Scheraga, Joel Coping with Clima

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Scheraga, Joel Coping with Clima Powered By Docstoc
					                                                                              APPENDIX 1: INVITED TALKS

           COPING WITH                                 the opportunities. Adaptation is one mechanism
                                                       for meeting this objective.
                                                       Some of the observed changes in climate are
                  Joel D. Scheraga*                    natural and some are human induced. We can-
         U.S. Environmental Protection Agency          not yet say how much of an influence humans
                    Washington, DC                     are having on the climate system, but we know
                                                       that humans are making a difference. For this
                                                       reason, the international community signed the
                                                       Framework Convention on Climate Change in

        his talk is about adaptation to climate
        change. It argues that adaptation is an        1992. Article 2 of the Convention states that the
        important strategy for protecting human        ultimate objective of the Convention is:
health, ecosystems, and economic activity as the
                                                            “ achieve, in accordance with the
climate changes. Adaptation is an essential com-
                                                            relevant provisions of the Conven-
ponent of any portfolio of actions that comprise
                                                            tion, stabilization of greenhouse gas
U.S. climate change policy.
                                                            concentrations in the atmosphere at
Several key questions are addressed. First, why             a level that would prevent danger-
should policymakers consider adaptation as one              ous anthropogenic interference with
component of a comprehensive response to cli-               the climate system. Such a level
mate change? Second, how much adaptation is                 should be achieved within a time-
enough? Third, what factors must decision mak-              frame sufficient to allow ecosystems
ers consider as they design adaptive strategies             to adapt naturally to climate change,
to ensure that they are effective?                          to ensure that food production is not
                                                            threatened and to enable economic
The paper concludes with a cautionary note that             development to proceed in a sustain-
adaptation is not a panacea. It should not be the           able manner.”
only strategy considered for the reduction of
risks posed by climate change. Adaptation              The Framework Convention only focuses on the
comes at a cost and society has limited resources      mitigation of greenhouse gas emissions which
to devote to this activity. Also, there are uncer-     will yield benefits in the future. However, the
tainties associated with the effectiveness of any      ongoing changes in climate already are having
adaptive response. Any portfolio of climate            real impacts on ecosystems and society. If the
change policies should consist of a mix of both        ultimate goal of climate policy is to protect
adaptation and mitigation strategies.                  human health, ecosystem health, and economic
                                                       activity, then adaptation must also be consid-
Why Adaptation?                                        ered as a policy response. In contrast to mitiga-
                                                       tion, adaptive responses can yield immediate
The climate system is dynamic. The climate             benefits in the form of reduced risks and new
has changed, is changing, and will continue to         opportunities. Also, since emissions of green-
change in the future. The ongoing changes in           house gases affect the climate system with a lag,
climate pose risks to human health, ecosystems,        past emissions from human activities have
and economic activity. They also present op-           already committed us to some future warming.
portunities. The ultimate objective of climate         Some human-induced climate change will
policy should be to reduce the risks and exploit


occur, providing a further motivation to adapt        is acceptable to society. That decision must be
now in anticipation of future changes.                left to policymakers.

