March 31, 1995
EPA-SAB-EPEC-95-003
Honorable Carol M. Browner
Administrator
U.S. Environmental Protection Agency
401M Street, S.W.
Washington, D.C. 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 which 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 methodologies 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.
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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 particularly important for managing ecological risks.
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 Agency's
Framework for Ecological Risk Assessment (EPA/630/R-92/001). In our report, we describe a
conceptual model for futures analysis which 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 which 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 ecosystems at risk, and evaluating risk management
options to avoid or mitigate ecological risks. This methodology can add value and broader
perspective to a wide range of planning, budget, and rulemaking activities.
The Committee demonstrated the approach for futures analysis by applying it to two
scenarios of energy development and consumption in the United States. 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 that would probably
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
environmental agenda on protecting the integrity of ecosystems and
landscapes.
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The ecosystem management paradigm, while still evolving, 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.
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
ecological 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 conceptual model and the
ecosystem management paradigm described in this report. We look forward to your response to
our recommendations.
Sincerely,
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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U.S. Environmental Protection Agency
NOTICE
This report has been written as part of the activities of the Science Advisory Board, a
public advisory group providing extramural scientific information and advice to the Administrator
and other officials of the Environmental Protection Agency. The Board 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 Environmental Protection Agency, nor
of other agencies in the Executive Branch of the Federal government, nor does mention of trade
names or commercial products constitute a 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.]
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6) Indoor Air Quality and Total Human Exposure Committee EPA-SAB-IAQ-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 any of these reports may be requested and obtained from the Science
Advisory Board, Committee Evaluation and Support Staff (1400), 401 M Street, S.W.,
Washington, D.C. 20460 or by FAX (202) 260-1889.
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ABSTRACT
This report by the Ecological Processes and Effects Committee (EPEC) of the Science
Advisory Board was part of an Environmental Futures Project which 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 which 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
m
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US ENVIRONMENTAL PROTECTION AGENCY
SCIENCE ADVISORY BOARD
ECOLOGICAL PROCESSES AND EFFECTS COMMITTEE
ENVIRONMENTAL FUTURES SUBCOMMITTEE
CHAIR
Dr. Kenneth L. Dickson, Director, Institute of Applied Sciences, University of North
Texas, Denton, Texas
MEMBERS
Dr. William E. Cooper, Institute of Environmental Toxicology, Michigan State University,
East Lansing, Michigan
Dr. Virginia Dale, Environmental Sciences Division, Oak Ridge National Laboratory, Oak
Ridge, Tennessee
Dr. Mark A. Harwell, Rosenstiel School of Marine and Atmospheric Science, University
of Miami, Miami, Florida
Dr. Robert J. Huggett1, Virginia Institute of Marine Sciences, College of William and
Mary, Gloucester, Virginia
Dr. Anne McElroy, State University of New York at Stony Brook, Stony Brook, New
York
Dr. Frederic K. Pfaender, Director, Carolina Federation for Environmental Studies,
University of North Carolina, Chapel Hill, North Carolina
Dr. William H. Smith, Professor of Forest Biology, School of Forestry and Environmental
Studies, Yale University, New Haven, Connecticut
Dr. Terry F. Young, Environmental Defense Fund, Oakland, California
SCIENCE ADVISORY BOARD STAFF
Ms. Stephanie Sanzone, Designated Federal Official, US EPA, Science Advisory Board
(1400F), 401 M Street, SW, Washington, DC 20460
IV
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JDr. Huggett resigned from the Science Advisory Board in April 1994.
