be
as effective if the process is
delayed. These options include:
National coastal planning:
o Development and implementation
in the short term of comprehensive
23
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national coastal zone management
plans which (a) deal with both
sea level rise and other impacts
of global climate change and (b)
ensure that risks to populations
are minimized while recognizing
the need to protect and maintain
important coastal ecosystems.
o Identification of coastal areas
at risk. National efforts are
needed to (a) identify functions
and resources at risk from a one
metre rise in sea level and (b)
assess the implications of
adaptive response measures on
them.
o Provisions to ensure that coastal
development does not increase
vulnerability to sea level rise.
Actions in particular need of
review include river levees and
dams, conversions of mangroves
and other wetlands for
agriculture and human habitation,
harvesting of coral and increased
settlement in low-lying areas.
In addition, while structural
measures to prepare for sea level
rise are not yet warranted, the
design and location of coastal
infrastructure and coastal
defenses should include
consideration of sea level rise
and other coastal impacts of
climate change. It is sometimes
less expensive to design a
structure today, incorporating
these factors, than to rebuild
it later.
o Review and strengthening of
emergency preparedness and
coastal zone response mechanisms.
Efforts are needed to develop
emergency preparedness plans for
reducing vulnerability to coastal
storms through better evacuation
planning and* the development of
coastal defense mechanisms that
recognize the impact of sea level
rise.
POLICYMAKERS SUMMARY WG III
International cooperation;
o Maintenance of a continuing
international focus on the
impacts of sea level rise.
Existing international
organizations should be augmented
with new mechanisms to focus
attention and awareness on sea
level change and to encourage
the nations of the world to
develop appropriate responses.
o Provision of technical assistance
and co~operation to developing
nations. Institutions offering
financial support should take
into account the need for
technical assistance and co-
operation in developing coastal
management plans, assessing
coastal resources at risk, and
increasing a nation's ability
- through education, training,
and technology transfer - to
address sea level rise.
Support
bv
international
organizations for national
efforts to limit population
growth in coastal areas. In the
final analysis, rapid population
growth is the underlying problem
with the greatest impact on both
the efficacy of coastal zone
management and the success of
adaptive response options.
Research, data, and information;
o Strengthening of resef*'rch on the
impacts of global climate change
on sea level rise. International
and national climate research
programmes need to be directed
at understanding and predicting
changes in sea level, extreme
events, precipitation, and other
impacts of global climate change
on coastal areas.
o Development and implementation
of a global ocean observi nq
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POLICYMAKERS SUMMARY WG III
network, for example through the
efforts of the IOC, WMO,and UNEP
to establish a coordinated
international ocean observing
network that will allow for
accurate assessment and
continuous monitoring of changes
in the world' s oceans and coastal
areas, particularly sea level
change and coastal erosion.
o Dissemination of data and
information on sea level change
and adaptive options. An
international mechanism could
be identified with the
participation of the parties
concerned for collecting and
exchanging data and information
on climate change and its impact
on sea level and the coastal zone
and on various adaptive options.
Sharing this information with
developing countries is
critically important for
preparation of coastal management
plans.
A programme could begin now to
enable developing countries to
implement coastal zone management
plans by the year 2000. The
programme would provide for
training of country experts, data
collection and technical assistance
and co-operation. Estimated
funding to provide the necessary
support over the next 5 years is
US$ 10,000,000. It is suggested
that international organizations
such as UNEP and WHO consider co-
ordinating this programme in
consultation with interested
nations.
6.2 Resource use ?nd n
The reports of Working Groups
I and II indicate significant and
unavoidable- impacts, both positive
and negative, upon the very
resources that humans and other
species rely on to live. These
resources include water,
agriculture,livestock, fisheries,
land, forests, and wildlife. The
RSWG addressed these resource
issues in the context of considering
options for ensuring food security;
conserving biological diversity;
maintaining water supplies; and using
land rationally for managed and
unmanaged ecosystems.
The potential impacts of climate
change on natural resources and
human activities are poorly
understood. First, credible
regional estimates of changes in
critical climatic factors, such as
temperature, soil moisture,annual
and seasonal variability, and
frequencies of droughts, floods and
storms, are simply not available.
For many of these critical climatic
factors even the direction of
change is uncertain. Secondly,
methods for translating these
changes into effects on the quantity
and quality of resources are generally
lacking. While it is clear that
some of the impacts of climate change
on resources could be negative and
others positive, a more specific
quantification of those impacts is
not possible at this time.
Nevertheless, these uncertainties
do not preclude taking appropriate
actions, especially if they are
worthwhile for other non-climate
related reasons. However, it can
be said that: (a) those resources
which are managed by humans (e.g.
agriculture, forestry) are more
suited to successful adaptation
than unmanaged ecosystems; and (b)
the faster the rate of change, the
greater the impact. In that regard,
it is very important to realize
that some species will not be able
to survive rapid climate changes.
Through the ages societies and
living things have developed the
capability to adapt to the climate1 s
natural variability and to extreme
events. Several climatic zones span
the globe, and resource use and management
25
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POLICYMAKERS SUMMARY WG III
is an ongoing challenge in each of
these zones. Therefore, society
could borrow from this existing
large reservoir of experience and
knowledge in developing policies
to adapt to possible climate
change. In addition, expected
future economic and technological
progress would provide the
financial and technical resources
required to better adapt to a
changing climate. Nevertheless,
significant costs, and legal,
institutional and cultural
adjustments may be necessary to
implement adaptation measures.
In recognition of the
uncertainties regarding the impacts
of climate change on resource use
and management, the following
sections provide general, rather
than specific, options in three
categories. The appropriateness
of these options for individual
countries may vary depending on the
specific social, environmental and
economic context.
Short-term research related options
There are a number of actions
which would augment our knowledge
base for making reasoned judgments
about response strategies. These
include:
o Developing inventories, data
bases, monitoring systems, and
catalogues of the current state
of resources and resource use
and management practices.
o Improving our scientific
understanding of and predictive
tools for critical climatic
factors, their impacts on natural
resources, and their socio-econo-
mic consequences.
o Undertaking studies and
assessments to gauge the
resilience and adaptability of
resources and their vulnerability
to climate change.
o Encouraging research and
development by both public and
private enterprises directed
toward more efficient resource
use and biotechnological
innovation (with adequate
safeguards for health, safety,
and the environment), including
allowing innovators to benefit
from their work.
o Continuing existing research and
development of methods to cope
with the potentially worst
consequences of climate change,
such as developing more drought-
or salinity-resistant cultivars
or using classical and modern
breeding techniques to help keep
farming and forestry options
open, and research on
agrometeorology or agroclimatol-
ogy.
o Increasing research on the
preservation of biological
resources in situ and ex situ.
including investigations into
the size and location of
protected natural areas and
conservation corridors.
Short-term policy options
Some response strategies are
available which are probably
economically justified under
present-day conditions and which
could be undertaken for sound
resource management reasons, even
in the absence of climate change.
In general, these relate to improving
the efficiency of natural resource
use, fuller utilization of the
"harvested" component of resources,
and waste reduction. Measures that
could be implemented in the short-term
include:
o Increased emphasis on the
development and adoption of
technologies which may increase
the productivity or efficiency
26
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POLICYMAKERS SUMMARY WG III
(per unit of land or water) of
crops, forests, livestock,
fisheries, and human settlements,
consistent with the principles
of sustainable development. Such
efficiencies reduce the demand
for land for human activities
and could also help reduce
emissions of greenhouse gases.
Examples of specific options
include more efficient milk and
meat production; improved food
storage and distribution; and
better water management
practices.
o Increased promotion and
strengthening of resource
conservation and sustainable
resource use - especially in
highly vulnerable areas. Various
initiatives could be explored
for conserving the most sensitive
and valuable resources, including
strengthening conservation
measures, managing development
of highly vulnerable resources,
and promoting reforestation and
afforestation.
o Acceleration of economic
development efforts in developing
countries. Because these
countries often have largely
resource-based economies, efforts
at improving agriculture and
natural resource use would be
particularly beneficial. Such
efforts would also promote
capital formation, which would
generally make adaptation to
climate change and sustainable
development more feasible.
o Developing methods whereby local
populations and resource users
gain a stake in conservation and
sustainable resource use, for
example by investing resource
users with clear property rights
and long-term tenure, and
allowing voluntary water transfer
or other market mechanisms.
o Decentralizing, as practicable,
decision-making on resource use
and management.
Longer-term options
There are also a number of other
possible responses which are costly
or otherwise appear to be more
appropriate for consideration in
the longer term, once uncertainties
regarding climate change impacts
are reduced. Options in this
category include:
o Building large capital structures
(such as dams) to provide for
enhanced availability of water
and other resources.
o Strengthening and enlarging
protected natural areas and
examining the feasibility of
establishing conservation
corridors to enhance the
adaptation prospects for
unmanaged ecosystems.
o As appropriate, reviewing and
eliminating direct and indirect
subsidies and incentives for
inefficient resource use, and
other institutional barriers to
efficient resource use.
7. MECHANISMS FOR IMPLEMENTING
RESPONSE STRATEGIES
The RSWG also considered several
priority areas which must be
addressed in order to adequately
implement limitation or adaptation
responses. These "implementation
mechanisms" represent the primary
vehicles through which national,
regional and international responses
to climate can be brought into force.
The specific implementation mechanisms
considered were:
o Public information and education;
o Technology development and
transfer;
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POLICYMAKERS SUMMARY WG III
o Economic (market) mechanisms;
o Financial mechanisms;
o Legal and institutional
mechanisms, including pos« sle
elements of a framr. ork
convention on climate change.
The results of the RSWG's
deliberations on these issues are
provided below.
7.1 Pnhi 4 n information and
education
A well informed global population
is essential for addressing and
coping with an issue as complex as
climate change. Because climate
change would affect, either
directly or indirectly, almost
every sector of society, broad
global understanding of the issue
will facilitate the adoption and
implementation of such response
options as deemed necessary and
appropriate. The dissemination
of information also represents a
powerful economic instrument for
ensuring that markets accurately
take into account potential
consequences and/or opportunities
of climate change.
The core aims of public education
and information programmes are to:
o Promote awareness and knowledge
of climate change issues;
o Provide guidance for positive
practices to limit and/or adapt
to climate change;
o Encourage wide participation of
all sectors of the population
of all countries, both developed
and developing, in addressing
climate change issues and
developing appropriate responses;
and
o Especially emphasize key target
groups, such as children an
youth, as well as individuals
at household levels, policymakers
and leaders, media, educational
institutions, scientists,
business and agricultural
sectors.
Given the importance of a
well-informed population, the RSWG
developed suggestions and approaches
for improving international awareness
of the potential causes and impacts
of climate change. In this process
it was recognized that, while
broad-based understanding is
essential, no single mechanism can
work for every group or in every
culture or country. The social,
economic, and cultural diversity
of nations will likely require
educational approaches and information
tailored to the specific requirements
and resources of particular locales,
countries, or regions. The importance
of education and information for
developing countries cannot be
overemphasized.
A number of national and
international actions should be
taken to disseminate broadly
information on climate change.
These include the:
o Establishment of national
committees or clearing houses
to collect, develop, and
disseminate objective materials
on climate change issues. This
could help provide focal points
for information on issues such
as energy efficiency, energy
savings, forestry, agriculture,
etc.
o Use by international organizations
(UNESCO, UNEP, WHO, etc.) and
non-governmentalorganizations
of IPCC and other relevant reports
in developing and providing to
all countries an adequate
understanding for future actions.
28
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o Use of an existing international
institution, or development of
a new institution, if necessary,
to serve as a clearinghouse for
informational and educational
materials.
o Upon completion of the IPCC
reports, or earlier, arrange a
series of short seminars targeted
to inform high priority decision
makers, world leaders and others
of causes and effects of climate
change.
7.2 Technology development and
transfer
The development and transfer of
technologies is vital to any effort
to address global climate change.
The development of new technologies
may provide the means by which
societies can meet their energy,
food, and other needs in the face
of changes in global climate, while
at the same time minimizing
emissions of greenhouse gases.
Prompt transfer of technologies,
especially to developing countries,
is likewise an important aspect of
any effort to limit or adapt to
climate change.
Technology research and development
Technological development,
including improvement and
reassessment of existing
technologies, is needed to limit
or reduce anthropogenic greenhouse
gas emissions; absorb such gases
by protecting and increasing sinks;
adapt human activities and resource
use and management to the impacts
of climate change; and detect,
monitor and predict climate change
and its impacts. Technological
development could be pursued in a
wide range of activities such as
energy, industry, agriculture,
transport, water supply, coastal
protection, management of natural
resources, and housing and building
POLICYMAKERS SUMMARY WG III
construction.
Adequate and trained human
resources are a prerequisite for
development and transfer of technologies,
and technological actions, founded
on a sound scientific basis, must
be consistent with the concept of
sustainable development.
Criteria for selecting technologies
include such factors as the existence
of economic and social benefits in
addition to environmental benefits,
economic efficiency taking into account
all the external costs, suitability
to local needs, ease of administra-
tion, information needs, acceptability
to the public.
Appropriate pricing policies
where applicable, information
exchange on the state of development
of technologies, and the support
of governments are important measures
that can promote technology development.
Also of importance are international
collaborative efforts, especially
between the industrialized and the
developing countries in the bilateral
and multilateral context.
Technology transfer
There is a need for the rapid
transfer to the developing countries,
on a preferential basis, of technologies
for addressing climate change. Developing
countries are of the view that
transfer of technologies on a non-
commercial basis is necessary and
that specific bilateral and
multilateral arrangements should
be established to promote this.
Some other countries where
technologies are not owned by the
government believe that transfer
of technologies would be a function
of commercial negotiations. The
issue of intellectual property
rights also presents a case where
international opinion is mixed.
A number of impediments also
29
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POLICYMAKERS SUMMARY MG III
exist which hinder the effective
transfer of technologies to
developing countries. These
include lack of financial
resources, necessary institutions,
and trained human resources.
Existing institutions could be
strengthened, or new mechanisms
established, where appropriate, to
finance technology transfers, train
human resources, and evaluate,
introduce and operate existing or
new technologies Legal barriers
and restrictive • .de practices are
also impeding £~ :ors.
It has not been possible to
bridge the difference on views on
some of the questions mentioned
above. It is extremely important
to reach early international
agreement on these issues in order
to promote effective flow of
technologies to monitor, limit or
adapt to climate change. One area
where international agreement may
be possible is the promo tier, of CFG
substitutes and provision of
assistance and cooperation to the
developing countries in the
acquisition and manufacture of such
substitutes.
Several countries have suggested
that the issue of technology
transfer to Eastern European
countries be addressed.
7.3
"han-i ana
It is important that any
potential measures to limit or
adapt to global climate change be
as economically efficient and
cost-effective as possible, while
taking into account important
social implications. In general,
environmental objectives can be
achieved either through regulations
requiring the'use of a specific
technology or attainment of
specified goals, or economic
instruments such as emissions fees,
subsidies, tradeable permits, or
sanctions.
Economic instruments, through
their encouragement of flexible
selection of abatement measures,
frequently offer the possibility
of achieving environmental
improvements at lower cost than
regulatory mechanisms. Unlike many
regulations, they tend to encourage
innovation and the development of
improved technologies and practices
for reducing emissions. Economic
mechanisms also have the potential
to provide the signals necessary
for more environmentally sensitive
operation of markets. It is
unlikely, however, that economic
instruments will be applicable to
all circumstances.
Three factors are considered as
potential barriers to the operation
of markets and/or the achievement
of environmental objectives through
market mechanises. These are:
information proolems. which can
often cause markets to produce less
effective or unfavourable environmental
outcomes; existing measures and
institutions, which can encourage
individuals to behave in environmentally
damaging ways; and hai^moing cciimttting
objectives (social, environmental,
and economic). An initial response
strategy may therefore be to address
information problems directly and
to review existing measures which
may be barriers. For example, prior
to possible adoption of a system
of emission charges, countries should
examine existing subsidies and tax
incentives on energy and other
relevant greenhouse gas producing
sectors.
A general advantage of market
based economic instruments is that
they encourage limitations or
reductions in emissions by those
who can achieve them at least cost.
They also provide an ongoing
incentive for industry and individual
consumers to apply the most efficient
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POLICYMAKERS SUMMARY NG III
limitation/reduction measures
through, for example, more
efficient and cleaner technologies.
Such incentives may be lacking in
the case of regulations.
Regulations, are the customary
means of controlling pollution in
both market and centrally planned
economies. An advantage of
regulations is that, in certain
circumstances, they create more
certainty as to desired outcomes,
whereas major disadvantages are
that they may discourage
innovation, introduce in-
flexibilities in meeting
objectives, can discourage resource
use efficiency, and offer few or
no incentives to reduce emissions
below specified levels.
It is evident that the question
of adoption of any form of economic
instrument, whether domestically
or internationally, raises many
complex and difficult issues.
Careful and substantive analysis
of all implications of such
instruments is needed. Possible
specific economic instruments which
have been identified for
consideration include:
o A system of tradeable emissions
permits; An emission permit
system is based on the concept
that the economic costs of
attaining a given environmental
goal can be minimized by allowing
for the trading of emissions
rights. Once an overall limit
on emissions has been set,
emissions entitlements amounting
to that limit could be provided
to emitting sources and free
trading of such entitlements
allowed. This would reduce the
costs of meeting a given emission
target because: (a) as in trade,
comparative advantages between
trading entities would be
maximized; and (b) economic
incentives would be created for
the development of improved
greenhouse gas limitation
technologies, sink enhancement,
and resource use efficiency
(energy conservation). Concerns
with this approach include the
limited experience with this
instrument, the potential scope
and size of trading markets and
the need for the development of
an administrative structure not
currently in place.
A system of emission charges:
Emission charges are levied on
specified emissions depending
on their level of contribution
to climate change. Such charges
may provide a means of encouraging
emitters to limit or reduce emissions
and provide an incentive for diverse
parties to implement efficient
means of limiting or reducing
emissions. Another advantage
of charges is that they generate
revenue which could provide a
funding base for further pollution
abatement, research, and
administration, or allow other
taxes to be lowered. Concerns
with this approach include the
difficulty of deciding on the
basis and size of the tax, and
the lack of certainty that the
tax will achieve the agreed emission
reduction target.
Subsidies; Subsidies are aimed
at encouraging environmentally
sound actions by lowering their
costs. Subsidies could be used,
inter alia, to encourage the use
of energy-efficient equipment
and non-fossil energy sources,
and the development and greater
use of environmentally sound
technologies. Concerns with
subsidies include the possible
size of the required financial
commitment of governments, the
need for careful design, the need
for review, and the international
trade aspects of such measures.
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POLICYMAKERS SUMMARY WG III
o Sanctions: A final type of
economic instrument is the use
of economic sanctions for the
enforcement of international
agreements. This would require
an international convention to
establish a system of agreed
trade or financial sanctions to
be imposed on countries not
adhering to agreed regimes. Many
contributors expressed
considerable reservations about
applying this approach to
greenhouse gas emissions because
of the complexity of the
situation. The concerns include
a belief that sanctions could
appear to be arbitrary, could
create confusion and resentment
and could be used as a pretext
to impose new non-tariff trade
barriers.
It has also been suggested that
the environmental protection could
be advanced and economic costs of
meeting greenhouse gas limitation
targets , if any, minimized by
addressing, to the extent feasible,
all greenhouse gas sources and
sinks comprehensively. This
approach could employ an "index"
relating net emissions of various
greenhouse gases by further
development of the index formulated
by Working Group I.
Each of the approaches outlined
above, however, poses potentially
significant challenges in terms of
implementation and acceptability.
There is an incomplete understand-
ing of the economic and social
consequences of these various
approaches. It is evident that
further work is required in all
countries, and in ongoing IPCC
work, to fully evaluate the
practicality of such measures and
costs and benefits associated with
different mechanisms, especially
with their use internationally.
It has, however, been pointed out
that an international system of
tradeable permits, or, altemativ
ly, an international system c.
emissions charges, could offer the
potential of serving as a cost-
efficient main instrument for
achieving a defined target for the
reduction of greenhouse gas
emissions.
Finally, it was stressed that
in order to share equitably the
economic burdens, implementation
of any of the international economic
instruments discussed above should
take into account the circumstances
that most emissions affecting the
atmosphere at present originated
in the industrialised countries where
the scope for change is the greatest,
and that, under present conditions,
emissions from developing countries
are growing and may need to grow
in order to meet their development
requirements and thus, over time,
are likely to represent an
increasingly significant percentage
of global emissions. It i-
appreciated that each instrumen
assessed has a role in meeting
greenhouse gas emission objectives,
but the suitability of particular
instruments is dependent on the
particular circumstances and at
this stage no measure can be
considered universally superior to
any other available mechanisms.
7.4 Financial mechani
Industrialized and developing
countries consider it important
that assurances of financial
mechanisms are needed for undertaking
adequate measures to limit and/or
adapt to climate change.
GUIDING PRINCIPLES
The following principles should
guide the financial approach:
a) Industrialized countries and
developing countries have a
common responsibility in dealinr
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POLICYMAKERS SUMMARY NG III
with problems arising from
climate change, and effective
responses require a global
effort.
b) Industrialized countries should
take the lead and have specific
responsibilities on two levels:
i) Major part of emissions
affecting the atmosphere at
present originates in
industrialized countries where
the scope for change is
greatest. Industrialized
countries should adopt domestic
measures to limit climate change
by adapting their own economies
in line with future agreements
to limit emissions;
ii) To cooperate with developing
countries in international
action, without standing in the
way of the latter' s development,
by contributing additional
financial resources, by
appropriate transfer of
technology, by engaging in close
cooperation concerning scientific
observation, by analysis and
research, and finally by means
of technical co-operation geared
to forestalling and managing
environmental problems;
c) Emissions from developing
countries are growing and may
need to grow in order to meet
their development requirements
and thus, over time, are likely
to represent an increasingly
significant percentage of global
emissions. Developing countries
should, within the limits
feasible, take measures to
suitably adapt their economies.
Financial resources channelled
to developing countries would be
most effective if focused on those
activities which contribute both
to limiting greenhouse gas
emissions and promoting economic
development. Areas for cooperation
and assistance could include:
o Efficient use of energy resources
and the increased use of fossil
fuels with lower greenhouse gas
emission rate or non-fossil
sources;
o Rational forest management
practices and agricultural
techniques which reduce greenhouse
gas emissions;
o Facilitating technology transfer
and technology development;
o Measures which enhance the
capacity of developing countries
to develop programmes to address
climate change, including
research and development
activities and public awareness
and education;
o Participation by developing
countries in international fora
on global climate change, such
as the IPCC.
It was also recognized that
cooperation and assistance for
adaptive measures would be required,
noting that for some regions and
countries, adaptation rather than
limitation activities are potentially
most important.
A number of possible sources for
generating financial resources
were considered. These include
general taxation, specific taxation
on greenhouse gas emissions, and
emissions trading. For the
significant complexities and
implications of such taxes, reference
is made to the economic measures
paper (section 7.3). Creative suggestions
include using undisbursed official
resources, which might result from
savings on government energy bills
and lower levels of military expenditures,
a fixed percentage tax on travel
tickets, and levies on countries
33
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POLICYMAKERS SUMMARY WG III
that have been unable to meet their
obligations. The question has also
been raised of whether such
financial cooperation and
assistance should only be given to
those countries which abstain from
activities producing greenhouse
gases. A positive international
economic environment, including
further reduction of trade
barriers, and implementation of
more equitable trade practices
would help to generate resources
which can be applied towards
pressing needs.
with respect to institutional
mechanisms for providing financial
cooperation and assistance to
developing countries, a two track
approach was considered:
i) one track built on work
underway or planned in
existing institutions. In
this regard, the World Bank,
a number of regional banks,
other multilateral organiza-
tions, and bilateral agencies
have initiated efforts to
incorporate global climate
change issues into their
programmes. Bilateral donors
could further integrate and
reinforce the environmental
components of their assistance
programmes and develop
cof inancing arrangements with
multilateral institutions
while ensuring that this does
not impose inappropriate
environmental conditions.
ii) parallel to this track the
possibility of new mechanisms
and facilities was considered.
Some developing and
industrialized countries
suggested that new mechanism
directly related to a future
climate convention and
protocols, such as a new
international fund, were
required. It was added that
such new instruments cou
be located within the Wor^
Bank (with new rules) or
elsewhere. It was also noted
that the Global Environmental
Facility proposed by the World
Bank in collaboration with
UNEP and UNDP was welcomed
by industrialized and
developing countries at the
World Bank Development Committee
meeting in Nay 1990.
It was noted that the issue of
generating financial resources was
distinct from that of allocating
those resources.
Areas identified for future work
include studies, with donor
assistance, for developing countries
on their current and projected net
emissions levels and assistance and
cooperation needs for limiting such
emissions. Further consideration
is also needed of the important role
which the private sector might play
through technology transfer, foreig
direct investment and other means
to assist and cooperate with
developing countries to respond to
climate change.
7.514
il and institutional mi limi' HIM
A number of institutions and
international legal mechanisms
exist which have a bearing on the
climate change issue, in particular
those dealing with the environment,
science and technology, energy,
natural resources, and financial
assistance. One of these existing
international legal mechanisms, the
Vienna Convention on the Protection
of the Ozone Layer and its associated
Montreal Protocol on Substances that
Deplete the Ozone Layer, deals
specifically with reducing emissions
of important greenhouse gases which
also deplete the ozone layer. However,
there is a general view that, while
existing legal instruments and
institutions related to
34
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POLICYMAKERS SUMMARY WG III
change should be fully utilized and
further strengthened, they are
insufficient alone to meet the
challenge.
A consensus emerged at the 44th
session of the UN General Assembly
on the need to prepare as a matter
of urgency a framework convention
on climate change, laying down, as
a minimum, general principles and
obligations. It should, in the
view of RSWG, be framed in such a
way as to gain the adherence of the
largest possible number and most
suitably balanced range of
countries while permitting timely
action to be taken. It may contain
provision for separate an-
nexes /pro tocol(s) to deal with
specific obligations. As part of
the commitment of the parties to
action on greenhouse gas emissions
and adverse effects of climate
change, the convention should also
address the particular financial
and other needs of the developing
countries (notably those most
vulnerable to climate change
agriculturally or otherwise), the
question of access to and transfer
of technology, the need for
research and monitoring, and
institutional requirements.
Decisions will have to be taken
on a number of key issues. These
include:
o the political imperative of
striking the correct balances
(a) between the arguments for
a far-reaching, action-oriented
convention and the need for
urgent adoption of a convention
so as to begin tackling the
problem of climate change; and
(b) among the risks of inaction,
the costs of action and current
levels of scientific uncertainty;
o the extent to which specific
obligations, particularly on
the control of emissions of
greenhouse gases, should be
included in the convention
itself, possibly as annexes, or
be the subject of a separate
protocol(s);
o the timing of negotiation of
protocol(s) in relation to the
negotiations on the convention;
o the introduction as appropriate
of sound scientific bases for
establishing emission targets
(such as total emission levels,
per capita emissions, emissions
per GNP, emissions per energy
use, climatic conditions, past
performance, geographic
characteristics, fossil fuel
resource base, carbon intensity
per unit of energy, energy
intensity per GNP, socio-economic
costs and benefits or other
equitable considerations);
o the extent to which specific
goals with respect to global
levels of emissions or atmospheric
concentrations of greenhouse gases
should be addressed;
o whether obligations should be
equitably differentiated
according to countries' respective
responsibilities for causing and
combatting climate change and
their level of development;
o the need for additional resources
for developing countries and the
manner in which this should be
addressed, particularly in terms
of the nature, size and conditions
of the funding, even if detailed
arrangements form the subject
of a separate protocol;
o the basis on which the promotion
of the development and transfer
of technology and provision of
technical assistance and co-
operation to developing countries
should take place, taking into
account considerations such as
35
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terms of transfer (preferential
or non-preferential, commercial
or non-commercial), assured
access, intellectual property
rights, the environmental
soundness of such technology,
and the financial implications;
o the nature of any new
institutions to be created by the
convention (such as a Conference
of the Parties, an Executive
Organ, as well as other bodies),
together with their functions,
composition and decision-making
powers, e.g. whether or not they
should exercise supervision and
control over the obligations
undertaken.
The international negotiation
on a framework convention should
start as quickly as possible after
the completion of the IPCC interim
report. The full and effective
participation of developing
countries in this process is
essential. Many, essentially
POLICYMAKERS SUMMARY WG III
developing, countries stressed tha
the negotiation must be conducte
in the forum, manner and with the
timing to be decided by the UN
General Assembly. This understanding
also applies to anyassociated protocols.
In the view of many countries and
international and non-governmental
organizations, the process should
be conducted with a view of
concluding it not later than the
1992 UN Conference on Environment
and Development.
The foregoing does not necessarily
constitute an exclusive list of issues
which will arise inthe negotiations.
However, a readiness to address these
fundamental problems will be a
prerequisite for ensuring the
success of the negotiations and the
support of a sufficiently wide and
representative spread of nations.
The legal measures topic paper
developed by the Working Group is
given in Annex I.
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POLICYMAKERS SUMMARY NG III
ANNEX I
LEGAL MEASURES: REPORT OF TOPIC CO-ORDINATORS
(Canada, Malta and the UK)
Executive Summary
1. The co-ordinators' report has as
its primary objective the
compilation of elements that might
be included in a future framework
Convention on Climate Change, and
a discussion of the issues that are
likely to arise in the context of
developing those elements.
2. There is a general view that
while existing legal instruments
and institutions with a bearing on
climate should be fully utilized
and further strengthened, they are
insufficient alone to meet the
challenge. A very broad
international consensus has
therefore emerged in the IPCC,
confirmed notably at the 44th
United Nations General Assembly,
on the need for a framework
Convention on Climate Change. Such
a Convention should generally
follow the format of the Vienna
Convention for the Protection of
the Ozone Layer, in laying down,
as a minimum, general principles
and obligations. It should further
be framed in such a way as to gain
the adherence of the largest
possible number and most suitably
balanced spread of countries while
permitting timely action to be
taken; it should contain provision
for separate annexes/protocols to
deal with specific obligations.
As part of the commitment of the
parties to action on greenhouse gas
emissions and the adverse effects
of global warming, the Convention
would also address the particular
financial needs of the developing
countries, the question of the
access to and transfer of
technology, and
requirements .
institutional
3 . The paper points out a number
of issues to be decided in the negotiation
of a Convention. In general these
are:
the political imperative of
striking the correct balances:
on the one hand, between the
arguments for a far-reaching,
action-oriented Convention and
the need for urgent adoption of
such a Convention so as to begin
tackling the problem of climate
change; and, on the other
hand, between the cost of inaction
and the lack of scientific certainty;
the extent to which specific
obligations, particularly on the
control of emissions of carbon
dioxide and other greenhouse gases,
should be included in the Convention
itself or be the subject of separate
protocol ( s ) :
the timing of negotiation of such
protocol(s) in relation to the
negotiations on the Convention.
4. In particular, within the
Convention the following specific
issues will need to be addressed:
a) Financial needs of developing
countries; The need for
additional resources for
developing countries and the
manner in which this should be
addressed, particularly in
terms of the nature, size and
conditions of the funding, even
if detailed arrangements form
the subject of a separate
37
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protocol, will have to be
considered by the negotiating
parties.
b) Development and transfer of
technology: The basis on which
the promotion of the development
and transfer of technology and
provision of technical assistance
to developing countries should
take place will need to be
elaborated, taking into account
considerations such as terms of
transfer, assured access,
intellectual property rights and
the environmental soundness of
such technology.
c) Institutions; Views differ
substantially on the role and
powers of the institutions to be
created by the Convention,
particularly in exercising
supervision and control over the
obligations undertaken.
POLICYMAKERS SUMMARY WG III
5. The inclusion of any particula
element in the paper does not impl^
consensus with respect to that
element, or the agreement of any
particular government to include
that element in a Convention.
6. The co-ordinators have not sought
to make a value judgement in listing
and summarising in the attached paper
the elements proposed for inclusion
in a framework Convention: their
text seeks merely to assist the future
negotiators in their task. They
note however that a readiness to
address the foregoing fundamental
problems in a realistic manner will
be a prerequisite for ensuring the
success of the negotiations and the
support of a sufficiently wide and
representative spread of nations.
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POLICYMAKERS SUMMARY WG III
POSSIBLE ELEMENTS FOR INCLUSION
IN A FRAMEWORK CONVENTION ON CLIMATE CHANGE
PREAMBLE
In keeping with common treaty
practice including the format of
the Vienna Convention, the Climate
Change Convention would contain a
preamble which might seek to
address some or all of the
following items:
- a description of the problem and
reasons for action (need for
timely and effective response
without awaiting absolute
scientific certainty);
- reference to relevant
international legal instruments
(such as the Vienna Convention
and Montreal Protocol) and
declarations (such as UNGA
Resolution 43/53 and Principle
21 of the Stockholm Declaration);
- recognition that climate change
is a common concern of mankind,
affects humanity as a whole and
should be approached within a
global framework, without
prejudice to the sovereignty of
states over the airspace
superadjacent to their territory
as recognized under international
law;
- recognition of the need for an
environment of a quality that
permits a life of dignity and
well-being for present and future
generations;
- reference to the balance between
the sovereign right of states to
exploit natural resources and the
concomitant duty to protect and
conserve climate for the benefit
of mankind, in a manner not to
diminish either;
endorsement and elaboration of
the concept of sustainable
development;
recognition of the need to improve
scientific knowledge (e.g. through
systematic observation) and to
study the social and economic
impacts of climate change, respecting
national sovereignty;
recognition of the importance
of the development and transfer
of technology and of the drcunstanoes
and needs, particularly financial,
of developing countries; need
for regulatory, supportive and
adjustment measures to take into
account different levels of
development and thus differing
needs of countries;
recognition of the responsibility
of all countries to make efforts
at the national, regional and
global levels to limit or reduce
greenhouse gas emissions and prevent
activities which could adversely
affect climate, while bearing
in mind that:
o most emissions affecting the
atmosphere at present originate
in industrialized countries
where the scope for change
is greatest;
o implementation may take place
in different time frames for
different categories of countries
and may be qualified by the
means at the <^«^n«s»T of individual
countries and their scientific
and technical capabilities;
o emissions from developing
countries are growing and
may need to grow in order to
meet their development
39
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POLICYMAKERS SUMMARY WG III
requirements and thus, over
time, are likely to represent
an increasingly significant
percentage of global
emissions;
recognition of the need to
develop strategies to absorb
greenhouse gases, i.e. protect
and increase greenhouse gas
sinks; to limit or reduce
anthropogenic greenhouse gas
emissions; and to adapt human
activities to the impacts of
climate change.
Other key issues which will have
to be addressed during the
development of the preambular
language include:
- should mankind's interest in a
viable environment be
characterized as a fundamental
right?
- is there an entitlement not to
be subjected, directly or
indirectly, to the adverse
effects of climate change?