How Much Adaptation is Enough?                        Things to Consider When Designing
                                                      Adaptation Strategies
Adaptation is an insurance policy. Only finite
amounts of insurance can be bought, since it          There are a number of factors that decision
has a cost associated with it. How much is            makers should consider as they design and
bought depends on the resources available to          implement adaptation strategies:
society, competing priorities, and the level of
risk that is deemed acceptable.                       (1) Adaptation must target both the positive and
                                                      negative consequences of climate change. Ad-
The concept of “adaptation as insurance” is a         aptation refers to more than risk reduction.
useful one. When people contemplate spend-            It also refers to the exploitation of opportuni-
ing resources on investments to deal with un-         ties. If the ultimate goal of climate policy is to
certain future climate outcomes, they sometimes       improve public health, ecosystem health, and
ask, “What if we guess wrong?” But uncer-             social well being (including economic growth),
tainty is at the heart of risk and insurance. A       then decision makers must invest scarce re-
person buys car insurance even though it is un-       sources to exploit the opportunities as well as
certain whether she will have a car accident. In      to reduce the risks. Most regions will be faced
fact, most people hope to avoid any accidents. I      with a mix of risks and opportunities.
will venture to say that when a person “guesses
wrong” by buying car insurance, but does not          (2) Adaptation comes at a cost. The scarce re-
have an accident, she is not upset that an acci-      sources that society uses to adapt to a changing
dent did not occur. She understands the value         climate must be diverted from other productive
of having purchased the insurance, and contin-        activities. The additional resources that will be
ues to do so in the future.                           needed to protect the elderly and very young
                                                      from heat stress during more frequent heat
Only society can decide how much adaptation           waves in a future climate could be used for al-
is enough. The timing and magnitude of the            ternative purposes. Society has limited re-
investment in adaptation depends on how much          sources to devote to adaptation, and decision
risk society is willing to accept.                    makers should ensure that the expected net ben-
                                                      efits (i.e., the benefits minus the costs) are posi-
It is interesting to note that the Framework Con-     tive. Also, the effects of climate change must
vention does not attempt to define a level of         be considered in the context of other stresses.
acceptable risk. Although the Framework Con-          Resources that are used to adapt to climate
vention refers to the concept of “dangerous an-       change could be used to reduce other stresses
thropogenic interference,” it is not explicitly       on human health, ecosystems, and economic
defined. This omission is intentional. Science        systems.
can identify the mechanisms by which changes
in atmospheric concentrations of greenhouse           Society either can delay investing in adaptation
gases may lead to climate change, and identify        and react to changes in climate as they occur
the risks and opportunities associated with           (reactionary adaptation), or it can anticipate
changes in climate. But science cannot make           future change and invest in adaptation now (an-
the value-laden judgement of what level of risk       ticipatory adaptation). In either case, there is a

                                                                                             APPENDIX 1: INVITED TALKS

cost associated with adaptation. It is a question                   in socioeconomic status (e.g., income). The
of when the costs are incurred and what they                        design of adaptive strategies should be tailored
buy. The decision of whether to adapt now or                        to the vulnerable demographic groups. For
later should be based on a comparison of the                        example, the elderly and very young are most
present value of expected net benefits associ-                      vulnerable to heat stress, and adaptive responses
ated with acting sooner versus later.                               have to be targeted to their needs.

(3) Climate change will have distributional                         (4) It is important to characterize the mecha-
effects across people and places. Figure 1 de-                      nisms by which impacts may occur. It is not
picts the changes in average temperature and                        enough to identify the potential consequences
precipitation that have occurred across the                         that climate change may have for a particular
United States during the last one hundred years.                    physical or human system. The mechanisms by
There is a regional texture to the changes. The                     which the impacts may occur must be under-
changes that occurred in the Great Lakes region                     stood to ensure the effectiveness of adaptation.
are different than those in the Southeast. In some
parts of the country, temperature and precipita-                    Consider, for example, how farmers might adapt
tion increased, and in other locations they de-                     to the expected increase in rainfall that will ac-
creased. The regional differences must be con-                      company a warmer world. If they anticipate that
sidered as one designs adaptive responses since                     the precipitation will occur as light, steady rain-
the resulting impacts will be site specific. Strat-                 fall events, then they might shift to alternative
egies that may be effective in California may                       types of crops that do better in wetter weather.
not be effective in Michigan.                                       However, if they anticipate that the intensity of
                                                                    rainfall will consistently increase over time, they
Also, different groups of individuals will have                     may choose different planting and tilling prac-
different levels of vulnerability to climate                        tices. In fact, a close examination of the historic
change, because of different physical charac-                       data reveals that there has been a noticeable
teristics (e.g., age, infirmities), and differences                 change in the character of precipitation events

   Temperature and Precipitation Trends, 1900 to Present

                     Temperature                                              Precipitation

Red circles reflect warming                                         Red circles reflect increasing precipitation
Blue circles reflect cooling                                        Blue circles reflect decreasing precipitation

Figure 1: Temperature and precipitation trends in the US. Source: Karl et al. (1996).