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TABLE OF CONTENTS
1. EXECUTIVE SUMMARY 1
2. INTRODUCTION 3
3. CONCEPTUAL MODEL FORFUTURES ANALYSIS 5
4. PROBLEM FORMULATION 7
4.1 Drivers 7
4.2 Stressors 8
4.3 Linkages Between Drivers and Stressors 9
4.4 Ecological Endpoints 12
5. RISK CHARACTERIZATION 14
6. RISK MANAGEMENT 15
7. EXAMPLE SCENARIOS 17
7.1 Low-Cost Energy Scenario 17
7.1.1 Primary and Secondary Drivers 17
7.1.2 Driver/Stressor Linkages 18
7.1.3 Ecological Endpoints 20
7.1.4 Risk Management 20
7.1.5 Insights Gained 21
7.2 Oil Depletion Scenario 21
7.2.1 Primary and Secondary Drivers 21
7.2.2 Driver/Stressor Linkages 22
7.2.3 Ecological Endpoints 24
7.2.4 Risk Management 24
7.2.5 Insights Gained 24
8. CONCLUSIONS AND RECOMMENDATIONS 26
8.1 Benefits of Using the Conceptual Model for Futures Analysis 26
8.2 Management of Future Ecological Risks 26
8.3 Information Inputs to Risk Management 28
8.4 Use of Computer Simulation Games 28
9. REFERENCES CITED 30
vi
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APPENDIX A. GLOSSARY A-l
APPENDIX B. ECOLOGICAL ISSUES FOR THE FUTURE B-l
VII
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1. EXECUTIVE SUMMARY
The Ecological Processes and Effects Committee (EPEC) of the EPA Science Advisory
Board 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
endpoints; 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 which 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 United States. 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 Environmental Futures Project (EPA-SAB-EC-95-009).
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 formalized 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 consequences that probably
would not have been determined through an unstructured brainstorming.
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For example, in the Low-Cost Energy Scenario, the availability of abundant, low-
cost energy was considered to result in expansion of human populations 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 landscapes. 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 Science Advisory
Board (SAB) undertake an initiative, termed the Environmental 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 components:
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 recommend actions for addressing them.
The Ecological Processes and Effects Committee (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 assessing 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
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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 t\\Q Framework for Ecological Risk Assessment (EPA/630/R-
92/001). In Appendix A of Reducing Risk, a matrix approach was utilized 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 evaluating 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, or ecorisk 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
ecological 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 which 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 application in two example scenarios of energy development and
consumption in the United States. 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.
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Figure 1. Conceptual Model for Futures Analysis
Problem Formulation
Drivers
Primary Resource
Use I
Stressors | 1 Ecosystems at Risk |=j|
Influence
Drivers
II
•
Regulate
Use
Ecological Endpoints
i
!
II
1 II
Manage Risk
Exposure Characterization
i
i
II
II
ii ii ii
— ! Risk Marmcrpmpnl- 1! '1
•
Restore
Ecosystems
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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.
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Table 1. Drivers of Ecological Change for a Global-Scale, Thirty-Year Scenario
PRIMARY DRIVERS SECONDARY DRIVERS
—human population growth, distribution, and age —patterns of resource use and
structure availability
agricultural expansion land
urbanization water
air
—resource utilization per capita biomass
minerals
—economic structure energy
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
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 ecosystem components. The Committee examined the stressors identified in
Reducing Risk as being most significant in 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,
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as the starting point for translating future scenarios into predicted ecological effects (Table 2).
Refinement of the stressor list for specific temporal and spacial 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, electro-magnetic fields (EMF),
and noise pollution as significant potential future stressors.
Table 2. Initial List of Drivers, Stressors, and Ecological Endpoints
Environmental Stressors1 Ecological Endpoints
Drivers
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
1 Modified from Reducing Risk: Setting Priorities and Strategies for Environmental Protection (EPA-SAB-EC-90-021)
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
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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).
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Table 3: Strength of Linkages Between Drivers and Ecological Stressors (Global Scale, 30 years)
drivers\stressors
population
consumption per
capita
globalization of
economy
technology
education
environmental laws
and policies
climate change
H +
H +
M+/-
M+/-
L-
H+/-
habitat
loss
H +
H +
H+/-
M/H+/-
M/H-
H+/-
uvb
levels
L +
L +
L-
L-
L-
H-
pesticide
use
H +
L +
H+/-
H+/-
M-
H+/-
pollution
H +
H +
M+/-
M+/-
M-
H+/-
nutrient
enrichment
H +
H +
L+/-
M+/-
L-
H+/-
i
c
s
Key: H, M, L=high, medium, or low degree of association, +/- means the driver increases or decreases the stressor
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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 that 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).
