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OCR for page 67
8
Findings and Conclusions
This study reviews current knowledge about greenhouse warming and
examines a wide variety of potential responses. The panel finds that, even
given the considerable uncertainties in our knowledge of the relevant phe-
nomena, greenhouse warming poses a potential threat sufficient to merit
prompt responses. People in this country could probably adapt to the likely
changes associated with greenhouse warming. The costs, however, could
be substantial. Investment in mitigation measures acts as insurance protec-
tion against the great uncertainties and the possibility of dramatic surprises.
In addition, the panel believes that substantial mitigation can be accomplished
at modest cost. In other words, insurance is cheap.
These responses, however, must be based on consideration of the uncer-
tainties, costs of actions and inaction, and other factors. The panel believes
they should be based on the approach outlined in Chapter 4. Actions that
would help people and natural systems adapt to climate change are described
in Chapter 5. Actions to mitigate greenhouse warming are described in
Chapter 6.
The findings and conclusions presented here draw on the detailed assess-
ments performed by the other three panels contributing to this study: the
Effects Panel, the Mitigation Panel, and the Adaptation Panel. The Synthesis
Panel, however, considered additional materials in its deliberations and in
the preparation of this report. These include, for example, the reports of the
three IPCC working groups, the conference statement from the Second World
Climate Conference, statements from other international meetings, publica-
tions of the national laboratories and other research organizations in the
United States, and documents prepared in other countries. The findings and
conclusions of this panel reflect additional analysis, deliberation, and judg-
ment beyond those of the other panels contributing to this study.
67
OCR for page 68
68
POLICY IMPLICATIONS OF GREENHOUSE WARMING
POLICY CONSIDERATIONS
The phenomenon of greenhouse warming is complex, and so are the
possible responses to it. First, the extent, timing, and variation of future
warming and its likely impacts need to be assessed. Second, both the cost
and the effectiveness of options to slow greenhouse warming must be esti-
mated and compared to the costs of postponing action. Third, the possible
advantages and disadvantages of these actions need to be evaluated in light
of the extent to which people, plants, and animals are likely to adjust by
themselves or with assistance to changes in the climate. Fourth, the policymaker
needs to evaluate these actions in comparison to other ways resources might
be used. Before acting, we need to be confident that expenditures to slow
climate change make sense. Fifth, decision makers will judge all these
factors in a broader context. Responses to greenhouse warming will be
determined by people worried about economic growth, food supply, energy
availability, national security, and a host of other problems. Many re-
sponses appear to produce sizable benefits with regard to other goals, such
as reducing air pollution. This study makes no attempt to assess these
additional dividends. Instead, it focuses on response to greenhouse warm-
ing as such.
Capacities of Industrialized and Developing Countries
Different countries have quite different capacities to respond to change.
Poverty, in particular, makes people vulnerable to change and substantially
reduces their flexibility in responding to change. Countries with low per-
capita income face difficult trade-offs between stimulating economic development
and alleviating environmental problems. These countries, which already
have difficulty coping with environmental stresses today, will be even more
sorely pressed when confronted by climate change.
This report examines response to greenhouse warming in the United States,
a country richly endowed with natural and human resources, and one benefiting
from a geography that encompasses many climate zones. Compared to
many other countries, the United States is well situated to respond to green-
house warming.
This panel does not attempt to view greenhouse warming from the per-
spective of a country less well-endowed. Of course, greenhouse warming is
a global phenomenon, and many global aspects must be included in any
analysis. Nevertheless, most of the data utilized in this study to evaluate
mitigation and adaptation options relate to the United States. A more com-
prehensive examination must wait for future studies.
OCR for page 69
FINDINGS AND CONCLUSIONS
69
Taxes and Incentives
Decisions about energy use and other activities that emit greenhouse
gases are made daily, even hourly, by 250 million people in the United
States in many different areas from transportation to hair drying. Experi-
ence here and abroad has shown the inducements of prices and taxes to be a
sure way to transmit government policies to decentralized decision makers.
Achieving significant reductions in greenhouse gas emissions, however, could
involve considerable sacrifice and economic disruption.
