United States Science Advisory EPA-SAB-EPEC-95-003
Environmental Protection Board March 1995
Agency Washington, DC 20460
SEPA An SAB Report:
Ecosystem Management
Imperative for a
Dynamic World
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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D.C. 20460
March 31, 1995
EPA-SAB-EPEC-95-003
OFFICE OF THE ADMINISTRATOR
Honorable Carol M. Browner SCENCE ADVISORY BOARD
Administrator
U.S. Environmental Protection Agency
401 M Street, SW
Washington, DC 20460
Subject: SAB Environmental Futures Project-EPEC Futures Report
"Ecosystem Management: Imperative for a Dynamic World"
Dear Ms. Browner:
The Ecological Processes and Effects Committee (EPEC) of the Science Advisory
Board (SAB) has completed its report on Environmental Futures that discusses ways to
use foresight in managing risks to ecosystems. This report is one of seven prepared by
the SAB in response to your request that we look at Environmental Futures methodolo-
gies and evaluate a few future developments in detail.
In response to your request, the Executive Committee formed an Environmental
Futures Committee to direct the activities of the Board. EPEC, which has primary
interest in assessing the ecological consequences of human activities, focused on three
elements of the overall charge:
a) developing a procedure for conducting in-depth examination of key future
developments;
b) demonstrating the procedure using example scenarios; and
c) drawing implications and recommending actions to address future ecological
risks. &
In addition, the Committee was most concerned with longer time horizons (30 years or
more) since ecosystems impacts and responses are best considered on decadal time
scales. The time lag between imposition of stresses and ecosystem response creates
unique challenges for managers and policy makers, making futures analysis particularlv
important for managing ecological risks.
The Committee based its approach on the principles developed in Reducing Risk:
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Setting Priorities and Strategies for Environmental Protection (EPA-SAB-EC-9d-021)
and the Agency's Framework for Ecological Risk Assessment (EPA/630/R-92/001) In
our report, we describe a conceptual model for futures analysis that combines the use of
future scenarios and the ecological risk assessment framework to provide a formalized
approach to assess future ecological risks. EPEC was the only Committee that used both
a conceptual model and scenarios in its futures assessment. The specific scenarios
chosen are less important than the intellectual process of making assumptions about
critical drivers of change, exploring the possible impact of such changes on stressors and
ecpsystemsat risk, and evaluating risk management options to avoid or mitigate ecologi-
cal risks. This methodology can add value and broader perspective to a wide range of
planning, budget, and rulemaking activities.
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Printed with Soy/Canota Ink on p*>er that
contains at loast 50% racyctodfeer
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The Committee demonstrated the approach for futures analysis by applying it to
two scenarios of energy development ana consumption in the U.S. As a result of this
exercise, we offer the following broad observations and recommendations:
a) The conceptual model for futures analysis can and should be used routinely and
systematically by the Agency to establish a broad, comprehensive perspective
on future ecological risks.
The intellectual exercise of developing and evaluating scenarios using the
conceptual model led us to consider ecological consequences mat would prob-
ably not have arisen during an unstructured brainstorming. For example, we
concluded that a future with abundant, very low cost energy may bring greater,
rather than fewer, ecological risks. Such an effort would greatly enhance the
Agency's ability to identify and evaluate emerging issues that pose the greatest
ecological risks (and, by extension, risks to humans) and determine those issues
for which the greatest risk reduction could be obtained per unit of funding or
research effort.
b) Futures analysis underscores the importance of focusing the national environ-
mental agenda on protecting the integrity of ecosystems and landscapes.
The ecosystem management paradigm, while still evolving, embodies the need
to consider ecosystem products and services, the chemicaiand energy linkages
within and between ecosystems, the importance to ecosystem health of human
actions and policies, and the integration of ecological and societal goals and
constraints.
c) Effective risk management requires information on societal goals and values,
improved monitoring of resource status and trends, and the greater emphasis on
transfer of environmentally friendly technologies to developing nations.
d) The Committee reaffirms the conclusions in Reducing Risk that national eco-
logical risks are dominated by larger-scale and longer-time issues, including
global climate change, habitat alteration, ozone depletion, and introduction of
exotic species.
EPEC appreciates the opportunity to participate in the Environmental Futures
Project, and we would like to assist the Agency in developing and applying the concep-
tual model and the ecosystem management paradigm described hi this report. We look
forward to your response to our recommendations.
Sincerely,
/&/h4*t*>^^
Dr. Genevieve M. Matanoski, Chair
Executive Committee
Dr. Raymond C. Loehr, Chair
Environmental Futures Committee
Dr. Mark A. Harwell, Chair
Ecological Processes and
Effects Committee
Dr. Kenneth L. Dickson, Chair
Environmental Futures Subcommittee
Ecological Processes and
Effects Committee
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EPA-SAB-EPEC-95-003
March 1995
Prepared
by the
Ecological Processes and Effects Committee
Science Advisory Board
U.S. Environmental Protection Agency
Washington, DC 20460
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Notice
This report has been written as part of the activities of the SAB, a public advisory group providing
extramural scientific information and advice to the Administrator and other officials of the U.S. Environmental
Protection Agency (EPA). The SAB is structured to provide balanced, expert assessment of scientific matters
related to problems facing the Agency. This report has not been reviewed for approval by the Agency and, hence,
the contents of this report do not necessarily represent the views and policies of the EPA, nor of other agencies
in the Executive Branch of the federal government, nor does mention of trade names or commercial products
constitute recommendation for use.
Seven reports were produced from the Environmental Futures Project of the SAB. The titles are listed
below:
(1) Environmental Futures Committee EPA-SAB-EC-95-007
[Title: "Beyond the Horizon: Protecting the Future with Foresight," prepared by the
Environmental Futures Committee of the Science Advisory Board's Executive Committee.]
(2) Environmental Futures Committee EPA-SAB-EC-95-007A
[Title: Futures Methods and Issues, Technical Annex to the Report entitled "Beyond the Horizon-
Protecting the Future with Foresight," prepared by the Environmental Futures Committee of the
Science Advisory Board's Executive Committee.]
(3) Drinking Water Committee EPA-SAB-DWC-95-002
[Title: " Safe Drinking Water Future Trends and Challenges," prepared by the Drinking Water
Committee, Science Advisory Board.]
(4) Ecological Processes and Effects Committee EPA-SAB-EPEC-95-003
[Title: "Ecosystem Management: Imperative for a Dynamic World," prepared by the Ecological
Processes and Effects Committee, Science Advisory Board.]
(5) Environmental Engineering Committee EPA-SAB-EEC-95-004
[Title: "Review of Environmental Engineering Futures Issues," prepared by the Environmental
Engineering Committee, Science Advisory Board.]
(6) Indoor Air Quality and Total Human Exposure Committee EPA-SAB-IAQC-95-005
[Title: "Human Exposure Assessment: A Guide to Risk Ranking, Risk Reduction and Research
Planning," prepared by the Indoor Air Quality and Total Human Exposure Committee, Science
Advisory Board.]
(7) Radiation Advisory Committee EPA-SAB-RAC-95-006
[Title: "Report on Future Issues and Challenges in the Study of Environmental Radiation, with a
Focus Toward Future Institutional Readiness by the Environmental Protection Agency," prepared
by the Radiation Environmental Futures Subcommittee of the Radiation Advisory Committee
Science Advisory Board.] '
Single copies of these reports may be requested and obtained from the SAB, Committee
Evaluation and Support Staff (1400), 401 M Street, SW, Washington, DC 20460 or by FAX (202)
260-1889.