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 differs 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.
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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)
1 modified 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 described 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 via 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 environment. 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 Agreement 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 utilization
controls, water allocation, and timing of resource 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.
Restoration includes a variety of remediation technologies, as well as
reintroduction of endangered species, revegetation, etc.
The selection of risk management options using the conceptual 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 management strategies are likely to be
most effective. Most often these goals will be implied since a clear statement is
rarely available.
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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 management 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 behavior.
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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 utilization of both biomass and mineral
resources would increase, as a result of the "ruralization" of the population and concomitant
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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.
7.1.2 Driver/Stressor Linkages
To evaluate the effects of the Low-Cost Energy Scenario on ecological stressors, the
Committee developed a driver/stressor matrix which 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 which 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 (EMF) associated with electric devices, power lines, and
wiring would be more prevalent and more widely distributed 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.
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Table 5: Linkages Between Drivers and Ecological Stressors: Low-Cost Energy Scenario
drivers\stressors
technology
development
climate
change
H-
habitat
altera-
tion
H+/-
toxics in
surface
waters
H+
acid
deposi-
tion
H-
airborne
toxics
H-
nutrient
enrich-
ment
M+/-
oil
H-
acid
inputs
to
surface
waters
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
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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 Warming, habitat destruction
associated with oil spills or terminal construction, and discharges from coastal population
centers).
Species which 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
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 which 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 effectively 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
environmentally 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.
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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).
7.1.5 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 ecological 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
7.2.1 Primary and Secondary Drivers
In order to place bounds on the effects of energy development as a driver, the Committee
developed a second scenario, 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 utilization
of non-renewable 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
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concurrent developing economies, it is likely that 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 becoming 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 regionally 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
resource 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 Driver/Stressor Linkages
The expected effects of the Oil Depletion Scenario drivers on the dominant ecological
stressors were evaluated by constructing 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.
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Table 6: Linkages Between Drivers and Ecological Stressors: Oil-Depletion Scenario
drivers\stressors
resource depletion
climate
change
L +
habitat
altera-
tion
H +
toxics in
surface
waters
H +
acid
deposi-
tion
H +
airborne
toxics
H +
turbidity
H +
oil
H+
groundw
contamir
tion
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:
oil:
groundwater contamination:
radionuclides:
acid inputs to surface
water:
switching to other fossil fuels, so carbon dioxide emissions not greatly affected
increased exploration/extraction, use of biomass for energy
increased exploration/extraction
greater coal use
greater coal use
generally not available
increased exploration/extraction
increased exploration/extraction, greater use of nuclear power
increased exploration/extraction (e.g., acid mine wastes), greater coal use
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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 United States, 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 development of
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
technology development for utilization of alternative sources of energy. In addition, the scenario
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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 geographic location as the demand (i.e., risks
and benefits fall to different populations). Thus, our choices will be greatly influenced by
international markets, multi-lateral negotiations, and information and technology transfer.
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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 developing 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 development. 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 comprehensive
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 conclusions 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 fore-
ordained 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 which incorporates ecorisk principles as contained in the Agency's ecorisk
framework.
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The ecosystem management paradigm, while still evolving, embodies numerous elements
based on our current understanding of ecosystem structure and function, including 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, the integration of
ecosystems into landscapes and landscapes into regions, and the need better to understand
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 formulated with a regional/landscape
perspective, implementation of these goals must occur at the "local" scale, with management 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 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;
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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 institutions, 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 indicators 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 environmental 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 assumptions from the game documentation), it did recognize
the utility for such a game in helping decision-makers explore the ecological ramifications of
future events.
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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. Kelly. 1990. Characterizing
ecosystem responses to stress, pp. 91-115. In: Grodzinski, W., E.B. Cowling, A.I.
Breymeyer, A.S. Phillips, S.I. Auerbach, A.M. Bartuska, and M.A. Harwell (eds). 1990.