- should there be a reference to
the precautionary principle?
- in view of the inter-relationship
among all greenhouse gases, their
sources and sinks, should they
be treated collectively?
- should countries be permitted to
meet their aggregate global
climate objectives through joint
arrangements?
- should reference be made to
weather modification agreements
such as the ENNOD treaty as
relevant legal instruments?
- is there a common interest of
mankind in the development and
application of technologies to
protect and preserve climate?
does the concept of sustainable
development exclude or include
the disposition of new ccnditionality
in the provision of financial
assistance to developing countries,
and does it imply a link between
the protection and preservation
of the environment, including
climate change, and economic
development so that both are to
be secured in a coherent and
consistent manner?
should the preamble address the
particular problems of countries
with an agricultural system vulnerable
to climate change and with limited
access to capital and technologies,
recognizing the link with «*aHi'inaKiA
development?
is there a minimum standard of
living which is a prerequisite
to adopting response strategies
to address climate change?
DEFINITIONS
As is the practice, definitions
will need to be elaborated in a
specific article on definitions.
The terms which will need to be
defined will depend on the purpose
of the Convention and thus the
language used by the negotiating
parties.
GENERAL OBLIGATIONS
following the fbanat of such treaties
as the Vienna Convention, an article
would set out the general obligations
agreed to by the parties to the
Convention. Such obligations may
relate to, for example:
the adoption of appropriate
measures to protect against the
adverse effects of climate
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POLICYMAKERS SUMMARY VPG III
change, to limit, reduce, adapt
to and, as far as possible,
prevent climate change in
accordance with the means at the
disposal of individual countries
and their scientific and
technical capabilities; and to
avoid creating other environmen-
tal problems in taking such
measures;
the protection, stabilization and
improvement of the composition
of the atmosphere in order to
conserve climate for the benefit
of present and future
generations;
taking steps having the effect
of limiting climate change but
which are already justified on
other grounds;
the use of climate for peaceful
purposes only, in a spirit of
good neighbourliness;
co-operation by means of
research, systematic observation
and information exchange in order
to understand better and assess
the effects of human activities
on the climate and the potential
adverse environmental and socio-
economic impacts that could
result from climate change,
respecting national sovereignty;
the encouragement of the
development and transfer of
relevant technologies, as well
as the provision of technical and
financial assistance, taking into
account the particular needs of
developing countries to enable
them to fulfil their obligations;
co-operation in the formulation
and harmonization of policies and
strategies directed at limiting,
reducing, adapting to and, as
far as possible, preventing
climate change;
co-operation in the adoption of
appropriate legal or administrative
measures to address climate change;
provision for bilateral,
multilateral and regional
agreements or arrangements not
incompatible with the Convention
and any annex/protocol, including
opportunities for groups of
countries to fulfil the
requirements on a regional or
sub-regional basis;
co-operation with competent
international organisations
effectively to meet the objectives
of the Convention;
the encouragement of and co-
operation in the promotion of
public education and awareness
of the environmental and socio-
economic impacts of greenhouse
gas emissions and of climate
change;
the strengthening or modification
if necessary of existing legal
and institutional instruments
and arrangements relating bo climate
change;
a provision on funding mechanisms.
Other key issues which will have
to be addressed in the process of
elaborating this article include
the following:
should there be a provision
setting any specific goals with
respect to levels of emissions
(global or national) or
atmospheric concentrations of
greenhouse gases while ensuring
stable development of the world
nony, particularly stabilization
by industrialized countries, as
a first step, and later reduction
of C02 emissions and emissions
of other greenhouse gases not
controlled by the Montreal Protocol?
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POLICYMAKERS SUMMARY WG III
Such provision would not exclude
the application of more stringent
national or regional emission
goals than those which may be
provided for in the Convention
and/or any annex/protocol.
in light of the preambular
language, should there be a
provision recognizing that
implementation of obligations may
take place in different time
frames for different categories
of country and/or may be
qualified by the means at the
disposal of individual countries
and their scientific and
technical capabilities?
should there be a commitment to
formulate appropriate measures
such as annexes, protocols or
other legal instruments and, if
so, should such formulation be
on a sound scientific basis or
on the basis of the best
available scientific knowledge?
in addressing the transfer of
technology particularly to
developing countries, what should
be the terms of such transfers
(i.e. commercial vs. non-
commercial, preferential vs. non-
preferential, the relationship
between transfers and the
protection of intellectual
property rights)?
should funding mechanisms be
limited to making full use of
existing mechanisms or also
entail new and additional
resources and mechanisms?
should provision be made for
environmental impact assessments
of planned activities that are
likely to cause significant
climate change as well as for
prior notice of such activities?
what should be the basis of
emission goals e.g., total
emission levels, per capita
emissions, emissions per GNP,
emissions per energy use, climatic
conditions, past performance,
geographic characteristics, fossil
fuel resource base, carbon intensity
per unit of energy, energy intensity
per GNP, socio-economic costs
and benefits, or other equitable
considerations?
should the particular problem
of sea-level rise be specifically
addressed?
is there a link between nuclear
stockpiles and climate change?
INSTITUTIONS
It has been the general practice
under international environmental
agreements to establish various
institutional mechanisms. The parties
to a Climate Change Convention might,
therefore, wish to make provision
for a Conference of the Parties,
an Executive Organ and a Secretariat.
The Conference of the Parties
may, among other things: keep under
continuous review the implementation
of the Convention and take appropriate
decisions to this end; review current
scientific information; and promote
harmonization of policies and strategies
directed at limiting, reducing,
adapting to and, as far as possible,
preventing climate change.
Questions that will arise in
developing provisions for appropriate
institutional mechanisms include:
should any of the Convention's
institutions (e.g. the Conference
of the Parties and/or the
Executive Organ) have the ability
to take decisions inter alia on
response strategies or functions
in respect of surveillance,
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POLICYMAKERS SUMMARY WG III
verification and compliance that
would be binding on all the
parties and, if so, should such
an institution represent all of
the parties or be composed of a
limited number of parties e.g.
based on equitable geographic
representation?
- what should be the role of the
Secretariat?
- what should be the decision-
making procedures, including
voting requirements (e.g.
consensus, majority)?
- if a trust fund or other
financial mechanism were
established under the Convention,
how should it be administered?
- should scientific and/or other
bodies be established on a
permanent or ad hoc basis, to
provide advice and make
recommendations to the Conference
of the Parties concerning
research activities and measures
to deal with climate change?
- should the composition of the
above bodies reflect equitable
climatic or geographic
representation?
- should there be a provision for
working groups, e.g. on
scientific matters as well as on
socio-economic impacts and
response strategies?
- is there a need for innovative
approaches to institutional
mechanisms in the light of the
nature of the climate change
issue?
- what should be the role of non-
governmental organizations?
RESEARCH, SYSTEMATIC OBSERVATIONS
AND ANALYSIS
It would appear to follow general
practice to include provision for
co-operation in research and systematic
monitoring. In terms of research,
each party might be called upon to
undertake, initiate, and/or co-
operate in, directly or through
international bodies, the conduct
of research on and analysis of:
- physical and chemical processes
that may affect climate;
- substances, practices, processes
and activities that could modify
the climate;
- techniques for monitoring and
measuring greenhouse gas emission
rates and their uptake by sinks;
- improved climate models,
particularly fty regional clinBtes;
- environmental, gr»"HaT and economic
effects that could result from
modifications of climate;
- alternative substances,
technologies and practices;
— environmental, **fviai and economic
effects of response strategies;
- human activities affecting
climate;
- coastal areas with particular
reference to sea-level rise;
- water resources; and
- energy efficiency.
The parties might also be called
upon to co-operate in establishing
and improving, directly or through
competent international bodies, and
taking fully into account national
legislation and relevant on-going
activities at the national, regional
and international levels, joint or
complementary programmes for
systematic monitoring and analysis
of climate, including a possible
worldwide system; and co-operate
in ensuring the collection,
validation and transmission of
research, observational data and
analysis through appropriate data
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POLICYMAKERS SUMMARY WG III
centres.
Other issues that will arise in
developing this provision include:
- should consideration be given to
the establishment of panels of
experts or of an independent
scientific board responsible for
the co-ordination of data
collection from the above areas
of research and analysis and for
periodic assessment of the data?
- should provision be made for on-
site inspection?
- should there be provision for
open and non-discriminatory
access to meteorological data
developed by all countries?
- should a specific research fund
be established?
INFORMATION
REPORTING
EXCHANGE
AND
Precedents would suggest the
inclusion of a provision for the
transmission of information through
the Secretariat to the Conference
of the Parties on measures adopted
by them in implementation of the
Convention and of protocols to
which they are party. In an annex
to the Vienna Convention, the types
of information exchanged are
specified and include scientific,
technical, socio-economic,
commercial and legal information.
For the purposes of elaborating
this provision, issues having to
be addressed by the negotiating
parties include the following:
- is there a need for the
elaboration of a comprehensive
international research programme
in order to facilitate co-
operation in the exchange of
scientific, technological an
other information on climate
change?
should parties be obliged to
report on measures they have
adopted for the implementation
of the Convention, with the possible
inclusion of regular reporting
on a comparable basis of their
emissions of greenhouse gases?
should each party additionally
be naTlfri upon to develop a national
inventory of emissions, strategies
and available technologies for
addressing climate change? If
so, the Convention might also
rail for the exchange of information
on such inventories, strategies
and technologies.
EEVELCWENT MO TCMSER OF
While the issue of technology
has been addressed in the sectioi
on General Obligations, it might
be considered desirable to include
separate provisions on technology
transfer and technical co-operation.
Such provisions could call upon the
parties to promote the development
and transfer of technology and technical
co-operation, taking into account
particularly the needs of developing
countries, to enable them to take
measures to protect against the adverse
effects of climate change, to limit,
reduce and, as far as possible, prevent
climate change, or to adapt to it.
Another issue which will arise
is: should special terms be attached
to climate-related transfers of
technology (such as a preferential
and/or non-ccnmercial basis and assured
access to, and transfer of,
environmentally sound technologies
on favourable terms to developing
countries), taking into consideration
the protection of intellectual property
rights?
44
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SETTLEMENT OF DISPUTES
It would be usual international
practice to include a provision on
the settlement of disputes that may
arise concerning the interpretation
or application of the Convention
and/or any annex/protocol.
Provisions similar to those in the
Vienna Convention for the
Protection of the Ozone Layer might
be employed, i.e. voluntary resort
to arbitration or the International
Court of Justice (with a binding
award) or, if neither of those
options is elected, mandatory
resort to conciliation (with a
recommendatory award).
OTHER PROVISIONS
It would be the usual
international practice to include
clauses on the following topics:
- amendment of the Convention;
- status, adoption and amendment
of annexes;
- adoption and entry into force
of, and amendments to,
protocols;
- signature;
- ratification;
- accession;
- right to vote;
- relationship between the
Convention and any
protocol(s) ;
- entry into force;
- reservations;
- withdrawal;
- depositary;
- authentic texts.
ANNEXES AND PROTOCOLS
The negotiating parties may
wish the Convention to provide for
the possibility of annexes and/or
POLICYMAKERS SUMMARY WG III
protocols. Annexes might be concluded
as integral parts of the Convention,
while protocols might be concluded
subsequently (as in the case of the
Montreal Protocol to the Vienna Convention
on Protection of the Ozone Layer).
While it is recognized that the
Convention is to be all-encompassing,
the negotiating parties will have
to decide whether greenhouse gases,
their sources and sinks, are to be
dealt with: individually, in groups
or comprehensively; in annexes or
protocols to the Convention. The
following, among others, might
also be considered as possible
subjects for annexes or protocols
to the Convention:
- agricultural practices;
- forest management;
- funding mechanisms;
- research and systematic
observations;
- energy conservation and
alternative sources of energy;
- liability and compensation;
- international emissions
trading;
- international taxation system;
- development and transfer of
climate change-related
technologies.
Issues that will arise in
connection with the development of
annexes and protocols include:
timing, i.e. negotiating parties
advocating a more action-oriented
Convention may seek to include
specific obligations in annexes
as opposed to subsequent
protocols and/or negotiate one
or more protocols in parallel
with the Convention negotiations;
sequence, i.e. if there is to
be a series of protocols, in what
order should they be taken up?
45
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POLICYMAKERS SUMMARY WG III
LIST OF ACRONYMS AND CHEMICAL SYMBOLS
AFOS Agriculture, Forestry and Other Human Activities Subgroup of
IPCC Working Group III
BaU Business as Usual Scenario. Same as Scenario A of Working
Group III
Bt Billion (1000 million) tonnes
BTC Billion (or 1000 millions) tonnes Carbon
CFCs Chlorofluorocarbons
CH4 Methane
CI Carbon Intensity in kilogram carbon per gigajoule
CO Carbon monoxide
C02 Carbon dioxide
EIS Energy and Industry Subgroup of Working Group III
Gg Gigagram (10 grams)
GHG Greenhouse Gas
GDP Gross Domestic Product
GNP Gross National Product
GtC Gigatonnes (10 tonnes) carbon
HCFC Hydrochlorofluorocarbon
HFC Hydrofluorocarbon
IOC Intergovernmental Oceanographic Commission of UNESCO
IPCC Intergovernmental Panel on Climate Change
ICSU International Council of Scientific Unions
ITTO International Tropical Timber Organization
Mt Megatonnes (10 tonnes)
N2O Nitrous oxide
NGOs Non-Governmental Organizations
NOx Nitrogen oxides
03 Ozone
OECD Organization for Economic Cooperation and Development
pa per annum
PC per capita carbon emissions in tonne carbon
ppra part per million
RSWG Respone Strategies Working Group of IPCC Working Group III
SOx Sulphur oxides
TC Tonne Carbon
TC-GJ Tonne Carbon per GigaJoule
TFAP Tropical Forstry Action Plan
Tg Teragrams (10 grams)
TgC Teragram Carbon
TgCH4 Teragram Methane
TgN Teragram Nitrogen
UN United Nations
UNDP United Nations Development Programme
UNEP United- Nations Environment Programme
UNESCO United Nations Educational, Scientific and Cultural Organization
VOCs Volatile Organic Compounds
WHO World Meteorological Organization
46
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&
WMO UNEP
INTERGOVERNMENTAL PANEL ON
CLIMATE CHANGE
POLICYMAKERS
SUMMARY
OF THE IPCC SPECIAL COMMITTEE ON THE
PARTICIPATION OF DEVELOPING COUNTRIES
AUGUST 1990
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POLICYMAKERS SUMMARY SPC
TABLE OF CONTENTS
Page
EXECUTIVE SUMMARY iii
1 . INTRODUCTION 1
1 .1 Establishment of the Special Committee 1
1.2 Joint partnership of the industrialized and developing
countries 1
1 .3 Structure of the policymakers summary 2
2. FULL PARTICIPATION OF THE DEVELOPING COUNTRIES 3
2.1 Objectives 3
2.2 Factors inhibiting full participation 3
2.3 Insufficient information 4
2.4 Insufficient communication 5
2.5 Limited human resources 5
2.6 Institutional difficulties 6
2.7 Limited financial resources 6
2.8 Progress in IPCC 7
3. AREAS OF ACTION 7
3.1 Development of information.... 8
3.2 Development of communication 9
3.3 Development of human resources 9
3.4 Functioning of institutions 10
3.5 Development of financial resources 11
4. CONCLUDING REMARKS AND RECOMMENDATIONS 12
4.1 Overview and need for action 12
4.2 Specific recommendations 13
Annex 1 Terms of reference of the IPCC Special Committee on the
Participation of Developing Countries 16
Annex 2 Contributions to the joint WMO/UNEP IPCC Trust Fund 17
ii
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POLICYMAKERS SUMMARY SPC
POLICYMAKERS SUMMARY OP THE IPCC SPECIAL COMMITTEE
ON THE PARTICIPATION OF DEVELOPING COUNTRIES
EXECUTIVE SUMMARY
1 . The Special Committee on the
Participation of Developing
Countries was established by the
Intergovernmental Panel on Climate
Change (IPCC) to promote, as rapidly
as possible, full participation of
the developing countries in IPCC
activities. Action was taken, funds
were raised and attendance of the
developing countries increased.
2. Full participation includes the
development of national competence
to address all issues of concern
such as the appreciation of the
scientific basis of climate change,
the potential impacts on society of
such change and evaluations of
practical response strategies for
national/regional applications.
3. There is a close link between
issues addressed by the IPCC Working
Groups such as access to technology
and financial resources and the
participation of the developing
countries in IPCC. The work of the
Special Committee was carried out
in parallel, necessitated by the
tight timetable and limited
resources, with work on such issues
carried out in Working Group III.
The Committee will need to meet
periodically to co-ordinate the
integration of its conclusions and
other concerns of the developing
countries in the work of the Working
Groups, particularly Working Group
III, and the implementation of its
recommendations.
4. The industrialized world today
emits about 75% of the world total
greenhouse gas emissions, and
although the emissions are
increasing in the developing
countries, where 75% of the world
population lives, they emit the balance.
The legitimate concerns on the part
of the developing countries that,
although their impact on global climate
change is minimal, its impact on them
can be grave, need to be taken into
account .
5. Any significant climate change
would affect every sector of individual
and social activity. Thus a single
nation or even a group of nations
cannot hope to manage the issue adequately
by itself. It would take the concerted
action of all nations to achieve that
end, taking into account not only
the past and present responsibility
of the industrialized world in the
accumulation of the greenhouse gases,
but also the present economic and
financial capacities of the developing
countries.
6. While the global environment
has assumed today greater significance
for the industrialized countries,
the priority for the alleviation of
poverty continues to be the overriding
concern of the developing countries;
they rather conserve their financial
and technical resources for tackling
their immediate economic problems
than make investments to avert a global
problem which may manifest itself
after two generations, particularly
when their contribution to it is
significantly less than that of the
industrialized countries.
7 . The Committee noted that developing
countries consider the lack of sufficient
assurance so far on the provision
and requisite, *>**j&:'*, new and additional
funding particularly for the
transfer, adaptation and implementation
iii
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POLICYMAKERS SUMMARY SPC
of alternative safer technologies
on a preferential, non-commercial
and grant basis added substantially
to the inhibition of the developing
countries in taking active part in
IPCC activities. It further noted
that these countries consider that
the formulation of guidelines for
funding mechanisms for transfer,
adaptation and implementation of
clean technologies as against legal
and economic measures would create
healthier conditions for the
participation of the developing
countries.
8. These considerations have led
the Specia. Committee to focus on
the following five factors that
inhibit the full participation of
the developing countries in the IPCC
process:
* insufficient information;
* insufficient communication;
* limited human resources;
* institutional difficulties;
* limited financial resources.
(i) Insufficient information: Many
developing countries do not have
sufficient information on the issue
of potential climate change to
appreciate the concern it evokes
elsewhere in the world. Information
is often insufficient with respect
to the scientific basis for concern,
on the potential physical and socio-
economic impacts of climate change
as well as on response options. This
applies not only to scientific
milieux but also to policymakers and
public opinion.
(ii) Insufficient communication:
Even if the situation with respect
to information were to improve,
there is the problem of insufficient
internal and external communication
mechanisms for the proper
dissemination of the information on
matters related to climate change.
(iii)Limited human resources: Lao
of adequate number of trained personnel
in almost a^ 1 areas ranging £iuu academic,
scientific efforts to applications
of knowledge to food and energy production,
to water management, to human settlements
problems, to trade and economic growth,
and to a host of other related endeavours
is common to many developing nations.
Most of them, if not all, can command
only limited pool of experts and
and knowledgeable officials, and even
that only in a few of these areas.
(iv) Institutional difficulties:
The multi-disciplinary and cross-cutting
nature of the issues involved demands
relatively high degree of co-ordination
among the various departments/ ministries
of governments.
(v) Limited financial resources:
Survival needs come first. After
that, the limited financial, and consequent
general lack of technological, resources
dictate the priorities. Means of
meeting the incremental costs of ensuring
a viable environment frequently cannot
be found. Also, local immediate,
environmental concerns generally receive
political priority over impersonal,
global concerns.
9. The Committee did not consider
in detail topics such as financial
assistance, economic incentives/disincent-
ives, formulation of legal instruments,
and development of, and access to,
envtronmentally-benign and energy-efficient
technologies. These were dealt with
by Working Group III and are likely
among governments. However, the Committee
expressed the view that actions to
promote the full participation of
the developing countries in climate
change issues should not await the
outcome of such negotiations.
10. Also, there are actions that
will arise as a result of negotiations
and agreements, and machinery will
have to be put in place to implement
iv
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POLICYMAKERS SUMMARY SPC
these. But there are others that
need to be taken now, that can be
done through existing arrangements;
most in this category should be
planned and carried out for several
years.
11. The impacts of climate change
will vary from region to region and
nation to nation. Although response
strategies for developing countries
have to take into account the need
for adequate funding and safer
technologies, country-specific
and/or region-specific approaches
will be necessary. For example,
response measures that small island
states require could be very
different from those for large
industrializing countries within the
developing world. Success in the
implementation of many of the
recommended actions depend not only
on national initiatives but also on
stronger regional or sub-regional
co-operation.
RECOMMENDED ACTIONS
12. Uninterrupted travel assistance
to the developing countries for
attendance at the meetings of IPCC
and follow-up activities should be
ensured. The Committee wishes to
call the attention of the Panel to
the importance of continuing this
effort and of the donor nations
continuing and increasing
contributions to the effort, with
no cessation after the fourth
plenary of IPCC.
13. Serious consideration should
be given to supporting more than one
expert from each participating
developing country to those climate
change-related meetings that deal
with several aspects of the problem.
The developing countries on their
part should facilitate action in
this regard as much as possible.
14. Governments and organizations
from the industrialized nations are
encouraged to continue and increase
their efforts in organizing seminars.
Developing countries could organize,
under the sponsorship of international
organizations or otherwise, regional
seminars and workshops in order to
exchange scientific and technical
information. For this purpose, necessary
programmes and lists of experts should
be developed. As part of the continuing
process of information exchange, the
Committee reccnmends that IPCC circulate
this policymakers suimary to all concerned
including those attending the Second
World Climate Conference. The developing
countries on their part could where
appropriate designate focal points,
as soon as possible, for transmittal
of reports, documentation, data and
information on seminars. Such focal
points should be briefed on forwarding
the material to appropriate recipients
within the nation for response, review
etc.
1 5 . The establishment of mechanisms
for national co-ordination of all
their activities related to climate
change could be considered by the
developing countries. The mechanisms
could aid such areas as information
dissemination, development and
implementation of plans for research
and monitoring, and formulation of
policy options. The industrialized
countries could consider assisting
the developing countries in these
areas with easy access to needed
technologies.
16. The Committee recommends that
acquisition, analyses and interpretation
of information on climatic and related
data would enable developing countries
to take more effective account of
climate change TT*?^ «jtoran T*? in fioniulating
national policies. Such actions are
necessary also at regional levels
to undertake and refine impact studies.
The current unevenness in the acquisition
and use of such data which is evident
between the hemispheres should be
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POLICYMAKERS SUMMARY SPC
eliminated. The Committee further
recommends that the developing
countries take immediate action to
identify their specific needs to
determine the financial implications
of such action. It would be
necessary to mobilize appropriate
funding in order to mount a
sustained programme and create
regional centres to organize
information networks on climate
change.
17. In many developing countries
the meteorological/ hydrological
service is the main and often the
only institution collecting and
recording data with relevance to
climate. If associated weather
patterns are modified/ as some
predict they would as a result of
climate change, then the
capabilities of such services need
to be reinforced to enhance their
contributions to sustainable
development.
18. The Committee recommends that
considerations of climate change
should b~ integrated in development
polici&-.< National environmental
studies should also take into
account predicted climate change in
order to determine sustainable
development strategies. To reach
these objectives, the developing
countries and many industrialized
countries consider ;-•; essential that
additional funding be available to
enable developing countries to meet
the incremental costs resulting frc
their efforts to combat climate change.
19. The Committee further recommends
that its findings be duly taken into
account in all relevant areas of the
work of IPCC. Programmes of action
should be developed and implemented
(and the concepts which would lead
to such programmes of action developed
where needed) without delay, with
a view to ensure, provided the necessary
means are made available, the full
participation of developing countries
in the future work and activities
on climate change. UNEP and WMO should
take the lead in this regard and initiate
the necessary consultations. Other
multilateral or bilateral organizations
should also be contacted for elaborating
and implementing these programmes
of action.
20. The Committee also recommends
that serious consideration be given
by IPCC to the provision of simultaneou
interpretation and documentation ir.
the customary UN languages for the
meetings of the Special Committee,
given the complex nature of the subject
matter covered a.:d the particular
difficulties encountered by the developing
countries.
21. The Special Committee is ready
to assist in monitoring and reviewing
the preparation and the implementation
of the above mentioned and other relevant
programmes of action.
VI
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POLICYMAKERS SUMMARY SPC
POLICYMAKERS SUMMARY
OP THE IPCC SPECIAL COMMITTEE ON THE
PARTICIPATION OF DEVELOPING COUNTRIES
1 .
INTRODUCTION
1 .1 Establishment of the Special
Committee
1.1.1 When the Intergovernmental
Panel on Climate Change (IPCC) began
its work in November 1988, only a
few developing countries attended.
The reason was not that they were
indifferent to the issue of climate
change. They were lacking in
neither interest nor concern.
Climate change had appeared only a
short while earlier on the
international agenda. By its
nature, it is a complex and multi-
sectoral issue. Few developing
countries have adequate data bases
and research facilities to address
the problem directly. For most of
them, national spending priorities
for rapid economic growth precluded
expenditure of scarce resources on
travel to attend IPCC meetings.
1.1.2 The Special Committee on the
Participation of Developing
Countries was established by IPCC
(in June 1989) to promote, as
rapidly as possible, active
participation of the developing
countries in IPCC activities. This
action followed the report of an Ad
Hoc Subgroup which was established
by the IPCC Bureau in February 1989
to promote ways and means of
increasing such participation. The
Subgroup was under the chairmanship
of Dr. A. Al-Gain, who is also the
Vice-chairman of IPCC. The members
of the Ad Hoc Subgroup were Brazil,
Saudi Arabia, Senegal and Zimbabwe.
1.1.3 The Special Committee's
deliberations owe much to the report
of the Ad Hoc Subgroup. The
Committee consists of the following
members: France (Chair), Algeria,
Brazil, India, Indonesia, Japan, Kenya,
Norway, USA and USSR. Dr. Al-Gain
is a co-opted member of the Committee.
(The Committee met as an open-ended
group during its plenary session held
in Geneva on 31 May and 1 June 1990
following a decision made at the third
plenary session of IPCC in Washington
D.C., on 5 to 7 February 1990.) The
Committee's terms of reference are
given in Annex I to this policymakers
summary.
1.1.4 There is a close link between
issues addressed by the Working Groups
of IPCC such as access to technology
and financial resources and the
participation of the developing countries
in IPCC. The work of the Committee
was carried out in parallel with work
on such issues carried out within
the subgroups, and the topics groups
on implementation measures, of Working
Group III. This parallel work was
necessitated by the tight timetable
and limited resources available to
the Committee. The Special Committee
stresses the importance of taking
into account, to the extent feasible,
the conclusions of this policymakers
summary in the report of Working Group
III. Further, the Committee will
need to meet periodically to co-ordinate
the integration of the concerns of
the developing countries in the work
of Working Group HE and the implementation
of its recommendations.
1.2 Joint partnership of the
industrialized and developing
countries
1.2.1 Global warming of current concern
results from emissions of the so-called
greenhouse gases into the atmosphere.
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POLICYMAKERS SUMMARY SPC
while many of these gases occur in
the natural atmosphere, recently
observed increases in them come
about because of activities that
have contributed in a very big way
to human survival and welfare such
as industrialization, food
production and general economic
development.
1.2.2 The industrialized world today
emits about 75% of the world total
greenhouse gas emissions, and
although the emissions are
increasing in the developing
countries, where 75% of the world
population lives, they emit the
balance. The source of the emissions
can be any nation but any warming
will not be confined to that nation
alone; it will go beyond,
encompassing the entire globe. Any
significant climate change would
affect every sector of individual
and social activity. Thus a single
'
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POLICYMAKERS SUMMARY SPC
2. FULL PARTICIPATION OP THE
DEVELOPING COUNTRIES
2.1 Objectives
2.1.1 The Committee recognized that
achieving full participation of the
developing countries in the IPCC
process is a necessary but difficult
goal: it embraces a number of
related objectives. These
objectives are both quantitative and
qualitative. With respect to
quantitative objectives, the
Committee acknowledged the need to:
(i) increase the number of
developing countries taking part in
IPCC meetings and actions arising
therefrom; these include seminars,
meetings of the Working Groups and
their subgroups etc.;
(ii) expand the travel support so
as to enable a number of experts
from each developing country to
attend meetings on climate change
and related issues to provide for
meaningful participation
particularly when meetings consider
different but related issues
simultaneously;
(iii)expand the opportunities for
developing countries to increase
their knowledge of the science on
climate change and policy-making
(e.g., energy policy), impacts, and
response options appropriate to
them, with respect to climate
change;
(iv) expand the opportunities for
developing countries to train and
enhance the skills of experts in
climate-related and climate change-
related research.
2.1.2 With respect to qualitative
objectives, the Committee
acknowledged the need to:
(i) provide for continuity of
participation from developing countries
in the IPCC process to further their
involvement;
( ii ) encourage dissemination within
the developing countries of information
and data on climate issues to increase
awareness and knowledge;
( iii) encourage that climate issues
are rationally considered in developing
national policies with respect to
science, economics and the environment
to achieve sustainable development;
( iv ) promote effective co-operation
within developing countries among
those responsible for the different
aspects of climate issues to foster
informed decision-making.
2 . 2
fiill articipatin
2.2.1 The factors identified by the
Special Committee which inhibit the
active participation of the developing
countries in IPCC activities can be
grouped into the following categories :
(i) insufficient information;
(ii) insufficient communication;
(iii) limited human resources;
(iv) institutional difficulties;
(v) limited financial resources.
2.2.2 The above factors have been
elaborated at length in the paragraphs
below. Without prejudice to their
generality, the Committee also took
note of the fact that most of the
developing countries faced the dilemma
of deciding allocation of priorities
between environmental issues and economic
development. While the global environment
has assumed today greater significance
for the industrialized countries,
the priority for the alleviation of
poverty continues to be the overriding
concern of the developing countries;
they rather conserve their financial
and technical resources for tackling
their immediate economic problems
than make investments to avert a global
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POLICYMAKERS SUMMARY SPC
problem which may manifest itself
after two generations, particularly
when their contribution to it is
significantly less than that of the
industrialized countries.
2.2.3 The Committee acknowledged
that the above dilemma of priorities
poses a serious obstacle to
enhancing the participation by
developing countries in the IPCC
process. The Committee further
acknowledged that, even as the
process of effective economic
development in the course of time
would increase the understanding
that developmental goals and
environmental concerns need not be
mutually exclusive, it was necessary
to enable the developing countries
to perceive the problem in its
correct perspective by deepening
their understanding of the science
of global climate change, its
potential physical and socio-
economic impacts and response
options.
2.2.4 The Committee noted that
developing countries consider the
lack of sufficient assurance so far
on the provision and requisite,
adequate, new and additional funding
particularly for the identification,
transfer, adaptation and
implementation of alternative safer
technologies on a preferential, non-
commercial and grant basis added
substantially to the inhibition of
the developing countries in taking
active part in IPCC activities. It
further noted that these countries
consider that the formulation of
guidelines for funding mechanisms
for transfer, adaptation and
implementation of clean technologies
as against legal and economic
measures would create healthier
conditions for the participation of
the developing countries.
2.3 Insufficient information
2.3.1 The Committee noted that many
developing countries do not have sufficient
information on the issue of potential
climate change to appreciate the
it evokes elsewhere in the world.
Information is often insufficient
with respect to the scientific basis
for concern, on the potential physical
and socio-economic impacts of climate
change as well as on response options
(see also para 2.2.4). This applies
not only to scientific milieux but
also to policymakers and public opinion.
2.3.2 Access to scientific data is
limited in the developing countries.
Many are unable to participate in
regional monitoring programmes, where
these exist, or to monitor weather
and climate continuously within their
national boundaries and in accordance
with international requirements.
2.3.3 As stated above, information
available in developing countrie
on the likely impacts of climate changv
within their national boundaries is
limited. While Working Group I of
IPCC has noted the inability of current
scientific models to anticipate specific
regional distributions of climate
change, the problem in developing
countries is more basic. Many do
not have the ability, for example,
to project how various increases in
sea level rise would affect them,
and hence what steps might be necessary
to adapt to it. Similarly, many
developing countries do not have sufficient
information to judge how best to achieve
energy efficiency, or to gauge its
costs, security and trade implications.
Another area where there is lack of
information is that of environmentally
less harmful technologies and products.
Gaps in information about proper
technologies in moisture conservation,
afforestation and soil protection
were noted as glaring examples in
this regard.
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POLICYMAKERS SUMMARY SPC
2.3.4 With adequate information,
developing countries would be able
to take more effective account of
climate change considerations in
formulating national policies. They
would also then be in a better
position to appreciate that the
deliberations on climate change had
far-reaching implications on their
economic and developmental
strategies, and to identify their
specific needs to determine which
may be met from existing resources
and which may require additional
resources.
2.4 Insufficient communication
2.4.1 The Committee noted that even
if information on climate change and
related activities were to be
provided, there was a need to
improve internal and external
communication to ensure the flow of
information to appropriate
recipients including economists,
scientists and policy-level
officials in the developing
countries. Internal communication
is important for informed
considerations of national policy
issues while improved external
communication facilitates the flow
of information to and from the
outside world.
2.4.2 The Committee also noted that
within the developing countries
there was need to strengthen and
streamline mechanisms to co-
ordinate, receive, store and
disseminate relevant information
either originating from within the
country and/or flowing from outside.
Lack of such mechanisms often
resulted in insufficient
appreciation of the need to
participate in the international
discussions on climate change.
2.4.3 In a similar manner, the
Committee noted that existing
international arrangements, to
transmit information on climate change
and related activities among the developing
countries were not yet effective enough.
2.5 Limited human resources
2.5.1 The Committee noted that to
receive, communicate and disseminate
information on climate change and
related activities, there was not
sufficient informed manpower available
within the developing countries. Full
participation by developing countries
has sometimes been hampered by the
limited pool of expertise available
in each country. Those few experts
as are available shoulder heavy
responsibilities and are extremely
hard pressed to take time away from
important national tasks.
2.5.2 Developing countries seek to
alleviate the problem in some instances
by having their embassy representatives
take part in those IPCC activities
that are scheduled in various capitals.