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Abstract
This report by the Ecological Processes and Effects Committee (EPEC) of the SAB was part of an
Environmental Futures Project that the Board conducted during FY 1994. EPEC developed a conceptual
model showing the relationship between the assessment of future environmental problems and the process
of environmental risk assessment. The model was evaluated by developing two scenarios, descriptions of
assumed possible future conditions, to reveal possible ecological consequences. EPEC concluded that the
model was valid and appropriate for use by the Agency in developing guidance for the analysis of future
environmental problems. They also noted that the process of considering possible future conditions and
the driving forces and societal decisions today that would lead to those problems was more critical than
the analysis. In addition, ecosystem management requires evaluations of very long-term trends, well
beyond human generation times. The results of this analysis contribute favorably to the conceptual model
and to an evolving ecosystem management paradigm that the Committee recommends the Agency
develop. Specific possible future problems and a glossary are also appended.
KEY WORDS: Futures Analysis, Scenarios, Ecological Risk Assessment, Ecosystem Management
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U. S. Environmental Protection Agency
Science Advisory Board
Ecological Processes and Effects Committee
Environmental Futures Subcommittee
Chair
Dr. Kenneth L. Dickson
Institute of Applied Sciences
University of North Texas
Denton, TX
Members
Dr. William E. Cooper
Institute of Environmental Toxicology
Michigan State University
East Lansing, MI
Dr. Virginia Dale
Environmental Sciences Division
Oak Ridge National Laboratory
Oak Ridge, TN
Dr. Mark A. Harwell
Rosenstiel School of Marine and Atmospheric Science
University of Miami
Miami, FL
Dr. Robert J. Huggett1
Virginia Institute of Marine Sciences
College of William and Mary
Gloucester, VA
Dr. Anne McElroy
State University of New York at Stony Brook
Stony Brook, NY
Dr. Frederic K. Pfaender, Director
Carolina Federation for Environmental Studies
University of North Carolina
Chapel Hill, NC
Dr. William H. Smith
Professor of Forest Biology
School of Forestry and Environmental Studies
Yale University
New Haven, CT
Dr. Terry F. Young
Environmental Defense Fund
Oakland, CA
'Dr. Huggett resigned from the SAB in April 1994.
iii
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Science Advisory Board Staff
Ms. Stephanie Sanzone
Designated Federal Official
Science Advisory Board (1400F)
USEPA
401 M Street, SW
Washington, DC 20460
IV
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Contents
Page
1. Executive Summary [[[ I
2. Introduction [[[ 2
3. Conceptual Model for Futures Analysis [[[ 3
4. Problem Formulation [[[ 4
4.1 Drivers [[[ 4
4.2 Stressors [[[ 4
4.3 Linkages Between Drivers and Stressors [[[ 5
4.4 Ecological Endpoints [[[ 5
5. Risk Characterization [[[ 7
6. Risk Management [[[ g
7. Example Scenarios [[[ 9
7.1 Low-Cost Energy Scenario [[[ 9
7.1.1 Primary and Secondary Drivers [[[ '9
7.1 .2 Driver/Stressor Linkages [[[ 9
7.1.3 Ecological Endpoints [[[ 9
7.1.4 Risk Management [[[ 10
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1. Executive Summary
The Ecological Processes and Effects Committee (EPEC) of
the EPA Science Advisory Board (SAB) developed a
methodology and then applied it to examine the ecological
consequences of future human activities. The Committee
based its approach on the principles developed in Reducing
Risk: Setting Priorities and Strategies for Environmental
Protection (EPA-SAB-EC-90-021) and the Framework for
Ecological Risk Assessment (EPA/630/R-92/001).
The conceptual model for futures analysis provides a
methodology for developing and evaluating future scenarios
by 1) making assumptions about driving forces and resource
use (the ultimate causes of change); 2) identifying the
interactions among drivers, stressors, and ecological end-
points; 3) delineating the causes and effects of environmental
changes; and 4) exploring ways in which management
actions can avoid, influence, or mitigate environmental risks.
Comparing a series of scenarios can help to define "no
regrets" actions that provide benefits under a wide range of
scenarios, encourage the development of a strategic vision,
and promote timely responses to unforeseen events.
The Committee evaluated the approach for futures analysis
by applying it to two scenarios of energy development and
consumption in the U.S. These scenarios (Low-Cost Energy
Scenario and Oil Depletion Scenario) illustrate how the
approach can be applied to identify the key components of
environmental problems and consider how risks can be
managed. Development and analysis of future scenarios are
also recommended in the Technical Annex for the Environ-
mental Futures Project (EPA-SAB-EC-95-007A).
Based on its futures exercise, the Committee developed the
following conclusions and recommendations:
a) The conceptual model for futures analysis, which
combines the use of scenarios and the analytical
framework for ecological risk assessment (ecorisk
framework), provides a formalked approach to
assess future environmental risks.
b) This approach, when applied to two scenarios
making assumptions about the cost and availability
of energy, revealed possible ecological conse-
quences that probably would not have been deter-
mined through an unstructured brainstorming.
For example, in the Low-Cost Energy Scenario, the
availability of abundant, low-cost energy was
considered to result in expansion of human popula-
tions into previously minimally disturbed areas and
increased per capita consumption, causing an
increase in habitat fragmentation, biological
depletion, and polluting by-products. In addition,
light and noise pollution were predicted to become
significant sources of ecological stress. Thus, a
very low-cost energy future is not necessarily a
"green" one.
c) Futures analysis reaffirms the importance of
focusing the national environmental agenda on
protecting the integrity of ecosystems and land-
scapes. The ecosystem management paradigm,
while continuing to evolve, embodies the need to
consider ecosystem products and services, the
chemical and energy linkages within and between
ecosystems, the importance to ecosystem health of
human actions and policies, and the integration of
ecological and societal goals and constraints.
d) Ecosystem management requires a larger-scale and
longer-term perspective than typical human
planning scales. However, management goals
formulated on a regional or landscape scale must be
implemented on a "local" scale by numerous public
and private sector entities.
e) Effective risk management using futures analysis
requires information on societal goals and values,
improved monitoring of resource status and trends,
and greater emphasis on transfer of environmentally
friendly technologies to developing nations.
f) The Committee reaffirmed the conclusions in
Reducing Risk that national ecological risks are
dominated by larger-scale and longer-time issues,
including global climate change, habitat alteration,
ozone depletion, and introduction of exotic species.
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2. Introduction
In July 1993, EPA Administrator Carol Browner requested
that the SAB undertake an initiative, termed the Environ-
mental Futures Project, to advise the Agency on ways to
identify future environmental problems and provide the
SAB's perspective on emerging environmental issues. The
SAB Executive Committee consequently formed the
Environmental Futures Committee (EFC) to direct the
effort. The EFC requested the standing committees of the
SAB to address the charge for areas of their particular
expertise and interest and to produce separate reports that
would supplement the overall report on Environmental
Futures to be written by the EFC.
The charge to the EFC consisted of the following compo-
nents:
a) develop a procedure for conducting a short- and
long-term scan of future developments that will
affect environmental quality and the nation's ability
to protect the environment;
b) conduct as comprehensive a scan as practical to
identify such important future developments;
c) choose a limited number of short- and long-term
future developments for in-depth examination;
d) develop a procedure for conducting in-depth
examination of key future developments;
e) apply the procedure; and
f) draw implications for the Agency from the in-depth
examination of future developments and recom-
mend actions for addressing them.