   The graph in Figure 2 (from the National                            as important, or more important, than the direct
   Climatic Data Center) shows that the percent-                       effects.
   age of area across the United States that has
   experienced extreme precipitation events –                          (6) There are uncertainties associated with the
   defined as greater than or equal to two inches                      effectiveness of any adaptive response. Policy
   per day – has increased. This change in charac-                     makers should not assume that adaptation will
   ter is an important consideration for farmers as                    be completely effective, as evidenced by the
   they adapt to a changing climate.                                   effectiveness of adaptive responses under cur-
                                                                       rent climatic conditions. People die of heat stress
   (5) Climate change will have indirect effects,                      every year, even though society has the know-
   as well as direct effects. As decision makers                       how and resources to prevent these deaths. If
   prioritize possible investments in adaptation,                      society is unable to prevent these deaths today,
   they must make sure to consider the indirect                        why should we assume that it will be any more
   effects of climate change. For example, climate                     effective preventing them tomorrow?
   change will have both direct and indirect effects
   on human health. The direct effects include the                     (7) Adaptation can have adverse impacts in
   mortality and morbidity effects of weather                          addition to their intended effects. Beware of
   extremes like heat waves. The indirect effects                      maladaptation. An adaptive response may have
   include outcomes that may be mediated through                       unintended secondary consequences that out-
   ecological changes that are caused by climate                       weigh the benefits of undertaking the strategy.
   change, like the spread of infectious diseases.                     For example, pesticides that are used to eradi-
   Depending on the geographic location under                          cate mosquitoes that may carry infectious dis-
   consideration and the characteristics of the vul-                   eases (e.g., dengue fever) may have their own
   nerable populations, the indirect effects may be                    adverse impacts on human health. These off-
                                                                       setting effects must be considered before the
                                                                       eradication program is implemented.
         Portion of the USA Affected by Much Above
         Normal Portion of Annual Precipitation from                   (8) Policies intended to adapt to future climate
             Extreme Events (≥ 2 inches per day)                       can increase the resiliency of systems to cur-
                                                                       rent climatic conditions. These are often termed
                                                                14     “no regrets” strategies. For example, the elimi-
                                                                       nation of federal flood insurance for new con-
                                                                       struction in flood plains will reduce the possi-

                                                                       bility of property damage under current climate,
                                                                       and increase the resiliency of infrastructure to
                                                                10     more frequent floods in the future. Strategies
                                                                       like this have the attraction of yielding imme-
                                                                       diate benefits to society, as well as potential
                                                                       future benefits. They also may be less expen-
                                                                       sive than adaptive responses that would have to
                                                                6      be undertaken in the future. And they might keep
   1900         1920        1940      1900       1980
                                                                       future options open.
   Figure 2: The change in the area of the US affected by              The design and implementation of an effective
   increases in the proportional of total annual precipitation
   derived from extreme daily precipitation events (great than or
                                                                       adaptation strategy is not an easy undertaking.
   equal to 2 inches per day).                                         Policymakers should not be cavalier about the

                                                                                                       APPENDIX 1: INVITED TALKS

ease with which adaptation can be achieved, nor                  types of considerations decision makers must
the expected effectiveness of any policies they                  make as they design adaptive responses.
                                                                 Human Health
The Consequences of Inaction
                                                                 The potential consequences of climate change
Figure 3 depicts the array of consequences that                  for human health are receiving increased atten-
climate change may have if society doesn’t                       tion as they are becoming better understood.
adapt. Some of these effects are well understood,                Figure 4 illustrates an array of health effects that
such as the implications of climate change for                   may be influenced by a changing climate
heat stress and deaths. In other cases, we have                  through a variety of pathways. The effects that
only begun to identify and understand the sen-                   are influenced through more direct pathways
sitivity of systems to weather and climate, and                  include death due to heat stress, and the impacts
do not have any idea of what will be the effects                 of extreme weather events like floods and
of a changing climate.                                           storms. Health impacts that occur through more
                                                                 indirect pathways include those mediated
The purpose of this section is to provide three                  through changes in ecosystems, such as vector-
examples of expected impacts to illustrate the                   borne and water-borne infectious diseases.