Even this measure is difficult for
smaller developing countries with
sparse representation. Another approach,
albeit less used at present, is to
designate regional experts to represent
a group of countries. There are drat&acks
inherent in both approaches. Embassy
officials may lack the background
information in the issues to take
effective part in meetings, particularly
those calling for specific expertise
in science, impacts, policy and legal
analyses, problems of human settlements
in coastal and low-lying areas, behavioral
sciences, and cost and economic analyses.
In addition, because IPCC meetings
take place in many areas of the globe,
it is difficult to provide for continuity
of representation through the use
of embassy officials. On the other
hand, designating regional experts
to represent a group of countries
invariably requires a high degree
of co-operation among such countries
and a relatively long preparatory
process, unless experts are designated
to serve on a long term basis.
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POLICYMAKERS SUMMARY SPC
2.6 Institutional difficulties
2.6.1 The Committee noted that in
many developing countries the
manpower engaged in co-ordinating
receiving, transmitting,
disseminating and effectively using
information on climace change and
related activities was not
sufficiently supported by
institutional infrastructure.
2.6.2 While this requirement for
national infrastructure has been met
successfully in some of the
developing nations, such is not the
general case. It is often not clear
which ministry or agency is
responsible or should have
responsibility for a particular
climate issue or decision. In
addition, co-ordination mechanisms
among ministries and agencies in
many developing countries are not
as well established or effective as
climate issues may demand.
2.7 Limited financial resources
2.7.1 For the reasons stated
elsewhere in the policymakers
summary, the Committee did not
consider in detail topics such as
financial assistance, economic
incentives/disincentives,
formulation of legal instruments,
and development of, and access to,
environmentally-benign and energy-
efficient technologies. These are
being dealt with by Working Group
III and are likely to form the
substance of future negotiations
among governments. However, the
Committee expressed the view that
actions to promote the full
participation of the developing
countries in climate change issues
should not await the outcome of such
negotiations. Some of them could be
taken now.
2.7.2 Limited financial resources
are intimately tied to a general
lack of access to new and bette
technologies. In addition, survival
needs have to be satisfied first.
Means of meeting the incremental costs
of ensuring a viable environment frequently
cannot be found. Also, local, immediate
environmental concerns generally receive
political priority over impersonal,
invisible, somewhat remote, global
concerns.
2.7.3 While the root causes of the
problem of lack of financial resources
may lie in the past patterns of economic
development, there are simpler but
nonetheless indispensable needs such
as travel funds, so that a nation
can keep itself informed of activities
elsewhere in climate change and related
fields.
2.7.4 Developing countries require
support for the attendance of their
experts at IPCC meetings. Travel
needs compete with other national
priorities for funds. Without travel
support, many developing countries
simply would not be able to attend
even a single meeting; for others,
adequate and effective representation
would not be pGRsihle. Here, as elsertere,
the issue is not so much an absolute
lack of financial resources as the
absolute necessity of establishing
spending priorities amid a large and
growing number of international
environmental and other meetings and
conferences. This is particularly
problematic for the least developed
countries as well as ft" smaller developing
countries, particularly those in the
Southern Hemisphere since the majority
of these meetings are held in the
Northern Hemisphere.
2.7.5 The Committee noted that the
attendance of the developing countries
in IPCC meetings has shown a steady
improvement (see sub-section 2.8 below).
Ironically, as the IPCC succeeds in
increasing the participation of developing
countries, the problem becomes more
complex unless funding assistance
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POLICYMAKERS SUMMARY SPC
for participation increases
commensurately. To date, ZPCC has
not established specific criteria
or priorities by which requests from
developing countries for travel
assistance should be considered.
2.7.6 In addition, while pledges to
the IPCC Trust Fund for the travel
support of invited experts from the
developing countries have been
generous and increasing, the process
has been ad hoc and the remittances
have not been timely to prevent
periodic acute shortfalls.
2.8 Progress in IPCC
2.8.1 In spite of the factors
discussed in the previous sections
which inhibit full participation by
the developing countries, it is
clear that IPCC has accomplished
much in its brief existence.
2.8.2 For example, the number of
developing countries attending the
first plenary of the Panel in
November 1988 was 11; this number
rose to 17 at the second plenary
(June 1989) and to 33 at the third
(February 1990). The number of
developing countries at the third
plenary surpassed that of the
industrialized countries (27).
2.8.3 In addition, the Panel had
initially allocated SF 222,510 for
travel support for the developing
countries in its 1989 budget
estimate. The actual amount spent
was approximately SF 383,904 (see
Annex II for a listing of
contributions). This amount paid
for 85 trips by 80 experts to attend
the meetings of the Panel, the
Bureau, the Working Groups and their
subgroups, and the Special Committee
in 1989. The budget for 1990 for
similar support is SF 794,000, which
is one half of the IPCC 1990 budget.
This has already been exceeded at
the time of the writing of this
policymakers summary and is in addition
to that channelled through bilateral
arrangements.
2.8.4 Moreover, several governments
(from the industrialized and developing
parts of the world) and regional
intergovernmental organizations are
holding information exchange and other
seminars, for the developing countries,
in 1990 and 1991 on the specific issue
of climate change. These are designed
to build awareness and assist the
understanding of the complex
interrelationship of the various aspects
of the subject.
2.8.5 The IPCC process itself has
served to increase awareness and knowledge
of the industrialized and the developing
countries with respect to climate
change issues. In this sense, while
more remains to be done to increase
the participation of developing countries,
IPCC has succeeded partially in an
essential function. The improving
situation cannot yet be termed satisfactory
by any means, as the full participation
by the developing countries is a
prerequisite for any successful action
such as the adoption of a climate
convention.
2.8.6 As a result of the combined
efforts and initiative of a few govemnents,
major financial institutions have
undertaken to raise fresh funds to
be allocated to the problems associated
with climate change. Specifically,
the World Bank has targeted climate
change as one of the four issues of
global iiqportance eligible for additional
funding at concessional rates.
3.
AREAS OF ACTION
The impacts of climate change
will vary from region to region and
nation to nation, as already stated
elsewhere in the policymakers summary.
Although response strategies fior developing
countries have to take into account
the needs for adequate funding and
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POLICYMAKERS SUMMARY SPG
safer technologies, country-specific
and/or region-specific approaches
will be necessary. For example,
response measures that small island
states require could be very
different from those for large
industrializing countries within the
developing world. Nevertheless, the
discussion in this section is
relevant in general to all
developing nations (and, indeed, to
all nations) and the Special
Committee will need to devote more
attention to specific requirements
in its future work.
Success in the implementation
of many of the recommended actions
(see section 4) depend not only on
national initiatives but also on
stronger regional or sub-regional
co-operation. Co-operation between
countries of the same region,
between countries and regional or
sub-regional institutions, and
between institutions themselves will
achieve cost savings and efficiency.
This is particularly indispensable
for the smaller countries, including
island nations.
Advantages of regional co-
operation are obvious for research
activities but they are there also
for many other sectors. For example,
with regards to energy savings,
countries could benefit from the
know-how of regional "technical
centres" which encourage research.
Together they could develop
technologies adapted to their
particular situation by sharing
their equipment and existing
infrastructures. The creation or
strengthening, for example, of
regional "departments" of energy and
environment would assist the
mobilisation of support and the co-
ordination of. research and
approaches common to many countries.
Also, there are actions that
will arise as a result of
negotiations and agreements, and machin
will have to be put in place to implemeu.
these. But there are others that
need to be taken now, that can be
done through existing arrangements;
most in this category should be planned
and carried out for several years.
The Committee compiled a list
of areas of possible action. This
list is not to be viewed as all-inclusive.
It is a beginning and is expected
to be reviewed periodically and modified
and added to as needed. The IHMLIHIM nations
of the Committee on specific action
items are given in section 4.
3.1 Development of information
3.1.1 While insufficient information
is not unique to the developing countries,
rectification of the associated problems
is likely to take longer in their
case.
3.1.2 The kind of information that
is insufficient includes:
* reliable scientific data,
predictions and interpretation;
* techniques of designing numerical
(computer) models;
* analytical tools for performing
impact analyses;
* cost and other implications of
addressing climate change;
* state-of-the-art methods of energy
production;
* availability and the nature of
possible policy options.
3.1.3 Such insufficiency can be part tally
redressed, inter alia, through:
* information exchange seminars;
* skill enhancement seminars;
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POLICYMAKERS SUMMARY SPC
* development of information
centres.
3.1.4 Information exchange seminars
should be undertaken on global,
regional and national levels. A few
governments and international
organizations have already planned
some. The seminars should be
periodic or cyclical to maximize
retention and wider dissemination
of information. They should be
aimed at senior officials, the media
and the public. Opportunities such
as World Meteorological Day, World
Health Day, the Earth Day and World
Environment Day could be taken
advantage of. The seminars could
include novel initiatives such as
conferences of planners. In this
respect, for example, a seminar
organized by the UNEP in Paris has
as its objective raising the
awareness of policy and opinion
makers on the issue of climate
change and of organizing, at the
same time, training activities on
the actions to be taken.
3.1.5 Skill enhancement seminars are
similar to training sessions. These
are best achieved in a regional
setting. A number of bilateral,
multilateral and international
organizations have such programmes.
These may require co-ordination to
increase their effectiveness.
3.1.6 As stressed in the relevant
part of the report of Working Group
III, an important component of this
effort is the introduction at all
stages of education and on a
continuing basis, curricula to
inform future citizens and decision-
makers. Wider public information
programmes are also important to
strengthen the mandate of
governments- to act.
3.2 Development of communication
3.2.1 Networking of scientific and
other experts on climate change and
related matters at national, regional
and international levels is a valuable
mechanism for rapid flow of information.
National, regional and international
conferences planned and held in the
developing countries would provide
good opportunities for such flow.
Existing plans of international
organizations such as UNEP and WMO
could play a critical catalytic role
in this regard.
3.2.2 One of the difficulties for
the timely transmittal of documents,
letters and requests for information
and action between, for example, the
IPCC Secretariat and governments is
that only a few countries have designated
focal/contact points for the purpose.
A related problem is that often the
focal/ contact point is not instructed
as to where, for example, a given
document should be sent for review
etc. Governments are urged to improve
appropriate national communication
mechanisms to ensure timely dissemination
of documents to relevant officials
and authorities. The establishment
of national climate committees composed
of all relevant expertise would be
one way to approach this issue (see
also section 2 and sub-section 3.5).
3.2.3 In the past, national embassies
have been used by governments to promote
this communication. This practice
could be helpful in selected cases.
Embassy staff, where available, can
also be designated to represent governnents
at IPCC meetings. This can especially
be helpful when designated experts,
for one reason or another, are unable
to attend.
3.3 Development of human resources
3.3.1 Development of informed manpower
is crucial if a developing country
is to contribute fully and effectively
to managing climate change. Any programme
in this area should address simultaneously
the related issues of education, training
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POLICYMAKERS SUMMARY SPC
and technical assistance (i.e.,
ready access to analytical tools,
techniques and methodologies, etc.).
3.3.2 Programmes for the training
of experts in the specific field
which is relatively new, namely,
climate change, are needed.
Specialization must be achieved in
such areas as the construction and
use of numerical models (e.g.,
climate prediction models,
biospheric models, econometric
models), observations and surveys
(e.g., atmospheric observations for
climate and related data, socio-
economic surveys), laboratory and
engineering techniques, human
settlements in coastal and other
low-lying regions, and data analyses
and interpretation for policy
applications. Programmes
specifically tailored to regional
questions would be helpful in
addressing common concerns such as
policy considerations.
3.3.3 Exchange of visits of experts
on climate change and related issues
between the industrialized and the
developing worlds should be
instituted on a continuing, long-
term basis. Academic staff from the
industrialized countries could be
encouraged to spend their
sabbaticals in the developing
countries with fellowships dedicated
for the purpose. Exchange between
academic institutions could be
encouraged. Account should be taken
of the particular difficulties that
will be encountered in those
developing countries with poorly
developed educational infrastruc-
tures where the capacity to respond
to new educational demands is
limited.
3.3.4 Involvement of local expertise
should be sought and encouraged when
studies in given geographical areas
are undertaken, and advantage taken
of opportunities for training which
arise as a result.
3.3.5 Programmes to provide ready
access to state-of-the-art technology
and investigative and implementation
tools and methodologies (e.g., computers
of adequate power that could be shared
on a regional basis, mass communication
methods) should be instituted.
3.3.6 In this context, the Committee
is of the view that assistance be
provided at the regional level by
the United Nations Development Programme
and specialized agencies such as WHO
and UNEP. Their assistance should
cover, inter alia, the development
of expertise in such areas as climate
modeling, formulation of scenarios
for decision makers, human settlements
programmes, and for transfer of adaptive
and updated technology. Existing regional
centres of relevance in this regard
should also be strengthened.
3.4 Functioning of institutions
3.4.1 Difficulties in national co-ordinatin.
are evident to most of the developing
countries. In the case of IPOC activities,
for example, only a few countries
have designated national focal points
(see also sub-section 3.3). This not
only hampers the flow of information
and the continuing participation of
the developing countries, but also
the follow-up actions needed to be
taken at the national level.
3.4.2 Efforts to promote national
co-ordination of activities on all
aspects of climate change should be
redoubled. This is imperative for
information flow, planning and
implementation of data collection
and analyses programmes, studies on
cost, international treaty and trade
implications, and policy options,
and to establish and maintain national
review and implementation machineries.
Achieving co-operation among the many
national agencies engaged in climate
change in one way or another is a
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POLICYMAKERS SUMMARY SPC
long process requiring many steps.
Any delay in initiating this effort
will make it that much more
difficult to respond to climate
change and maintain sustainable
development. Information on
effective institutional arrangements
and their establishment should be
exchanged between countries.
3.4.3 National centres would provide
natural foci for timely and
effective flow of internal and
external information. This is
important in view of the possibility
of concerted regional and
international actions in addition
to purely national ones. The
centres would facilitate
communication among experts in
different discipline areas; the
necessity for such communication
cannot be overemphasized in the
context of climate change, which is
inherently multi-disciplinary.
3.4.4 There are many international
organizations that are involved in
climate change studies and issues
such as ICSU, UNEP, WMO, WHO, FAO
and the World Bank. While their
work is necessarily mission-specific
as mandated by their respective
governing bodies, the efforts are
quite complementary to each other
and can profit from more cross-
referencing. In this regard; it
would be very helpful if the same
briefs are provided on the climate
change issue to all delegations from
a nation to the different meetings
of the various international
organizations. The respective
governing bodies would then be kept
fully in the picture and can make
decisions in a wider context. This
would avoid unintended duplication
of work and at the same time help
identify questions that are likely
to be missed because of novel
inter-disciplinary and multi-
disciplinary characteristics. All
this can, in turn, only strengthen
national co-ordination. The offices
of the UNDP resident representatives
and resident co-ordinators could assist
recipient governments in their efforts
of co-ordination at country level
in this regard.
3.5 Development of fjnanr"ial resoiiT'css
3.5.1 Plans and action strategies
of developing countries for their
economic development should be respected.
Developmental assistance should in
general be enlarged and accelerated.
3.5.2 The question of access to new
technologies and methodologies for
undertaking studies as well as putting
into effect implementation measures
is intertwined with that of general
lack of financial resources . Bilateral
and multilateral technical assistance
is imperative for initiating and/or
modernizing existing installations
and practices to address climate change .
(The problem of technology development
and its transfer to the developing
countries, and financial assistance,
is dealt with by Working Group III,
as already stated.)
3 . 5 . 3 The Committee, however, wants
to stress that developing countries
would require financial assistance
to meet the incremental costs of
incorporating climate change
in their current developmental planning.
Such assistance should be extended.
tterever it is feasible for the developing
countries to incorporate climate change
considerations in their action strategies
without incurring additional costs,
such incorporation should be made.
The modalities ( the amount and method
of funding, for example) form part
of the consideration of Working Group
III . The Committee noted the conclusions
of the Working Group III financial
measures paper on a future work programme,
including the need to advance the
concept of a new mechanism, in the
context of a future climate convention
or its protocols. It considered that
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POLICYMAKERS SUMMARY SPC
this issue should be given a high
priority.
3.5.4 Recognizing the need to
incorporate measures for adjusting
to climate change with developmental
planning, all developing countries
which are in a position to integrate
activities such as climate
monitoring, impact analyses and
studies on adaptation opticr.s should
be encouraged to promote them and
carry out research with financial
assistance that primarily aims at
securing the following:
* data acquisition 2nd exchange;
*
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POLICYMAKERS SUMMARY SPC
through the life of IPCC. Some of
the actions are of such a nature
that international organizations
(e.g., WMO, UNDP, UNEP, ICSU, WHO)
can implement them.
4.1.6 The Committee emphasizes that
having regard to the global nature
of climate change and the need for
participation by all States if the
objectives of the recommended
activities are to be achieved, the
total programme will stand or fall
depending on the availability of
adequate funding to those countries
in need.
4.2 Specific recommendations
4.2.1 The Committee recognizes that
there are several issues justifying
actions in their own right and which
will contribute to dealing with the
longer term climate change issues.
It is thus evident that no country
should rely solely on the
international processes leading to
protection of the climate to deal
with all the issues which have been
identified.
4.2.2 Uninterrupted travel
assistance to the developing
countries for attendance at the
meetings of IPCC should be ensured.
The Committee wishes to call the
attention of the Panel to the
importance of continuing this effort
and of the donor nations continuing
and increasing contributions to the
effort, with no cessation after the
fourth plenary of IPCC.
4.2.3 Serious consideration should
be given to supporting more than one
expert from each participating
developing country to those climate
change-related meetings that deal
with several aspects of the problem.
The developing countries on their
part:
* should compile a list of
national experts and make it
available for travel assistance;
* should agree to contribute to
the effort through travel subsidies
when their national air carriers
fly to meeting places;
* should agree to designate jointly
an expert or a single group of
experts to attend meetings where
their interests can be commonly
represented.
4.2.4 Governments and organizations
from the industrialized nations are
encouraged to continue and increase
their efforts in organizing seminars.
Developing countries could organize,
under the sponsorship of international
organizations or otherwise, regional
seminars and workshops in order to
exchange scientific and technical
information. For this purpose, necessary
programmes and lists of experts should
be developed. As part of the continuing
process of information exchange, the
Committee recommends that IPCC circulate
this policymakers sunmary to an concerned
including those attending the Second
World Climate Conference. The developing
countries on their part should designate
focal points, as soon as possible,
for transmittal of reports, documentation ,
data and information on seminars.
Such focal points should be briefed
on forwarding the material to appropriate
recipients within the nation for response,
review etc.
4.2.5 Developing countries should
consider the establishment of mechanisms
for national co-ordination of all
their activities related to climate
change. The mechanisms would aid
such areas as information dissemination,
development and implementation of
plans for research and monitoring,
and formulation of policy options.
The industrialized countries should
consider assisting the developing
countries in these areas with easy
access to needed technologies.
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4.2.6 The Committee recommends that
acquisition, analyses and
interpretation of information on
climatic and related data would
enable de sloping countries to take
more effective account of climate
change considerations in formulating
national policies. Such actions are
necessary also at regional levels
to undertake and refine impact
studies. The current unevenness in
the acquisition and use of such data
which is evident between the
hemispheres should be eliminated.
The Committee further recommends
that the developing countries take
immediate action to identify their
specific needs to determine the
financial implications of such
action. It would be necessary to
mobilize appropriate funding in
order to mount a sustained programme
and create regional centres to
organize information networks on
climate change.
4.2.7 In many developing countries
the meteorological/ hydrological
service is the main and often the
only institution collecting and
recording data with relevance to
climate. If associated weather
patterns are modified, as some
predict they would as a result of
climate change, then the
capabilities of such services need
to be reinforced to enhance their
contributions to sustainable
development.
4.2.8 The Committee recommends that
considerations of climate change
should be integrated in development
policies. These policies could
favour projects which have as their
objective the prevention of and
adjustment to adverse effects of
climate change, promotion of the
awareness of, and education on, the
problem and the development and
deployment of appropriate techniques
and methodologies. National
environmental studies should also
take into account predicted climate
change in order to determine sustainable
development strategies. To reach these
objectives, the developing countries
and many industrialized countries
consider it essential that additional
funding be available to enable developing
countries to meet the incremental
costs resulting from their efforts
to combat climate change.
4.2.9 The Committee further recommends
that its findings be duly taken into
account in all relevant areas of the
work of IPCC. Programmes of action
should be developed and implemented
(and the concepts which would lead
to such programmes of action developed
where needed) without delay, with
a view to ensure, provided the necessary
means are made available, the full
participation of developing countries
in the future work and activities
on climate change. UNEP and HMO should
take the lead in this regard and initiate
the necessary consultations. Other
multilateral or bilateral organizations
should also be contacted for elaborating
and implementing these programmes
of action, such as:
(i) In the field of research and
monitoring
* the United Nations and its
Specialized Agencies
* regional intergovernmental
organizations such as the European
Community
* non-governmental organizations
such as the International Council
of Scientific Unions.
(ii) On seminars and workshops in
such areas as public information,
negotiations and legal aspects
* non-governmental organizations
in addition to the UN and its
Specialized Agencies and regional
intergovernmental organizations.
14
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(iii)On education and training and
technical assistance
* UN and its Specialized Agencies
(iv) On financing or funding
* multilateral financing
institutions such as the World
Bank, the Regional Development
Banks, the UN Development
Programme etc.
The Committee also recommends
that serious consideration be given
by IPCC to the provision of
simultaneous interpretation and
documentation before, during and
after a session in the customary UN
languages for the meetings of the
Special Committee, given the complex
POLICYMAKERS SUMMARY SPC
nature of the subject matter covered
and the p*H-iniTar" difficulties encountered
by the developing countries.
The Special Committee should
be mandated by IPCC to monitor and
review the preparation and the
implementation of the above mentioned
and other relevant programmes of action.
4.2.10 To provide a basis for future
programmes of action, the Committee
requested the Chairman, within the
financial resources available, to
arrange for the extraction of the
recommendations and action options
arrived at by the Working Groups of
IPCC; this document should be circulated,
after review by the Special Committee,
to donor and other countries, international
organizations and regional groups.
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ANNEX 1
TERMS OF REFERENCE OF THE IPCC SPECIAL COMMITTEE
ON THE PARTICIPATION OF DEVELOPING COUNTRIES
1 . The Committee will recommend to IPCC and its Bureau, specific measures
to be undertaken for promoting the full participation of the developing
countries in all IPCC activities.
2. It will include in such recommendation institutional arrangement(s)
and implementation schedule(s) if and as needed.
3. It will develop action plans for the implementation of its recommendations.
4. It will identify the resource requirements and the means of meeting
them to accomplish the task outlined in (1) above.
5. It will periodically review the progress of the implementation of
its recommendations and make modifications thereof, as appropriate.
6. It will work closely with IPCC Working Groups.
7. It will continue its work until its dissolution by IPCC.
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POLICYMAKERS SUMMARY SPC
ANNEX 2
31 August 1990
Table 1
1989 Contributions to the -Joint WMO/UNEP IPCC Trust Fund
CONTRIBUTOR AMOUNT SFR CURRENCY RECEIVED
Australia 24,963.05 $ 15,175.00
Canada 14,519.50 C$ 11,000.00
China 16,400.00 $ 10,000.00
Denmark 7,550.00 $ 5,000.00
Finland 7,950.00 $ 5,000.00
France 25,303.00 FF 100,000.00
Federal Republic 43,750.00 Sfr 43,750.00
of Germany
Japan 75,500.00 $ 50,000.00
Netherlands 40,250.00 $ 25,000.00
Norway 25,050.00 $ 15,000.00
Saudi Arabia 16,500.00 $ 10,000.00
Switzerland 55,000.00 SFr 55,000.00
UK 90,578.85 E 35,000.00
USA 199,500.00 $ 120,000.00
UNEP 125,000.00 SFr 125,000.00
WMO 125,000.00 SFr 125,000.00
TOTAL SFr 892,814.40
a. The IPCC budget is in Swiss francs (SFr) since this is the currency
of the WMO budget. The joint WMO/UNEP IPCC Trust Fund is administered
by the Secretary-General of WMO in accordance with WMO Financial Regulations.
b. The amount contributed exclusively for travel support to developing
countries in 1989 was SFr 182,000. Many contributors gave flexibility
to the IPCC Secretariat on expenditures, while all affirmed their desire
that at least part of their contributions should be spent on travel support
to developing countries to attend IPCC meetings.
c. One-half of the 1989 expenditures in the IPCC Trust Fund was
devoted to the travel support of the developing countries.
d. The 1989 account of the IPCC Trust Fund showed a surplus which
was carried over to 1990. Nevertheless, the Fund was experiencing acute
and continuing cash shortages throughout 1989.
e. The Government of Norway has given Nkr 700,000 to the IPCC Secretariat
for organizing an information exchange seminar for the developing countries
on climate change issues. This has not been shown in the table, since this
contribution is through a special Memorandum of Understanding and not to
the Trust Fund.
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In this connection, it may be noted that several countries a:
planning regional seminars on the same and related topics. These countrie.
are:
France: Seminar on greenhouse warming in late 1990/early 1991
jointly with the Energy and Industry Office of UNEP;
Japan: Seminar on the environment and fossil fuel consumption
in the Pacific Region, mid-December 1990; information exchange
seminar for the developing countries in Asia at the end of January
1991;
Spain: Seminar for the Spanish-speaking developing countries
in the third quarter of 1990;
Australia: possible joint seminar with the Economic and Social
Commission for Asia and the Pacific (ESCAP).
Table 2
Receipts. IPCC Trust Fund, for 1990
MEMBER
Australia
Canada
Denmark
Finland
France
Federal Republic of
Germany
Italy
Japan
Netherlands
Norway
Sweden
Switzerland
UK
USA
UNEP
WHO
Rockefeller
Foundation
TOTAL
USSR
AMOUNT EO.SFR
83,490 *(4)
30,506 *(7)
153,000 *(3)
15,743
48,573 *(5)
70,494 *(2)
83,500
75,500 paid in 1989
151,384
33,985 *(6)
43,075 *<8)
30,000
86,224 *(10)
298,970 *(1)
329,000
125,000
68,000
1,726,444
85,000 *(9)
*(1 ) Of the US contribution, $ 100,000 is earmarked for the travel support
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POLICYMAKERS SUMMARY SPC
to the developing countries.
*(2) The Federal Republic of Germany contribution is DM 160,000 for both
IPCC and the Second World Climate Conference. The contribution to
IPCC is one-half of this amount.
*{3) The Denmark contribution is specifically for travel and other assistance
to the low income developing countries for 1989 and 1990 (see the
following page for a listing).
*(4) Of the Australian contribution, AUD 20,000 was earmarked for the travel
support of South Pacific delegates to the meeting of the Coastal Zone
Management Subgroup of Working Group III (Perth, 19-23 February 1990).
*(5) In addition, France has contributed Ffr 200,000 to augment the staff
of the IPCC Secretariat; the Secretary-General of WHO has assigned
to the IPCC Secretariat a full-time Scientific Officer seconded to
WHO by the Government of France.
*(6) In addition, Norway has given Nkr 700,000 for the purpose of holding
an IPCC Information Exchange Seminar for the developing countries
on climate change issues through a special Memorandum of Understanding
*(7) The Canadian contribution is part of Can$ 100,000; the full Canadian
contribution includes translation of the three IPCC Working Group
reports into French.
*(8) This is in addition to the support provided by Sweden to the 4th Plenary
of IPCC.
*(9) The equivalent in roubles was provided by the USSR to support travel
of experts from developing countries to meetings of Working Group
II.
*(10)In addition, UK may give E 100,000 .for a series of seminars for
policymakers in developing countries, through a special Memorandum
of Understanding, in a manner similar to the contribution of Norway
reflected in (6) above.
19
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LIST OF LOW INCOME DEVELOPING COUNTRIES
Afghanistan
Bangladesh 160
Benin 270
Bhutan 160
Botswana 840
Burkina Faso 150
Burma 200
Burundi 240
Cape Verde 500
Central African Rep. 310
Chad
Comoros
D]ibouti
Equatorial Guinea
Ethiopia 130
Gambia 230
Guinea 290
Guinea-Bissau 170
Haiti 330
Kiribati
Yemen Dem. 480
Laos
Lesotho
Malawi
Maldives
Mali
Mauritania
Nepal
Niger
Rwanda
Sao Tone & Principe
Sierra Leone
Somalia
Sudan
Tanzania
Togo
Tuvalu
Uganda
Vanuatu
Western Samoa
Yemen
410
160
310
170
420
160
260
290
340
310
280
320
230
250
690
S50
OTHER LOW INCOME COUNTRIES:
Anguilla
Bolivia 540
China 280
Cote d'Zvoire 720
Dominican Republic 710
Egypt 730
Ghana 390
Guyana 500
Honduras 740
India 270
Indonesia 500
Kampuchea
Kenya 310
Liberia 450
Madagasca 230
Mayotte
Mongolia
Mozambique
Nicaragua 790
Pakistan 380
Papua New Guinea 690
Senegal 420
Solomon Islands
Sri Lanka 400
St. Helena
Swaziland 610
Tonga 690
Turks it Caicos Islands
Viet Nam
Zaire 160
Zambia 300
Zimbabwe 620
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APPENDIX C
REPORT OF THE TASK FORCE
THE COMPREHENSIVE APPROACH
TO CLIMATE CHANGE
-------
A COMPREHENSIVE APPROACH
TO ADDRESSING POTENTIAL CLIMATE CHANGE
Report of the Task Force on
the Comprehensive Approach
to Climate Change
February 1991
Table of Contents
Section
Overview:
Chapter I:
Chapter II:
Chapter III:
Chapter IV:
Chapter V:
Chapter VI:
Chapter VII:
Chapter VIII:
Conclusion:
Title Page
An Outline of Key Points 1
The Setting 11
The Science of Climate Change 16
Defining a Comprehensive Approach 31
A Comprehensive Approach to Research 39
and Monitoring
Environmental Advantages of a 46
Comprehensive Approach
Economic and Institutional Flexibility 60
Potential Objections and Replies 70
Market-Based Incentives 77
Toward a Comprehensive Approach 92
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A COMPREHENSIVE APPROACH
TO ADDRESSING POTENTIAL CLIMATE CHANGE
OVERVIEW: AN OUTLINE OF KEY POINTS
As negotiations on a Framework Convention on Climate
Change begin, it is timely to consider the best approach to
addressing potential human-induced global climate change in a
convention and in possible subsidiary instruments. We know from
experience that the success of environmental policy instruments
and institutions is critically related to their design. If law
fails to match the environmental system to which it is addressed,
the results are frustrating failures and missed opportunities.
It is therefore crucial that careful attention be given to the
question of how best to match the structure and content of any
international agreement to the science and economics of human
interactions with climate.
The best design for the climate change convention, and
for any policy responses, would be a "comprehensive" approach
that addresses all relevant trace gases, their sources and sinks.
In August 1990, the Intergovernmental Panel on Climate Change
(IPCC) Overview stated: "A comprehensive strategy addressing all
aspects of the problem and reflecting environmental, economic and
social costs and benefits is necessary." In November 1990, the
government ministers at the Second World Climate Conference
(SWCC) declared: "We recommend that in the elaboration of
response strategies, over time, all greenhouse gases, sources and
sinks be considered in the most comprehensive manner possible..."
A comprehensive approach is needed in order to deal
with all of the many the scientific, environmental and economic
aspects of the climate system, which involves many trace gases
affected by activities in every sector of human society. From
the point of view of environmental quality, the focus of interest
is the combined effect of all the greenhouse gases on the
environment. A "piecemeal* approach, focusing narrowly on only
one aspect of the system such as one greenhouse gas, would be
scientifically inadequate, environmentally ineffective, and
economically inefficient. It would repeat the mistakes made in
many traditional environmental policies over the last two
decades.
In contrast, a comprehensive approach addresses all
greenhouse gases, their sources and sinks together. The result
is more coherent understanding of the factors contributing to
potential global climate change and their impacts, and more
effective and efficient design of any policies to address those
factors, including both limitation and adaptation responses. In
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- 2 -
order to address all greenhouse gases together, a comprehensive
approach employs a measure, such as an 'index,1' to compare the
contributions of different gases to total global climate change.
A comprehensive approach also employs the concept of "net
emissions,* taking into account the uptake of gases by sinks as
well as their release from sources.
The comprehensive concept is an "approach" or heuristic
that offers insight into any discussion of any response
strategies for potential climate change. The comprehensive
approach is the proper framework for pursuing scientific research
and monitoring, predicting future climate forcing, developing new
technology, and evaluating policy actions; its utility is not
limited to the design of emissions limitations. And it chiefly
addresses how to design sound policies, not how much to respond.
As an approach to improving scientific understanding,
the comprehensive approach addresses all of the anthropogenic
factors contributing to potential climate change. It assembles
the elements needed for a full appreciation of potential climate
change factors, and helps identify the areas most in need of
further research. As the framework convention seeks to improve
both the physical science and the social science of global
change, a comprehensive approach will be essential to any efforts
to research, measure, and forecast the potential for future
climate change associated with human emissions of trace gases a
its impacts on society and the environment.
If any measures to prevent climate change prove to be
warranted — such as national strategies, technology development,
emissions limitations, or others — a comprehensive approach
would be the most environmentally effective as-well as
economically efficient design. By addressing all the human-
influenced factors in potential global climate change and using
an index of relative impacts, a comprehensive approach maximizes
the environmental value of every investment in response
strategies. It provides the tool for evaluating the full effects
of technologies and practices on climate. It highlights and
avoids the shifts by economic actors from regulated to
unregulated activities that are likely to occur under narrowly
aimed piecemeal policies; these shifts can undercut or even
reverse the benefits of the piecemeal measure. The comprehensive
approach also encourages the use of the most innovative and
resource-efficient responses, including efforts to conserve and
expand greenhouse gas sinks, such as forests, with related
benefits. Furthermore, because each nation has a different
economy, society, and portfolio of greenhouse gas sources and
sinks, the best set of response measures will be different for
each nation; a comprehensive approach provides the needed
flexibility for each nation to develop its most cost-effective
mix of measures to fit its particular domestic needs while
achieving global results.
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"Comprehensive Approach'' described
o It is an approach to structure consideration of climate
change issues — scientific, economic and policy — on a
comprehensive basis, addressing all the human interactions
with the climate system.
o It stands in contrast to a "piecemeal" approach, which
focuses narrowly on emissions of one gas, carbon dioxide
(CO2), primarily from the energy sector, and omits other
critical factors.
o It considers all of the significant human-influenced
"radiatively active trace gases" (RATGs) that affect
climate:
Carbon dioxide (C02)
Methane (CH4)
Nitrous oxide (N20)
Chlorofluorocarbons (CFCs), Hydrochlorofluorocarbons
(HCFCs), and related substances
Tropospheric Ozone (O3) and its precursors:
Nitrogen oxides (NOx)
Carbon monoxide (CO)
Volatile organic compounds (VOCs or NMHCs)
o It considers all sources and sinks (such as vegetation,
soils and oceans) of the relevant gases, in every sector of
human activity:
Energy production and use
Transportation
Agriculture
Forestry and land clearing
Industry
It focuses on "net emissions* (sources less sinks), the
important variable for determining atmospheric
concentrations.
o A comprehensive approach is in use in other areas:
The Montreal Protocol's use of an Ozone Depletion
Potential (OOP) index to phase out CFCs and related
substances
"Multimedia* approaches to integrated management of
land, air, and water pollution.