The EPEC held three public meetings, in January, February,
and June of 1994, to discuss the Environmental Futures
Project. EPEC has primary interest and expertise in assess-
ing the ecological consequences of human activities. The
Committee's contribution to the Environmental Futures
Project focuses primarily on the last three components of the
charge, although a discussion of ecological issues for the
future is also included (Appendix B). In addition, the
Committee was most concerned with longer term horizons,
since ecosystem impacts and responses are best considered
on decadal time scales (20 to 30 years, or more). Because of
the time lags between imposition of stresses and ecosystem
response, protection and management of natural systems
raise issues of intergenerational equity; the policies and
practices of one generation have strong impacts on future
ecosystem values for succeeding generations.
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3. Conceptual Model for Futures Analysis
The Committee adopted an approach for futures analysis
based on the principles developed in Reducing Risk: Setting
Priorities and Strategies for Environmental Protection
(EPA-SAB-EC-90-021) and the Framework for Ecological
Risk Assessment (EPA/630/R-92/001). In Appendix A of
Reducing Risk, a matrix approach was used to evaluate the
intensity of potential ecological effects, the uncertainties of
these estimates, the type of ecological responses, and the
time scales for ecosystem recovery following removal of the
stressors. This approach provides a rational basis for evaluat-
ing ecological problems at various spatial scales (e.g., local,
regional, and global) and temporal scales (e.g., 20 years, 100
years, and 1000 years). Similarly, the Framework for
Ecological Risk Assessment, orecorisk framework, provides
a process for analyzing stressors and effects, characterizing
risks, and examining consequences of risk management
decisions. The premise of the ecorisk approach is that
adverse ecological effects occur as a result of exposure to
one or more stressors.
The conceptual model for futures analysis posed by the
Committee (Figure 1) provides a methodology for evaluating
future scenarios (developed using assumptions about
driving forces) by 1) identifying the interactions among
drivers (ultimate causes of change), stressors, and ecologi-
cal endpoints; 2) delineating the causes and effects of
environmental changes; and 3) exploring ways in which
management actions can avoid, influence, or mitigate
environmental risks. Comparing a series of scenarios can
help to define "no regrets" actions that provide benefits
under a wide range of scenarios, as well encouraging the
development of a strategic vision, and promoting timely
responses to unforeseen events.
Subsequent sections of this report describe the components
of the conceptual model for futures analysis and its applica-
tion in two example scenarios of energy development and
consumption in the U.S. These scenarios illustrate how the
approach can be applied to identify the key components of
environmental problems and how risks can be managed.
This exercise is the basis for recommendations in Section 8
for research and monitoring that would improve the
Agency's ability to address future environmental problems.
Problem Formulation
Drivers
Primary
Influence
Drivers
Resource Use
Stressors
Regulate
Use
Ecosystems at Risk
Ecological Endpoints
Manage
Exposure
Risk
Characterization
Risk Management
Restore
Ecosystems
Figure 1. Conceptual Model for Futures Analysis.
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4. Problem Formulation
4.1 Drivers
The first step of the scenario-building process is to define the
"drivers"-- i.e., the major variables that determine trends in
resource use and disturbance. Like the drivers that are
commonly used to formulate societal, economic, and
political scenarios, the primary drivers of ecological change
are anthropogenic factors that affect ecological stressors.
These drivers include human population characteristics,
consumption per capita, globalization of the economy,
technology, education, and environmental laws and policies.
Of course, the primary drivers may differ depending on the
issue and the temporal and spatial scales of interest.
While it is useful to begin with broadly defined categories of
drivers, the Committee found it helpful to consider more
detailed subcategories of these primary drivers in order to
create a more focused scenario. For example, assumptions
about human population growth and distribution might
include increasing proportions of urban, as opposed to rural,
populations worldwide. Similarly, assumptions about
technology development and use might include broader use
of existing industrial technologies in the developing world or
development of more environmentally benign technologies
distributed globally.
The Committee also recognized that each of the primary
drivers affects patterns of resource use and availability. The
latter, termed "secondary drivers" to acknowledge that they
are dependent variables, may also be used to develop
scenarios and determine linkages between the drivers and
stressors. Relevant primary and secondary drivers for a
global-scale, 30-year scenario are given in Table 1. For
example, rapid human population growth might cause
competition for water resources, both for agricultural and
domestic use. Similarly, broader use of existing industrial
technologies in less-developed nations may cause increased
use and depletion of oil resources.
When developing a future scenario, it is important to identify
the broad categories of primary and secondary drivers that
are relevant to the chosen temporal and spatial scales, then to
make focused assumptions about each of the drivers. The
benefit of considering the effects of the primary drivers on
each of the categories of secondary drivers is to develop
scenarios that encompass situations outside of the universe
of standard predictions. Recording these assumptions helps
assure internally consistent scenarios.
4.2 Stressors
After the initial scenario is developed, the implications of the
scenario for ecological systems can be evaluated using the
ecorisk framework, i.e., identifying the causes of ecological
change or damage, termed "stressors," and evaluating the
effects of these stressors on relevant ecosystems and ecosys-
tem components. The Committee examined the stressors
identified in Reducing Risk as being most significant in
Table 1. Drivers of Ecological Change for a Global-Scale, 30-Year Scenario
Primary Drivers
Secondary Drivers
-human population growth, distribution, and age structure
agricultural expansion
urbanization
—resource utilization per capita
-economic structure
globalization of the economy
-technology
development of more benign technologies
broader use of existing industrial technologies
-education
increasing environmental ethics and stewardship
-government laws and policies
public/private resource ownership
Third-world environmental institution development
-patterns of resource use and availability
land
water
air
biomass
minerals
energy
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influencing future environmental problems and concluded
that they pose the greatest risks to the integrity and
sustainability of ecosystems. Thus, the Committee used the
list of stressors in Reducing Risk, with a few modifications,
as the starting point for translating future scenarios into
predicted ecological effects (Table 2).
Refinement of the stressor list for specific temporal and
spatial scales, as well as for particular scenarios, may be
useful. For example, in evaluating the "Low Cost Energy"
Scenario, described in Section 7.1, the Committee identified
light pollution, electromagnetic fields (EMF), and noise
pollution as significant potential future stressors.
4.3 Linkages Between Drivers and Stressors
Each of the drivers (primary and secondary) may influence
ecological stressors. In order to determine the relationships
between the anthropogenic drivers and the ecological
stressors and to determine which effects are the most
significant, the Committee found it useful to develop a
matrix showing both the strength and direction of each
linkage.
A sample matrix for the global, 30-year time scale is shown
in Table 3. For each driver and stressor, the strength of the
linkage or association was classified as high, medium, or
low, and the direction of the 'linkage was characterized as
positive, negative, or positive/negative (scenario-dependent).
For example, an increase in the rate of human population
growth would likely be strongly related to an increase in
habitat loss, while stabilization of population growth would
be strongly related to a decrease in the rate of habitat loss.
For this reason, the linkage is characterized as high/positive.
In contrast, increasing education levels would be expected to
have little effect on climate change, but the small effect
might be to decrease it (a low/negative association). In cases
where the effect might be either to increase or decrease the
stressor, depending upon the particular assumptions of a
scenario, the indeterminate positive/negative designation was
used.