There are advantages of market-incentive approaches, but they are not
universal. For particular technologies, like the chlorofluorocarbons (CFCs),
it may be quicker to use direct regulatory interventions such as emissions
limits or caps, although buttressing these with taxes can ensure that the
regulations are enforced. An alternative to taxes that has been suggested,
and endorsed by several foreign governments and the United States in the
Clean Air Act, is establishing emission limits. While this approach seems
reasonable on the surface, it has significant shortcomings in implementa-
tion.
The major defect with regulatory actions such as emission limits is that
there is no easy way that the government can directly control emissions
from so many different and separate sources. However, regulation as a
technology-forcing mechanism has contributed to reducing emissions of key
air pollutants in the United States. It other areas it has been less successful.
Taxes and regulations can discourage or prevent people from taking actions
that would increase greenhouse gas emissions; incentives of various kinds
can encourage them to act in ways that reduce emissions. If interventions
are needed, this panel believes that, in general, incentive-type measures are
preferable.
Fundamental and Applied Research
Research is inexpensive in comparison with many other policy options
that could make a difference in greenhouse warming. The federal research
budget on topics related to global climate change is a little more than
$1 billion for fiscal year 1991, which is small in comparison to the expected
impact or costs of climate change. Although these funds have been identi-
fied as applying to greenhouse warming research, some of them contribute
to other objectives as well. Policy should be designed and executed in ways
that increase our understanding of the way human activity affects greenhouse
warming.
Research on the actual impacts of climate change may identify vulnerabilities
and highlight areas for policy action. Every year there are droughts, heat
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70
POLICY IMPLICATIONS OF GREENHO USE WARMING
waves, severe storms, and other such phenomena. Understanding how economies
and communities of plants and animals are affected by extreme climate
events, and whether those responses are changing over time, could provide
important guidance for policy choices.
Better understanding of how biological communities function as both
sources and sinks of greenhouse gases, especially CO2, might also help an-
ticipate the consequences of greenhouse warming. More detailed knowledge
about phenomena affecting radiative forcing, such as cloud physics and
chemistry, or of key mechanisms in the global climate system, such as
ocean currents and heat transfers, could help identify where actions might
have greatest leverage. Research satellites capable of measuring the energy
balance of the earth are necessary, as is maintaining thermometer measure-
ment networks.
Most research up to now has emphasized climatological issues. The
global climate change budget in the United States is about 95 percent on the
physical phenomena of atmosphere, oceans, and so on and 5 percent on
mitigation, adaptation, and impacts. We need to know more about the
social and economic processes generating greenhouse gas emissions and
about the costs of mitigating these emissions, especially in the energy sector.
We need reviews and assessments of policy options to slow climate change,
and improvements in the data base for understanding economic and environmental
trends relating to global change. Because greenhouse warming is a global
problem encompassing a wide range of areas, it will be important to estab-
lish programs that are interdisciplinary and examine developing countries as
well as high-income countries like the United States.
A PROPOSED FRAMEWORK FOR RESPONDING TO THE
THREAT OF GREENHOUSE WARMING
The analyses performed for this study show that the United States should
be able to adapt to the changes in climate expected to accompany greenhouse
warming. They have also identified a number of options that could slow or
offset the buildup of greenhouse gases. Other options could help position
us to ease future adaptations to the consequences of greenhouse warming.
The fact that people can adapt, or even that they are likely to do so, does
not mean that the best policy is to wait for greenhouse warming to occur
and let them adapt. Waiting and adapting may sacrifice overall economic
improvement in the long run.
The panel has sorted response policies into five categories: (1) reducing
or offsetting greenhouse gas emissions, (2) enhancing adaptation to greenhouse
warming, (3) improving knowledge for future decisions, (4) evaluating
geoengineering options, and (5) exercising international leadership. The
recommended options in each category are described in Chapter 9.
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FINDINGS AND CONCLUSIONS
71
GENERAL CONCLUSIONS
In conducting this study, the panel first established the approach and
framework described in Chapter 4. The information and data summarized
in Chapters 5 and 6 were then gathered and analyzed. On this basis, the
Synthesis Panel reached the collective judgment that the United States should
undertake not only several actions that satisfy multiple goals but also sev-
eral whose costs are justified mainly by countering or adapting to greenhouse
warming. The panel believes that a systematic implementation of the com-
plete set of low-cost options described in Chapter 9 is appropriate. The
panel concludes that options requiring great expenses are not justified at
this time.
Representative terms from entire chapter:
gas emissions