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Comparing trace gases
o A comprehensive approach employs a measure, such as an
index, of the comparative environmental impacts of the
gases. This index reflects the fact that gases vary in
their environmental characteristics:
1. Heat trapping ability ("radiative forcing")
2. Residence time in the atmosphere
3. Reactivity with other gases (affecting both the
gas' own residence time and the production of
other radiatively active trace gases)
4. Other attributes, such as ozone depletion or plant
fertilization.
One possible index is the "Global Warming Potential" (GWP)
index of "radiative forcing," presented in the IPCC Report:
Instantaneous
radiative forcing
Gas per kg (rel. to C02)
CO2 1
CH4 58
N20 206
CFC-11 3970
CFC-12 5750
HCFC-22 5440
HCFC-134a 4130
Atmospheric
residence years
(estimated!
120
10
150
60
130
15
16
Relative radiative
forcing potential
over years
10
1
63
270
4500
7100
4100
3200
100
1
21
290
3500
7300
1500
1200
500
1
9
190
1500
4500
51C
42C
(Source: IPCC Scientific Assessment, 1990, Tables 2.3, 2.8.)
Use of an index provides a guide to environmentally optimal
choices, maximizing the environmental value of each
investment of society's resources. It also helps ensure
that decisions are not made that limit one gas while
ignoring and inadvertently increasing others.
Use of an index also allows flexibility to design a mix of
measures addressing the various gases, toward any overall
goal.
Some index or weighting system is unavoidable, whether
implicit or explicit. A C02-only policy implicitly weights
the other gases at zero.
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- 5 -
A Comprehensive Approach has multiple applications
o Research. Designing research strategies to improve
understanding of all relevant gases, sources, sinks, and
source/sink processes. Many are not yet sufficiently well
understood and require significant study. Development of
trace gas indices, and integrated science/economics
research, should also be pursued.
o Monitoring and Inventories. Calculating current atmospheric
concentrations and net emissions for all relevant gases by
nation and sector. Today the ability to measure sources and
sinks of several trace gases, such as N20 and CH4, and to
measure sinks of C02, is incomplete.
o "Report cards.* Calculating the likely effects of current
policy actions on net emissions of all relevant gases. This
task depends on reliable forecasts of trace gas emissions
trends, which also require a comprehensive approach.
o Technology evaluation. Calculating the effects on net
emissions for all gases of technologies and practices.
Possible uses in technology transfers, financial assistance,
R&D funding.
o Policy choices. Calculating the effects on net emissions of
proposed policy actions. The comprehensive approach
provides a powerful analytic tool for evaluating piecemeal
policy proposals.
o Policy design. Defining any proposed or agreed response
measures in terms of a comprehensive approach, accounting
for and allowing flexibility among all relevant gases,
sources and sinks.
The policy context of a Comprehensive Approach
o The comprehensive concept is an "approach" or heuristic that
offers insight into any discussion of response strategies
for potential climate change. The utility of the approach
is not limited to the design of emissions limitation
policies; it suggests the proper scope and optimal design
for pursuing scientific research, developing technology,
evaluating current policy actions, or designing emissions
limitations policies (whether domestic or international).
o It chiefly considers how to design sound policies, not how
much to respond, though it does shed light on the latter
question by focusing analysis on the full environmental
benefits and economic costs of potential actions.
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Advantages of a Comprehensive Approach
A. Environmental advantages
o Piecemeal policies have often proved environmentally
ineffective or even counterproductive. Historically,
environmental policy design has been piecemeal: efforts have
been aimed separately at emissions into the air, water, and
land "media.* This piecemeal approach has led to "cross-
media shifts* in "residuals* (emissions and wastes), moving
pollution around without reducing it.
o Piecemeal pitfalls! shifting residuals in the climate
context. A narrow focus on limiting emissions of one trace
gas, or one sector, could induce counterproductive shifts in
emissions to unregulated gases and sectors. For example:
Piecemeal policy aimed at C02 alone would induce fuel-
switching from coal to natural gas, because natural gas
emits less CO2 per BTU than coal. But a CO2-only
approach would overlook the resulting increased methane
(CH4) emissions from leakage of natural gas facilities.
At a CH4 leakage rate of about 6%, roughly all of the
CO2-related reduction in radiative forcing from the
coal-to-gas fuel switch is offset by CH4 leaks. (Rodh-
(1990), using a 100-year GWP; not counting CH4 ventin
from fuel extraction.) since CH4 leaks are thought to
average about 2-4% worldwide, about half the C02-
related savings would be offset. And CH4 leaks may
average 5-10% in the Soviet Union, where coal-to-gas
switching under a C02-only emissions limitation could
actually increase net radiative forcing.
Moreover, capturing fugitive CH4 emissions might
be a highly cost-effective means of limiting contri-
butions to radiative forcing, especially where leakage
rates are high. A C02-only policy ignores that option.
Piecemeal focus on limiting agricultural CH4 from wet
rice farming could induce use of nitrogenous
fertilizers that reduce CH4 emissions per rice yield,
but also raise N20 emissions.
— Piecemeal focus on a subgroup of emitters, such as only
a few nations, would omit major sources of future
emissions, and would be undercut by shifts in
emissions-intensive activities to other nations.
A comprehensive approach ensures that policy makers are
aware of and account for such shifts.
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Advantages, continued
o Optimal signals. A comprehensive approach would provide
optimal incentives in any efforts, if warranted, to develop
new technology or limit emissions. It maximizes the
environmental benefit from any investment of social
resources. It provides an environmentally sound guide to
selection of technologies for development and transfer, or
to enacting incentive policies, across the entire range of
socioeconomic activities affecting trace gas net emissions.
o Inclusion of Sinks. By focusing on "net* emissions, the
comprehensive approach fosters sink protection and
expansion, such as afforestation and protection of carbon-
fixing phytoplankton. Benefits may include biodiversity,
reduced soil erosion, and protected food webs. (Management
of sinks is a complex endeavor, and poorly designed sink
enhancement policies could have adverse impacts.)
B. Economic and social advantages
o Piecemeal approach is economically inefficient. Piecemeal
policy would exclude policy options that address other
gases, other sources, or sinks, and could achieve the same
environmental outcome at less cost. For example, a policy
aimed only at energy sector C02 would bar potentially less
costly yet equally effective abatement options such as
enhancement of C02 sinks, CH4 reductions, faster CFC
reductions, and attention to CFC-substitutes.
o Flexibility reduces costs. Because each nation has a
different economy, society, and set of sources and sinks,
the costs of different options will vary across gases and
sectors and across nations. While limiting C02 emissions
from energy might be best for one nation, limiting CH4
emissions from waste disposal (or rice or livestock) might
be best for another, afforestation best for a third, and
reducing tropospheric ozone precursors best for another.
Requiring them all to take the same action would impose
needless costs. Affording each nation the flexibility to
design its best policy mix to address the various gases,
sources and sinks helps minimize the economic costs and
institutional dislocations of any emissions limitations.
o Level Playing Field. A piecemeal approach inevitably favors
some nations while disproportionately burdening others. For
example,- a CO2-only approach penalizes nations with
relatively greater dependence on fossil fuels or fossil fuel
revenues. A comprehensive approach provides a more "level
playing field" across nations, increasing the likelihood of
cooperation.
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Potential Objections to a Comprehensive Approach, and Replies
o ''Data and monitoring of sources and sinks are inadequate."
Better data and monitoring are being pursued, and this
work needs to be accelerated. The convention should
advance international cooperation in this effort.
Where direct measurement is impractical, carefully
chosen proxies or surrogates can be employed.
Incentives could spur monitoring improvements, such as
offering rewards to those who develop and demonstrate
better monitoring techniques.
The groundwork needed to flesh out a workable
comprehensive approach is very likely to be less costly
than the environmental and economic losses due to a
piecemeal approach that is ineffective and inflexible.
o "We can't afford to wait for a comprehensive approach; we
need to do what we can now to address C02."
Development of a comprehensive approach does not mean
delay. A comprehensive approach can be phased in as
other actions (e.g. forestry agreement), and harder-to-
monitor sources and sinks, are integrated.
But the framework needs to begin as a comprehensive
approach; experience shows that once a piecemeal
approach is adopted, interests favored by its narrow
scope become entrenched and a sound approach is
blocked.
Given its environmental and economic advantages, taking
the time to develop a comprehensive approach is
worthwhile. Hasty resort to a piecemeal approach would
achieve less overall environmental gain than fashioning
a sound comprehensive approach.
By sharing burdens on a level -playing field, a
comprehensive approach eases the route to consensus; a
piecemeal approach imposes disproportionate burdens
that will generate resistance.
A comprehensive approach makes better use of scarce
resources. It thus better provides for sustainable
development, which requires both effective and
efficient policies since environmental protection
ultimately depends on the resources that economic
growth provides.
A comprehensive approach does not prevent action.
Nations who wish to limit net emissions of any of the
range of trace gases may do so now; indeed taking a
comprehensive approach broadens the set of
opportunities to address potential climate change.
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- 9 -
Objections and Replies, continued
o "CFCs should not be included in comprehensive basket."
All substances contributing to radiative forcing should
be included. For example, CFCs and CFC substitutes
(HCFCs, MFCs) may be quite important to radiative
forcing. The Montreal Protocol does not account for
these impacts, nor fully control CFC substitutes.
— The comprehensive approach would not allow violation of
the Montreal/London phaseout schedule. Crediting
faster or deeper reductions would spur further efforts.
— Some nations are doing more to reduce global CFCs than
others, and their contribution should be recognized.
Existing reservoirs of CFCs are leaking into the
atmosphere, but are not covered by the Montreal
Protocol. Giving credit for reductions in these CFCs
would provide helpful incentives.
o "The Global Warming Potential Index is uncertain."
There is emerging international consensus that the
scientific fundamentals are sound.
Uncertainties will be reduced as methods, data and
estimates improve.
Absolute precision is not necessary for practical uses.
Some weighting system is unavoidable.
A good index is better than no index.
o "A comprehensive approach is complex and unworkable."
— Experience shows that a comprehensive approach need not
be complex or unworkable. The Montreal Protocol
successfully employs a multi-gas approach with an OOP
index.
As experience with traditional environmental issues
shows, piecemeal approach means scrambling to redress
unintended shifts and dysfunctions.
Comprehensive approach eases workability by affording
nations needed economic and institutional flexibility.
Practical indices are being developed (see above).
o "Other discrete actions will have already been taken, such
as the forthcoming forestry agreement, limits on CFCs in the
Montreal Protocol, and limits on VOCs."
Integration of prior and current actions into
comprehensive approach will be appropriate in any case.
A comprehensive approach provides the opportunity for
integrating domestic actions that reduce net trace gas
emissions but are taken for other reasons.
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Options for Including a Comprehensive Approach in a Framework
Convention. As described earlier, the comprehensive approach h
multiple applications. Each could be incorporated into the WOTK
of the IPCC, the convention, and any program the convention
establishes. For example, the convention could charge the IPCC
or other body to coordinate and assess work on the following:
(1) Research strategy. Pursue integrated scientific and
economics research on a comprehensive basis: ensure
attention to the sources, sinks, atmospheric properties, and
socioeconomic and ecological impacts of all the relevant
trace gases.
(2) Monitoring. Develop techniques and systems for
comprehensive source and sink monitoring: cooperative
international networks measuring emissions and uptake of all
relevant trace gases. Establish centers for data sharing,
harmonizing methodologies, R&D on new techniques.
(3) International inventories. Build the capacity to estimate
international net emissions of relevant trace gases: base-
line levels and changes due to policy actions. Provide for
national reporting, workshops to compare data and methods.
(4) Indices. Cooperative development and refinement of indices.
The IPCC or other expert body could conduct regular
assessments and keep policy makers informed of development
(5) Technology evaluation. Employ a comprehensive approach to
assess the net emissions impact of any technology transfer
and financial assistance activities.
The convention could also:
(6) Ensure a comprehensive framework for policy. Ensure that
any policy discussion, any calls for "national plans," or
any limitations obligations (if any, whether now or in the
future), are defined in terms of a comprehensive approach.
This could be required, or at least endorsed, in the
convention.
(7) Offer incentives through advance assurance. Give advance
assurance that current actions will receive "credit" against
any future obligations, in accordance with a comprehensive
approach. This would help avoid disincentives to taking
actions justified on other grounds, which nations may hold
in abeyance until credit for them is assured. Actions could
include afforestation, energy conservation, and trace gas
reductions, and both national and international programs.
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Chapter Z: The Setting
Negotiations are beginning on a "framework convention
on climate change." Following the report of the Inter-
governmental Panel on Climate Change (IPCC) in August 1990, in
particular its paper on legal measures, the convention is likely
to contain provisions relating to scientific research,
monitoring, information exchange, economics research, and other
issues of importance to the negotiating parties. At the same
time, the IPCC considered, and some have urged, adoption of
response measures to mitigate or adapt to potential climate
change.
Any analysis of important events and outcomes requires
understanding the underlying systems at work and the
interrelationship of the variables that make up those systems.
One cannot look only at isolated events or outcomes and expect to
understand the complex system as a whole. As the conservationist
John Muir put it, "when we try to pick out one thing by itself,
we find it hitched to everything else in the universe."
Perhaps no problem exemplifies Muir's adage better than
what we have come to call "global change." The intricate web of
biological, chemical, geologic, anthropogenic, and other
processes at work in the earth system cannot be understood by
simple reference to one of its myriad component elements.
Forecasts of future global change — such as potential climate
change, stratospheric ozone depletion, or changes in the chemical
composition of the atmosphere — necessarily involve an
understanding of biogeochemical trends and equilibria,
predictions about the enormously diverse socioeconomic activities
that might perturb these equilibria, models of the likely
resultant physical changes in the earth.system, estimates of any
eventual impacts on societies and ecosystems, and appreciation of
interwoven feedbacks and synergisms.1
Several different "radiatively active trace gases"
(RATGs)2 are emitted, removed, and influenced by human
1 See, e.g., J. Smith and D. Tirpak, eds., The Potential
Effects of Global Climate Change on the United States (1989), ch.
2.
2The term "radiatively active trace gases" (RATGs) refers to
the group of- substances that trap thermal radiation in the
atmosphere, and that interact with other substances in the
atmosphere to produce such gases indirectly or to prolong their
atmospheric lifetimes. The related term "greenhouse gases" is
also used.
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activities. Because these gases are "radiatively active," thei-
presence in the atmosphere may tend to raise the atmosphere's
average temperature at the Earth's surface, and may thereby
change the global climate. The greenhouse gases affected by
human activities include carbon dioxide (CO2), methane (CH4),
nitrous oxide (N20), halocarbons such as chlorofluorocarbons
(CFCs) and related substances (HCFCs, MFCs), and tropospheric
ozone (03), whose precursors include oxides of nitrogen (NOx),
volatile organic compounds (VOCs), and carbon monoxide (CO).
Each greenhouse gas is emitted from a variety of sources and each
has a different residence time in the a'~-osphere, a different
ability to trap heat, and different pot^itial impacts on the
environment.
Policy formulations need to match the underlying
ecological systems they address. The optimal design for the
climate change convention, and for any policy responses, would
a "comprehensive" approach that addresses all relevant tr-v~
gases, their sources and sinks. This approach has been d.-:
by United States officials in several papers.3 The incernac.
perspective now seems to be broadening to match the ecological
reality: integration of physical and social science is making
clear that a comprehensive approach to the complex global system
is essential, addressing all the relevant trace gases, their
sources and sinks. In August the Intergovernmental Panel on
Climate Change (IPCC) stated in its Overview: "A comprehensive
strategy addressing all aspects of the problem and reflecting
environmental, economic and social costs and benefits is
necessary."4 In November, the government ministers at the Second
World Climate Conference (SWCC) declared: "We recommend that in
the elaboration of response strategies, over time, all greenhouse
gases, sources and sinks be considered in the most comprehensive
manner possible... "5
In keeping with its commitment to a comprehensive
approach, the United States has undertaken a set of policy
3 See U.S. "Concept Paper" submitted to the IPCC, 29
December 1989; U.S. Papers on "U.S. Experience with Comprehensive
and Emissions Trading Approaches to Environmental Policy,"
Informal Seminar for IPCC WGIII officers, Washington, D.C.,
February 3, 1990; Richard B. Stewart and Jonathan B. Wiener, "A
Comprehensive Approach to Climate Change," 1 American Enterprise
75 (November-December 1990); Interagency Task Force, "The
Economics of Long-Term Global Climate Change: A Preliminary
Assessment," U.S. Department of Energy, OPPA, DOE/PE-0096P,
September 1990, pp. vii, 21-22.
4 IPCC Overview, August 1990, p. 14.
5 Ministerial Declaration of the SWCC, paragraph 14.
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measures that together constitute a comprehensive approach,
addressing several RATGs, sources and sinks. Preliminary
analysis indicates that this set of measures will keep U.S.
contributions to radiative forcing at current levels through the
year 2000. These actions are shown in Table 1 below. Several
other nations have also endorsed or proposed following a
comprehensive approach.6 Because each nation has a different
economy, society, and portfolio of greenhouse gas sources and
sinks, the best set of response measures will be different for
each nation; a comprehensive approach provides flexibility for
each nation to develop its most cost-effective mix of measures to
fit its particular domestic needs while achieving global results.
If the international response to potential climate
change is to be scientifically, environmentally and economically
sound, it needs to take a comprehensive approach. Yet all too
often, policy discussions zero in hastily on only one of many
variables, in spite of our experience that narrow policies
addressing only one attribute of a complex system typically
provide little environmental benefit and incur significant cost.
Where the understanding of the environmental system is highly
incomplete, hasty adoption of policy measures may apply leverage
to the wrong variables, missing or even exacerbating the true
problem. In the current discussion, policy commentators
initially gravitated to a narrow focus on one aspect of the
issue: the potential global warming effects of carbon dioxide
(C02) emissions from energy sector activities. This piecemeal
approach ignores all the other aspects of climate change,
including the several other RATGs, their diverse sources and
sinks in all sectors of human activity, and their multiple
environmental attributes. The result is an approach that omits
most of the science and neglects the lessons of past policy.
The challenge is to frame the discussion in terms of
the environmental system and its comprehensive character. If the
framework is comprehensive, sound science and policy may follow.
6 See Canada's Green Plan (1990), pp. 97-108. Canada
proposes actions on several RATGs in several sectors, and terms
the strategy a "comprehensive response," id. p. 102. Other
nations have announced proposals that address not only C02 but
also other RATGS. See "Climate Change Policy in the Netherlands
and Supporting Measures," Netherlands Ministry of Housing,
Physical Planning and the Environment, D.G. for Environment,
November 1990 (addressing CO2 sources and sinks, CFCs, and CH4);
"Protecting the Earth's Atmosphere," Report of the Federal
Cabinet Study Commission, Bonn, Germany, November 7, 1990
(addressing C02 and CH4); "Action Program to Arrest Global
Warming," Decision made by the Council of Ministers for Global
Environmental Conservation, Government of Japan, October 23, 1990
(addressing C02 sources and sinks, CH4, N2O).
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Table l.A
Emissions Reductions Expected in the Year 2000
Due to current Environmental Commitments
Millions of Tonnes of
Current Commitment Carbon-Equivalents Reduced
fwith RATC affacted1 through 2000
Tree Planting Initiative (C02) 9
DOE Energy Efficiency Initiatives (C02) 28
DOE Appliance Standards (C02) 4
DOE Renevables Initiatives (C02) 4
1990 Clean Air Act
Acid deposition provision (C02)7 17
Other provisions (NOx, CO, VOCs)8 51
EPA Landfill Regulation (VOCs, CH4) 44
CFC Phaseout (CFCs)9 551
Total Reduction from 2000 Trend 657
Source: Alex Cristofaro and Joel Scheraga, "Policy Implications
of a Comprehensive Greenhouse Gas Budget,* U.S. EPA, OPPE, draft
September 1990, Table 2. Calculations use the IPCC 100-year
radiative forcing ("GWP") index.
7 The 1990 Clean Air Act will reduce CO2 as electric
utilities are encouraged to pursue energy conservation under the
innovative emissions trading system the Administration created to
reduce acid deposition precursors.
8 These reductions of NOx, CO, and VOCs are achieved mainly
through restrictions on mobile source emissions.
9 The figure includes only actions pursuant to the 1987
Montreal Protocol and 1990 London update; it does not take into
account additional reductions the U.S. will achieve under its
1990 Clean Air Act.
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- 15 -
Table l.B
D.8. Emissions Today and in 2000
(Million tonnes of carbon-equivalent)
2000, with
RATG Current Current Commitments
C02 1310 1503
CH4 234 208
VOCS 72 48
NOX 218 199
CO 52 45
N2O 74 74
CFCs 367 256
TotaL; 2328 2332
Source: Alex Cristofaro and Joel Scheraga, "Policy Implications
of a Comprehensive Greenhouse Gas Budget,* U.S. EPA, OPPE, draft
September 1990, Figures 4-5. Calculations use the IPCC 100-year
radiative forcing ("GWP") index.
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- 16 -
Chapter ZZ: The Science of Climate Change
Several different "radiatively active trace gas?
(RATGs)10 are emitted, removed, and influenced by human
activities. Because these trace gases are "radiatively ac . e,"
their presence in the atmosphere may tend to raise the
atmosphere's average temperature at the Earth's surface, and may
thereby change the global climate.11 The RATGs affected by human
activities include carbon dioxide (C02), methane (CH4), nitrous
oxide (N2O), halocarbons such as chlorofluorocarbons (CFCs) and
related substances (HCFCs, HFCs), and tropospheric ozone (O3),
whose precursors include oxides of nitrogen (NOx), volatile
organic compounds (VOCs), and carbon monoxide (CO). Each RATG is
emitted from a variety of sources and each has a different
residence time in the atmosphere, a different ability to trap
heat, and different potential impacts on the environment.
From the point of view of environmental quality, the
focus of interest is the combined effect of all the RATGs.
Assessing the combined effect of trace gases requires an
understanding of their varied characteristics. RATGs vary by
several characteristics:
1. Heat trapping ability ("radiative forcing")
2. Residence time in the atmosphere
3. Reactivity with other gases (which affects both the
gas' own residence time and the production of
other radiatively active trace gases in the
atmosphere)
4. Other attributes, such as other effects on the
environment
RATGs and radiative forcing
RATG molecules affect the radiative balance of the
atmosphere, tending to trap heat and warm the Earth's surface.
But RATGs do not all have the same impact on atmospheric warming:
different molecules absorb thermal radiation at different
10The term "radiatively active trace gases" (RATGs) refers
to substances that, when present in the atmosphere, act to trap
thermal radiation; and to other substances that interact in the
atmosphere to produce such greenhouse gases indirectly or to
prolong their atmospheric lifetimes.
11The term "potential global climate change" refers to
possible changes in global and regional climate that may result
from changes in the atmosphere's thermal radiation budget.
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- 17 -
efficiencies. That is, a molecule of CO2 has a different
potential for "radiative forcing" than a molecule of, say, N20.
Estimates of this "instantaneous radiative forcing" impact are
shown in the first column of Table 2. Estimating the
instantaneous radiative forcing abilities of different trace gas
molecules is generally a straightforward matter of laboratory
research, and there is high confidence in these numbers. Certain
complications arise due to the fact that the forcing effect is
dependent on the ambient concentration: as the existing
concentration of the gas in question rises, additional molecules
add less and less to total radiative forcing. Thus, estimates of
the instantaneous radiative forcing of a molecule (or kilogram)
can be obtained given knowledge about the concentration of the
gas; the estimates presented in the first column of Table 2 are
for current concentrations. These estimates show that C02 is the
weakest of the RATGs, unit-for-unit, at trapping thermal
radiation at a given instant in time: CH4 is 58 times more
effective than C02, N2O is about 200 times more effective, and
CFC-11 and CFC-12 are about 4000 and 6000 times more effective,
respectively.
The atmospheric residence time of RATGs also varies.
Different trace gases remain in the atmosphere for different
periods of time. Their "atmospheric lifetimes" or "residence
times" depend on such variables as the rates at which they react
with other gases in the atmosphere, and the rates at which they
are removed by sinks. The prediction of the atmospheric lifetime
of a trace gas is thus a mathematical function that depends,
among other things, on the atmospheric concentration of relevant
gases in the atmosphere, reaction rates in the atmosphere, and
sink removal rates. The concentration of gases in the atmosphere
depends, in turn, on such variables as the emissions rates,
existing concentrations, reactions, and sink removal rates for
those gases. Estimates of typical lifetimes, assuming current
levels of relevant variables, are shown in the second column of
Table 2. These estimates are subject to uncertainties., chiefly
because the sink removal processes are not all well understood.
For example, each CO2 molecule cycles in and out of the
atmosphere every 5-10 years, but is not finally removed from the
atmosphere and deposited in the deep ocean for several hundred
years; the "120 years" figure in Table 2 is a current best
estimate, but may change as the ocean-atmosphere carbon cycle is
better understood.12
12 The lifetime of gases also may have independent policy
relevance because it affects the irreversibility of emissions,
the ability to "back out" of unexpected difficulties. An
erroneous underestimate of the severity of climate change may be
harder to reverse if gases being emitted are long-lived than if
they are short-lived.
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- 18 -
The reactivity of RATGs varies as well. Reactions are
important sinks for RATGs, because as the molecules react they
are broken apart and their atoms combined into new compounds.
Some gases, such as N2O, are fairly stable, and do not react much
with other gases in the atmosphere. In contrast, CH4, CO, vocs,
and HCFCs are all highly interactive. They often react with the
hydroxyl (OH) radicals that abound in the lower atmosphere,
indirectly affecting the abundance of other gases that would
otherwise have reacted with the OH radicals. The presence of NOx
accelerates the formation of tropospheric ozone (03) from CO and
VOCs; 03 is itself a RATG. These kinds of "indirect" effects are
included in the cumulative radiative forcing estimates shown in
Table 2.
Scientists attempting to judge the cumulative radiative
impact of each additional molecule added to the atmospheric
concentration of a trace gas must take into account the
instantaneous radiative forcing potential of the gas, its likely
lifetime in the atmosphere, and its interactions with other
gases. The calculation of the cumulative contribution to
radiative forcing of each additional molecule over its lifetime
can be complicated. Nevertheless recent attempts to calculate
the different cumulative contributions of various RATGs, using
the "global warming potential* (GWP) method of mathematically
integrating the instantaneous radiative forcing of the gas over
its probable lifetime, have reached fairly similar results.13
Table 2 presents the IPCC's estimates of relative radiative
forcing per unit mass (kilogram) of each gas emitted, based on
the GWP method.
13See, e.g., IPCC Scientific Assessment (1990), Chapter 2;
Daniel Lashof and Dilip Ahuja, "Relative Global Warming
Potentials of Greenhouse Gas Emissions,* 344 Nature 529 (April 5,
1990); Thomas Levander, 'The Importance of Greenhouse Gases other
than Carbon Dioxide and Other Possible Differences Between
Various Fuels," Swedish National Energy Administration (Heat &
Electricity Production Div.) memorandum Sept. 14, 1989, presented
to the OECD Group on Energy and Environment, Oct. 13, 1989.
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- 19 -
Table 2
ZPCC "Global Warming Potential" (GWP) Indices
Instantaneous
radiative forcing
ner ko frel. to CO21
CO2
CH4*
N20
CFC-11
CFC-12
HCFC-22
CFC-113
CFC-114
CFC-115
HCFC-123
HCFC-124
HFC- 12 5
HFC-134a
HCFC-141b
HCFC-142b
HFC-143a
HFC-152a
CC14
CH3CC13
CF3Br
1
58
206
3970
5750
5440
3710
4710
4130
2860
3480
4920
4130
2900
4470
4100
4390
1640
900
4730
Atmospheric
residence years
(estimated)
120
10
150
60
130
15
90
200
400
1.6
6.6
28
16
8
19
41
1.7
50
6
110
Relative radiative
forcing potential
over vears
20 100 500
111
63 21 9
270 290 190
4500 3500 1500
7100 7300 4500
4100 1500 510
4500 4200 2100
6000 6900 5500
5500 6900 7400
310 85 29
1500
4700
3200
1500
3700
4500
510
1900
350
5800
430
2500
1200
440
1600
2900
140
1300
100
5800
150
860
420
150
540
1000
47
460
34
3200
Indirect RATGs
CO (tropospheric O3)
CO (CO2)
NOx (tropospheric O3)
vocs (tropospheric O3)
VOCs (C02)
5
2
150
28
3
1
2
40
8
3
0
2
14
3
3
Source: IPCC Scientific Assessment, 1990, Tables 2.3, 2.8.
^Including indirect effects of CH4 on tropospheric O3, C02,
and stratospheric H2O.
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- 20 -
Preliminary calculations with another method, employin
large climate models to test the relative effect of a change in
each gas on the realized temperature projected by the models,
yield index values for other RATGs relative to CO2, over a 100-
year time horizon, that are roughly twice as large as the GWP
method generates.14 In other words, this method shows C02 to be
roughly half as important relative to the other RATGs as the I?cc
GWP estimates (over 100 years). The differences between the
climate model approach and the GWP calculation arise in part
because the climate model approach calculated realized
temperature change while the GWP calculated equilibrium
temperature change, so the two measures may be useful for
different purposes. Moreover, while the GWP method assumes
possibly simplified dissipation functions and does not depict
synergistic effects of multiple forcing agents, the climate
models carry many other uncertainties (e.g. the crude or
incomplete coupling or atmosphere, oceans, and land, or the
limited ability to model cloudiness) that may affect their
accuracy.
In any event, all of these studies make it clear that,
even taking into account the potentially long atmospheric
lifetime of C02 molecules, CO2 has the least impact per unit on
atmospheric radiative forcing: it is the weakest RATG. When one
looks only at current human contributions to potential
atmospheric warming, the effects of C02 appear to be large
because the volume of C02 concentration and emissions is large
compared to other anthropogenic trace gases. Assessments of the
total contribution from each trace gas to changes in total
atmospheric radiative forcing have estimated that CO2 is
responsible for roughly one half of current anthropogenic
contributions, while other trace gases account for the
remainder.15 This is illustrated in Figure 1, below. But
because the concentrations of most other trace gases are growing
more rapidly than those of CO2,16 and because of the relatively
14 T.H.L. Wigley, H.K. Hulme, and T. Holt, "An Alternative
Approach to Calculating Global Wanning Potentials," Climate
Research Unit, University of East Anglia, Norwich UK (draft
November 1990).
15See IPCC Scientific Assessment (1990), Policy makers
Summary, p. xx; U.S. Environmental Protection Agency, "The
Potential Effects of Global Climate Change on the United States,"
Report to Congress, Dec. 1989, pp. 12-15 and Figure 2-4.
16 The IPCC Scientific Assessment (1990), Policymakers'
Summary/ P- xvi, reports the following current annual growth
rates: C02 CH4 N2O CFC-11 CFC-12
0.5% 0.9% 0.25% 4% 4%
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- 21 -
larger cumulative impact per molecule of other trace gases
relative to C02 (as described above), the relative contribution
of C02 to total atmospheric radiative forcing has declined since
1880.17 Looking ahead, policy measures would have to address
future increments of RATG emissions, so the environmental impact
of each additional molecule is necessarily of primary concern.
Figure 1
Radiative Forcing in the 1980s
CARBON
DIOXIDE
NITROUS
OXIDE
METHANE
Source: IPCC Scientific Assessment (1990),
Policymakers' Summary, p. xx. The contribution
from ozone may also be significant, but cannot be
quantified at present.
17See U.S. Environmental Protection Agency, "The Potential
Effects of Global Climate Change on the United States," Report to
Congress, Dec. 1989, p. 15, Figure 2-4. EPA estimates that C02
represented 66% of contributions to radiative forcing over 1880-
1980, but only about 50% in the 1980s. Because of the imminent
phaseout of CFCS, which represented 15-20% of radiative forcing
in the 1980s, CO2's relative share of radiative forcing is
predicted to be stable or increase in the future.
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- 22 -
Developing the radiative forcing indices
The time horizons used in the IPCC index — 20, 100,
and 500 years — define the time over which one considers the
impacts of radiative forcing. It is not clear which of these
three tine slices, or others, is appropriate for making decisions
about potential climate change. Would the impacts of one unit of
atmospheric warming be worse now, or in 2100, or in 2600? Given
possible advances in technology and knowledge, and other
potential changes in the environment, it virtually impossible to
predict what the impact of warming might be 500 years from now,
and so one might decide to ignore radiative forcing effects
beyond, say, 100 years. On the other hand, it is possible that
distant future warming will burden an already increasingly
stressed planet, and hence be more damaging. Put another way,
what is the value to present persons of avoiding a unit of
warming now, versus a unit of warming 100 years from now? At
what rate might we "discount" future warming, as a proxy for
discounting the future adverse impacts of warming? Adop ,ing a
shorter time horizon has the same effect as adopting a higher
discount rate: future effects are deemed less worrisome than
near-term effects. A simple linear extrapolation of the effects
of warming over time is probably not exactly accurate,18 yet it
is hard to tell today how else to estimate the importance of
future radiative forcing. Every calculation of a radiative
forcing index has used some form of weighting present and future
effects.19
Other improvements could be made in the radiative
forcing index. Work is needed to harmonize various quantitative
approaches and extend international understanding of indices, and
to improve the accuracy of estimated residence times of RATGs,
Scientific uncertainties in the current estimates remain
surrounding the residence time of C02, due to complications in
the carbon cycle and uncertainties in C02 sink removal processes.
Atmospheric chemical reactions involving other gases, such as CH4
and precursors to tropospheric 03, complicate estimates of their
residence times. Recent work at the National Oceanic &
Atmospheric Administration (NOAA) laboratories is substantially
improving estimates of the dissipation rate and residence time of
CH4 (which now appear to be longer than previously thought, thus
18 See Richard Eckaus, "Comparing the Effects of Greenhouse
Gas Emissions on Global Warming,* MIT Center for Energy Policy
Research, November 1990.
19 The IPCC uses time horizons. Lashof & Ahuja, supra use
a discount rate.
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- 23 -
raising the relative GWP of CH4). As work on indices is ongoing,
uncertainties in best estimates can be expressed and revised.