In this example, the matrix displays the linkage with primary
drivers, and assumptions regarding the secondary drivers are
implicit; a similar matrix developed using secondary drivers
would be equally informative. Similarly, although only the
major categories of stressors were used in the current
example, particular scenarios might suggest the use of the
longer, disaggregated list of stressors (Table 2).
4.4 Ecological Endpoints
The concept of ecological endpoints (also termed assessment
endpoints) is to identify particular attributes of ecological
systems that can be used to characterize the health of an
ecosystem. A suite of ecological endpoints is necessary,
explicitly cutting across organizational hierarchy; i.e., at
population, community, ecosystem, and landscape levels
(Table 4). These endpoints are ecological characteristics, but
they are selected to include both ecologically important
features (e.g., biodiversity, primary productivity, critical
species) and those that are important to humans (e.g.,
endangered, aesthetic, nuisance, or economic species).
However, not all endpoints are necessary for every system
and stress situation. Ideally, a set of ecological endpoints
should be identified such mat a significant change in one or
more ecological endpoints indicates a change in the health of
the ecosystem. Conversely, changes in ecological health
should change one or more endpoints. Changes in ecological
endpoints may be measured directly or assessed indirectly
using ecological indicators (also termed measurement
endpoints).
Table 2. Initial List of Drivers, Stressors, and Ecological Endpoints
Drivers
Environmental Stressors1
Ecological Endpoints
1. Government policies
2. Population growth/distrib
3. Globalization of economy
4. Distribution of wealth
5. Consumption per capita
6. Education
7. Energy
8. Urbanization
9. Water availability
10. Environmental ethics
11. Resource ownership
12. Resource depletion
13. Agriculture
14. Technology
15. War
1. Global climate change
2. Habitat alteration
3. Stratospheric ozone/UVb levels
4. Herbicide/pesticide use
5. Toxics in surface water
6. Acid deposition
7. Airborne toxics
8. Nutrients
9. Biochemical oxygen demand
10. Turbidity
11. Oil
12. Groundwater contamination
13. Radionuclides
14. Acid inputs to surface water
15. Thermal pollution
16. Exotic species introduction
1. Ecological condition
-species
-population
-community
-ecosystem
-landscape/region
2. Habitat quality/quantity
3. Biodiversity
4. Productivity
5. Products and services
6. Welfare/vista/aesthetics
'Modified from Reducing Risk: Setting Priorities and Strategies for Environmental Protection (EPA-SAB-EC-90-021).
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While the structure and criteria for selecting ecological
endpoints can be specified in generic terms, particular
ecological endpoints for any environmental problem are
ecosystem- and often stress-specific. For example, the
endangered species of concern differ with the ecosystem at
risk and the stress the ecosystem experiences. Thus, the
problem formulation stage of ecorisk assessment includes
identifying the specific ecosystems at risk and ecological
endpoints to be used for evaluating the status and trends of
the health of the ecosystem.
Table 3. Strength of Linkages Between Drivers and Ecological Stressors (Global Scale, 30 Years)
Stressors
Drivers
Population
Consumption
per capita
Globalization
of economy
Technology
Education
Environmental
laws and
policies
Climate
Change
H +
H +
M+/-
MW-
L-
H+/-
Habitat
Loss
H +
H +
HW-
M/H +/-
M/H-
HW-
uvb
Levels
L +
L +
L-
L-
L-
H-
Pesticide
Use
H +
L +
H+/-
H+/-
M-
HW-
Pollution
H +
H +
MW-
M+/-
M-
HW-
Nutrient
Enrichment
H +
H +
LW-
M+/-
L-
H+/-
Introduction
of Exotic
Species
L +
M +
H +
H +
M-
LW-
Key: H, M, L - high, medium, or low degree of association; +/- means the driver increases or decreases the stressor.
Table 4. Categories of Ecological Endpoints1
Human Health and Welfare Concerns
vectors for exposure to humans of diseases or toxics (e.g., distribution of disease-bearing insects)
Species-Level Endpoints
species of concern selected based on having one or more of the following characteristics:
Direct Interest
-economic, aesthetic, recreational, nuisance, or endangered species
Indirect Interest
-interactions between species (e.g., predation, competition, or parasitism)
-habitat role (e.g., physically dominant species such as mangrove tree species)
-ecological role
—trophic relationships
-functional relationships
-critical species (e.g., keystone species that affect overall trophic structure or control important ecological processes)
Community-Level Endpoints
-food-web structure
-species diversity of ecosystems
-biotic diversity of ecosystems
Ecosystem-Level Endpoints
-ecologically important processes (e.g., decomposition, nutrient recycling)
-economically important processes (e.g., wastewater treatment)
-water quality
-habitat quality
Landscape-Level Endpoints
-mosaic of ecosystem types (e.g., relative coverage of plant communities)
-corridors for migration (e.g., habitat for endangered species)
-spatial and temporal patterns of habitat (e.g., timing of and location of wetland areas necessary for bird nesting)
-feedbacks to regional- and global-scale physical systems (e.g., albedo, evapotranspiration, or sources of biogenic gases)
1Modified from Harwell et al., 1990.
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5. Risk Characterization
After determining the relevant drivers and stressors, and
evaluating the linkages between them, the next step in the
conceptual model is to evaluate how the set of stressors
translates into ecological responses and effects. As de-
scribed in the previous section, ecological endpoints should
be selected collectively to describe an ecosystem across a
hierarchy of spatial, temporal, and organizational scales
appropriate to the particular scenario under consideration.
Since species-level endpoints will be ecosystem-specific and
ecological endpoints are generally not stressor specific (i.e.,
endpoints are characteristics to describe ecological condition,
not specific indicators of the presence or effects of a specific
stressor), a matrix of stressors and ecological endpoints
would likely have all cells filled in, as the effects of a
stressor are likely to transcend ecological hierarchy.
The methodology proposed in the conceptual model (Figure
1), therefore, is to make the stressor-endpoint linkage by first
identifying ecosystems at risk. For a given scenario, the
ecosystems at risk can be identified by determining the
spatial extent and co-location of a stressor and the environ-
ment. Based on the specific ecosystems at risk, appropriate
ecological endpoints can then be selected to evaluate the
condition and anticipated change of condition under the
scenario, and specific measurements or indicators can be
identified that need to be monitored. Monitoring changes in
ecological condition of the ecosystems at risk then provides a
basis for adjusting the management of drivers and/or
stressors to achieve environmental goals.
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6. Risk Management
A logical outcome of using the conceptual model for futures
analysis to evaluate a particular scenario is identification of
the risks associated with the specific problems defined and
possible risk management strategies. In the conceptual model
(Figure 1), we have identified four types of risk management
options:
a) Influence Drivers: the risk may be managed by
impacting the primary drivers of environmental
change. Examples of this approach include changes
in regulatory policy, incentives for technology
development, and international agreements to
enhance globalization of the economy (e.g., North
American Free Trade Agreement, General Agree-
ment on Tariffs and Trade).
b) Regulate Resource Use: risks can be reduced at the
level of resource utilization through controls on
resource use, e.g., land-use planning, energy utiliza-
tion controls, water allocation, and timing of re-
source use.
c) Manage Exposure: this type of control impacts the
stressors by limiting exposure of specific ecosystem
components to stress. This can be accomplished, for
example, by a variety of innovative technologies that
either prevent pollution (via process modification or
material substitution) or control the release of
materials that can impact the ecosystem (e.g.,
seasonal wastewater releases to minimize exposure
to critical life stages, changes to aircraft flight
patterns).
d) Restore Ecosystems: this type of management applies
to the specific ecosystems at risk, as identified by the
targeting of where the stressors will impact. Restora-
tion includes a variety of remediation technologies,
as well as reintroduction of endangered species,
revegetation, etc.