                          Potential Climate Change Impacts
                                                                         Health Impacts
                                                                         Weather-related Mortality
                                                                         Infectious Diseases
                                                                         Air Quality-Respiratory Illnesses

                                                                         Agriculture Impacts
                     Climate Changes                                     Crop yields
                                                                         Irrigation demands

                              Temperature                                Forest Impacts
                                                                         Change in forest composition
                                                                         Shift geographic range of forests
                                                                         Forest Health and Productivity
                                                                         Water Resource Impacts
                                                                         Changes in water supply
                                                                         Water quality
                               Sea Level                                 Increased competition for water
                                                                         Impacts on Coastal Areas
                                                                         Erosion of beaches
                                                                         Inundate coastal lands
                                                                         Costs to defend coastal communities

                                                                         Species and Natural Areas
                                                                         Shift in ecological zones
                                                                         Loss of habitat and species

Figure 3: Potential climate change impacts; Source: US Enviornmental Protection Agency.


Indirect health effects also include those asso-                  2020 and 2050. The results for one scenario of
ciated with changes in air quality and the qual-                  future climate change, as well as data on actual
ity of drinking water.                                            recorded deaths in 1993, are shown.

The direct effects of heat stress can be used to                  It is known from the medical literature that the
illustrate some of the factors that must be con-                  elderly, the very young, and people suffering
sidered when designing an adaptive response.                      with various illnesses tend to be the most vul-
Climate change is expected to increase the fre-                   nerable to heat stress. But Figure 5 also sug-
quency of summertime heat waves, and increase                     gests that the impacts of climate change on hu-
the risk of death due to heat stress. But a pos-                  man mortality are city-specific. There is a re-
sible benefit might be a decline in the number                    gional texture to the effects of heat stress. This
of extremely cold days in wintertime, with an                     may be due to a number of factors, such as dif-
accompanying reduction in the number of win-                      ferences in infrastructure, the extent to which
tertime deaths. (The potential magnitude of this                  people have physiologically adapted to extreme
positive wintertime effect is not well under-                     heat, air conditioning use, and the number of
stood.)                                                           elderly and very young living in each city. The
                                                                  conclusion is that remedial actions must be city
Figure 4 depicts results of a study done by                       specific and targeted to specific populations
Kalkstein and Green to project potential in-                      within each city.
creases in deaths due to heat stress in the years

          Average Annual Excess Weather-Related Mortality
                  for 1993, 2020 and 2050 Climate

Figure 4: Average annual excess weather-related mortality for 1993, 2020 and 2050 climate based on GFDl climate change scenario.
Note: Includes both summer and winter mortality. Assumes full acclimation to changed climate. Includes population growth.;
Sources: Kalkstein and Green (1997); Chestnut et al.(1995)