The indirect effects attributable to various gases'
atmospheric reactions also need additional analysis. Certain
trace gases react to form other radiatively important trace
gases, or react with substances that would otherwise affect RATG
abundances. These effects may be especially important for CH4
and HCFCs. Another step to be taken is modeling index values as
they are affected by "saturation" effects: as concentrations of
gases grow, the band of the electromagnetic spectrum blocked by a
gas may become occluded so that additional increments of the gas
have diminishing marginal radiative forcing impacts. Current
radiative forcing estimates could be revised to account for these
diminishing potencies in future years with higher
concentrations.20 And estimates need to take account of the
implications that vertical and other distribution of RATGs in the
atmosphere may have for calculated index values. Most generally,
institutional mechanisms for developing a consensus index and
adjusting it to new research results need to be developed. The
framework convention could spur the formation or nomination of
such institutions.
Although these uncertainties remain in the GWP values,
the consensus of the IPCC was that the scientific method of
calculating GWPs is sufficiently sound to permit its use.
Similarly, an international workshop on GWP Indices organized by
NOAA, EPA, NASA, UKDOE and others in Boulder, Colorado in
November 1990, concluded that though these uncertainties require
urgent attention, they do not undermine the scientific
fundamentals of the GWP index and do not warrant abandoning it.
For practical policy purposes, some weighting system is
unavoidable: not using an explicit index means weighting other
gases at zero, or haphazardly. A fairly good index,
appropriately employed, is a great deal better than no index at
all. A good but imperfect index could serve well and then be
amended later when knowledge improves.
20 This phenomenon is accounted for in the estimates of
relative warming potential based on climate models instead of GWP
extrapolations, as discussed above.
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- 24 -
More complete indices: toward a "global change index*
RATGs also have other environmental impacts, but these
characteristics are not accounted for in the radiative forcing
index. Radiative forcing is only an intermediate physical effect
of trace gases, and is really a proxy used as a common metric to
compare the diverse RATGs.21 But RATGs have multiple attributes
of societal and ecological concern; they yield other, non-warming
environmental impacts of global and local significance which may
be more important (in magnitude, timing, or other features) than
their contributions to radiative forcing. For example, CO, NOx,
and urban O3 are reactive and/or toxic. CFCs and related
substances deplete the stratospheric ozone layer. Higher CO2
concentrations increase plant photosynthesis and increase plants'
water use efficiency,22 increasing crop yields and improving
their drought-resistance.
Accurate understanding of the environment that will
prevail in a world of higher RATG concentrations, as well as the
optimal design of incentives for policy choices, would entail
developing a comparative index that incorporates the full
externalities (social and ecological costs) imposed by increments
of each RATG.23 And it might try to take account of the
variations in the cost of warming incurred at different times and
different places.24 Without a more "complete" index, a simple
radiative forcing index could provide signals or incentives thai
yield desirable changes in aggregate radiative forcing but
undesirable changes in other impacts; in economists' words,
significant externalities will remain uninternalized, and the
incentive signals of the narrow index may produce perverse
outcomes. Efforts to limit warming that totally ignored other
2Measurement of the ultimate impacts of wanning itself on
biological and other systems, though critical for assessing the
costs and benefits of climate change, are not generally
incorporated into the radiative forcing index because such
impacts stem from warming generically, and are not expected to
vary depending on the type of gas enhancing the warming.
22 See Norman Rosenberg, et al., "From Climate and C02
Enrichment to Evapotranspiration," in Paul Waggoner, ed., Climate
Change and U.S. Water Resources (1990), pp. 151-75.
23 See John Reilly, "Climate Change Damage and the Trace
Gas Index Issue," USDA, Economic Research Service, draft November
1, 1990.
24 See Richard Eckaus, "Comparing the Effects of Greenhouse
Gas Emissions on Global Warming," MIT Center for Energy Policy
Research, November 1990.
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- 25 -
consequences might generate unacceptable increases in ozone
depletion or toxic air pollutants, or deprive crops of needed
atmospheric carbon.
For example, if only C02 concentrations double over the
next several decades, climate-induced crop yield losses may be
largely offset by the positive yield effects due to C02's
"fertilization" and water use efficiency effects on plants, if
equivalent RATG doubling were, however, due completely to gases
other than C02, then these positive offsets would not be
realized. And if the RATG increase were made up of gases with
other harmful effects, such as CFCs or very large quantities of
CFC substitutes that still deplete the ozone layer, there would
be additional negative consequences besides warming. The upshot
is that society should be interested in focusing any control
efforts where they will do the most good, considering all
environmental impacts.
Crafting a "complete" index of ultimate costs poses
quite difficult analytic and technical problems. Data are not
yet adequate on important aspects of the magnitude and variations
of the diverse impacts; for example, data are lacking on the
effects of ozone depletion on UV-B irradiance, and on the effects
of changes in UV-B irradiance on biota. Comparing the dissimilar
warming and non-warming impacts on a common scale, something like
comparing apples and oranges, is a challenge requiring serious
analytic efforts. Predicting economic effects far into the
future is, as noted earlier, a highly inexact science.
A somewhat more realistically achievable index would
incorporate only the key "global change" attributes of each RATG,
namely their radiative forcing and the other salient non-warming
global impacts of RATGs, such as the direct effects of C02
enrichment and the ozone depletion impacts associated with CFCs
and other halocarbons.25 The diverse global impacts of the gases
would be estimated using best economic forecasting tools, coupled
with expert evaluations of the ecological impacts and of the
relative importance of the diverse impacts. This "global change
index" would thus be an improved, albeit still incomplete, proxy
for ultimate economic and ecological damages. It would capture
the main global externalities associated with the gases,
providing significantly better policy signals than an index
limited to radiative forcing. It would nonetheless require
effort and time to construct; the global change index should
therefore be developed as a complement to and in tandem with the
more technically manageable radiative forcing index.
25 Essentially local attributes of the gases, such as their
toxicity, would be left to local policy strategies.
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- 26 -
A very preliminary estimate has been made of a somewhat-
more complete index of global environmental impacts. By
incorporating the incremental impact of RATGs due to only two
effects — radiative forcing and CO2 enrichment of agriculture —
one study has estimated the following index values:
Table 3
Comparisons of Trace Gas Indices
Physical Effects: Impacts:
Instantaneous Climate Effects
RATG Radiative Forcing + C02 Fertilization
C02 1 1
CH4 58 92
N2O 206 260
CFC-11 3970 6343
CFC-12 5750 9119
Source: From John Reilly, "Climate Change Damage and
the Trace Gas Index Issue," USDA, Economic Research
Service, draft November 1, 1990, Table 3.
The "instantaneous radiative forcing" index values in column 1
are simply taken from the IPCC, as shown above in Table 2. The
estimates in column 2 of the impacts of climate change — due to
radiative forcing and C02 fertilization of crops — are derived
by computing the effects of radiative forcing in climate
forecasting models, and using estimates of future economic and
environmental impacts under different climate and CO2 regimes to
estimate net economic impacts. Both the climatological and the
economic forecasting models are subject, to significant
uncertainties, so the "economic" impacts index shown in column 2
of Table 3 above is necessarily uncertain. In addition, the
index computed here only accounts for the economic impacts of
warming and C02 fertilization on global agriculture, omitting
effects on other sectors and on ecosystems.26
Nevertheless, the index in Table 3 suggests the great
importance of the non-warming impacts of the RATGs. It suggests
26 In addition, Reilly's economic effects index does not
account for the depletion of stratospheric ozone due to CFCs,
which would 'markedly increase CFCs' index values (assuming ozone
depletion is highly damaging to humans and the environment). Nor
does it account for the local toxicity of certain RATGs. All of
these would further increase the index values of other RATGs
relative to C02.
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- 27 -
that a unit of social resources expended to limit emissions of
CH4 generates about 90 times more benefit than the same unit of
resources spent to limit C02 — rather than roughly 60 when
considering only radiative forcing. It thus suggests that
counting radiative forcing alone leads to an substantial
underestimate (by about a third) of the value of controlling CH4
relative to C02, and likewise a substantial overstatement of the
value of controlling C02 relative to CH4. Similar comparisons
may be made for the other trace gases. And because the index
shown in Table 3 does not account for the ozone-depleting effects
of CFCs, a more complete index incorporating those serious
environmental impacts would raise the CFC figures further, above
the 6300 and 9000 figures shown here; in other words, the
relative benefit of controlling CFCs is still understated in this
index.
Policy implications of RATG science
These scientific observations lead to the conclusion
that any sound effort to address potential global climate change
must address all relevant trace gases, and treat them in
accordance with their different environmental impacts.
Considering both radiative forcing potential, of which C02 is the
least potent anthropogenic agent, and the non-warming impacts of
the RATGs, it is clear that unit-for-unit, C02 is the most
environmentally benign of the RATGs. If society and the
biosphere had to accept any given amount of predicted warming,
then on purely environmental grounds (abstracting from the costs
of limitation strategies), it would prefer to have as much of
that given amount of warming due to CO2 and as little due to
other RATGs.
At the same time, the lifetime of gases has independent
policy relevance because it affects the irreversibility of
emissions, that is, the ability to 'back out* of unexpected
difficulties. An erroneous underestimate of the severity of
climate change is harder to reverse if gases being emitted are
long-lived than if they are short-lived.27 Thus, while the
residence time is already incorporated in measures such as the
GWP index, it has additional importance where the ultimate impact
of radiative forcing is highly uncertain.
Whether the goal is to understand, predict, or limit
potential atmospheric warming, attention must be paid to all the
gases contributing to that result. Predicting radiative forcing
27 On the other hand, if for some unforeseen reason it
later turns out that warming is desirable but difficult to
generate quickly, it might be better to have emitted more long-
lived RATGs.
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- 28 -
without good data on the RATGs other than CO2 would clearly be
unsatisfactory, as elaborated in Chapter IV. An understanding
the relative contributions of different trace gases to potential
atmospheric wanning (and other environmental impacts) is a
prerequisite for setting a research agenda and for assessing the
costs and benefits of different policy responses. Placing limits
on emissions of just one gas would leave other gases
unrestricted; this problem is discussed further in Chapter v.
And limiting emissions of certain gases may be less costly to
society (or to different nations or sectors of society), or more
beneficial to the environment, than limiting others; this topic
is taken up in Chapter VI.
Diverse sources and sinks
Similarly, the scientific nature of how RATGs enter and
leave the atmosphere indicates that attention should be paid to
the full range of their sources and sinks. Trace gases are
generated by numerous sources, including human ("anthropogenic17)
activities, other biological activities, and non-biological
processes. Among the anthropogenic sources of trace gases are
virtually every sector of human activity, including mining,
energy generation, transportation, agriculture, forestry, waste
disposal, industry, building and residential services, and
others. Biogenic sources are similarly diverse. The full
of sources deserves attention in developing effective response
strategies.
Meanwhile, some gases are removed from the atmosphere
by "sinks" such as trees, phytoplankton, ocean mixing, and
chemical reactions. Whether the goal is to predict or limit
emissions of RATGs, contraction and expansion of sinks is an
important component. Sink conservation and expansion might
achieve net emissions limits at potentially lower cost per
molecule than restrictions on some sources of trace gases.
Moreover, expanding sinks such as forests can have other
important environmental and economic benefits, such as protection
of biodiversity and soil conservation. If response strategies
are to address the possible causal factors of potential global
climate change, the variety of both sources and sinks of trace
gases must be included.
Examples of the sources and sinks of each of several
RATGs are presented in Table 4. Other sources and sinks not
affected by human activity have been omitted from the Table, such
as photochemical destruction of N2O in the upper atmosphere.
Some technological methods of capturing emissions have also been
omitted from Table 4, such as flue gas removal ("scrubbing"),
fluidized bed desulfurization, and other means of removing SO2
from the combustion process. Similarly, CO2 might be "scrubbed"
from combustion smokestacks, though present technology is
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- 29 -
generally extremely expensive. CH4 might be recaptured from
natural gas pipeline and distribution leaks and from landfill
wastes.
The enormously diverse set of sources and sinks shows
the pervasive and complex web of human activities that affect
RATG concentrations. This is both an opportunity and a
challenge: an opportunity to understand the full set of human
interactions that may contribute to climate change, and a
challenge to avoid focusing narrowly on one source or sink while
ignoring others. As Chapter V explains in greater detail, the
interconnected web of human activities worldwide that affect RATG
emissions makes narrow policies inappropriate: narrow regulations
are likely to be undermined as economic actors shift away from
regulated sources toward unregulated ones.
For certain of the sources and sinks listed in Table 4,
data and models are not yet sufficient to quantify precisely
their contributions to net emissions on a national basis. As
Chapter IV describes, a critical goal of the framework convention
and other efforts should be to improve understanding and
measurement of these sources and sinks.
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Table 4
Gas
Carbon
dioxide
(C02)
Methane
(CH4)
Nitrous
oxide
(N20)
Halocarbons
(CFCs and
related)
Tropospheric
Ozone
(03)
Carbon
monoxide
(CO)
Nitrogen
Oxides
(NOx)
Volatile
Organic
Compounds
(VOCs)
Aerosols/sulfates
(e.g. S02)
;ea
Sources
Fossil fuel combustion
Land clearing
Biomass combustion
Livestock: enteric
fermentation, wastes
Rice cultivation
Wetlands
Landfills
Natural gas extraction,
venting, transmission,
distribution
Coal mining
Biomass combustion
Agricultural fertilizers
Land clearing
Biomass combustion
Refrigerants
Aerosol propel1ants
Foam blowing agents
Solvents, cleaning agents
Fire retardants
Precursors: CH4, CO, VOCs,
in the presence of NOx
Transport of strat. O3
into troposphere
Fossil fuel combustion
Biomass combustion
Precursors: CH4, VOCs
Fossil fuel combustion
Biomass combustion
Agriculture
Fossil fuel combustion
Biomass combustion
Industrial processes
Fossil fuel combustion
Sinks
Ocean biota
& storage
Forests
Soils
Grasses
Atmospheric OH
interaction
Soil removal
Soil removal
Recapturing a:
destroying
existing
supplies
Halocarbon
depletion
Atmospheric OH
interaction
Atmospheric OH
interaction
Atmospheric
interaction.*-
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- 31 -
Chapter ZZZ: Defining a Comprehensive Approach
A. Description of the comprehensive approach.
The "comprehensive'' approach seeks to address all the
important contributors to potential climate change, in contrast
to a piecemeal focus on C02 from the energy sector. It therefore
addresses all radiatively active trace gases (RATGs), their
sources and sinks. RATGs include carbon dioxide (C02), methane
(CH4), nitrous oxide (N2O), halocarbons such as chloro-
fluorocarbons (CFCs) and related substances (HCFCs, MFCs), and
tropospheric ozone (03), whose precursors include oxides of
nitrogen (NOx), volatile organic compounds (VOCs), and carbon
monoxide (CO). Different RATGs arise from different sources28
and are removed from the atmosphere by different sinks,29
yielding a "net emissions" budget.
Different RATGs have different impacts on the
environment; for example, each gas has a different ability to
alter the earth's heat balance by trapping certain radiated
energy (or reflecting it). This influence on the earth's thermal
balance, referred to as "radiative forcing," is described in
Chapter III. In order to relate the comparative environmental
impacts of the various RATGs, the comprehensive approach employs
a parameter or "index" that calculates the relative environmental
impact of each gas. One basis for such an index is the
contribution of increments of each gas to physical effects, such
as radiative forcing, used as proxies for global environmental
impacts. The comprehensive approach thereby avoids ignoring the
important gases that would be omitted from a CO2-only approach,
and avoids ignoring important sources and sinks that would be
omitted from an energy-only approach.
28For purposes of predicting trace gas concentrations and
lifetimes, "sources" includes all anthropogenic, biogenic and
other sources of RATGs emitted into the atmosphere. When
calculating nations' RATG net emissions inventories and the
effects of policy actions, the sources of concern are those
influenced by human activity.
29For purposes of predicting RATG concentrations and
lifetimes, "sinks" includes all anthropogenic, biogenic,
atmospheric and other activities, processes, and phenomena that
remove greenhouse gases from the atmosphere or reduce their
atmospheric lifetimes. Examples of sinks include soils and
trees, oceanic phytoplankton, ocean mixing, and atmospheric
chemical reactions. When calculating nations' RATG net emissions
inventories and the effects of policy actions, the sinks of
concern are those influenced by human activity.
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RATGS also emanate from diverse sources and are removv
from the atmosphere by diverse sinks (see Table 4). Because the
focus of environmental inquiry is the change in atmospheric
concentrations of the gases, not source emissions per se, the
comprehensive approach encompasses all of these sources and sinks
in the concept of "net emissions."
B. Policy context
The comprehensive concept is an ''approach* or heuristic
that offers insight .into any discussion of response strategies
for potential climate change. It addresses the "how to" question
— how to design any policy (including research, technology
development, and other options) that might be adopted to respond
to potential climate change. Its principal aim is to improve the
framework of research and analysis, and the cost-effectiveness of
any choice, by encompassing all the important variables and
guiding investments of time and effort to those that are most
important. It does not directly address the larger cost-benefit
question of "how much" investment of time and effort should be
made — what level of social investment, if any, is warranted by
risks of potential climate change. By shedding light on the full
costs and benefits of alternative proposals, it does help to
answer the "how much" question.
C. Multiple applications.
The utility of a comprehensive approach is not limited
to the design of emissions limitation policies. Whether the
strategy is pursuing scientific research, promoting new
technology, evaluating policy proposals, identifying measures
warranted on other grounds that also have potential climate
benefits, or designing actual emissions limitations policies
(whether domestic or international), a comprehensive approach
suggests the desirable breadth, emphasis and direction of the
strategy. It provides the guide to maximize the environmental
benefit of any expenditure of social resources.
As a means of defining the agenda for science and
economics research (such as research on the likelihood or impacts
of potential climate change, or on the means, costs and benefits
of response options), the comprehensive approach ensures that all
RATGs, sources and sinks are considered, and that environmental
impacts (including radiative forcing and other effects) are
considered. It also suggests the key areas for improved
measurement of sources and sinks of RATGs. And it provides a
guide to the benefit that will be obtained from improved
knowledge of each variable in the human-climate system. A
framework convention on climate change could take a comprehensi
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approach to the cooperative scientific and economic research to
which the parties commit, including the development of
international monitoring networks, as well as to any national
emissions reporting. This suggestion is illustrated in Chapter
IV.
As an approach to technology development, a
comprehensive approach assists in identifying and comparing the
relative importance of technologies and practices affecting
potential climate outcomes. For example, if nations are to
develop or transfer technology under a climate convention, or to
provide financial assistance, a comprehensive approach could be
used to assess the impact of each project on potential climate
change. How would a new facility, or a new method of crop
cultivation, affect net RATG emissions? How can ozone-depleting
substances be replaced without generating other RATGs? The
comprehensive approach provides the tools to answer such
questions.
As a means of evaluating current policies or proposed
policies, a comprehensive approach provides a metric for
identifying and assessing the impacts of policy actions in the
climate context. It could form the basis for calculating the
aggregate impact of various measures on a nation's net RATG
emissions. What would be the climate impact of a new energy tax,
revised forestry policies, or a change in agricultural subsidies?
Using a comprehensive approach would provide the basis for the
proper consideration of any policy options.
As an approach to possible emissions limitation rules
or obligations (whether domestic or international), a
comprehensive approach provides an environmentally coherent and
least-cost design for limitations policy. It provides the proper
signals to guide responses to maximize the environmental benefits
of each investment of resources in response strategies.
The comprehensive approach avoids the environmental
defects of a piecemeal approach to policy, focused on one gas
(e.g. C02) or one sector (e.g. energy), which would omit salient
RATGs, sources and sinks and hence could induce unintended shifts
of economic activities from the narrowly regulated aspect to
unregulated modes that effectively offset or even increase
emissions of RATGs. This danger is evident from experience in
more traditional contexts, where, for example, focusing on air
emissions alone has led to shifts of pollutants from air to toxic
solid sludge discharges. In the climate context, for example,
focusing on C02 alone could induce fuel-switching from high-C02
coal to lower-CO2 natural gas, meanwhile leading to increased
emissions of CH4 from natural gas facility leaks.
The comprehensive approach also allows the flexibility
to choose the least-cost mix of policy options yielding any
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- 34 -
desired overall RATG limitation. And, by addressing "net
emissions,' it encourages sink enhancement such as through
afforestation or safeguards against pollution of oceanic
phytoplankton. A comprehensive approach could be applied to a
variety of emissions limitation measures, including emissions
taxes and emissions trading, and including both domestic and
international measures. If applied internationally, it has the
additional benefit of reserving to each nation the flexibility
and autonomy to decide its mix of domestic policies regarding the
array of gases, sources and sinks that that nation determines
would best accomplish policy goals in light of that nation's
unique social, economic, cultural and institutional
circumstances.
A comprehensive approach to policy encompasses
adaptation responses as well as emissions limitation. As the
IPCC noted, limitations and adaptation need to be considered as
an integrated package. Additional discussion of adaptation is
found in Chapter VIII.
D. Experience with the Comprehensive Approach.
1. Stratospheric ozone depletion; the Montreal
Protocol. A recent example of a "comprehensive" approach adopted
by the international community to address atmospheric
environmental policy is the method employed in the Montreal
Protocol on Substances that Deplete the Ozone Layer. Indeed, the
description above of a comprehensive approach for trace gases
bears resemblance to the approach taken in the Montreal Protocol
for ozone depleting substances. Parties to the Montreal Protocol
are obligated to limit and then reduce their production (and
their imports, exports and consumption) of two Groups of
substances listed in Annex A.30 Each substance in Annex A is
assigned an "Ozone Depleting Potential" value, calculated to
represent the average cumulative contribution of an additional
increment of the substance to ozone depletion. Rather than
requiring each nation to achieve specific percentage reductions
in each ozone depleting substance, the Protocol requires an
overall percentage reduction in the total production of each of
the two Groups. Under Article 3, 'production" of each Group to
be restricted is calculated by multiplying annual production of
each substance by its Ozone Depleting Potential, and then adding
30Annex A may be amended in the future to list additional
substances that deplete stratospheric ozone.
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- 35 -
together the resulting figures.31 Consumption, imports and
exports are limited according to the same approach.
The comprehensive approach employed in the Montreal
Protocol is likely to prove advantageous in several respects.
First, environmental quality — in this case, protection of the
stratospheric ozone layer — will be furthered. Each nation will
meet its obligation to restrict total production from each Group
of substances. If the Montreal Protocol had restricted
production of only one substance, economic activity could have
adjusted to reduce output of that substance while increasing the
output of other ozone depleting substances. In contrast, the
approach taken in the Montreal Protocol improves the chances that
the most important ozone depleting substances will be restricted,
and that activities will not shift to producing other substances
that pose as large a threat to the ozone layer.
Second, the comprehensive approach preserves
flexibility for nations to design their own best means of
compliance. In a piecemeal approach, specific limitations would
be required for each substance. Each nation would find some of
those limitations extremely costly, but others so inexpensive
that further reductions (though not required) would not have been
burdensome. Under the Montreal Protocol, however, these
inefficiencies are, in principle, largely avoided by permitting
each nation to choose within each Group which substances to
restrict, so long as the overall weighted production limits are
met. Different nations can choose different mixes that take
account of the varying Ozone Depleting Potential of each
substance and of the varying socioeconomic value of each
substance to different societies. For example, a nation whose
economy depends heavily on one CFC can reduce those emissions
more slowly but take extra steps to reduce its use of another
CFC, so long as the overall reduction in weighted production
fulfills its obligations. Each nation can thus choose the cost-
minimizing mix of restrictions to achieve its combined limit of
the weighted production amounts of each substance.32
31The Montreal Protocol also allows for limited transfer of
this calculated level of production among parties, for the
purpose of industrial rationalization. See Article 1, paragraph
8, and Article 2, paragraph 5.
32The United States, for example, is implementing its
obligations under the Montreal Protocol through domestic use of a
"comprehensive" approach: U.S. industry must limit its total
production, weighted by the Ozone Depleting Potential index.
This permits industry to devise the best mix of reductions in
regulated substances, encouraging least-cost, innovative
responses.
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- 36 -
Similarly, the Montreal Protocol prudently employs
performance-based limits. In contrast to an approach imposing
"design standards" or other rules requiring use of specific
technologies, the performance-based approach used in the Montreal
Protocol requires those who emit a substance to limit emissions,
and leaves to the emitter the choice of what methods,
technological or otherwise, to employ. As compared to design
standards, performance-based limits encourage lower-cost
responses by emitters, more innovations in control techniques,
and more efficient resource uses,,to the benefit of society,
while achieving the emissions limit desired.
The concept of "net emissions* described above is not
pertinent in the context of the Montreal Protocol because
significant human-influenced "sinks" do not exist for the CFCs
and haIons regulated in Annex A.
2. Multimedia policy. Restrictions on emissions that
apply narrowly to one kind of source of a pollutant can result in
compliance strategies that, while adhering to the law, fail to
reduce environmental degradation. Regulations on one
environmental "medium," such as air quality, can induce shifts in
pollution to another medium, such as land or water disposal.
Recognizing the inherent and recurring problems in a single
medium approach, the U.S. is now developing and implementing a
more comprehensive, integrated strategy to address the "cross-
media" difficulties of our initial system of environmental
control. It is examining strategies for "pollution prevention"
that address the multiple pollutants that may enter the several
environmental media, and that attempt to reduce risk by reducing
the total generation of pollution rather than focusing only on
the "end of the pipe." It is bringing enforcement actions t- -
simultaneously charge violations under several laws, in ord.:
achieve a multimedia solution to an area's environmental
problems. For example, the United States recently brought
enforcement actions against several facilities in Northwest
Indiana, along the Grand Calumet River, charging violations of
the Clean Air Act, the Clean Water Act, the Resource Conservation
and Recovery.Act (the lav governing hazardous waste management),
and the S^fe Drinking Water Act. By bringing simultaneous
actions r ainst several neighboring facilities and for multimedia
discharges under several statutes, the United States is seeking
to ensure that the pollutants addressed by one statute are not
simply converted into a different form of pollution, and that
pollution control at one facility is not offset by increases at
another; the goal is to promote the overall environmental quality
of the area by dealing with all environmental impacts in a
comprehensive fashion.
3. "Bubbles." The use of "bubbles" for air quality
protection is a program that bears similarity to the
"comprehensive" approach, and it is a program with which the
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United States has extensive, positive experience. Under the
Clean Air Act, each region of the United States must attain
ambient air quality standards. Existing, modified, and new
sources of emissions are all regulated to achieve the ambient
standards; depending on the type of source and whether the area
is "in attainment" or not, sources must employ a range of
emissions controls. As part of its efforts to implement the
ambient air quality requirements and the emissions control
requirements, the U.S. Environmental Protection Agency (EPA)
designed the "bubble" program. The word "bubble" is used because
the design suggests an imaginary bubble covering a plant with
multiple emissions sources. Under the "bubble" program and
related rules, in attainment areas, the EPA allows existing
industrial and utility plants with emissions emanating from
multiple sites to reallocate emissions among the sites within the
plant or set of plants, so long as total emissions do not
increase. Thus, if a plant has several smokestacks, it can
rearrange the emissions released from each smokestack so long as
the total emissions from all its smokestacks does not increase.
States that are delegated authority to implement the Clean Air
Act's requirements have also designed "bubble" programs that they
allow industrial emitters to adopt.
The "bubble" is a good example of a kind of
comprehensive approach to environmental protection. It has been
in place since 1979 and has proved successful. The fundamental
principle of the bubble, like that of the comprehensive approach
described here for trace gases, is the same: actors should retain
the flexibility to rearrange their emissions so long as their
total quantity of emissions achieves the aggregate goal.33
United States experience with the "bubble" has been
extensive and promising. There were 132 approved bubble
reallocations in the U.S. between 1979 and 1985. The bubble
program has resulted in significant cost savings to society: over
these 132 bubble reallocations, savings amounted to over $430
million, for an average of over $3 million per use of the bubble
program. And these cost savings were obtained even with the
potentially expensive requirement that emitters must receive
approval for the bubble reallocation from the state and, if the
state has not been delegated authority to implement the program,
from the regional and national EPA as well.
33Because the Clean Air Act regulates individual pollutants,
each "bubble" is applied to emissions of a single pollutant, and
in that respect the "bubbles" differ from the comprehensive
approach suggested for application to the multiple array of
greenhouse gases. But the bubble approach derives from the same
policy rationale that supports the comprehensive approach:
promoting least-cost approaches to effective environmental
protection.
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- 38 -
Moreover, the significant savings under the bubble
program have been achieved without any increase in total
emissions. In fact, some early evidence indicates that the
bubble program has induced net reductions in total emissions.
4. Administration proposal to limit acid precipitation.
The Administration proposed, but Congress did not enact, a
provision for multipollutant trades as part of legislation to
reduce emissions of air pollutants that contribute to acid
precipitation. Because acid precipitation is believed to be the
result of both SOx and NOx emissions, the Administration proposal
regulated both substances and allowed trading between the two.
Emitters would have been required to reduce SOx and NOx
emissions, but each emitter could have varied its own mix of SOx
and NOx reductions, so long as the overall target was attained.
The gases were weighted in the proposal so that an extra pound of
emissions of SOx above the limit must be matched by more than a
pound of reduction in NOx emissions.
5. Canadian NOx-VOCs Management Plan. As part of its
recent "Green Plan," the Canadian government has proposed a
program to reduce urban smog by limiting emissions of NOx and
VOCs. Canada proposes to allow trading between sources and
between NOx and VOCs emissions, using a ratio of the gases'
impacts on smog production to calibrate the trades, and reguiri-
that aggregate emissions do not exceed issued allowances.3*
6. Agricultural toxics. Recognizing that "it is not
just one pesticide that is the source of ... contamination," one
commentator has suggested using a comprehensive approach to
regulation of the numerous pesticides that are applied to
farmers' fields. Using an index to relate the comparative
impacts of the different chemicals on the environment, the
approach would leave to farmers the choice of which chemicals to
apply ~ so long as the aggregate index-weighted set of chemicals
did not exceed the regulated limit. This approach would allow
diverse farmers the flexibility to employ different pesticides in
different circumstances, while protecting environmental quality
by reducing overall contamination effectively, without such a
comprehensive approach, an inflexible requirement of identical
reductions by all would deny farmers in different settings, or
growing different crops, the opportunity to vary their mix of
protective substances; and limits on one pesticide might induce
increased use of another, more harmful substance.35
34 Canada's Green Plan. 1990, pp. 53-55.
35 See Susan Capalbo and Tim Phipps, "Designing in
Environmental Quality: Possibilities in U.S. Agriculture,"
(continued...\
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- 39 -
Chapter IV:
A Comprehensive Approach to Research and Monitoring
A. Measuring and Monitoring Atmospheric Concentrations
Any environmental impacts resulting from RATGs would be
associated with changes in the actual concentrations of RATGs in
the atmosphere, not with emissions per se. The comprehensive
approach ensures that data are gathered on atmospheric
concentrations of all relevant trace gases. Over the last decade
much work along these lines has already been undertaken or
accelerated, including (i) direct measurement through ground
station, aerial, and satellite observation of atmospheric
(tropospheric and stratospheric) concentrations of several trace
gases (chiefly C02, CH4, N20, O3, and CFCs), and (ii) sample
records of past climate change found in ice cores, tree rings,
and other sites. Measuring and monitoring past, current and
future concentrations, temporal and spatial (e.g. vertical)
distributions, chemistry, removal, and other dynamics of trace
gases will remain an essential function under a comprehensive
approach.
Clearly, exclusive attention to CO2 concentrations,
disregarding other RATG concentrations, would not make scientific
sense. No professional atmospheric scientist would limit his or
her attention to C02 alone, for even at their current small
concentrations, the effect of the other RATGs on additional
(human-induced) radiative forcing are believed to be equal in
magnitude to the effects of CO2. A comprehensive approach to
research and monitoring of atmospheric concentrations, addressing
all the RATGs, is clearly warranted. The framework convention
should include steps to fill the gaps in our understanding of
RATG concentrations, atmospheric processes and dynamics. For
example, the convention could:
o Establish or enhance a global concentration monitoring
network for the relevant trace gases. Ensure
appropriate geographic coverage to measure gradients
and distributions. Develop techniques, methodologies
and standards for monitoring, and disseminate this
information. Nations would agree to undertake
monitoring and share methods and data. The network
would build on the many existing systems, such as the
WHO Global Atmosphere Watch, rather than create new
institutions.
35(...continued)
Conference paper presented at American Enterprise Institute,
Washington D.C., June 11-12, 1990, pp. 23-24.
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- 40 -
Organize data collection centers and structures to
receive, code, interpret and report on data collected
by the network. Charge the IPCC to coordinate and
assess this work.
B . Measuring and Monitoring Net Emissions.
Assessment of current and future net emissions is
critical to the task of predicting the contribution of net
emissions to atmospheric concentrations and hence to forecasting
potential climate change, regardless of whether any emissions
limitations are ever adopted.
The comprehensive approach emphasizes attention to all
RATGs, sources and sinks. Baseline data on all of these are not
always currently available. In addition, much of the data that
are available derives from estimates using data on inputs (e.g.
fuel quantities) and knowledge of or assumptions about input-
output ratios associated with technologies or practices.
Better measurement, forecasting and actual monitoring
of net RATG emissions is suggested by, and needed to support, the
comprehensive approach. First, such data are needed to establish
current baseline net emissions of RATGs, in order to validate
current model estimates and resolve uncertainties in the
calculations of national and sectoral net emissions. These dat
will serve to improve estimates of current net emissions, for
aggregate and national or sectoral predictions.
Second, these data will be essential to resolving
uncertainties in the calculation of comparative gas indices,
which depend on estimates of the typical residence times of gas
molecules, and thus in turn on information about source-sink
balances.
Third, these data will be critical to projecting future
net emissions. Predictions of future net emissions trends are a
key input into global climate models used to predict atmospheric
warming. A piecemeal approach, focusing on CO2, could seriously
undermine the accuracy of estimates of the real rate and extent
of future climate change. A comprehensive approach to net
emissions of all RATGs, however, would ensure more accurate and
reliable forecasts of future net emissions, and hence of future
concentrations .
The measurement of net emissions faces many obstacles
and uncertainties, and the framework convention could address
these data gaps. Many current studies confine themselves to CO 2
and energy policy alone simply for the reason that, in the words
of one analyst, *[t]his focus suggests itself because the
necessary quantitative data for a least-cost analysis are far
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- 41 -
more developed in the case of energy than for other major sources
of greenhouse gases.*36 Unless research is carried out along a
comprehensive approach/ a narrow and incomplete knowledge base
will yield surprises for policy makers, and incomplete and flawed
piecemeal policy responses.
Comprehensive measurement needs
Current efforts to measure and predict net emissions of
RATGs from human activities are impressive, but incomplete.
Better measurement is needed on several fronts. The net
emissions data base is perhaps least well-developed for the
diffuse, non-point sources and sinks of greenhouse gases that are
typical in the agriculture and forestry sectors, and for net
emissions of all kinds in the developing countries and Eastern
European countries. A piecemeal approach, content to focus on
C02 from the energy sector, would not pay attention to the need
to improve measurement of other sources, sinks, and RATGs. A
comprehensive approach would, in contrast, direct attention to
all the RATGs, their sources and sinks. It would address
measurement efforts such as the following:
carbon dioxide. Although CO2 from industrialized
nation energy and transport sources is generally well documented,
even CO2 emissions from energy are not generally measured
directly (at the smokestack) but are computed from information on
the carbon content of the fuel and the efficiency of combustion.