The selection of risk management options using the concep-
tual model must also incorporate information on societal
values and goals, environmental research and monitoring,
and environmental education:
a) Societal Values and Goals: public perceptions of
values and goals for an ecosystem will impact how
the risks are characterized, what ecological endpoints
are identified as important, and which risk manage-
ment strategies are likely to be most effective. Most
often these goals will be implied since a clear
statement is rarely available.
b) Research: in many cases the necessary information
will not be available to characterize a risk or define
what portions of an ecosystem will be impacted by a
particular stressor. In these cases, research will be
required to generate the information.
c) Monitoring: to assess changes in drivers and/or
stressors realistically, as well as to evaluate the
impact of risk management strategies, it will be
necessary to have data on the status and trends of
specific ecological parameters. The conceptual model
for futures analysis assumes that the status of the
resource is known. It may be necessary, therefore, to
obtain additional data in order to construct and
evaluate various futures scenarios.
d) Education: an important component of risk manage-
ment is technology transfer, education, and training
for the public and private sector on environmental
issues. Education and risk communication play an
important role at all points in the conceptual model as
a mechanism for changing public values and behav-
ior.
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7. Example Scenarios
In order to demonstrate the application of the conceptual
model for futures analysis, the Committee formulated two
scenarios focusing on alternative assumptions regarding
energy development. More surprising, and therefore more
useful, results would probably be generated from a set of
scenarios with varying assumptions about multiple drivers.
Nonetheless, even the two example scenarios yielded
unpredicted and useful conclusions.
7.1 Low-Cost Energy Scenario
7.1.1 Primary and Secondary Drivers
In the Low-Cost Energy Scenario, the Committee adopted
the 30-year, regional scale (North America) for assessing
effects and assumed that a major energy technology
breakthrough in unexpected fields such as fusion power,
plasma energy generation, or renewable energy would result
in energy costs significantly lower than those of today.
Minimal changes in current trends were assumed for the
other primary drivers:
a) human population: population increases would
continue at current rates, although distributions
might change;
b) consumption per capita: resource consumption per
capita would increase;
c) globalization of the economy: fundamental changes
in economic structure and processes would not
occur, aside from continuation of the current trend
towards removal of trade barriers; and
d) education: education levels, including perceptions of
environmental ethics, and government laws and
policies would remain similarly unchanged.
The effects of the primary drivers on resource use and
availability (the secondary drivers) are dramatic. Limits on
water resources in arid regions would be largely removed
because very low-cost energy would allow both desalination
and widespread transport of water. Similarly, patterns of
land use would change dramatically with the advent of low-
cost transportation. As a result, human populations would
spread to areas, particularly in the west, which are currently
sparsely inhabited; most privately owned (but currently
undeveloped) lands would be developed for business or
recreational purposes; and increasing leisure time would
result in greater human intrusion on publicly owned lands.
Competition for and use of both biomass and mineral
resources would increase, as a result of the "ruralization" of
the population and concomitant construction, as well as a
general increase in the standard of living. In other words,
eliminating the current constraints to consumption,
transportation, water use (and so forth) currently imposed
by energy availability and price would cause North
Americans to expand and consume more.
7.7.2 Driver/Stressor Linkages
To evaluate the effects of the Low-Cost Energy Scenario
on ecological stressors, the Committee developed a driver/
stressor matrix that summarizes the predominant effect of
the scenario on each of the stressors (Table 5). The
development of a new energy technology was predicted to
reduce air emissions associated with the use of fossil fuels
(e.g., carbon dioxide, SOx, and NOx) thus decreasing
climate change and air quality stressors. On the other hand,
increased availability of energy and potable water was
predicted to promote expansion of human populations into
areas that are currently minimally disturbed. The spread of
human development, in combination with increased per
capita consumption, would increase habitat fragmentation,
noise and light pollution, introduction of exotic species,
and water pollution. In addition, electric and magnetic
fields associated with electric devices, power lines, and
wiring would be more prevalent and more widely distrib-
uted in the environment. Although the human health and
ecological effects of exposure to EMF are not yet clear, the
exposure would be greatly increased under this scenario.
7.1.3 Ecological Endpoints
The Committee then considered ecosystems at risk under
the Low-Cost Energy Scenario and selected ecological
endpoints of concern. Under this scenario, cheap energy
would increase water availability and reduce transportation
costs so that people could live in areas currently considered
inhospitable. Thus, desert and high mountainous systems
would be at risk to intense habitat degradation. In general,
any non-urban, terrestrial system would be at risk. In
contrast, there would be fewer atmospheric impacts (e.g.,
air pollution from burning of fossil fuels) and coastal
impacts (e.g., sea level rise associated with global warm-
ing, habitat destruction associated with oil spills or
terminal construction, and discharges from coastal popula-
tion centers).
Species that would be negatively affected under this
scenario include those that live in xeric or high elevation
environments, species with large home ranges (because of
fragmentation of the natural landscape), nocturnal species
(because of increased light pollution), and species highly
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Table 5. Linkages Between Drivers and Ecological Stressors: Low-Cost Energy Scenario
Stressors
Drivers
Climate
Change
Habitat
Alteration
Toxics in
Surface
Waters
Acid
Deposition
Airborne
Toxics
Nutrient
Enrichment
Acid Inputs
to Surface
Oil Waters
Thermal
Pollution
Exotic
Species
E
M
F
Technology
development H-
H+/-
H+
H-
H-
M+/-
H-
H-
H+
H+
H+
Key: H, M, L = high/medium/low degree of association; +/- means the driver increases or decreases the stressor.
Assumptions
climate change:
habitat alteration:
toxics in surface waters:
acid deposition:
airborne toxics:
nutrient enrichment
oil:
acid inputs to surface water:
thermal pollution:
exotic species introduction:
EMF:
greatly reduced use of fossil fuels, so reduced carbon dioxide emissions from that source
reduce stress from energy extraction, but increase stress from expansion of human populations
abundant, low-cost energy increases production by other polluting industries, speeds cycling of chemicals
greatly reduced use of fossil fuels, so reduced SOX/NOX from that source
greatly reduced use of fossil fuels
changes in population distribution will expand areas experiencing anthropogenic nutrient enrichment
reduced extraction and transport of fossil fuels
greatly reduced use of fossil fuels
greater energy use
more travel would increase opportunities for exotic species transport/introduction
expect more power generation and wider distribution systems
sensitive to noise pollution. Some beneficial impacts on
natural productivity would occur as a direct result of plastics
being used more commonly. For example, plastics would
replace some use of wood products that would lessen
harvesting pressure on old-growth timber stands. In general,
however, terrestrial ecosystems would be relatively more
impacted than aquatic/coastal ecosystems.
7.1.4 Risk Management
The greater terrestrial impacts of the Low-Cost Energy
Scenario would require more information on how terrestrial
systems interact. In particular, more information would be
needed on landscape processes (e.g., how large do preserved
areas need to be? how can buffers and corridors be effec-
tively designed to preserve species at risk from habitat loss?)