Ecological Risks: Perspectives from Poland and the United States. National Academy of
Sciences Press. 415pp.
Science Advisory Board. 1990. Reducing Risk: Setting Priorities and Strategies
for Environmental Protection (EPA-SAB-EC-90-021).
U.S. Environmental Protection Agency. 1992. Framework for Ecological Risk
Assessment (EPA/630/R-92/001).
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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 which affects
ecological stressors
ecological endpoint: an explicit expression of the ecological 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 ecosystem
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 assessment 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 which 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 Ecological Processes and Effects Committee 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 which 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 alteration 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 alterations, damming, siltation, and nutrient enrichment
eliminate and degrade aquatic habitats, thus impacting aquatic biota.
B-l
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b) Exotic Species - Accidental or misguided introduction of exotic species (both plant
and animal, terrestrial and aquatic) pose 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 applications is causing eutrophication of freshwater and near-coastal
ecosystems which 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 groundwater 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-
exploitation of near-coastal and marine fisheries have decimated many stocks of
fish. Non-sustainable harvesting of timber, particularly in the tropics, is causing
unprecedented losses of biodiversity. Surface mining of minerals destroys
terrestrial habitats and contaminates aquatic ecosystems.
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3. Stressors Causing Effects in the Longer-Term (30+ years)
The Committee continues to be concerned about the ecological consequences of global climate
change caused by build up of greenhouse gases and increases in ultraviolet light (UV6) reaching
the Earth because of depletion of stratospheric ozone. Adverse ecological effects from these
stressors (e.g., inundation of coastal wetlands and marshes from thermal expansion of the oceans,
and UVj impacts on phytoplankton photosynthesis in the oceans) may not be realized until many
years in the future. However, because of long lag-times in realizing the benefits of mitigation
activities, efforts should begin immediately to address these issues.
4. Other Possible Future Concerns/Stressors
Using the conceptual model for futures analysis to evaluate two energy scenarios, the
Committee identified light pollution, noise pollution, and electro-magnetic fields as having
possible adverse ecological effects in the future.
a) Light pollution: If energy becomes inexpensive and widely available globally
associated with advances in fusion and/or hydrogen technologies, it is likely that
this energy will be used to light up the planet. Many animals and plants use light
cues to initiate their reproductive activities. Nocturnal animals have evolved life
strategies which partition niches based on nighttime activities. Excessive light
could significantly disrupt plant and animal physiology and behavior, potentially
causing significant effects.
b) Noise pollution: A more populated Earth with increased dependency on
technology (machines) will also be a noisier place. This noise has the potential to
disrupt communication critical for reproductive behavior and territorial defense for
many species. For example, many birds use calls to mark and defend their
territories, and whales, whose population numbers are small, communicate with
sound over long distances. As noise pollution increases, interference with essential
communication activities will increase. Aircraft flying in remote areas (e.g., parts
of Alaska) have already been implicated in noise stress for animals.
c) Electro-magnetic fields: With inexpensive, widely available energy, it is likely that
electro-magnetic fields (EMF) will increase and with it the potential for impacts on
terrestrial plants and animals.
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5. Effects Caused By Cumulative Stresses (Syndromes)
Individual organisms, populations, communities of organisms, and ecosystems respond to
the cumulative impacts of stressors. Examples of significant ecological problems that appear to
be caused by cumulative stresses are: marine mammal die-off, forest decline, and coral reef
bleaching. These phenomena appear to be increasing in frequency and extent. Protecting
ecological resources from cumulative stresses will require an integrated and long-term
commitment to pollution prevention and resource protection.
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EPA Laboratory Libraries
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United States Science Advisory Board EPA-SAB-EPEC-95-003
Environmental 1400 March 1995
Protection Agency Washington, DC
&EPA AN SAB REPORT:
ECOSYSTEM
MANAGEMENT-
IMPERATIVE FOR A
DYNAMIC WORLD
PREPARED BY THE
ECOLOGICAL PROCESSES AND
EFFECTS COMMITTEE
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