Data on energy emissions in developing nations are generally less
thorough, and are also complicated by lack of information on non-
commercial energy consumption, such as rural biomass combustion.
Sinks of CO2 remain less well identified. Recent
studies are advancing understanding of both the total size of the
oceanic versus terrestrial sinks,37 as well as the more localized
effectiveness of different types of forestry in sequestering
carbon.38 But the uncertainties surrounding these processes are
still significant. Apportioning sink uptake of C02 among nations
36 F. Krause, et al., Energy Policy in the Greenhouse.
(IPSEP / European Environmental Bureau / Dutch Ministry of
Housing, Physical Planning and Environment, September 1989),
Volume One, p. 1.1-3.
37 See P. Tans, I. Fung, & T. Takahashi, "Observational
Constraints on the Global Atmospheric C02 Budget," 247 Science.
23 March 1990, p. 1431.
38 See M. Harmon, w. Ferrell, & J. Franklin, "Effects on
Carbon Storage of Conversion of Old-Growth Forests to Young
Forests," 247 Science. 9 February 1990, p. 699.
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is quite complex; and difficulties and differences of view atter
efforts to monitor forest cover from remote sensing stations
(satellites).
Methane. Efforts are underway to characterize the
diverse sources of CH4 in wet rice cultivation, ruminant
livestock (such as cattle and sheep), the energy sector
(including fossil fuel extraction and natural gas transmission
and distribution), and waste disposal,39 and its sink in
tropospheric chemical reactions.*0 But gaps remain significant.
At the same time, better measurement of several kinds of methane
emissions, such as natural gas system leaks, may be practicable
now or in the near future at reasonable cost. Using proxies or
surrogates to measure CH4 emissions is also a possibility, but
they would have to be carefully chosen; for example, calculating
livestock CH4 emissions by multiplying the herd size times a
fixed estimate of average CH4 emissions per animal would give no
incentive to farmers to reduce CH4 emissions per animal by
improving feed or other techniques, and would reward only
reducing the total number of animals.
Nitrous oxide. Data are improving but still generally
lacking on emissions of N2O from the application of agricultural
fertilizers and from biomass burning. Surrogates could be useful
in such measurements, such as N20 emissions per amount (and type)
of fertilizer applied.
Chlorofluoroearbons. CFCs and related substances are
generally quite well measured today. CFCs are produced in only a
few places, easing the monitoring task. The Montreal Protocol
contains provisions requiring emissions monitoring.
CO. NOx. and VOCs. Measurements of energy and
industrial emissions of these gases are generally available in
industrialized nations, but may need improvement in some
developing nations.
Emissions measurements could also be organized
according to sectors; energy sector CO2, CH4, CO, NOx, and VOCs;
agricultural CH4 and N2O; industrial CFCs, HCFCs, MFCs, CO, NOx,
and VOCs; and forestry CO2 and CH4. A sectoral'analysis may
offer a more practical route to real-world measurement
39 See IPCC Response Strategies Working Group, "Methane
Emissions and Opportunities for Control," coordinated by Japan
Environment Agency and U.S. EPA (September 1990).
40 For example, recent work at the NOAA Aeronomy Lab on the
reaction rate of CH4 in the lower atmosphere shows that the
typical CH4 residence time is 12.5 years, not 10 years.
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techniques. In either analysis, all RATGs, sources and sinks
need to be considered.
Options for the convention
In order to improve net emissions monitoring, the
Convention should set goals and priorities for research and
monitoring following a comprehensive approach. The IPCC or
another appropriate body could be tasked to coordinate and assess
this work. The convention could advance efforts along the
following lines:
o Organize efforts to harmonize current emissions monitoring
methodologies, techniques and systems.
For example, the convention could assemble
multinational programs to compare and harmonize the methods
used to monitor CH4 emissions from fossil fuel mines and
transmission systems, from livestock, or from rice fields;
N20 emissions from soil biota under different agricultural
practices; and so forth.
To take a recent example: there is some controversy
over the proper way to monitor emissions from forestry. At
the macro level, there is debate over the techniques for
interpreting satellite data in estimating forest cover. At
the micro level, there are differences of view over the
effectiveness of different tree types, tree ages, and
forestry practices (through their effects on trees, soil
biota, and moisture) at fixing atmospheric carbon.
The convention could address these topics and set up
workshops, expert panels, and research programs to encourage
harmonization.
o Identify and calculate accurate proxies or surrogates to
estimate net emissions factors from hard-to-measure
activities, such as diffuse sources and sinks in agriculture
and forestry. Even today, energy C02 emissions are not
measured directly by smokestack monitoring devices, but are
calculated from data on the carbon content of fuels and the
efficiency of the combustion process. Similarly, CH4
emissions factors for livestock could be tested under
diverse conditions and diets, and calculated by applying the
emissions factor to the number of cattle (perhaps counted by
satellite sampling and ground observation).
o Sponsor workshops or research programs on atmospheric
chemical reactions of relevant trace gases. For example,
host a Workshop on Methane 'Interactions, or a Workshop on
HCFC Interactions. The output from the Workshops would help
describe how concentrations change (through better knowledge
of residence times and dynamics), what gases are indirectly
affected or produced by molecules of the subject gas, and
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hence feed into projections of total warming, calculation <
the GWP Index, and consideration of non-warming impacts.
Interactions with hydroxyl (OH) radicals in the lower
atmosphere are of special interest and in need of study; OH
interactions affect (or are affected by) numerous RATGs,
including CH4, NOx, CO, 03, and VOCs, yet information is
needed about trends in the ambient abundance of OH, specific
reaction dynamics, and synergistic effects when multiple
RATGs are present.
Organize a thorough study of the carbon cycle (atmosphere-
ocean-terrestrial sinks). This could build, for example, on
the U.S. CEES effort to understand all carbon processes.
This work would generate critical information about, among
other important topics, CO2 residence time. CO2 residence
time is uncertain because each carbon atom cycles in and out
of the ocean over 5-10 year periods, but is not fully
removed from the cycle for hundreds of years or more.
Better understanding of the carbon cycle would help s-z-
the radiative forcing index values relative to CO2.
Create micro-monitoring field programs, to match the
concentration monitoring programs described above by
measuring actual emissions and uptake from surface
activities. For example, better understanding of the
biological, chemical, and physical processes involved in th
emissions and deposition of N2O, CH4, and NOx is needed.
"Agricultural Methane Emissions Monitoring Program," for
example, could provide technical assistance, operate a
network of experimental monitoring stations (with host
nation permission), operate pilot test monitoring stations
to gather data on typical agricultural practices where on-
site monitoring is impractical or not permitted, etc. A
"Soil Net Emissions Project" could be similarly designed.
Monitoring could be organized on topical/sectoral, regional
or national emissions bases. The effort would make sure to
include coverage of both industrialized and developing
country emissions. Clinical and field studies of the key
processes involved would also be undertaken. These programs
could also develop a data set of emissions/uptake factors
for current and potential technologies and practices,
covering all relevant gases, sources and sinks, to be used
as proxies or surrogates in estimating difficult-to measure
(diffuse or non-point) sources and sinks (see bullet 2
above).
Develop national inventories. Efforts are already underway
to assemble inventories of net emissions of RATGs for many
nations, including OECD and U.S. EPA's analysis of CO2, CH4,
CFCs, HCFCs, N2O, CO, NOx, and NMHCs for the US and other
nations. The convention could build outward from these
projects to calculate baseline net emissions inventories f
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all nations. It could invite all nations to regional
workshops, and feed the data into centers where these data
can be used in emissions forecasting efforts.
o Develop comprehensive economic models. To forecast future
emissions and the effects of policy proposals, new and
expanded economic models are needed that cover multiple
trace gases, multiple sectors, sinks as well as sources,
better detail on developing countries, international trade
effects, and so forth. An economics research program could
pursue this effort.
o Organize a program to develop monitoring technology,
including remote sensing (satellite observation using
lasers, etc.), aerial reconnaissance, on-site instruments,
flux measurement techniques, etc. For example, it could
create a Tropospheric Ozone Monitoring Technology
Clearinghouse. It could encourage development of devices
that can be operated in the field at modest skill levels.
The program could award recognition, funding, and/or
possible forms of international intellectual property rights
to scientists, engineers, and others who invent useful
devices.
The convention could also address, or task the IPCC to
assess, options for institutional arrangements to improve
monitoring. These options include arrangements for monitoring
and reporting and their relation to sovereignty concerns, e.g.
voluntary or mandatory national reporting; remote sensing;
atmospheric observations; international oversight bodies;
permission for on-site field studies; incentives and
institutional designs to encourage development and application of
accurate monitoring & reporting, for example by assuring credit
for net RATG limitation actions upon a showing by the emitter of
successful monitoring practices; international expert panels;
international research centers; cooperative monitoring projects.
These options are meant to illustrate the range of
research and monitoring topics embraced and spurred by a
comprehensive approach. Certainly other research efforts, such
as into the role of clouds and oceans, would be needed to develop
a complete understanding of the climate system. Yet without
attention to a comprehensive approach, even a full understanding
of the ocean-atmosphere system would lack crucial knowledge of
the human-influenced inputs to potential climate change.
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Chapter V: Environmental Advantages of a Comprehensive Approac
A. The Pitfalls of Piecemeal Approaches
A comprehensive approach to environmental policy, and
to issues of climate change in particular, is highly desirable
because its alternative — a piecemeal approach that focuses on
one gas and sector — is environmentally flawed. If the goal is
sound environmental protection, a piecemeal approach is unlikely
to succeed and could backfire.
Piecemeal policies are typically beset by a notorious
drawback: 'shifts* or ''displacements* of pollution as activities
move away from the regulated area to unregulated but still
deleterious forms. Piecemeal policies place a regulatory or
financial burden on certain targeted activities, such as
emissions sources of a certain pollutant. Rational, law-abiding
businesses and individuals react to that burden by finding other
legal ways of running their operations —- new emissions controls,
new fuels, new product materials, new process designs, new
products, new plant locations, new emissions outlets — that
avoid the burden. But the new operations typically produce other
types of "residuals* — emissions or wastes that injure the
environment — thus undermining, counteracting, or even reversi'
the protective effect of the piecemeal policy. By squeezing or.
only one end of the socioeconomic balloon, piecemeal policies
simply make the balloon bulge out at another end.
This problem is especially acute in the climate
context, where the several trace gases are emitted by virtually
every sector and type of human activity, from energy to industry
to agriculture, on every part of the planet. The social and
economic activities that produce these trace gases, from fuel
combustion to traditional agriculture, are intricately
interrelated and widespread. Policies that restrict emissions of
one trace gas from one source, such CO2 from energy production,
are bound to induce shifts to activities that yield emissions of
other gases, or in other sectors, not targeted by the piecemeal
policy. These shifts would seriously impair the environmental
effectiveness of the piecemeal policy, and could even mean net
increases in contributions to radiative forcing.
1. Past Experience with Piecemeal Policies
Historically, piecemeal policies have often proved
environmentally ineffective or even counterproductive. The
history of environmental policy has been piecemeal; command and
control efforts have in almost every country been aimed
separately at the three main environmental "media*: air, water,
and land. This has often led to "cross-media shifts* in
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residuals, moving pollution around without reducing it.41 Past
experience in the United States, for example, demonstrates the
reality and the likelihood of such shifts. The major U.S.
environmental lavs, such as the Clean Air Act, the Clean Water
Act, and the hazardous waste statutes, were each written to
address one environmental medium. Breaking pollution control
down into these piecemeal categories may initially seem logical,
but we have learned through frustrating experience that shifts
from one environmental medium to another have thwarted attempts
to reduce pollution. One commentator has aptly observed: "In
attempting to help Eastern Europe, the Soviet Union, and the
Third World with air pollution problems, western industrial
countries should not simply transfer wholesale the [end-of-pipe]
pollution control strategies that have not been entirely
successful at home. An ill-conceived approach such as this could
do more harm than good. ... A comprehensive approach will be
necessary that focuses on pollution prevention rather than
pollution control."42
For example, stringent regulations on water pollution
have induced industry to convert liquid pollutants into sludge,
in turn creating toxic waste disposal problems. Similarly, to
reduce air pollution, standards were written to require
installation of "scrubber" technology to remove sulphur dioxide
(S02) emissions from electric utility smokestacks. Yet these
rules have resulted in increased generation of solid wastes.43
Another unanticipated dysfunction of the scrubber requirement is
that while it removes S02, attaching the scrubber impairs the
operating efficiency of the utility boiler, so that more fuel is
needed to produce the same amount of energy. In consequence, S02
emissions were reduced but other pollutants generated by fuel
combustion — such as C02 ~ were increased.44
Restrictions on emissions that apply narrowly to one
kind of source of a pollutant can also result in compliance
strategies that, while adhering to the law, fail to reduce
41 See U.S. EPA, Science Advisory Board, "Reducing Risk:
Setting Priorities and Strategies for Environmental Protection,"
SAB-EC-90-021 (September 1990), Recommendation 7, p. 22, and
Strategic Options Report, section 4.3.
42 Hilary F. French, "Clearing the Air," in WorldWatch
Institute, State of the World 1990 at 118.
43 See Dudek, "Lessons," supra; Hilary F. French, "Clearing
the Air," in'WorldWatch Institute, State of the World 1990 at ill.
44 See Daniel J. Dudek, Alice M. LeBlanc, and Peter Miller,
"S02 and CO2: Consistent Policymaking in a Greenhouse,"
Environmental Defense Fund, New York, January 1990.
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environmental degradation. For example, laws regulating .
smokestack air pollution were written to require that the ambie.
air quality in the locality of the smokestack not fall below
certain levels. One industry response to this approach was to
build taller smokestacks, so that the pollutant plumes were fed
into higher wind currents and were dispersed more rapidly from
the local area. Although pollutants were removed from local
areas, they often continued to degrade the environment farther
downwind. The result was that, although no law was violated,
overall pollution was reduced much less than the law had
contemplated. Although spreading these pollutants downwind did
dilute their concentrations and thus reduce threats to human and
ecological health, the strategy of building tall smokestacks
meant that the environmental benefits were much less than hoped.
And populations downwind received unexpected pollutant loadings.
Later, the laws were amended to try to prevent such outcomes.
Recognizing the inherent and recurring problems in a
piecemeal approach to pollution, the U.S. is now developing and
implementing a more comprehensive, integrated strategy to address
the "cross-media* and "cross-source* difficulties of our system
of environmental control.45 It is examining strategies for
''pollution prevention* that address the multiple pollutants that
may enter the several environmental media, and attempt to reduce
risk by reducing the total generation of pollution rather than
focussing on the "end of the pipe."46 It is bringing enforcemer4-
actions that simultaneously charge violations under several lav
in order to achieve a multimedia solution to an area's environ-
mental problems. For example, the United States recently brought
enforcement actions against several facilities in Northwest
Indiana, along the Grand Calumet River, charging violations of
the Clean Air Act, the Clean Water Act, the Resource Conservation
and Recovery Act (the law governing hazardous waste management),
and the Safe Drinking Water Act.
By designing policy and enforcement to address
simultaneously several pollutants at several facilities under
several statutes, the United States is seeking to ensure that the
pollutants targeted by one statute are not simply converted into
a different form of pollution, and that pollution control at one
45 See Office of Technology Assessment, From Pollution to
Prevention 1987; Daniel J. Dudek, "Lessons from U.S. Experiments
in Environmental Reform," Environmental Defense Fund, presented
at the international workshop on Institutional Design for
Environmental Protection in Poland, September 17-20, 1990, at 9.
46 See U.S. EPA, Science Advisory Board, "Reducing Risk:
Setting Priorities and Strategies for Environmental Protection,"
SAB-EC-90-021 (September 1-J90) , Recommendation 7, p. 22, and
Strategic Options Report, section 4.3.
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facility is not offset by increases at another. The goal is to
reduce overall pollutant emissions as pollution is prevented, and
to enhance the overall environmental quality of the nation.
Dealing with all environmental impacts in a comprehensive fashion
will substantially improve the ability to reduce deleterious
pollution while heading off compliance strategies that merely
shift pollution around.
Along these lines, one of the best examples of a global
environmental policy — the Montreal Protocol — was itself
designed in a comprehensive way that reduced the potential for
cross-pollutant shifts. If the Protocol had restricted
production of only one substance, such as the most prevalent CFC,
economic activity might have adjusted to reduce output of that
substance while increasing the output of other ozone depleting
substances. In contrast, the multi-substance approach taken in
the Montreal Protocol, using the Ozone Depleting Potential (ODP)
index to weight the substances, greatly improves the chances that
the most important ozone depleting substances will be restricted,
and ensures that activities will not shift to producing other
substances that pose as large a threat to the ozone layer.47
2. Shifts in the Climate Context
Unwanted shifts of emissions to unregulated activities
are likely to plague piecemeal policies in the climate context as
well, if not more. Rational actors reacting to piecemeal
policies are likely to pursue unregulated means to their goals,
potentially inadvertently continuing to contribute to radiative
forcing. The dominant tenor of current policy discussion on
climate has focused piecemeal on one narrow aspect: C02 emissions
from the energy and transport sectors. Yet that focus, or any
other piecemeal focus in the climate context, is likely to yield
dysfunctional shifts in emissions. Precisely because the human
activities that produce radiatively active trace gases are so
47 At the same time, the ODP values do not account for the
global warming potential of the CFCs or their substitutes. See
Donald A. Fisher, et al., "Model Calculations of the Relative
Effects of CFCs and their Replacements on Stratospheric Ozone,"
344 Nature 508 (April 5, 1990); and Fisher, et al., "Model
Calculations of the Relative Effects of CFCs and Their Replace-
ments on Global Warming," 344 Nature 523 (April 5, 1990). In
this sense the Montreal Protocol is piecemeal, addressed only at
the stratospheric ozone depletion problem, and in compliance with
the Protocol- economic activity may shift to CFC-substitutes that
have lower ODPs but have significant GWPs. A more comprehensive
approach that accounts for all of the CFCs' and CFC-substitutes'
atmospheric impacts, including both ozone depletion and climate
change, would address this problem.
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widespread, varied, and currently ingrained in both
industrialized and developing societies, shifts are especially
likely to occur in the climate context.
(a) Fuel switching. CO2 and CH4. A salient example of
a plausible cross-gas shift is the case of "fuel switching."
Under a piecemeal CO2-only limitations policy, utilities and
businesses would likely be encouraged to switch from coal or oil
to natural gas, because with current combustion techniques coal
burning produces almost twice as much CO2 per BTU as burning
natural gas, and oil burning produces about 50% more.48 Several
studies show that imposition of a constraint on CO2 emissions
would lead to considerable fuel-switching from coal and oil
toward natural gas,49 because fuel switching is estimated to be
one of the most cost-effective means utilities have to reduce
their C02 emissions.50 Several national plans have proposed
switching to natural gas as key parts of their domestic policies
to limit C02 emissions.51
48 See Rodhe, "A Comparison of the Contribution of Various
Gases to the Greenhouse Effect," 248 Science. 8 June 1990, p.
1218.
49 See, e.g., Interagency Task Force, "The Economics of
Long-Term Global Climate Change: A Preliminary Assessment," U.S.
Department of Energy, OPPA, DOE/PE-0096P, September 1990, pp. 26
29; Manne & Richels, "C02 Emission Limits: An Economic Analysis
for the USA," paper presented at the Workshop on Energy and
Environmental Modeling and Policy Analysis, MIT Center for Energy
Policy Research (July-Aug. 1989); U.S. Congressional Budget
Office, "Carbon Charges as a Response to Global Warming: the
Effects of Taxing Fossil Fuels," August 1990, pp. 27-30, 44;
Commission of the European Communities, DG XII, JOULE Program,
"CO2 Study: Crash Programme: Cost-Effectiveness Analysis of CO2
Reduction Options, 'Bottoms-Up' Approach," Parts I and II
(working draft Oct. 1990).
50 See Daniel J. Dudek and Alice LeBlanc, "Offsetting New
C02 Emissions: A Rational First Greenhouse Policy step," 8
Contemporary Policy Issues 29 (July 1990), pp. 38-39, Table 4;
Commission of the European Communities, DG XII, JOULE Program,
"CO2 Study: Crash Programme: Cost-Effectiveness Analysis of CO2
Reduction Options, 'Bottoms-Up' Approach," Parts I and II
(working draft Oct. 1990).
51 See, e.g., "Climate Change Policy in the Netherlands and
Supporting Measures," Netherlands Ministry of Housing, Physical
Planning and the Environment, D.G. for Environment, November
1990, § 3.2.1., p. 6; "Protecting the Earth's Atmosphere," Report
of the Federal Cabinet Study Commission, Bonn, Germany, November
7, 1990.
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But use of natural gas means methane (CH4) leakage from
natural gas mining and transmission systems (pipelines and local
distribution networks). Because CH4 is itself the product being
transported and sold, where energy markets are competitive there
is a market incentive to capture fugitive CH4 emissions. But
where markets are less competitive or where the cost of capture
exceeds the revenue to be gained from the leaking CH4, leaks go
uncorrected. Today CH4 leaks from natural gas transmission
average about 2-4% worldwide.52 For example, the average is
probably about 1% in the U.S.,53 it is 3% in Australia,54 and is
probably in the range of 5-10% in the Soviet Union and Eastern
Europe.55
Switching from coal to natural gas would be encouraged
by a CO2-only policy, but might not reduce, or could even
increase, contributions to radiative forcing. One recent
study56 estimates that a 6% rate of CH4 leakage from natural gas
transport would completely negate all of the C02-related
radiative forcing avoided by switching from coal to natural gas
(and a 4% leakage rate would completely negate all of the CO2-
related radiative forcing avoided by switching from oil to
natural gas).57 Thus, at today's world average CH4 leakage
52 See IPCC Response Strategies Working Group, ''Methane
Emissions and Opportunities for Control,* coordinated by Japan
Environment Agency and U.S. EPA (September 1990), p. 34.
53 Communication from John Hoffman, U.S. EPA, Office of Air
& Radiation.
54 See Jim Falk & Andrew Brownlow, The Greenhouse Challenge
(Penguin Books Australia, 1989), p. 270, citing Walker, I.J., and
Lydall, K.O., 'The Potential for Reduced C02 Emissions through
Increased Energy Efficiency and the Use of Renewable Energy
Technologies in Australia," Commonwealth Dept. of Primary
Industries and Energy, Canberra (1989), p. 13.
55 communication to U.S. EPA, Office of Air & Radiation,
Office of Atmospheric & Indoor Air Programs, Global Change
Division, from OEKO-Institute Bro Darmstadt, FRG, based on study
by A.A. Arbatov, Deputy Chairman, USSR Academy of Sciences
Commission for the Study of Production Forces and Natural
Resources.
56 Rodhe, "A Comparison of'the Contribution of Various Gases
to the Greenhouse Effect," 248 Science. 8 June 1990, p. 1217.
57 Rodhe's calculations do not account for CH4 leaks from
coal mining, so these leakage rates would need to be slightly
(continued...)
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rates, the reduced CO2-related radiative forcing achieved by
coal-to-gas fuel switching would be offset about 50% by CH4
leaks. In other words, if implemented through coal-to-gas fuel
switching, a policy to reduce CO2 emissions by, say, 20% would
actually achieve only a 10% reduction in C02-equivalent
contributions. That would be a major failure of the CO2
limitations policy. And in the Soviet Union and Eastern Europe,
currently major coal consumers with access to large supplies of
natural gas, the C02-related reductions from coal-to-gas
switching would be offset more than 100% — that is, net
contributions to radiative forcing would actually increase in
response to the C02-only emissions policy.
If implemented through oil-to-gas fuel switching, tne
reduced C02-related radiative forcing induced by the CO2-only
policy would be offset even more, by about 100% worldwide — that
is, the CO2-only policy would have no effect whatsoever on
aggregate radiative forcing, with the likelihood of quite
significant net increases in radiative forcing when applied in
Eastern Europe.
The comprehensive approach, on the other hand, would
account for CH4 emissions and thereby ensure that methane leakage
is included in a nation's net trace gas emissions inventory and
in the incentives and efforts to limit net emissions. Indeed, in
some nations the capture of CH4 leaks might be a highly cost-
effective strategy for limiting contributions to radiative
forcing. But a C02-only policy would ignore that option and
discourage it, in effect encouraging CH4 leaks.
(b) Shifts in agriculture and forestry. Shifts among
trace gases are possible in the agriculture and forestry sectors
as well. Some proposals to reduce methane emissions from wet
rice cultivation involve increased application of nitrogenous
fertilizers, which yield nitrous oxide emissions.58 Certain
proposals to reduce methane emissions from livestock also depend
on increased use of feed grains grown with nitrogenous
fertilizers.59 Given that the radiative forcing potential of
nitrous oxide over a mid-range period (100 years) is over 10
times larger than that of methane,60 small tradeoffs could be
57(...continued)
higher to offset all the radiative forcing avoided by reducing
coal consumption.
58 EPA, Policy Options for Stabilizing Global Climate (Draft
August 1990)', pp. V-157, V-161, V-163.
59 EPA, Policy Potions for Stabilizing Global Climate (Draft
August 1990), p. V-166.
60
IPCC Scientific Assessment (1990), Table 2.8.
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significant enough to offset or outweigh the savings in methane-
equivalent emissions. Similar risks are present in the forestry
sector, where calls to increase the productivity of trees as C02
sinks might be pursued by applying nitrogenous fertilizers.
(c) Shifts across sectors. Shifts could occur across
sectors as well. If a C02-only policy induced the substitution
of ethanol (made from corn) for carbon-containing petroleum
gasoline, C02 emissions would decline, assuming the corn farm did
not displace C02 sinks. But corn cultivation is one of the most
fertilizer-intensive of crops,61 and nitrous oxide emanating from
the application of nitrogen fertilizers to corn fields is roughly
200 times more potent a RATG than C02.62 Similarly, a policy
aimed at the transport sector alone could encourage the use of
electric vehicles (EVs), which themselves emit no C02. But the
full emissions of the EVs depend on what source of energy charges
their batteries: if the charging came from coal-fired power
plants (whose emissions are not counted in the "transport-only1*
policy), the net contribution to C02 emissions and to radiative
forcing could actually increase.63 To take another example,
policies to stop deforestation and thereby preserve C02 sinks
could inadvertently increase C02 emissions, because communities
that now burn harvested wood for fuel may turn to coal for their
energy.
These shifts may not be inevitable; technologies and
practices could perhaps be chosen that take account of all
relevant trace gas emissions. But the opportunities for shifts
are present,64 and without the system-wide outlook and the
incentives provided by a comprehensive approach, the choice of
optimal technologies is extremely unlikely. Under piecemeal
proposals, there is no reason to think that an overall optimal
emissions outcome would emerge, and there is every reason to
think that narrow efforts will yield narrow results. Piecemeal
61 EPA, Policy Options for Stabilizing Global Climate (Draft
August 1990), p. V-160.
62 ZPCC Scientific Assessment (1990), Table 2.8.
63 This observation is buttressed by data in a recent study
and a seminar presentation by its authors. See Hadi Dowlatabadi,
Alan Krupnick, and Armistead Russell, "Electric Vehicles and the
Environment: Consequences for Emissions and Air Quality in Los
Angeles," Resources for the Future, Draft 1990.
64 See the illustrative list in Dennis Tirpak and Dilip
Ahuja, "Implications for Greenhouse Gas Emissions of Strategies
Designed to Ameliorate Other Social and Environmental Problems,"
draft November 5, 1990, Table 1.
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policies to limit air, water and land pollution have regularly
produced inadvertent shifts of emissions — shifts that we see i.
hindsight but that were not expected when policy was first
developed. The much more numerous and interrelated socioeconomic
systems and practices that generate net emissions of the several
trace gases provide a much more complex catacomb of unseen
passageways for such shifts to occur. In the climate context
perhaps more than in traditional environmental areas, piecemeal
policies seem to be a recipe for unanticipated problems,
dysfunction and disappointment.
3. Piecemeal coverage of emitters
A different kind of inadvertent shift is the result of
policies that address only a subgroup of emitters. If the
environmental problem were pollution of a lake, it would make
little sense to restrict pollutant discharges from one beach on
the lake, but leave sources of pollution around the rest of the
lake unregulated; polluting industry on the regulated beach could
comply with the law by moving around the lake, or by extending
discharge pipes around the lake to emit pollutants in the
unregulated zone. Similarly, if one is worried about regional
air pollution, it makes little sense to forbid emissions in one
local area while leaving neighboring areas unrestricted; industry
will move to the unregulated area and continue emitting. These
are examples of a general flaw in policies that apply piecemeal
to subgroups of sources emitting pollutants that mix in the
shared environment: if the scope of policy coverage fails to
encompass all the emitters, emissions will shift to the
unregulated areas and the environment will not be much improved.
In the climate context, such shifts would be likely to
attend restrictions on trace gas emissions applied piecemeal to
one nation or group of nations. Because the trace gases relevant
to climate change mix globally in the atmosphere and their
effects would be global, emissions at any location are equally
important to the global ecosystem. Limits on emissions by one
subgroup of emitters must be evaluated in terms of their
influence on overall global emissions.
Take for example the proposal for only a few nations to
restrict their C02 emissions, or the view that climate change
could be adequately addressed by CO2 emissions limits imposed
solely in the industrialized nations of the OECD. These
proposals are inadequate for several reasons. First, any trace
gas limits would need to be global because the emissions of the
industrialized nations make up a rapidly declining share of
global emissions:
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Growth Rates of CO2 Emissions65
Time Period U.S. OECD Non-OECD
1966-1976 2.40 3.51 5.22
1976-1986 -0.47 0.58 2.43
If the developing nations continue on current trends, absent
steps to avoid land use practices and energy production methods
that emit substantial amounts of trace gases, by 2030 they will
account for roughly half of global C02 emissions. Even at
today's shares, a 20% reduction in current energy sector C02
emissions by the OECD alone would remove only 3% of current
global human contributions to radiative forcing. (CO2 from
fossil fuels makes up 34-37% of global contributions to the
enhanced greenhouse effect in the 1980s (with deforestation
accounting for 22-26%, CFCs 20%, and other gases 20-21%),66 so a
20% reduction in global C02 would be about a 7% reduction in
global radiative forcing; and OECD nations now account for 43% of
fossil fuel C02 emissions,6' so a 20% reduction in their CO2
emissions would reduce global human contributions to radiative
forcing by about 3%.) OECD-only policies simply could not
achieve a global 20% reduction in C02 emissions — to say nothing
of RATG emissions generally — without action by the developing
nations as well. Without developing country reductions, the OECD
would have to eliminate more than 100% of its CO2 emissions to
reduce global emissions by 20%.68
65 Calculated from Gregg Marland, "Estimates of C02
Emissions from Fossil Fuel Burning and Cement Manufacturing Based
on U.N. Energy Statistics and U.S. Bureau of Mines Cement
Manufacturing Data,* Oak Ridge National Laboratory, ORNL/CDIAC-
25, NDP-030 (1989). If these data included C02 emissions from
land clearing, the growth rates in the Non-OECD would be even
higher.
66 R.A. Houghton, "The Global Effects of Tropical
Deforestation," 24 Env't Science & Technology (1990) p. 414.
67 Interagency Task Force, "The Economics of Long-Term
Global Climate Change: A Preliminary Assessment," U.S. Department
of Energy, OPPA, DOE/PE-0096P, September 1990, p. 18, Table
III.l.
68 Interagency Task Force, "The Economics of Long-Term
Global Climate Change: A Preliminary Assessment," U.S. Department
of Energy, OPPA, DOE/PE-0096P, September 1990, pp. 19-21, Tables
III.2 & III.3.
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Second, the effectiveness of an OECD-only reduction
policy would be limited by the possibility of shifts in emissior
to other nations where no restrictions apply, offsetting or evei.
increasing in emissions worldwide. As the nations who decided to
reduce CO2 emissions (the "signatories* to a limitations
agreement) restricted their consumption of fossil fuels, world
prices of those fuels would fall. The reduced prices would lead
to increased consumption in other nations where limits on C02
emissions were not in place ("non-signatories"). The increased
consumption could partially or even totally offset the reduced
C02 emissions achieved by the signatories.59 In addition, if the
change in the world fuel price led to more consumption by the
non-signatories than the initial reduction by the signatories
(i.e. if the price elasticity of demand of the non-signatory
economies were high), net fossil fuel consumption could actually
increase as a result of the signatories' action. And net C02
emissions would be given additional upward pressure if the amount
of C02 emitted per unit of fuel consumed were higher in the non-
signatory economies than in the signatory economies.
Third, over the slightly longer term, restrictions by
the subgroup of emitters would be offset as products made with
high-emitting technologies were increasingly manufactured in the
non-signatory areas and imported back into the signatories, and
as high-emitting industries moved out of the signatory states to
unregulated locations in the non-signatory states.
Fourth, as described earlier in this Chapter, limits c
CO2 alone would not effectively address overall contributions to
radiative forcing. A comprehensive approach to all RATGs is
warranted.
Comprehensive .scope of coverage and wide global
participation in any trace gas limitations measures would
therefore be essential. As the IPCC noted, 'Climate change is a
global issue; effective responses would require global
cooperation.*70
69 See Znteragency Task Force, "The Economics of Long-Term
Global Climate Change: A Preliminary Assessment,* U.S. Department
of Energy, OPPA, DOE/PE-0096P, September 1990, p. 27; Peter Bohm,
"Mitigating Effects on Fuel Prices from Incomplete International
Cooperation to Reduce C02 Emissions," (draft December 1990).
70 IPCC RSWG Policymakers' Summary p. ii.
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B. Optimal Environmental Signals
A comprehensive approach to research and policy
provides optimal environmental signals to guide choices. While a
piecemeal approach would ignore and omit important RATGs, sources
and sinks, a comprehensive approach would make clear the relative
environmental significance of each factor, and encourage
decisionmakers to design responses — whether they be research
strategies, technology choices, or emissions limitation
incentives — that generate optimal environmental results. The
comprehensive approach would maximize the environmental benefit
of each unit of social resources invested in climate response
strategies.
In order to provide a sound guide to policy choices, a
measure of the relative environmental impacts of the gases, an
''index' as described in Chapter II above, should be used to set
priorities. Rather than taking piecemeal stabs in what might be
called the proverbial "radiative darkness,* good policy choices
demand elucidation of the relative effects of the various
emissions. And it must be recognized that some weighting of the
gases is unavoidable: a piecemeal policy targeting C02 alone
effectively weights the other gases at zero.