Possible risk management options in the four categories
discussed in Section 6 include the following:
a) Influence Drivers: Important drivers in this scenario
would be technology development and government
policies. Therefore, incentives to produce environ-
mentally friendly technologies would mitigate
negative ecological effects. Government policies to
protect land areas at risk would also be beneficial.
b) Regulate Resource Use: Improved ecosystem
management, for example via land use regulations,
could protect habitats at risk. Regulation of water
redistribution would also be important. In addition,
increased taxation might be used to raise the cost of
energy.
c) Manage Exposure: Control toxics in surface waters,
nutrients, thermal pollution, EMF, light pollution, and
noise pollution.
d) Restore Ecosystems: Clean up/restore areas impacted
by prior oil transport and extraction activities (e.g.,
coastal wetlands).
7.7.5 Insights Gained
Perhaps the most significant outcome under the Low-Cost
Energy Scenario was the predicted dramatic increase in the
rate of habitat loss and biological depletion resulting from
human intrusion into areas previously protected indirectly by
resource limitations. In other words, the decrease in ecologi-
cal stress related to extraction and use of fossil fuels would
be more than offset by stresses resulting from the spread of
human activities into previously undisturbed or minimally
disturbed areas. Extensive fragmentation of terrestrial
ecosystems was predicted, which would put particular
pressure on species with large home ranges. Nocturnal
animals would be stressed by continuous nighttime light
pollution from ubiquitous human settlements.
Similarly, the future appeared increasingly polluted. Energy
and water limits would no longer constrain the extraction or
harvest of resources, nor constrain industrial processes. As a
result, consumption of most products would increase,
thereby increasing polluting by-products.
In short, a future with abundant, low-cost energy is not
necessarily a "green" one.
7.2 Oil Depletion Scenario
7.2.7 Primary and Secondary Drivers
In order to place bounds on the effects of energy develop-
ment as a driver, the Committee developed a second sce-
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nario, the Oil Depletion Scenario, which considers the
ecological impacts of a high-cost energy future. In the Oil
Depletion Scenario, the Committee assumed that global
crude oil resources would be seriously depleted in a 30+ year
timeframe and that new sources of energy or technology
other than that currently available would not be developed.
The use of nonrenewable resources ultimately leads to
depletion of those resources and a shift to alternative
materials or processes in order to satisfy needs or demand.
Such is the case with natural liquid petroleum hydrocarbons
(crude oil), which is being extracted at rates that will result
in severe resource depletion over the next 30 to 50 years.
With increasing world population and concurrent developing
economies, it is likely mat demand for petroleum products
will increase and that the rate of crude oil depletion will
accelerate.
The effects of oil depletion on resource use/availability
(secondary drivers) will be several. As crude oil resources
diminish, prices will increase and marginal oil fields will
become profitable and will be brought on line. The pressure
to exploit fields in areas that are now protected because of
sensitive or fragile environments will also increase (e.g.,
areas along the Mid-Atlantic continental shelf or in Alaska).
In addition, increasing volumes of surface waters will be
injected underground in order to raise oil yields. Rising oil
prices will also result in alternate sources of energy becom-
ing profitable, necessary, and implemented. These will
probably include an increase in nuclear power generation,
greater use of coal, and the extraction of hydrocarbons from
oil shale, all of which have associated environmental
problems.
As alternative sources of energy come into greater use, the
economic benefits and environmental risks will shift region-
ally and institutionally, reflecting resource ownership
patterns (e.g., use of coal deposits in China and India, oil
shale deposits in Siberia, and oil and gas resources in the
China Sea). While rising energy costs could result in a
decline in per capita consumption, which in turn would have
positive ecological effects by reducing polluting and re-
source extraction, the scenario assumes that the effect of this
driver would be slight because of the relatively inelastic
consumer demand for energy.
7.2.2 DriverlStressorLinkages
The expected effects of the Oil Depletion Scenario drivers on
the dominant ecological stressors were evaluated by con-
structing a driver/stressor matrix (Table 6). The key stressors
under this scenario are contamination of air, ground and
surface waters, and habitat alteration. Sources of pollution
include radioactive nuclear waste, formation water from oil
extraction, and wastes and emissions associated with use of
coal and oil shale. The composition of the wastes is largely
unknown but will surely include polynuclear aromatic
hydrocarbons (PAH), some of which are know mammalian
carcinogens, in addition to trace metals (e.g., mercury) and
natural radioactivity.
7.2.3 Ecological Endpoints
Under the Oil Depletion Scenario, oil field development
activities would disrupt large marine ecosystems associated
with the Mid-Atlantic continental shelf, the China Sea, and
wilderness areas of Alaska. Mining of oil shale deposits in
Wyoming and Siberia, lignite in the southwestern U.S., and
coal in China and India would threaten the integrity of
relatively pristine and protected areas because of strip mining
and deforestation. Transportation of crude and refined
hydrocarbons will place at risk those coastal ecosystems near
loading/unloading terminals, thus threatening a diverse group
of species ranging from commercially important fish to
caribou.
7.2.4 Risk Management
Research should be conducted to determine the ecological
risks from developing alternative energy sources such as
coal, oil shale, and lignite in anticipation of their greater use
as oil prices rise. Possible risk management options to
minimize the ecological impacts under this scenario include:
a) Influence Drivers: although resource depletion is
identified as the primary driver in the scenario, there
are opportunities to manage risks by influencing
related drivers such as technology development (e.g.,
technologies to minimize risks from extraction of
alternative sources of hydrocarbons fuels) and
government policies (e.g., revise water and land use
laws and policies to improve water management and
allocation among competing needs).
b) Manage Exposure: site loading/unloading terminals
for hydrocarbons away from sensitive coastal
resources such as wetlands and productive estuaries.
c) Restore Ecosystems: develop land restoration
techniques to reclaim surface-mined lands.
7.2.5 Insights Gained
The plausibility of the Oil Depletion Scenario rests in its
long-time scale; the question is not whether crude oil
resources, or other nonrenewable resources, will be depleted,
but rather when. Placing the scenario well into the future
allows policy makers to consider more effectively the
implications of such depletion. For example, the scenario
argues for a thoughtful discussion of the best uses for
remaining crude oil supplies, anticipation of geographic
areas where public goals of preservation and oil extraction/
use will come into conflict, and needed research and technol-
ogy development for using alternative sources of energy. In
addition, the scenario highlights the truly global nature of the
issue, since environmental effects from depletion of finite
resources such as crude oil are often not in the same geo-
graphic location as the demand (i.e., risks and benefits fall to
different populations). Thus, our choices will be greatly
influenced by international markets, multilateral negotia-
tions, and information and technology transfer.
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Table 6. Linkages Between Drivers and Ecological Stressors: Oil Depletion Scenario
Stressors
Toxics in Ground Acid Inputs
Climate Habitat Surface Acid Airborne Water to Surface
Drivers Change Alteration Waters Deposition Toxics Turbidity Oil Contamination Radionuclides Waters
Resource
depletion L+ H+ H+ H+ H+ H+ H+ H+ H+ H+
Key: H, M, L = high/medium/low degree of association; +/- means the driver increases or decreases the stressor.
Assumptions
climate change: switching to other fossil fuels, so carbon dioxide emissions not greatly affected
habitat alteration: increased exploration/extraction, use of biomass for energy
toxics in surface waters: increased exploration/extraction
acid deposition: greater coal use
airborne toxics: greater coal use
oil: generally not available
ground water contamination: increased exploration/extraction
radionuclides: increased exploration/extraction, greater use of nuclear power
acid inputs to surface waters: increased exploration/extraction (e.g., acid mine wastes), greater coal use
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8. Conclusions and Recommendations
8.1 Benefits of Using the Conceptual Model
for Futures Analysis
The conceptual model for futures analysis described in this
report combines the commonly used techniques for develop-
ing future scenarios with the analytical framework that has
been developed by the Agency to analyze ecological risks
(the ecorisk framework). As a result, the technique can be
used to explore the ecological impacts of future human
activities. The benefits of routinely using a formalized
approach to assess future environmental risks are evident
from the results of the two scenarios explored by the
Committee. For example, unstructured brainstorming about a
future characterized by unlimited energy resources would
probably not have resulted in the Committee's strong
conclusions regarding the importance of light and noise
pollution on ecosystems currently far from human develop-
ment. Second, the process clearly identified "no regrets"
actions, outlined in Sections 8.2 and 8.3, which could be
pursued in light of either energy extreme (very low-cost or
high-cost energy futures). Finally, the conceptual model
includes explicit consideration of a variety of management
actions that could be undertaken to prevent or mitigate
predicted future risks.
As part of the Environmental Futures Project, the Committee
did not attempt individual ecological risk assessments for
each identified stress and each ecosystem at risk for each
scenario, as that would be well beyond the scope of the
present activity. Rather, we have developed an approach that
should be used in such a comprehensive exercise, and we
strongly recommend that the Agency complete this exercise
systematically to establish a broader and more comprehen-
sive perspective on future ecological risks. Such an effort
would greatly enhance the Agency's ability to identify
emerging issues that pose the greatest ecological risks (and,
by extension, risks to humans) and determine those issues for
which the greatest risk reduction could be obtained per unit
of funding or effort.
8.2 Management of Future Ecological Risks
The scenario/futures analysis exercise reaffirms the conclu-
sions in Reducing Risk that national environmental risks are
dominated by larger-scale and longer-time issues, including
global climate change and habitat alteration. Moreover, these
risks may already in large part be foreordained by current
trends. Therefore, the national environmental agenda needs a
dramatic shift in emphasis toward protecting the integrity of
ecosystems and landscapes to supplement the historical focus
on single-chemical, human-health risks; an ecosystem
management regime should be developed that incorporates
ecorisk principles as contained in the Agency's ecorisk
framework.
The ecosystem management paradigm, while still evolving,
embodies numerous elements based on our current under-
standing of ecosystem structure and function, including the
need to consider ecosystem products and services, the
chemical and energy linkages within and between ecosys-
tems, the importance to ecosystem health of human actions
and policies, the integration of ecosystems into landscapes
and landscapes into regions, and the need better to under-
stand ecosystem resilience and sustainability.
Ecosystem management to avoid or mitigate future harm
also requires a larger-scale and longer-term perspective, in
which ecological time frames (e.g., generation times of forest
trees) rather than human-perception times (e.g., time between
elections) are followed. Moreover, landscape- and regional-
scale issues are necessary to specify what mix of ecological
systems are to be located where and what environmental
health levels are to be attained for each ecosystem in this
management mosaic. This may require, for example,
identification of certain locations or certain ecological
systems to be selected for greater environmental alterations
(e.g., agricultural areas, urban areas) in order for other areas
to be afforded higher levels of protection from human
stresses (e.g., national parks, wildlife refuges). This process
occurs throughout the nation at present but is often the
inadvertent result of policies or individual activities; in
contrast, the ecosystem management approach is to do this in
a systematic, risk-based, holistic framework that brings
together into one picture both the ecological and the societal
constraints and relationships.
Although ecosystem management goals should be formu-
lated with a regional/landscape perspective, implementation
of these goals must occur at the "local" scale, with manage-
ment units of relatively small size (e.g., watershed units) by
numerous public and private sector entities. In many cases,
this will require the development of new management tools
that incorporate key ecosystem and habitat management
principles.
In summary, components of a futures-oriented ecosystem
management system include:
a) identification of ecosystems for various levels of
protection (e.g., core/unmanaged and intermediate/
buffer areas of protection, and areas with greater
human use); this requires development of a shared
13
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vision of the regional landscape and is not always
compatible with the concept of "multiple use";
b) management of the environment at regional spatial
scales and intergenerational time scales, recognizing
the characteristic heterogeneity in space and time of
both ecological and societal systems;
c) establishment of ecological endpoints for each
ecosystem type in each area to evaluate the health and
change of health of the systems;
d) selection of goals for environmental condition for
each ecosystem type and for each protection area
based on both ecological considerations and societal
values (i.e., explicit incorporation of humans as part
of ecosystems, recognizing that ecological and
societal sustainability are mutually dependent);
e) identification and development of the human institu-
tions, policies, and activities, relying on adaptive
management and risk-based approaches based on the
best science available, that need to be implemented in
order to attain those ecological goals; and
f) institution of long-term environmental monitoring/
characterization studies to measure progress in
attaining the ecological goals, and continued research
to reduce uncertainties.
8.3 Information Inputs to Risk Management
Effective risk management using the conceptual model for
futures analysis requires information on societal goals and
values, improved monitoring of resource status and trends
(including recurrent, high quality assessment of key indica-
tors of ecosystem health), and greater emphasis on transfer
of environmentally friendly technologies to developing
nations. New technologies must be systematically evaluated
with regard to risks and positive and negative impacts on
ecosystem values (both monetized and non-monetized). The
conceptual model for futures analysis is a suitable approach
for conducting this analysis. The Agency should also make a
strong commitment to provide education on the environmen-
tal risks and benefits of emerging technologies.
8.4 Use of Computer Simulation Games
As part of the Environmental Futures Project, the Committee
also explored the use of computer simulation games as an aid
to understanding the impacts of future environmental
problems. SimEarth: The Living Planet, software by
MAXIS, is a computer game that projects maps and data on
vegetation types, dominant sentient beings, air and sea
temperatures for the Earth under varying scenarios using
simple models for the geosphere, atmosphere, biosphere, and
human civilization. While the Committee was frustrated by
the technical limitations of the SimEarth game (e.g., the
unrealistic initial conditions of the models, unrealistic rates
of change, and difficulty in identifying modeling assump-
tions from the game documentation), it did recognize the
utility for such a game in helping decision-makers explore
the ecological ramifications of future events.
The Committee encourages the Agency to pursue the use of
computer games in futures analysis, particular those games
that operate on ecosystem or regional scales. The gaming
exercise is not intended to replace the development of
scientifically rigorous models but to provide managers with
an easily accessible tool for considering the implications of
future developments. Careful consideration should be given
to the assumptions, spatial scale, time step, grid size, and
initial conditions of selected games. It may be useful to
develop simulation games focusing on a select set of issues
in order to refine the intuition of scientists and policy-makers
about potential outcomes of particular future scenarios.
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9. References Cited
Harwell, M.A., C.C. Harwell, D.A. Weinstein, and J.R. Science Advisory Board. 1990. Reducing Risk: Setting
Kelly. 1990. Characterizing ecosystem responses to Priorities and Strategies for Environmental Protection
stress, pp. 91-115. In: Grodzinski, W., E.B. Cowling, A.I. (EPA-SAB-EC-90-021).
Breymeyer, A.S. Phillips, S.I. Auerbach, A.M. Bartuska,
and M.A. Harwell (eds). 1990. Ecological Risks: Perspec- U.S. Environmental Protection Agency. 1992. Framework
tives from Poland and the United States. National for Ecological Risk Assessment (EPA/630/R-92/001).
Academy of Sciences Press. 415 pp.