The comprehensive approach provides the signals that
enable the environmental benefit of any response measures to be
maximized. Such environmental signals are needed if real
environmental benefit is to be achieved. Otherwise, priorities
will be set haphazardly, rather than in furtherance of ecological
well-being.
Aiming at one RATG alone, for example, would omit other
gases with potentially greater adverse impact on the ecological
system. Take the case of C02-only policies: C02 is, molecule for
molecule, the least potent radiative forcing agent of the major
anthropogenic trace gases. Because any limitation policies must
necessarily address future increments of net emissions, it is the
comparative impact of additional amounts of each gas that must be
addressed. Meanwhile, C02 may provide significant environmental
benefits that the other trace gases do not: C02 is the grist of
photosynthesis, and can improve plants' water use efficiency as
well. The other trace gases confer no such benefits, and some
pose serious threats beyond radiative forcing; CFCs deplete the
stratospheric ozone layer, while other RATGS are toxic. In sum,
if one is really interested in promoting global environmental
welfare, and if global wanning is really a threat warranting
preventive action, then policies aimed at restricting C02 alone
would not be ideal, and could be counterproductive: C02 is in a
sense the most benign of the RATGs, and for any given level of
warming that might occur, one would probably prefer (assuming for
the moment equal costs of abatement across gases) to have as much
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of that given warming due to emissions of low-forcing, plant-
enriching CO2 as possible, and less due to the other RATGs
according to their relative environmental impacts.
Beyond the case of C02-only emissions limitations, the
comprehensive approach continues to offer the guidance for
optimal decisions to r-=iximize environmental benefits per unit of
social resources expended. How is a project manager to choose
between two agricultural techniques, one which emits methane and
the other nitrous oxide? How is a nation to make the same kind
of choice? The comprehensive approach provides the signals to
yield optimal environmental outcomes to these choices.
The use of performance-based incentives under a
comprehensive approach would also improve the environmental
performance of any response measures. Command-and-control
regulations have often required those who emit a substance to
apply specific technological controls, such as "best available
control technology.* That approach discourages innovation in
control technologies, because the mandated "best" technology is
"locked in" and innovations are not rewarded. And it discourages
improvements in raw materials choices and resource use efficiency
that would limit the total amount emitted, because it gives
businesses no incentive to conserve fuels or otherwise minimize
emissions once the control technology is in place.71 Hence
technology standards dampen the innovation and resource use
efficiency that is critical to promoting environmental quality
over the longer term. The comprehensive approach, by employing
performance-based incentive that leaves the choice of the means
to comply to the individual emitter, encourages least-cost,
innovative, and resource-efficient responses.
C. Net emissions; enhancing sinks
The comprehensive approach gives sinks the serious
attention they deserve. For RATGs, it is net emissions that
would be of ecological concern, the result of both emissions from
sources and removal by sinks, including trees, grasses, soil
biota, oceanic phytoplankton that fix atmospheric carbon, and
crops.
By addressing "net emissions," the comprehensive
approach would thus give incentives for sink conservation and
enhancement. Preserving and properly managing forests and other
71 That is why, as described in Chapter IV, mandating
scrubbers to remove S02 resulted in increased C02 emissions. See
Daniel J. Dudek, Alice M. LeBlanc, and Peter Miller, "SO2 and
C02: Consistent Policymaking in a Greenhouse," Environmental
Defense Fund, New York, January 1990.
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vegetation, or protecting carbon-fixing phytoplankton from
anthropogenic injury such as from toxic waste disposal at sea,
could help sequester carbon released from surface sources. These
sink-enhancement actions could carry with them significant side-
benefits in biodiversity, oceanic food webs, reduced soil
erosion, and better timber management. At the same time,
management of sinks is a complex endeavor, and poorly designed
sink enhancement policies could have adverse impacts on sink
ecosystems.
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Chapter VI: Economic and Institutional Flexibility
A. Economic flexibility.
If emissions limits are warranted, the comprehensive
approach allows each emitter to use that combination of source
and sink controls and other measures that is best suited to its
economic and other circumstances, achieving environmental
protection at significantly lower cost than a gas-by-gas
strategy. This approach maximizes the opportunity for and
encourages the adoption of diverse, flexible, innovative, and
cost-effective solutions to global climate change.
Some have proposed dictating specific percentage
emissions reductions for each RATG, and applying those limits
uniformly to every nation. It has been suggested that every
nation should reduce CO2 by 20%, CH4 by 10%, and so on. Yet
mandating specific limits on each gas would be significantly more
costly than limits designed according to a comprehensive
approach, in which an overall limit would apply to each nation's
aggregate contribution of net RATG emissions, weighted by an
appropriate index. Both approaches would limit net emissions,
but the comprehensive approach would permit each nation to adopt
its best, least-cost mix of choices for achieving the overall
limit.
1. The prevalence of cost variations.
The costs of RATG abatement are certain to vary
considerably across countries and across gases, sources and
sinks. The variation of costs across gases, sources and sinks,
and nations means that what is a least-cost policy for one nation
will almost certainly not be the least-cost policy for another.
Under the comprehensive approach, each nation would have the
autonomy and flexibility to des.ign its own least-cost mix of
policies addressing the various RATGs, sources and sinks. Under
a piecemeal or gas-by-gas approach, nations would be bound to
adhere to the uniform reduction goals set by the international
negotiations; this centralized control of response options would
clearly impose extreme costs on certain nations, and would
unnecessarily raise overall costs worldwide.
Allowing each nation the flexibility to design its
least-cost policy response mix will reduce global costs of any
response. Some nations might find it inexpensive to reduce CO2
emissions significantly, but be unable to reduce CH4 output
(e.g., a nation importing oil and dependent on rice crops, but
endowed with untapped geothermal and wind power opportunities).
Those nations would prefer to meet any net emissions limits by
reducing CO2 more rapidly than CH4; requiring them to limit each
gas by a set amount would prove much more costly (perhaps in
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terns of lower economic growth, higher taxes, or reduced rice
production) and would leave additional affordable C02 reductions
unexploited. Other nations night find themselves in the opposite
situation, able to afford to limit CH4 nore than C02 (e.g., a
nation dependent on coal reserves but able to modify the diet of
its ruminant animal husbandry).72
Including sinks in the calculation of "net emissions"
will also offer desirable economic flexibility to nations who are
able to comply with trace gas limits more cost-effectively by
restoring and promoting sink expansion than by restricting
sources. For example, a nation might find it less costly to
remove a quantity of trace gases from the atmosphere by planting
trees than to prevent emissions of the same quantity of gases
from industrial sources. Moreover, sink development could yield
additional economic advantages, including reducing soil erosion
from agricultural lands; improving forest management; enhancing
forest biodiversity, which may contribute to useful products such
as medicines; and protecting fish habitats or spawning areas by
limiting pollution of waters that also serve as phytoplankton
habitats. It should also be noted that management of sinks is a
delicate and complex endeavor, and sound strategies would require
careful analysis. Poorly designed sink enhancement policies
could have adverse impacts.
These points are intuitively obvious, because each
nation has a different inventory of sources, sinks, and RATG
emissions, and hence a different set of RATG emissions reduction
options. Illustrative examples of the diversity of nations' RATG
portfolios are shown in Table 5. It makes no sense for a central
body to dictate to each nation what that nation's response must
be, when the same environmental result could be achieved by that
nation at much less cost through a different set of responses.
72 A similar analysis applies to approaches mandating
specific changes in sources alone or sinks alone, rather than
combining them in a "net emissions" requirement that leaves the
domestic policy mix to each nation.
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Table 5
Estimated Percentage Contribution by Greenhouse Gas
for 1985 Emissions Excluding N2O (100 year IPCC GWP)
CFC«
17.6%
United
States
United
Kingdom
NMHCs
2.2%
NMHCs
0.4%
India
Sources: A. Cnstofaro and J. Scrteraga, "Policy Implications of a Comprehensive Greennouse Gas BudgeT, USEPA. Sept.
1 990, draft: R.G.Derwent, Trace Gases and tneir Relative Contribution to the Greennouse EffecT. Harwell Laboratory.
Oxfordshire. UK. January 1990: D. Ahuja, 'Estimating Regional Anthropogenic Emissions of Greenhouse Gases', in Jbs.
Biosphere T.N. Khoshoo and M.Sharma. eds. (New Delhi, Vikas Publishing House. 1991). pp 119-15
Indian
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The fact that nations' net emissions inventories are
different under a comprehensive (all RATG) approach than under a
C02-only approach, it should be noted, does not mean that some
nations "win" or "lose" under a comprehensive "ranking* system.
"Ranking" is not the point; the point is reducing the marginal
cost of RATG abatement. The total size of a nation's emissions
does not determine the nation's cost of abatement. For example,
Nation A might have small C02 emissions and large CH4 emissions,
so it would "rank" lower on a C02-only approach. But it would
nevertheless benefit from a comprehensive approach, because of
the flexibility offered by the comprehensive approach in
selecting least-cost response options and the most productive use
of resources to yield any emissions reductions. Indeed, the cost
of abatement in Nation A might well be lower for CH4 than for C02
— that is, the marginal cost of reducing its large CH4 emissions
might be less than the marginal cost of reducing its CO2
emissions — in which case it would clearly be better off under a
comprehensive approach even though its "ranking" could be higher.
The key issue for cost-minimization is the marginal cost of
abatement, not total emissions, and a comprehensive approach is
very likely to offer reduced marginal cost of abatement to all
nations — so that every nation "wins."73
It is also increasingly clear as an empirical,
quantitative matter that the cost of abatement varies
significantly across gases and nations. First, recent analyses
confirm that costs of abatement vary widely across RATGs.
Analysis of additional steps the U.S. might take to limit net
RATG emissions in 2000 shows that planting an additional billion
trees per year (doubling the billion per year to be planted under
the President's Tree Planting Initiative) would cost about $55
per ton of carbon-equivalent avoided in 2000 (and $11 per ton in
2010, as the trees sequester more carbon), while imposing tighter
landfill restrictions could reduce VOCs and CH4 at a cost of only
about $11 per ton of carbon-equivalent avoided in 2000. These
figures are shown in Table 6 below. William Nordhaus has
estimated that in the U.S., the cost of phasing out CFCs is about
$5 per ton of carbon-equivalent avoided, while options for
73 A nation whose emissions inventory grew enormously under
a comprehensive approach might be somewhat worse off. If Nation
B had zero C02 emissions and truly gigantic CH4 emissions, it
might prefer to be governed under a C02-pnly approach. But under
a C02-only approach, the significant environmental impact of
Nation B's CH4 emissions would be ignored — not a result that
serves the global interest.
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reducing CO2 emissions begin at about $10 per ton and quickly
rise to hundreds of dollars per ton.74
These are simply illustrative examples; these cost
figures would not apply in all nations, at all times, or in all
regions of the U.S. They make clear, however, that the costs of
RATG abatement vary quite widely from gas to gas.
Table 6
Costs Vary Across RATQs
RATG units avoided Annual Cost per
(million tons of Costs RATG unit
Project carbon-equivalent) (millions) avoided75
Tighter EPA Landfill
Restrictions 39 $431 $11
(VOCs, CH4)
Planting 1 Billion 2000 2010 2000 2010
More Trees $545
Yearly (C02) 9 42-52 $55 $11
Sources: Alex Cristofaro and Joel Scheraga, "Policy
Implications of a Comprehensive Greenhouse Gas Budget,'
U.S. EPA, OPPE, draft September 1990, Table 7; and R.J.
Moulton and K. Andrasko, "Reforestation,*' 16 EPA
Journal 14 (March/April 1990). Calculations use the
IPCC 100-year radiative forcing ("GWP") index.
Second, costs vary considerably even among different
types of projects to restrict emissions of one gas. Economists
at Environmental Defense Fund have estimated the costs of CO2
avoidance through various measures, and have found a wide range
of costs per ton avoided, as shown in Table 7. Similarly, the
U.S. Forest Service has estimated that the cost of sequestering
74 See William Nordhaus, "Economic Policy in the Face of
Global Warming," Yale University, draft March 9, 1990.
75 Note that the cost per carbon-equivalent VOC and CH4
removed does not account for other benefits of such reductions,
such as reduced air toxics.
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C02 in U.S. trees varies from $5.26 to $43.33 per ton of
carbon.76
Table 7
Costs Vary Across Sources and sinks
Option Cost per Ton C02 Avoided
Trees with Conservation Reserve $3.48-$5.49
Program (CRP) Contribution
Trees Without CRP Contribution $6.64-$10.67
Biomass Plantation $8.16
CO2 Scrubbing and Disposal $59.41
Shade Trees $1.35-$6.74
Conservation $5.73
Fuel switching (oil to gas) $4.48
Source: Daniel J. Dudek and Alice LeBlanc,
"Offsetting New C02 Emissions: A Rational First
Greenhouse Policy Step," 8 Contemporary Policy Issues
29 (July 1990), Table 4.
Third, costs can also vary for different levels of
investment in a single project, as opportunities to restrict the
source or expand the sink become more scarce. That is, there are
typically rising marginal costs to expanding RATG avoidance
efforts. For example, EPA estimates that sequestering 9 million
tons of carbon in trees in the U.S. in the year 2000 would cost
about $545 million per year, but sequestering an additional 9
million tons of carbon in U.S. trees would cost about $850
million per year — about 75% more — for a total of $1.4 billion
per year for 18 million tons sequestered. And repeating that
effort, i.e. sequestering another 18 million tons for a total of
36 million tons, would cost another $2.3 billion per year —
about 165% more.77
76 Robert Moulton and Kenneth Richards, "Costs of
Sequestering Carbon Through Tree Planting and Forest Management
in the United States," U.S. Department of Agriculture, Forest
Service, GTR WO-58 (December 1990).
77 R.J. Moulton and K. Andrasko, "Reforestation," 16 EPA
Journal 14 (March/April 1990).
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These kinds of cost variations, all estimated for the
U.S. economy, would undoubtedly occur across nations as well.
The great differences in circumstances of different economies —
variations in energy, industrial, transportation, agricultural
and forestry systems, in consumption patterns, in capital
formation, in labor force characteristics, in land availability,
in population density, and so forth — almost guarantee that the
costs of abatement of any one RATG, let alone the costs for
abating different RATGs, will be quite different in different
nations. Allowing different nations the flexibility to choose
different abatement options allows each nation to design its
least costly set of measures to achieve global results — thus
reducing net global costs. The comprehensive approach allows
such flexibility; a piecemeal approach prevents flexibility
across gases, sources and sinks, at higher cost to all.
The socioeconomic costs of policy responses to global
climate change could be great. Some studies have indicated that
significant emissions reductions would be associated with
substantial impairment of economic growth.78 Other studies
suggest the potential to achieve reductions at low cost through
efficient policies. If poorly designed, inflexible piecemeal
emissions limits would impose significantly higher costs than
properly designed policies, they could impair efforts to achieve
sustainable development and could restrict needed growth in
developing nations. It is thus imperative that we choose
strategies that will maximize nations' flexibility to select
least-cost options and that will provide maximum incentives ana
opportunities for development of new technologies and other
innovative responses that will further reduce costs. A
comprehensive approach would contribute substantially to
achieving this goal.
2. Performance-based incentives
The use of performance-based standards under a
comprehensive approach would also improve the economics of
response measures. Piecemeal, command-and-control regulations
are often implemented by using "design standards* requiring those
who emit a substance to apply specific technological controls,
such as "best available control technology.* That approach would
have numerous drawbacks in the climate context. First, it is
insensitive to the costs and benefits of applying each control
technology at each site, thus resulting in the same kinds of
78 Several studies are summarized and assessed in
Interagency Task Force, "The Economics of Long-Term Global
Climate Change: A Preliminary Assessment," U.S. Department of
Energy, OPPA, DOE/PE-0096P, September 1990. pp. 23-29.
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inefficiencies described above with respect to requiring
identical emissions limitations in all nations; environmental
protection could be achieved at less cost if limitations were
obtained using the least-cost option in each place. Second, it
discourages innovation in control technologies, because the
mandated "best" technology is "locked in" and innovations are not
rewarded. Third, it discourages improvements in raw materials
choices and resource use efficiency that would limit the total
amount emitted, because requiring application of a specific
control technology gives businesses no incentive to conserve
fuels or otherwise minimize emissions, once the control
technology is in place. These drawbacks make technology
standards much less economically efficient than performance-based
incentives. The comprehensive approach, by employing a
performance-based incentive that leaves the choice of the means
to comply to the individual emitter, would encourage least-cost,
innovative, and resource-efficient responses.
At the same time, performance-based strategies imply
good knowledge of performance — in this case, probably defined
by RATG net emissions. Work is needed to improve measurement
capabilities, both to predict future RATG concentrations, and to
allow performance-based incentives should they be warranted.
B. Social and institutional flexibility.
Taking a comprehensive approach to any emissions limits
would reserve to each nation the freedom to employ whatever
economic and institutional mechanisms it wishes to use to achieve
its objective. Nations would retain the flexibility necessitated
by the widely varying legal and cultural systems in different
countries. A comprehensive approach would avo~id imposing on the
autonomy of sovereign states, as would a piecemeal or "design
standard" approach that dictates to each nation how it must
manage its climate-related policies and sectors.
Under a comprehensive approach, the institutional
response of each nation would be its own choice. A free market
economy would not be required to employ strict command and
control regulations; by the .same token, a centrally planned
economy would not be required to employ market measures.
In addition to the desire to minimize the costs of
achieving any emissions limitation, as described in the previous
section, nations may have special needs to continue certain
activities intimately tied to their cultures or social systems.
A comprehensive approach would be sensitive to these needs,
giving nations maximum flexibility to choose their own response
options. For example, a mandated CH4 reduction standard that
applied uniformly to all nations would be very intrusive to a
nation in which CH4 derives largely from livestock and the
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livestock are considered sacred. A piecemeal CH4 limitation
would leave that nation no option but to restrict its herd.
Under a comprehensive approach, nations would not be relieved 01
the obligation to share in any global effort to limit emissions;
but by defining the obligation in terms of net RATG emissions and
allowing each nation to select its preferred mix of policies that
achieve that end, nations would be better shielded from the havoc
that could attend an international mandate to disturb deeply
rooted social and cultural practices. Instead, nations could
choose their steps to limit other RATGs or to address other
sources or sinks.
C. "Level plavina field."
A piecemeal approach inevitably favors some nations
while disproportionately burdening others. For example, a C02-
only approach penalizes nations with relatively greater
dependence on fossil fuels or fossil fuel revenues, while a CH4-
only limit could burden nations who rely on rice as a staple. A
comprehensive approach provides a more equitable "level playing
field* across nations. A comprehensive approach is consequent!.
likely to avoid some of the obstacles to international agreemer.-
that would be faced by a piecemeal gas-by-gas approach, such as
"blocking* by nations who feared that the initial burden would
fall on them.79 The comprehensive approach would ease such
fears.
Moreover, experience shows that once adopted, piecemeal
initiatives rarely evolve into a comprehensive strategy.
Piecemeal measures tend to create constituencies with vested
interests that ensure their perpetuation. For example, the
Prevention of Significant Deterioration (PSD) provisions, enacted
in the early versions of the U.S. Clean Air Act, potentially
limit industrial development in many regions of the nation, often
without environmental justification. Other regions oppose
efforts to relax or rearrange these limits, for fear that
industrial and economic development will shift to the regions
that are now subject to PSD controls. The result is pressure by
vested interests to keep the PSD controls in place to constrain
balanced economic growth.
Similarly, any global climate agreement that aimed at
energy sector CO2 limitations would benefit certain nations
relative to others. The favored nations would resist development
79 Compare James Sebenius', "Negotiating a Regime to Control
Global Warming," in Greenhouse Warming: Negotiating a Global
Regime. World Resources Institute (January 1991), pp. 75-78.
Sebenius discusses (and conflates) several ways in which issues
for negotiation might be combined to avoid "blocking" coalition?
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of a more comprehensive approach that would treat all nations
with an even hand. The result would be incomplete environmental
protection, the flaws of a piecemeal policy immovably entrenched,
and serious economic distortions. It is accordingly vital to
ensure a "level playing field'' by adopting a comprehensive
approach at the outset. It is much better to get the policy
design right at the beginning, and to fill in any gaps through
hard work, than to start with a defective policy design and be
saddled with it indefinitely.
In a related manner, a comprehensive approach reduces
the ability of nations to manipulate the design of international
regulatory measures to advance their own competitive or other
economic advantage. A gas-by-gas command and control approach is
vulnerable to attempts by nations to "game" the standard-setting
agenda in their favor. For example, a nation reliant on non-
fossil fuel energy sources, and whose chief rival earns its
income from fossil fuel exports, could press for limits on CO2
emissions not for their environmental value but to improve its
own competitive standing relative to its rival. Or a wheat-
growing nation could press for methane emission limits at the
expense of its rice-growing neighbor. Such attempts would hinder
international agreement on limits on any particular gas. Such
attempts to "game" the design of international regulatory
controls are also likely to distort trade and reduce global
welfare, as well as impede environmental improvement. By leaving
the mix of compliance policies to each nation's discretion so
long as the overall limit is not exceeded, a comprehensive
approach greatly reduces the potential for such gaming. And a
comprehensive approach is likely to promote sober consideration
of any emissions limitation proposals by all nations, because few
nations could evade all responsibility under a .comprehensive
approach (as some might under a narrow piecemeal approach).
The comprehensive approach thus reduces the likelihood
of "blocking" by those who would be disproportionately burdened
by piecemeal measures; and it reduces the ability of rival
nations to distort the climate protection effort toward their own
parochial ends. At the same time, its broad coverage encourages
all nations to examine carefully the costs and benefits of any
response measures. These advantages suggest that consensus on
any warranted steps would be easier to define, and would better
reflect real costs and benefits, under a comprehensive approach.
A comprehensive approach would then share burdens more equitably,
to everyone's gain.
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Chapter "II: Potential Objections
to a Comprehensive Approach, and Replies
A variety of concerns has been raised about the meaning
and use of a comprehensive approach. This chapter addresses the
objections most often voiced. None of these objections, nor all
taken as a whole, warrants rejection of a comprehensive approach.
Indeed, several of the objections simply provide the opportunity
to clarify the rationale for and workings of a comprehensive
approach, and to explain how a comprehensive approach would
better serve environmental and economic goals.
A. *Data and monitoring of sources and sinks are inadequate.*
The major objection that has been raised to the
comprehensive approach is that the current science is not up to
monitoring certain sources and sinks, such as non-point sources
of methane and nitrous oxide. The objectors say that we should
"do what we can now' and wait until later to design a
comprehensive approach. Yet focusing on C02 from energy
emissions, merely because that is the source most easily measured
at present, bespeaks a certain complacency with the current stock
of research. Many current studies confine themselves to energy
policy alone simply for the reason that, in the words of one of
the more candid analysts, *[t]his focus suggests itself because
the necessary quantitative data for a least-cost analysis are far
more developed in the case of energy than for other major sources
of greenhouse gases.*80 And unless comprehensive research is
carried out, a narrow and incomplete knowledge base will yield
incomplete and flawed piecemeal policy responses.
The more inquisitive comprehensive approach thirsts for
research into the key unknowns. Measuring many such emissions
will not be easy. But it is not beyond our reach, if we focus
current research efforts to support a comprehensive approach. It
is particularly in agriculture and forestry that the research
toward improved monitoring is most needed. The net emissions
data base is perhaps least well-developed for the diffuse, non-
point sources and sinks of greenhouse gases that are typical in
the agriculture and forestry sectors. For example, recent
studies are advancing understanding of carbon sinks: both the
80 F. Krause, et al., Energy Policy in the Greenhouse.
(IPSEP / European Environmental Bureau / Dutch Ministry of
Housing, Physical Planning and Environment, September 1989),
Volume One, p. 1.1-3.
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total size of the oceanic versus terrestrial sinks,81 as well as
the more localized effectiveness of different types of forestry
in sequestering carbon;82 but the uncertainties surrounding these
processes are still significant. As to methane, we are beginning
to understand its diverse sources in rice cultivation, livestock,
the energy sector, and waste disposal,83 and its sink in
tropospheric chemical reactions; but while we have fairly good
data on certain sources such as landfills, the gaps in the data
on other sources remain significant. The same holds for nitrous
oxide. We will need better estimates of these sources and sinks
if we are to forecast future concentrations of the gases, fashion
reliable greenhouse gas indices, or calculate baseline and future
net emissions for each nation or sector.
The pertinent question, however, is not what is
immediately "feasible," but whether the costs of proceeding with
a flawed piecemeal policy design are less than the costs of doing
the necessary groundwork to develop a comprehensive approach.
The groundwork needed to flesh out a workable comprehensive
approach is very likely to be less costly than the environmental
and economic losses that would attend implementation of a
piecemeal approach that is ineffective and inflexible. And as
indicated in Section C of Chapter VI, it is better to start with
a proper policy design and work hard to fill in any gaps, than to
start with a flawed policy design and be stuck with it
indefinitely.
And one need not wait for perfection; in the interim,
proxy-based estimates of difficult-to-measure emissions could be
used. Continuing research, bringing together physical and social
scientists with expertise on the critical areas of uncertainty
about emissions, is indispensable. International efforts such as
the framework convention should build cooperative networks to
measure net emissions. International agreements could include
incentives for improvements in monitoring, such as offering
awards or even emissions credit to those who demonstrate better
monitoring techniques.
81 See P. Tans, I. Fung, & T. Takahashi, "Observational
Constraints on the Global Atmospheric C02 Budget," 247 Science.
23 March 1990, p. 1431.
82 See M. Harmon, W. Ferrell, & J. Franklin, "Effects on
Carbon Storage of Conversion of Old-Growth Forests to Young
Forests," 247 Science. 9 February 1990, p. 699.
83 See IPCC Response Strategies Working Group, "Methane
Emissions and Opportunities for Control," coordinated by Japan
Environment Agency and U.S. EPA (September 1990).
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Then, if emissions limits are warranted, a
comprehensive approach can be phased in as other actions (e.g.
forestry agreement) are integrated, and as the inclusion of
harder-to-monitor sources and sinks becomes manageable. Although
it is vital to begin with as fully comprehensive an approach as
possible, an approach that is substantially comprehensive, in
principle covering all RATGs, sources and sinks, could be
supplemented with additional items as research and data brought
them to a practical stage.
B. *We can't afford to wait for a comprehensive approach; we
need to do what we can now to address CO2.*
It might be argued by some that employment of the
"comprehensive* approach could add delay to the process of
reaching international agreement on global climate change issues.
Some say that the fastest approach is to adopt protocols quick:v
for substances we can agree on now, and then proceed to thorni-: r
issues as we go.
First, development of a comprehensive approach does not
mean delay. It is ready for implementation today in the
framework co. vention, to define the scope and key elements of
research and monitoring.
Second, if emissions limits are warranted, a
comprehensive approach can be phased in as other actions (e.g.
forestry agreement) are integrated, and as the inclusion of
harder-to-monitor sources and sinks becomes manageable. Although
it is vital to begin with as fully comprehensive an approach as
possible, an approach that is substantially comprehensive, in
principle covering all RATGs, sources and sinks, could be
supplemented with additional items as research and data brought
them to a practical stage.
Third, given its environmental and economic advantages,
taking the time to develop a comprehensive approach is
worthwhile. A piecemeal approach would mean environmental
frustration and dysfunction, due to such defects as the potential
for unintended shifts of residuals (see Chapter V); adrpting a
piecemeal approach sooner would probably not be a big
improvement. A comprehensive approach could achieve better
overall environmental protect J*n than a piecemeal approach, even
if it does take slightly long to achieve than the first single-
gas protocol would take.
Fourth, if there is agreement that response measures
are warranted, use of a comprehensive approach to policy measures
could in fact advance the date of agreement because (as discussed
in Chapter VI) it raises the .kelihood of broad consensus by
eliminating the divisive inequitable effects of a piecemeal
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approach. Under almost any piecemeal approach, some party would
be disproportionately burdened, and would be likely to block
effective agreement; a comprehensive approach would ease the way
to equitable and sober consideration of response options.
Fifth, the suggestion that we ought to "do what we can
now" is generally incorrect. As discussed extensively under
Section A of this Chapter and Section C of Chapter VI, it is
better to develop a sound approach at the outset than to launch
an approach that is likely to fail at great cost. The framework
needs to begin as a comprehensive approach, because starting with
a piecemeal approach will likely leave it entrenched, rather than
encouraging evolution toward a comprehensive approach. Those who
are favored by the initial piecemeal approach would try to block
any attempts to broaden its scope.
Sixth, many nations are already taking action. These
steps should be accounted for and recognized through a
comprehensive approach.
Seventh, a comprehensive approach makes better use of
scarce resources, because it achieves results at less cost (see
Chapter VI) and because it maximizes the environmental benefit
for any investment of social resources. It thus better provides
for sustainable development, which requires both effective and
efficient policies since environmental protection ultimately
depends on the resources that economic growth provides.
Finally, a comprehensive approach does not prevent
action. Nations who wish to limit net emissions of any of the
range of trace gases may do so now; indeed taking a comprehensive
approach broadens the set of opportunities that nations have to
act now to address potential climate change.
C. "CFCs should not be included in comprehensive basket."
As an initial matter, all anthropogenic substances
contributing to radiative forcing should be included. Use of
CFCs and in particular of CFC substitutes (HCFCs, MFCs) in the
future may be quite important to radiative forcing, but the
Montreal Protocol does not account for these impacts.84 Nor does
the Protocol fully control the HCFCs, which have high GWP index
values. Failing to address these radiatively active gases in the
84 See Donald A. Fisher, et al., "Model Calculations of the
Relative Effects of CFCs and their Replacements on Stratospheric
Ozone," 344 Nature 508 (April 5, 1990); and Fisher, et al.,
"Model Calculations of the Relative Effects of CFCs and Their
Replacements on Global Warming," 344 Nature 523 (April 5, 1990).
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climate context could invite perverse environmental results. Fa-
from any "double counting," such an approach would account for
the climate impacts of CFCs, HCFCs and HFCs that the Montreal
Protocol omits.
Second, it should be clear that a comprehensive
approach to climate change would not allow nations to violate
their obligations under the Montreal Protocol.
Third, the climate agreement could reward reductions in
ozone-depleting substances that are more ambitious than required
by the Montreal Protocol ~ faster reductions, or reductions in
other uncontrolled substances, or reductions achieved in nonparty
nations. This would provide supportive incentives to phase out
ozone-depleting substances even more quickly. Consider the
incentive effects of the following options for addressing CFCs in
an RATG agreement:
(a) not giving credit for any limitation of CFCs and
haIons;
(b) giving credit for limitations of CFCs and halons,
to the extent they go faster than or beyond the limits
required under the Montreal Protocol, and/or for
limitation of ozone depleting substances that are also
RATGs but that are not covered by the Montreal
Protocol; and
(c) giving credit for all limitation of CFCs and
halons to the extent that they are RATGs.
Each of these options would have different effects on CFC and
CFC-substitute consumption. Option (a), no credit, would provide
no additional incentive to nations producing CFCs, halons, HCFCs,
MFCs, and related substances to achieve further reductions beyond
required limits. Option (b) would provide such an incentive, but
by disallowing credit once the limitation is covered by the
Montreal Protocol, option (b) would perversely discourage nations
who are parties to both agreements from seeking further
expansions of the Montreal Protocol. That is, if the credit
afforded under a climate agreement were made unavailable for
reductions required by the Montreal Protocol, nations reducing
gases that yield both OOP and GWP might delay the expansion of
the Montreal Protocol (e.g. expansion to require faster phaseout,
or to cover more substances such as HCFCs more stringently), lest
the expansion cancel their GWP credits. And option (c) would
provide such an incentive as well as recognize the value to
potential global climate change of limits on CFCs and halons
under the Montreal Protocol.
Fourth, some nations are doing more to reduce global
CFCs than others, at their own expense, and their contribution
should be recognized.
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Fifth, including CFCs helps attract nonpar-ties to both
agreements. Put another way, excluding emissions reductions
already covered by the Montreal Protocol would reduce the
likelihood of attracting new parties to the Montreal Protocol:
nations who are not now parties to the Montreal Protocol would
face disincentives to joining the Protocol if joining meant that
their CFC reductions lost credit under the climate agreement.
Sixth, there is a large existing reservoir of CFCs and
halons slowly leaking from in such containers as abandoned
refrigerators and automobile air conditioners. Leaks of such
CFCs and halons constitute both OOP and RATG emissions, but they
are not controlled by the Montreal Protocol. Giving climate
credit for reductions in these CFCs would provide helpful
incentives to store or recycle such gases safely, reducing GWP
while helping to prevent ozone depletion..
D. *The Global Warming Potential Index is uncertain.*
There is emerging international consensus that the
scientific fundamentals are sound. Although uncertainties remain
in the index values, relating principally to the residence times
of gases such as C02 and N20, the IPCC found general acceptance
for its GWP method; and the consensus of an international
workshop on GWP Indices organized by NOAA, EPA, NASA, UKDOE and
others in Boulder in November 1990 was that although these
uncertainties require urgent attention, they do not warrant
abandoning the index. Some of the estimates in the GWP index are
expected to change as new research is undertaken. For example,
recent work shows that the lifetime of CH4 is 12.5, not 10,
raising the GWP of CH4. The residence time of CO2 is an estimate
because carbon cycles between the ocean and atmosphere every 5-10
years, ultimately sequestered much later. This estimate will
probably change as research proceeds. Methodological suggestions
may also be made to improve the index.
For practical policy purposes, some index is much
better than no index. The major choice is between no index (a
piecemeal approach) and a good index; the choice between a good
index and a near-flawless index is something more of a luxury. A
good but imperfect index could serve well and then be amended
later. Absolute precision is not necessary for practical uses,
such as providing general guidance to decisionmakers, and
affording them the flexibility to select a mix of response
options among the several RATGs.
E. *A comprehensive approach is complex and unworkable.*
First, a comprehensive approach is not complex or
unworkable. A comprehensive approach to research and monitoring
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is not only workable, it is the only practical apprc_ n. As an
approach to any agreed emissions limitations, the Montreal
Protocol has quite successfully demonstrated the feasibility of
employing a multi-gas approach with an index of gases' relative
impacts on the environment.
Second, as experience with traditional environmental
issues shows, adopting a piecemeal approach means scrambling to
redress unintended shifts and dysfunctions. The reality of
shifts in traditional environmental contexts, and the potential
for shifts in the climate context, elaborated in Chapter V,
should indicate the serious workability problems facing a
piecemeal approach.
Third, a comprehensive approach would ease the
workability and complexity of any agreed emissions limits, by
affording economic and institutional flexibility to nations to
design their own best mix of response options. Piecemeal
measures might be "easier said than done": easier to write down
on paper, but harder for diverse nations to implement in light of
their diverse circumstances, needs and capabilities. Further,
the comprehensive approach avoids the complex, cumbersome, and
bureaucratized central determination of precise uniform gas-by-
gas or source-by-source emissions targets, or selection of
uniform "best available control technology," some or all of which
would likely be called for under a piecemeal approach.
F. "Other discrete actions will have already been taken."
It is inevitable that other discrete actions will
already have been taken by the time any climate agreement is
signed. These include limits on CFCs in the Montreal Protocol,
and could include forthcoming agreements on forestry and on VOCs.
Any international agreement employing the comprehensive
approach would be constructed out of a number of institutional
building blocks: the several international accords and national
actions contemplated or already in place, each of which addresses
a discrete term in the global change equation. Related national
actions would similarly be recognized, to avoid giving
disincentives to useful measures that nations wish to take for
other reasons. Indeed, these actions could be recognized in the
convention, to provide incentives in advance for nations to take
actions justified on other grounds that also address net RATG
emissions.
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Chapter VIII: Market-based Incentives
If any international emissions limitations are deemed
warranted and agreed to, they should allow nations the
opportunity to employ, at their voluntary discretion, market-
based incentives in implementation. We have learned a great deal
about the drawbacks of traditional "command-and-control"
regulatory approaches: by mandating uniform adoption of centrally
chosen abatement techniques, they raise costs, discourage
innovation and resource use efficiency, and raise administrative
burdens. The virtues of market-based economic incentives for
environmental protection are now increasingly well-recognized.
The common feature of the new tools is that they respond to
market-failure — such as excessive pollution — by redirecting
and harnessing market forces to correct the problem. They allow
flexibility among market actors, promote decentralized
decisionmaking about response tactics, further least-cost
solutions by allowing those who can fix the problem most cheaply
to do so roost, and stimulate efficient resource use and
innovation in technologies and practices.
A. Voluntary Use.
Any use of market-based incentives should be at the
voluntary election of the nation or nations involved.
Domestically, each nation should have the option of employing any
implementation mechanisms it prefers. These may include
technology development, market-based incentives such as tradeable
emissions allowances or fees, conventional regulations,
technology standards, or other techniques. Any international
agreement to respond to potential climate change should avoid
impairing nations' freedom to choose their domestic policy tools.
Internationally, the use of market-based incentives
would likewise be voluntary. For example, emissions trading is
by its nature a voluntary enterprise. If the opportunity for
international emissions trading is left open, it would mean that
two or more nations could, at their voluntary election, cooperate
on joint activities that together achieve their aggregate
international obligation. It would simply allow a nation to
achieve its goals abroad as well as at home. Similarly, a
grouping of a region of nations, or a grouping of similarly
interested nations, could elect to allow trading — cooperative
joint efforts to accomplish aggregate emissions goals — among
the member nations. No nation would be obliged to participate in
any mandatory trading "system."
Market-based incentives could be employed under a
single-gas approach or a comprehensive approach. Their
advantages would be maximized when coupled with a comprehensive
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approach, since the flexibility of choices among gases, sources,
sinks, and location of investments would magnify the economic an.
incentive gains.
B. Examining current government interventions.
Before devising new policies, the first step in a
market-based approach should be to examine current government
policies and their effects on markets relevant to global change.
What are their effects on the inputs to global change, and on the
ability to adapt to any global change? on the input side, it is
often government policies that subsidize activities in the
energy, agricultural and forestry sectors and thereby increase
net emissions of trace gases. These include counterproductive
agricultural price supports and other policies that induce excess
crop planting and unduly intensive use of nitrogenous
fertilizers, adding to nitrous oxide emissions as well as
erecting trade barriers. And they include rules that needlessly
encourage even below-cost forest clearing, reducing carbon
sinks.85 On the adaptation side, policies that prevent the
development of efficient markets for natural resources — such as
water — may undermine the incentives that would be provided to
induce conservation if global change put pressure on supplies.
Better operation of private markets, on both the input and
adaptation side, could help address climate change without major
social expenditure.
C. Harnessing market forces toward environmental progress: U.S.
experience.
Where market failures demand policy interventions,
market-based tools can provide the best response options. Fees,
tradeable allowances, and deposit-refund programs have
demonstrated success in several important environmental
applications, including the tradeable credits program used to
phase out lead in gasoline —- achieved at about half the cost of
a traditional regulatory program (amounting to savings of
hundreds of millions of dollars). Both fees and tradeable
allowances are now being used in the U.S. program to phase out
CFCs under the Montreal Protocol. And tradeable allowances will
be employed in the acid rain reduction provisions of the new
Clean Air Act, with projected national savings of $1 billion
annually as compared to a command-and-control program.
85See, e.g., Randall O'Toole, Reforming the Forest Service
(1989); Robert Repetto, "Deforestation in the Tropics," 262
Scientific American. April 1990, p. 36.
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The use of market-based instruments for environmental
protection is not just the stuff of theory; it is already the
reality of practical application in the United States and
elsewhere. In several areas of environmental policy, market-
based instruments such as tradeable allowances, fees, and
deposit-refund systems are in place and have been operating with
general (and often great) success.
The attractiveness of market-based economic instruments
relates to the goal of environmental policy interventions: to
correct failures of private markets to achieve society's
environmental goals. The background presumption is that private
markets will provide the goods and services that consumers
desire. But private markets may provide inadequate environmental
protection when environmental values are 'externalities* not
adequately reflected in the prices consumers pay for goods and
services, or when environmental values are "public goods" from
which all individuals benefit but in which no individual has an
adequate incentive to invest.
In remedying such market failures, governments (the
United States included) have traditionally employed "command-and-
control" regulations. Such regulation relies on uniform,
inflexible, technology-based standards that result in high
compliance costs, restrict innovation, discourage efficient use
of resources, and require detailed central planning of economic
activity. While some of these regulatory controls have been
initially effective in limiting environmental degradation, they
have also proved to be costly and burdensome. Because the cost
of controlling pollution varies among those subject to
regulation, a command-and-control policy requiring them all to
meet the same target, or to install the same technology, means
that some could have achieved the same environmental protection
outcome through less costly means. Society is consequently
forced to pay more for environmental protection than it needs to,
wasting resources and potentially arousing resistance to further
environmental policy measures. In the longer run, command-and-
control regulation deters innovation by selecting a chosen
technology and giving no reward to those who devise a better
techniques; this in turn weakens the ability of command-and-
control regulation to prevent environmental degradation
effectively.
Since the underlying problem is that private markets
are operating imperfectly, the better approach for government
action will often be to "reconstitute" the market: to orient it
toward providing incentives that promote the desired
environmental outcome. By revising the market's own system of
pricing and allocating environmental protection responsibilities,
market-based mechanisms turn the power of the marketplace — the
indefatigable creativity of diverse and flexible responses by
motivated market actors — to environmental advantage. Overall
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social costs are reduced because those who can prevent
degradation most cheaply have the most incentive to do so.
Environmental protection is advanced as the incentives spur
innovation in technologies and processes, and as efficient use of
resources (such as conservation of fuels) is put on equal footing
with installation of control technology.
Among the several types of economic instruments that
might be used to implement environmental policy, current
applications have generally employed a few basic techniques:
fees, tradeable allowances (also called marketable permits), and
a hybrid form called deposit-refund systems.
A fee can be attached to each unit of emissions,
effectively forcing the emitter to "internalize" the cost that
the emissions impose on society. Each emitter reduces emissions
to the point that its costs of control become as expensive as
paying the fee; this point will vary for each emitter, but the
aggregate emissions reduction will correspond to the size of the
fee exacted.
Under tradeable allowances, a constraint is imposed on
the total quantity of emissions, allowances adding up to that
total are issued, and emitters are allowed to reallocate
allowances among themselves. The aggregate emissions cannot
exceed the total level set, but the amount controlled by any
individual emitter may vary — provided that it must hold
allowances for each unit of emissions, or face heavy penalties.
Those who can control emissions more cheaply free up excess
allowances to sell at a profit, while those for whom control is
more expensive purchase allowances. The market price of the
allowances is effectively similar to a fee on emissions, forcing
purchasers to internalize the costs of their excess emissions.
A deposit-refund system is like a fee with a rebate:
those who generate a waste, or purchase a product, must pay a
deposit on the item; when they return the item for proper
treatment, they receive a refund. This .arrangement provides an
incentive for proper handling, whereas a mandatory return rule
could induce illegal disposal to avoid the costs of return.
The United States has used each of these market-based
mechanisms as tools to implement environmental policy. This
section provides a picture of the great diversity of contexts in
which these tools are being applied, and the general features of
each program.86
86 This discussion draws heavily on Bruce Ackerman and
Richard Stewart, 'Reforming Environmental Law: The Democratic
Case for Market Incentives," 13 colum. J. Envtl. L. 171 (1988);
Robert Hahn and Gordon Hester, "Marketable Permits: Lessons for
Theory and Practice," 16 Eeol. L. O. 361 (1989); Richard Stewart,
"Current Experiments with Economic Instruments in Environmental
(continued...)
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1. Current programs.
Emissions "trading under the ambient air quality rules
of the Clean Air Act: bubbles, netting, and offsets. Under the
Clean Air Act, each region of the country must attain ambient air
quality standards. Existing, modified, and new sources of
emissions are all required to employ emissions controls.
Starting in the late 1970s and increasingly in the last decade,
the U.S. Environmental Protection Agency (EPA) has employed
several different emissions trading programs: "Offsets" allow new
sources of emissions to be added to an area (provided they employ
stringent control technology) so long as they obtain
corresponding decreases in emissions from existing sources in the
same area. "Netting" allows an existing source to add a
modification that produces additional emissions, without having
to install the most stringent emissions control technology, if it
obtains a corresponding decrease in emissions from other parts of
the same unit. "Bubbles" allow existing plants with emissions
emanating from multiple units (such as several smokestacks) to
reallocate emissions among the sites within the plant, and
existing plants to reallocate emissions among a set of plants, so
long as total emissions do not increase. In addition, a banking
program lets existing sources store excess reductions in
emissions for future use.
Experience has been different under each of these
programs, but in general, there have been significant cost
savings over traditional regulations. The netting and bubble
programs, for example, achieved savings estimated at several
billion dollars in the first seven years of the program. And
these substantial savings have been obtained despite the fact
that the trading program is a modest modification to a
traditional, command-and-control technology design regulatory
program. Meanwhile, no reduction in environmental quality has
been observed; there has been no increase in the aggregate
emissions level.
Lead phasedownt content reduction credits. Also under
the Clean Air Act, the EPA issued regulations reducing the
allowable lead content of gasoline. In 1982 EPA instituted
limits on lead content and permitted trading within and among
refiners: leaded gasoline producers and importers could transfer
(i.e., buy and sell) lead content credits freely among themselves
86(... continued)
Policy," paper presented at the EDF/AER*X/USSR Academy of
Sciences "Soviet-American Conference on Economic Instruments for
Environmental Protection," Washington D.C., November 12, 1990;
and James Tripp and Daniel Dudek, "Institutional Guidelines for
Designing Successful Transferable Rights Programs," 6 Yale J.
Regulation 369 (1989).
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through 1986, or could apply such credits to their own gasoline
But such credits expired quarterly if unused. In 1985, EPA
substantially reduced the lead content limit further; the content
was required to decline, in phases, from 1.10 grams of lead per
gallon (gpg) to no more than 0.10 gpg by the end of 1985. To
provide leaded gasoline producers and importers with some
flexibility in complying with the new limits, EPA also issued
regulations in 1985 permitting producers and importers whose
gasoline in 1985 contained less lead per gallon than the
applicable standard, to "bank" lead content credits (i.e., to
avoid the expiration of credits). The "banking" regulations then
permitted gasoline producers and importers to "withdraw" those
lead content credits through the end of 1987 and to apply them to
help meet the new, more stringent lead content standards that
took effect in 1985.
The banking and trading system helped the industry as a
whole to comply with the new lead limits, while ensuring that the
total amount of lead content did not exceed the maximum that
otherwise would have been allowed under the lead content
standards in the absence of the banking provisions. Data
indicate that banking and trading were active, and that they
resulted in substantial cost savings (on the order of hundreds of
millions of dollars over the few years of the program).
The design of the lead phasedown facilitated widespread
trading. Firms were not required to apply to the EPA for
permission to enter into trades; they simply reported their
trades to the government, as part of their regularly required
reports of the lead content in their gasoline. Each firm was
simply required to have a net balance of lead content credits
greater than or equal to zero in each quarter. In addition,
because gasoline refiners and importers were accustomed to
trading feedstocks and other commodities with each other, trades
in lead content credits did not require new information networks.
In sum, the lead phasedown was highly successful.
CFCs reduction; production allowances. Both trading
and taxes are being used in the effort to phase out
chlorofluorocarbons (CFCs) in order to protect the stratospheric
ozone layer. Internationally, the 1987 Montreal Protocol obliges
each nation to cut in half its consumption of CFCs by 2000; the
1990 update of the Protocol accelerates that schedule to a total
phaseout by 2000. The Protocol allows a small amount of trading
among nations in CFC production, a flexibility that was expanded
in the 1990 update. To date little if any trading under this
provision has occurred, probably because the Protocol explicitly
constrains the extent of the trading, and also because trading is
only allowed in production (i.e in the physical location of
production facilities) and not in consumption (defined as
production plus imports less exports).
Domestically, in order to implement the first phase of
the 1987 Montreal Protocol and the national legislation following
from it, the U.S. EPA has issued regulations requiring the 50%
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phaseout by 2000 and implementing the phaseout by issuing
allowances to each producer and importer of CFCs. These
allowances may be traded among producers, importers and other
interested parties. EPA is able to monitor production and
imports of CFCs, and to keep track of allowance trades.
Producers are aware of potential buyers and sellers and can trade
allowances freely. But the small number of producers and
importers may limit the number of trades that actually occur.
It is sometimes assumed that market-based instruments
are a substitute for tough enforcement programs, which they are
not. As indicated earlier, tradeable allowance systems depend on
preventing emitters from emitting more than the allowances they
hold. The CFCs program is a good example of our vigorous
enforcement efforts: this past summer we brought the first
enforcement actions by any government worldwide, so far as we
know, to enforce compliance with obligations under the Montreal
Protocol. We sued six companies for importing CFCs without
obtaining allowances; the violators were required to purchase
allowances on the open market and in addition to pay penalties.
In addition to issuing CFC allowances, the United
States has imposed an excise tax on CFC production and
importation. Like the allowance trading system, this tax will
encourage the transition to higher-priced substitutes for CFCs.
The tax is a multiple of the OOP value for each CFC, calibrating
the incentive to the environmental impact of the substance.
An important issue in protecting the earth's ozone
layer is the large reservoir of CFCs remaining stored in coolant
systems and other end uses. The tax and tradeable allowance
systems will provide some incentives to recover and recycle old
CFCs, but a direct refund might be offered to encourage more
recovery.
Pinelands development! tradeable development rights.
A somewhat different kind of allowance approach has been used
successfully by the State of New Jersey .to regulate development
of the Pinelands, a forest zone the State wishes to protect from
excessive development. Here the allowances are not for
emissions, but for rights to develop certain property. Property
in parts of the Pinelands is slated for preservation, and the
owners of that property may agree to be prohibited from
developing their land. In return, they are issued "transferable
development rights* (TDRs) which they may sell to others wishing
to develop land in the other areas of the Pinelands. Different
amounts of TDRs are issued to each owner, depending on the value
to society of preserving that owner's property. In areas in
which development is permitted, landowners must hold TDRs to
develop their property. Thus, the total amount of development in
the Pinelands is capped, and the regional distribution is partly
restricted; but the precise allocation of development on
permissible properties is left to the market for TDRs. In
addition, no current landowner is entirely deprived of the former
market value of his or her land, because those who are barred
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from developing their own land receive TDRs to sell others.
The government has established a TDK exchange to fa: .itate
trades: the exchange buys TDRs from willing sellers and sells
them to interested buyers.
Pox River water quality: discharge renegotiations.
Under the Clean Water Act, sources of discharges into water
supplies must meet emissions limits to achieve water quality
standards. The State of Wisconsin adopted a discharge limit
system for the Fox River that set the limit for each source, but
also permitted sources to devise new discharge limits, by mut-.; .
agreement, so long as the total discharge did not rise. In
principle, the plan implements a market in transferable emissions
allowances. In practice, however, the system has proved
cumbersome. Sources hold five-year permits from the state, and
trades may expire at the close of a permit cycle, impairing their
use for reallocations that involve long-term investments in
capital equipment. No allowances or credits are actually issued
to sources; instead, each agreement between sources must be
submitted for approval to the state agency. Parties must
demonstrate to the state that they "need" to make changes in
their permits. Review by the agency can be complex and time-
consuming. And there is no broker to help arrange trades. Thus,
transaction costs are high and the market is sluggish. Agency
review of proposed trades is deemed necessary, moreover, by the
fact that agreements between sources can yield very low
discharges of toxic substances in one local area and very higr
discharges of toxics.in another, potentially placing too great aii-
ecological burden on the latter area. Hence the spectrum of
possible trades is limited, and few trades have occurred.
Dillon Reservoir water quality! point/nonpoint trades.
In the state of Colorado, discharges from economic activity were
endangering the drinking water supplies in the Dillon Reservoir.
Emissions came from both point sources (e.g. factory discharge
pipes) and nonpoint sources (e.g. runoff). The government issued
annual discharge allowances to all sources. It then required
that sources may increase their discharges only if they acquire
allowances from nonpcint sources, at a ratio of 2:1. That is,
for each pound of discharges a source wishes to add, it must
reduce discharges by two pounds from nonpoint sources. Because
control of point sources is about seven times as expensive as
control of nonpoint sources, the 2:1 trading ratio leaves
dischargers considerable room for cost-saving trades. Thus,
trading will likely both save costs and reduce emissions.
Although the program is just getting under way, observers expect
active trading and significant cost savings.
Beverage containers; deposit-refunds. In order to
reduce litter and encourage recycling of glass and aluminum
beverage containers, several states have enacted "bottle bills."
These laws institute a deposit-refund system for bottles and
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cans, in which a deposit (typically 5 cents per container) is
charged at the point of purchase and is refunded upon delivery of
the containers to a retailer or recycling depot. Although these
programs may reduce litter, they typically charge the same
deposit regardless of the type of container (e.g. metal or
plastic) and thus fail to provide incentives to consumers to
choose the material whose disposal is least costly to society.
And the social desirability of these deposit-refund systems
depends on how much time consumers must spend returning the
containers; curbside pickup programs could be preferable.
Debt-for-nature swaps; international environmental
trading. Arrangements in which banks forgive debt in return for
the debtor's agreement to conserve natural resources, dubbed
"debt-for-nature swaps," are a kind of trading applied to
environmental protection. These ad hoc arrangements are not a
government "program"; rather they illustrate that private markets
can offer mutual benefits to the trading of one asset (debt) for
another (environmental protection). A few such swaps have
occurred to date. These swaps might serve as a model for more
institutionalized international trading on global environmental
issues.
2. Programs about to be implemented.
Administration plan to reduce acid precipitation;
tradeable allowances. The Bush Administration proposed, and
Congress has just enacted, new Clean Air Act legislation to
reduce emissions of materials that contribute to acid
precipitation. A key feature of the Administration plan is the
use of transferable emission allowances. The law sets a
permanent cap on emissions of sulfur dioxide (S02) (one of the
main precursors of acid precipitation) from fossil fuel-burning
electric utilities larger than 25 megawatts (the primary source
of SO2 emissions in the U.S.). Initially, annual emissions
allowances will be issued to existing utilities in two phases
according to a formula that multiplies each plant's historic
energy capacity factor by a target average SO2 emissions rate
which is generally lower than the current actual average
emissions.-rate. Under this formula, utilities operating plants
with high emissions would not be allocated enough allowances to
cover their emissions at historical levels.
To make up this allowance shortfall, which will amount
to about 10 million tons of SO2 per year, individual utilities
could reduce their emissions by switching to cleaner fuels,
installing additional emissions.control equipment or taking
conservation measures, or could purchase additional allowances;
overall, the industry as a whole will reduce emissions by 10
million tons. Utilities that can afford to reduce their
emissions below the target average emissions rate (i.e. below the
number of allowances they have been allocated) will be able to
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sell those 'extra* allowances as "credits* to other utilities fcr
when purchasing allowances is cheaper than investing in emissior
reductions. New entrants to the electricity industry can acquire
allowances from existing utilities, or from occasional auctions
of a small percentage of allowances reserved by the government.
The cost savings of this trading plan over a plan not
employing trading are estimated at about one billion dollars per
year or higher. This plan also creates a strong financial
incentive for utilities to engage in energy conservation and
technological innovation, whereas both would be discouraged by a
rule requiring utilities to adopt specific emissions control
mechanisms such as scrubbers.
Clam and ouahoa harvesting! individual transferable
quotas. Traditionally, harvesting of surf clam and quahog (a
related species) off the East coast of the U.S. have been capped
at an aggregate amount; but individual boats' quahog fishing had
been otherwise generally unregulated while certain aspects of
individual boats' surf clam fishing (such as the frequency of
outings and their length) had been carefully regulated. A new
program has been developed to employ trading to allocate
harvesting activities more efficiently. Under the recent
"Amendment 8" to the Fisheries Management Plan for the Mid-
Atlantic region of the United States, a system of "individual
transferable quotas" (ZTQs) for clams and quahogs will be
created, with each ITQ representing a percentage of each market.
They are initially to be issued to each vessel based on the
vessel's historical fishing. The ITQs may then be traded among
vessels. This plan has recently been challenged on a variety of
legal grounds by plaintiffs including vessel owners and seafood
processors.
Mobile sources; averaging, banking and trading. Mobile
sources (vehicles) consume fuel and emit pollutants, and trading
is being employed in programs to limit both of these activities.
A kind of "internal" trading (trading within a firm) is
already allowed under the rules requiring vehicles to attain fuel
economy (miles per gallon) standards. The government might have
required every individual vehicle to achieve a specified minimum
fuel economy standard. Instead, the "Corporate Average Fuel
Economy" (CAFE) rules govern the average efficiency of each
manufacturer's entire fleet in each model year. This gives the
manufacturer flexibility to reach the same aggregate fuel economy
while varying the characteristics of each vehicle to suit the
spectrum of consumer needs and tastes.
Even more flexibility could be obtained if fuel economy
achievements could be tradeable. among manufacturers: if one
manufacturer who achieved a fleet average lower than the
applicable CAFE rule could sell its excess as a "credit" to
another manufacturer whose fleet exceeded the rule.
Along these lines, EPA has recently revised its Clean
Air Act program governing the particulate and nitrogen oxides
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emissions of heavy-duty truck engines. For several years £PA has
set an average emissions standard for the line of truck engines
produced by each manufacturer, thus affording each manufacturer
the internal flexibility to make a range of engines so long as
their average cleanliness meets the standard (similar to the CAFE
program for fuel efficiency). In its new regulation, EPA now
allows emissions trading among manufacturers and banking over
time. EPA provides that a manufacturer whose line of engines
emits less on average than the standard will earn "credits* which
can be banked for application to future model years, or traded to
other engine manufacturers. The greatest emissions reductions
will be achieved by those manufacturers who can do so at least
cost, reducing the overall social cost of the program. And
manufacturers will have additional incentives to reduce emissions
in order.to generate credits to sell at a profit. In an effort
to provide assurance that the trading and banking program will
not impair environmental protection, EPA is providing that
credits will be redeemable at 80% of their face value, reducing
by 20% the emissions allowed upon each trade, but also reducing
somewhat the attractiveness of investment in additional emissions
reductions. EPA projects that the profits from credit sales will
still be sufficient to stimulate trades and emissions reductions
even with the 20% discount.
Other air quality programs. The 1990 Clean Air Act
amendments call for the establishment of other programs in which
the trading of marketable allowances is envisioned. One such
program is the clean fuel vehicles program, requiring both
manufacture of vehicles capable of using cleaner fuels, and
purchase of such vehicles by owners of vehicle fleets. Under
each part of the program, those who make or purchase more clean
fuels vehicles would receive tradeable credits. Another program
requires sale of cleaner fuels, including cleaner gasoline,
reformulated gasoline, and oxygenated fuels, to reduce VOCs, CO,
and toxic air pollutants; it awards tradeable credits for those
who exceed production targets.
3. Programs under discussion.
Municipal solid waste. The large volume of municipal
solid wastes is prompting concern that landfill capacity will run
out. As landfills have become scarce, some of the waste stream
has been diverted toward incineration, but that route can pose
air pollution problems and generates incinerator ash. Another
option might be water disposal in lakes or seas, but tight rules
already constrain that possibility. Command-and-control
regulation to specify the technology and design of landfills and
incinerators can offer some improvements in those facilities, but
is not likely to affect the total stream of solid waste directly,
and can simply shift wastes from land disposal to air
incineration. Mandating that residents separate materials for
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recycling can also be useful, but does not assure a market for
the recyclable materials and does not directly discourage
generation of waste by residents.
One proposal to address these problems is to impose a
cost on the generation of solid waste that reflects its social
cost of disposal. Such a fee would provide an incentive to
reduce the total volume of wastes produced, not just to shift it
from land to air to water. The harder questions are how to set
the-fee and where to assess it. The marginal social cost of
disposal may vary from one community to another, so the fee may
need to vary across localities, but the products that become
solid waste are generally produced and sold in a national retail
market. Assessing the fee at the curbside (the point where
households put their trash out for pickup) can be successful, as
it has been in cities such as Seattle, Washington and Perkasie,
Pennsylvania, where a fee is assessed per container (barrel or
bag) on the trash that households set out for pickup. But these
programs have some difficulty calibrating the fee to the unique
disposal costs of each specific material being discarded.
Another option87 is to assess the fee at the point of purchase,
by charging a disposal cost on each retail item according to its
ingredients and packaging, and reflecting that cost on the
receipt the customer receives from the store. This option is
facilitated by the use of computerized cash registers and optical
scanners that read a "bar code* printed on the package; the
disposal fee can then be programmed into the cash register's
computerized price list, and revised periodically or by localit:
to reflect changing costs. Optical scanners and computerized
cash registers are now in use in over half of the retail
supermarkets in the U.S. But this option has the drawback that
it is difficult to predict in advance how the product will be
handled after purchase — discarded, incinerated, or recycled.
Perhaps some combination of local curbside fees and point-of-
purchase fees would perform best.
Hazardous wastes. For several types of hazardous
wastes, such as lead-acid batteries and solvents, it is important
not only to reduce total quantities generated but also to ensure
that whatever is generated is carefully handled. Prohibiting
landfill disposal of such substances, or mandating disposal in
certain designated sites, can lead to "midnight dumping' and
other socially damaging evasive tactics. An alternative, market-
based option is the use of deposit-refund systems to encourage
proper disposal. A deposit is charged on the sale of the item,
which is refunded when the item is returned to the retailer or
treatment facility. This gives the purchaser an incentive to
return the waste properly, not to discard it randomly. Deposit-
87 See Peter Menell, "Beyond the Throw-Away Society: An
Incentive Approach to Regulating Municipal Solid Waste," 17 Ecol.
L.O. 655 (1990).
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refund systems for lead-acid batteries are now operated by the
states of Maine and Rhode Island, one possible difficulty with
offering a refund on returned batteries is that it might
encourage theft of batteries; various measures, such as lockable
battery cases, or requiring a receipt to be presented with the
battery, could be used to deter theft.
D. Harnessing market forces to address climate change.
If the threat of global change is a market failure
worthy of policy intervention, then market-based incentive
techniques are especially well-suited to implementing limitation
measures for trace gases contributing to global change. The
current U.S. policy to phase out CFCs is a prime example of this
approach. Because trace gas emissions arise from so many diverse
and pervasive sources, the costs of abatement are bound to vary
widely among emitters. Market-based mechanisms use that
variation to social advantage by imposing some restraint on total
emissions — a limit on the net quantity emitted, or a fee on
each unit emitted — but then letting the market allocate the
burden of mitigative measures to those who can most easily
shoulder it. Because the trace gases mix essentially globally
and have essentially only global impacts, the possibility under
market-based incentives that the spatial distribution of
emissions may become uneven — called "hotspots" in the context
of toxic substances — would not be of concern.
In the context of limiting inputs to global change, two
main economic instruments have been suggested: tradeable
emissions allowances, and emissions fees. Both instruments hold
the potential for achieving environmental goals at least cost.
Tradeable allowances set a total limit on net emissions, issue
that sum of allowances to emitters, and .let emitters trade them.
Those for whom emissions reductions or sink expansions are
relatively more expensive will buy allowances, while those who
can achieve them cheaply will sell allowances. This gives an
incentive to each emitter to develop new means of limiting
emissions at less cost than its competitors, so that it can sell
its allowances at a profit. The choice of response tactics —
emissions controls, efficient use of fuels and other inputs, and
innovation of new emissions limitations techniques — is left to
the emitter. The market allocates abatement actions to those who
do so at least cost, reducing the overall cost to society.
Trading could be employed domestically (within a
nation) by nations taking steps to limit their emissions of trace
gases, as we are using trading in the new Clean Air Act acid
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deposition program and in the phaseout of CFCs.88 Thus, any
nation that decided to limit its emissions of one or more RATGs
could allow emitters within its borders to trade their emissions
allowances.
Allowing the opportunity for voluntary reallocations
among nations of any agreed international obligations would also
be advantageous. Such trades could consist of informal,
bilateral reallocations of any obligations to limit net
emissions. One nation could satisfy such obligations by
investing in response actions in another, with the latter's
consent. Any such reallocations would be entirely at the
discretion of the participating nations; no nation would be
obliged to participate. For example, nation A might approach
nation B with a proposal: A will provide new energy technology or
agricultural research to B, if B will assign to A some of the
resulting emissions reductions. Given the significant
international variations in the marginal costs of RATG abatement,
the opportunity for such trades would likely enable the world
economy to realize substantial cost savings. Limited
international CFCs trading of this sort is now authorized under
the Montreal Protocol, but it remains to be seen whether the
Protocol's strictures on trading will leave room for market
activities.
Such trading would also serve as a market-based,
decentralized vehicle for introducing needed technology into thi
developing world. Developing countries could exchange excess
emissions allowances for low- or non-RATG-emitting technology
from industrialized nations; thus, the developing nation would
receive needed resources and a means to pursue economic growth
without emitting RATGs. This system would reduce global
emissions, while pointing technology toward those who needed it
most and stimulating innovation by industrialized nations of
technologies useful in developing nations. At the same time,
this framework could obviate creation of a heavily bureau-
cratized, centralized regulatory authority and technology
assistance fund that would be less efficient at routing needed
resources and technology to recipients.
Emissions fees are another important option. The fee
could be calibrated to the environmental impacts index value of
the net emissions activity. Like emissions trading, emissions
fees offer a least-cost solution that promotes innovation and
efficient resource use. Such a plan could make excellent sense
88 See U.S. EPA, "Protection of Stratospheric Ozone,* 53
Fed. Reg. 30,566 (1988) (to be codified at 40 C.F.R. pt. 82)
(Final Rule) (capping CFC production with marketable permits); 53
Fed. Reg. 30,604 (1988) (Advance Notice of Proposed Rulemaking)
(proposing allocation of permits).
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domestically, especially where the focus is on specifying the
cost of a limitation program more precisely than the quantity of
emissions avoided, or where revenue raising is a major goal.
Indeed, the U.S. is employing fees on CFCs in addition to
tradeable allowances. International application of a fee would
raise many more difficult questions: Would nations cede their
sovereignty to an international tax authority? How would the fee
be set in light of varying effective marginal tax rates, and
diverse taxation structures, across nations? How would the
potentially enormous revenues raised be allotted and expended?
Market-based incentives could also be used to encourage
efficient adaptation practices. Long-range investments, such as
coastal construction or water use planning, might, because of
market failures or other institutional failures, be undertaken
without giving appropriate weight to any global change risks
(such as rising sea levels or shifting precipitation). Such
failures, might be addressed by informational or incentive-based
policies, such as by requiring coastal construction to purchase
subsidence (coastal erosion) insurance, or by fostering a market
in water resources that provides incentives for efficient use and
long-range risk management.
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CONCLUSION
Toward a Comprehensive Approach
Addressing the potential problems of global climate
change will require creative thinking. Treating the causal
factors of global climate change in a piecemeal fashion, gas-by-
gas and source-by-source, would ignore the science of climate,
jeopardize sound environmental protection, squander scarce
resources, and impose inequitable burdens and unreasonably
uniform requirements on nations with diverse needs and
capabilities. Instead, a "comprehensive" approach to addressing
potential global climate change, treating all radiatively active
trace gases, their sources and sinks collectively, should be
employed in any international agreements addressing potential
climate change. Such a comprehensive approach provides a better
understanding of human interactions with climate, and, if policy
responses are deemed warranted, the means to achieve real
environmental quality improvements while preserving economic and
institutional flexibility.
Several steps could be taken to incorporate a
comprehensive approach into the framework convention on climate
change.. As described earlier, the comprehensive approach has
multiple applications. Each could be incorporated into the wor.
of the IPCC, the convention, and any program the convention
establishes. For example, the convention could charge the IPCC
or other body to coordinate and assess work on the following:
Research strategy. The convention could advance
integrated scientific and economics research on a comprehensive
basis, ensuring attention to the sources, sinks, atmospheric
properties, and socioeconomic and ecological impacts of all the
relevant trace gases.
Monitoring. The convention could spur development of
techniques and systems for comprehensive source and sink
monitoring, such as cooperative international networks measuring
emissions and uptake of all relevant trace gases. It could
establish centers for data sharing, harmonizing methodologies,
and research & development of new techniques.
International inventories. The convention could help
build the capacity to estimate international net emissions of
relevant trace gases, including-baseline levels and changes due
to policy actions. It could provide for national reporting, and
for workshops to compare and improve data and methods.
Indices. The convention could continue the IPCC's
cooperative development and refinement of indices. It could
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charge the ZPCC or other body to conduct regular assessments and
to keep policy makers informed of developments.
Technology evaluation. The convention could employ a
comprehensive approach to assess the net emissions impact of any
technology transfer and financial assistance activities. This
would provide guidance to maximize the environmental benefits of
any such projects.
The convention could also:
Ensure a comprehensive framework for policy. It could
provide that any policy discussion, any calls for "national
plans," or any limitations obligations (if any, whether now or in
the future), are (will be) defined in terms of a comprehensive
approach.
Offer incentives through advance assurance. The
convention could give advance assurance that current actions will
receive credit against any future obligations, in accordance with
a comprehensive approach. This would help avoid disincentives to
nations taking actions justified on other grounds, which nations
may hold in abeyance until credit for them is assured. Actions
could include such measures as afforestation, energy
conservation, and trace gas reductions, and both national and
international programs.
Taking a comprehensive approach to all aspects of the
climate issue, including all aspects of the convention — from
science research to technology transfer to any response measures
— would be a substantial scientific, environmental and economic
improvement over piecemeal solutions to.complex environmental
issues. A comprehensive approach can deliver the scientific
understanding, environmental effectiveness and economic
efficiency required of any sound climate convention in the
service of sustainable development.
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