R-l
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Appendix A. Glossary
Biological diversity: a measure of the variety and relative
abundance of plants, animals, and microbes present in an
ecosystem in terms of number of species and genetic
diversity
Community: an assemblage of populations of different
species within a specified location in space and time
Driver: a natural or anthropogenic force or agent of change
that affects ecological stressors
Ecological endpoint: an explicit expression of the ecologi-
cal characteristic that is to be protected, also known as
an assessment endpoint
Ecological risk assessment: the process that evaluates the
likelihood that adverse ecological effects may occur or
are occurring as a result of exposure to one or more
stressors
Ecosystem: the biotic community and abiotic environment
within a specified location in space and time
Ecosystem management: integrated management of
resources within the geographical boundaries of an
ecosystem based on a knowledge of ecosystem function
and explicit attention to human linkages to the ecosys-
tem
Exposure: co-occurrence of or contact between a stressor
and an ecological component
Landscape: the pattern and distribution of natural and
human land uses in an area
Risk characterization: a phase of ecological risk assess-
ment that integrates the results of the exposure and
ecological effects analyses to evaluate the likelihood of
adverse ecological effects associated with exposure to a
stressor
Scenario: a story about the future that is used as a tool for
ordering one's perceptions about alternative future
environments in which one's decisions might be played
out
Stressor: any physical, chemical, or biological entity that
can induce an adverse response
A-l
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Appendix B. Ecological Issues for the Future
The EPEC focused its efforts primarily on developing a
conceptual model/process for futures analysis. However,
during the development of the conceptual model and its
application to a range of energy scenarios, the Committee
identified a number of ecological issues that may be very
significant in the future. These issues can be organized into
five categories: Issues from Reducing Risk, Stressors
Causing Effects in the Near Term (0-30 years), Stressors
Causing Effects in the Longer Term (30+ years), Other
Possible Future Concerns/Stressors, Effects Caused by
Cumulative Stresses (Syndromes).
1. High Risk Problems Identified in Reducing Risk
The Committee reaffirms the importance, significance, and
relative ranking of the risks to ecological resources (i.e.,
Stressors) identified in Appendix A of Reducing Risk. Risks
that received high rankings included:
a) global climate change
b) habitat alteration and destruction
c) Stressors that cause loss of biological diversity
d) stratospheric ozone depletion
These four environmental problems continue to present high
risks to ecological systems and human welfare because the
geographical scale of all four is very large (regional to
global), the time that could be required to mitigate all four is
very long, and some effects are irreversible.
2. Stressors Causing Effects in the Near Term (0-30 years)
a) Habitat Alteration and Destruction - The greatest
stressor to the world's biological resources is alter-
ation and loss of habitat. Loss, degradation, and
fragmentation of habitat associated with urbanization,
land use changes associated with agricultural and
silviculture activities, and transportation stress
terrestrial biota. Flow modifications, channel alter-
ations, damming, siltation, and nutrient enrichment
eliminate and degrade aquatic habitats, thus impact-
ing aquatic biota.
b) Exotic Species - Accidental or misguided introduc-
tion of exotic species (both plant and animal, terres-
trial and aquatic) poses a significant threat to endemic
species and overall biodiversity. Introduced species
often out-compete native species because of a lack of
natural predators and disrupt the structure and
functioning of ecosystems. Examples include zebra
mussels in Lake Erie, Asiatic clam, kudzu, chestnut
blight, Dutch Elm disease, water milfoil, hydrilla,
mesquite, Japanese beetle, and sea lamprey. With
globalization of the economy, a significant risk exists
for an increase in the transport and introduction of
exotic species. Development of transgenic species
may pose a similar threat if not carefully evaluated
and managed.
c) Pollution - Persistent bioaccumulative chemicals,
metals, some pesticides, and nutrients (phosphorous
and nitrogen) continue to have adverse impacts on
terrestrial, freshwater, and near-coastal ecosystems in
many parts of the world. Bioaccumulative chemicals
such as dioxin and polychlorinated biphenyls (PCBs)
concentrate in top predators and can adversely affect
growth, development, and reproduction of terrestrial
and aquatic consumers. Metals in soil, sediments, and
water can exert acute and chronic toxic effects on
plants and animals. Continued use of highly toxic and
persistent pesticides, particularly in developing
countries, threatens ecological resources. Excessive
use of fertilizers in urban and agricultural applica-
tions is causing eutrophication of freshwater and
near-coastal ecosystems that smothers habitats,
encourages growth of nuisance organisms (e.g., "red
tide"), and depletes dissolved oxygen.
d) Over-Exploitation of Natural Resources - Adverse
impacts on ecological systems from over-exploitation
of natural resources are significant. Excessive
withdrawals of ground water and surface water for
irrigation, industrial use, and drinking water supply
are contributing to the spread of deserts in many parts
of the world. Poor agricultural practices contribute to
erosion and subsequent loss of soils. Over-exploita-
tion of near-coastal and marine fisheries have
decimated many stocks of fish. Nonsustainable
harvesting of timber, particularly in the tropics, is
causing unprecedented losses of biodiversity. Surface
mining of minerals destroys terrestrial habitats and
contaminates aquatic ecosystems.
3. Stressors Causing Effects in the Longer Term (30+ years)
The Committee continues to be concerned about the ecologi-
cal consequences of global climate change caused by build
up of greenhouse gases and increases in ultraviolet light
(UVb) reaching the Earth because of depletion of strato-
spheric ozone. Adverse ecological effects from these
Stressors (e.g., inundation of coastal wetlands and marshes
from thermal expansion of the oceans, and UVb impacts on
B-l
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phytoplankton photosynthesis in the oceans) may not be disrupt communication critical for reproductive
realized until many years in the future. However, because of behavior and territorial defense for many species. For
long lag-times in realizing the benefits of mitigation activi- example, many birds use calls to mark and defend
ties, efforts should begin immediately to address these their territories, and whales, whose population
issues. numbers are small, communicate with sound over
long distances. As noise pollution increases, interfer-
4. Other Possible Future Concerns/Stressors ence with essential communication activities will
Using the conceptual model for futures analysis to evaluate increase. Aircraft flying in remote areas (e.g., parts of
two energy scenarios, the Committee identified light Alaska) has already been implicated in noise stress
pollution, noise pollution, and EMF as having possible for animals.
adverse ecological effects in the future.
c) EMF: With inexpensive, widely available energy, it is
a) Light pollution: If energy becomes inexpensive and likely that EMF will increase and with it the potential
widely available globally associated with advances in for impacts on terrestrial plants and animals.
fusion and/or hydrogen technologies, it is likely that
this energy will be used to light up the planet. Many 5- Effects Caused By Cumulative Stresses (Syndromes)
animals and plants use light cues to initiate their Individual organisms, populations, communities of organ-
reproductive activities. Nocturnal animals have isms, and ecosystems respond to the cumulative impacts of
evolved life strategies that partition niches based on stressors. Examples of significant ecological problems that
nighttime activities. Excessive light could signifi- appear to be caused by cumulative stresses are marine
cantly disrupt plant and animal physiology and mammal die-off, forest decline, and coral reef bleaching.
behavior, potentially causing significant effects. These phenomena appear to be increasing in frequency and
extent. Protecting ecological resources from cumulative
b) Noise pollution: A more populated Earth with stresses will require an integrated and long-term commitment
increased dependency on technology (machines) will to pollution prevention and resource protection.
also be a noisier place. This noise has the potential to
B-2
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