                                                                                 APPENDIX 1: INVITED TALKS

Figure 4 also depicts the preventable deaths that        will vary by region (as seen in Figure 1). Some
occur each year under current climatic condi-            regions will benefit, while others may suffer.
tions. The people who died in 1993 from heat             The frequency of extreme precipitation events
stress might have been saved if response strate-         like floods and droughts will also increase. At
gies had been more effective. It is essential that       the same time, warming will increase evapora-
policy makers discover the reasons for these             tion, tending to lower lake levels, reduce stream
deaths, so that more effective responses can be          flows, and dry soils. The ultimate effect on
implemented in the future. For example, it is            available water supplies and water quality is
not enough to issue “heat wave alerts” over              uncertain.
radio stations. In some cases (as in Chicago in
1995), the elderly may live in high crime areas          There also will be indirect effects on water sup-
and be afraid to open their windows or travel to         plies due to changes in the demand for water
air conditioned environments, even if they hear          across regions and sectors as the climate
the alerts.                                              changes. The water required for human con-
                                                         sumption in urban areas is the same water that
Adaptation during heat waves can be costly. It           is needed for irrigation in agriculture, to sup-
is expensive to run air conditioners, although           port fish habitat, for hydropower, to sustain eco-
many can afford it. However, the most vulner-            systems, and for recreational purposes. As
able people, like the elderly, often are those least     water becomes scarcer in some areas, and as
able to afford to use air conditioners. This prob-       the demand for water increases in some sectors,
lem can be overcome by implementing city                 there will be additional stresses on available
emergency response programs. These programs              water supplies.
might, for example, provide transportation for
the elderly to air conditioned environments, or          The unique role of water as an “integrator”
deliver water to people to avoid dehydration.            across sectors makes the development of any
These programs also come at a cost, but if they          adaptation strategy complex. There are certainly
are successfully implemented, they will provide          “no regrets” strategies that can increase the
immediate benefits in the form of saved lives.           resiliency of water supply systems to current
They also will increase the resiliency of urban          climate and climate change. More efficient mar-
populations to future climate change.                    kets for water, particularly in the western United
                                                         States, will lead to a more efficient allocation
Water Resources                                          of water among competing uses, reduce the
                                                         possibility of water shortages under current
Water is the “lynchpin” that integrates many             climate, and increase the resiliency of systems
regions and sectors. Water quantity and quality          to future climate change. But this type of
will be affected directly and indirectly by              adaptation also has costs associated with it.
climate change. The development of strategies            Establishment of more efficient markets for
for adapting to these effects will be complex.           water may also lead to increases in the costs of
                                                         water to end users as water is distributed to its
The cumulative effect of climate change on               highest valued uses.
water supplies and water quality is complex and
not easy to predict. As the climate changes, it is       The story does not end there. As established
expected that precipitation will increase. The           “property rights” for water are eliminated,
hydrologic cycle is expected to intensify, caus-         adaptation decisions by various end users of
ing the world to become wetter. However, at              water may be affected. For example, farmers
any point in time, the changes in precipitation          may no longer be able to assume that irrigation

will be a viable and affordable adaptation strat-       logic cycle intensifies, and the frequency and
egy. The water may be available to them in              intensity of extreme precipitation events be-
markets, but may be too costly for them to use.         comes more difficult to predict, farmers may
                                                        have more trouble making decisions about what
Maladaptation may also occur. Water markets             to plant and when to plant. This illustrates why
may have unintended negative side effects on            it is important to characterize the mechanisms
systems that are not represented in markets (e.g.,      by which impacts may occur.
ecosystems). These systems may suffer as
water is diverted to other uses, unless their needs     If farmers decide to adapt to warming by in-
are somehow “internalized” in water markets.            creasing fertilizer use, increases in intense pre-
                                                        cipitation events may lead to more runoff into
All of these factors must be considered as adap-        streams and lakes, degrading water quality.
tive responses are developed. The development           From society’s perspective, this may be viewed
of strategies for ensuring adequate water sup-          as maladaptation. Similarly, if a changing
plies and water quality, even under current             climate leads to the spread of pests, farmers may
climatic conditions, is complex.                        choose to increase their use of pesticides. But
                                                        this may have unintended and undesirable
Agriculture                                             effects on human health and the health of
Most existing studies suggest that climate
change will be beneficial to U.S. agriculture if        The ultimate consequences of climate change
one accounts for the effects of international           for U.S. agriculture are unclear. And adaptive
trade, declines in agricultural productivity that       responses taken by farmers may have impor-
are likely to occur in developing countries,            tant implications for other sectors in society.
changes in world food prices, and the ability of
U.S. farmers to adapt to a changing climate.            Conclusion
However, this conclusion is incomplete, and
when reported by itself, is misleading. It fails        Adaptation is a necessary strategy for respond-
to convey the regional distribution of agricul-         ing to climate change. In contrast to efforts to
tural impacts within the U.S. Although the U.S.         mitigate greenhouse gas emissions, adaptation
as a whole might benefit, some regions may be           can yield immediate benefits to society and the
harmed. There also will be distributional effects       environment in which we live. Society must
within any particular region. For example, farm-        decide what constitutes acceptable risks to hu-
ers who plant wheat in Texas may experience             man health, ecosystems, economic activity, and
increases in yields as the climate changes, but         social well being, and how much adaptation is
farmers who plant corn in Texas may experi-             desirable. It must also decide on a combination
ence declines in yields. The latter may adapt by        of mitigation and adaptation options.
switching the types of crops they plant.
                                                        The development of adaptive responses can be
The uncertainty about the impact of climate             a complex undertaking. Many factors must be
change on U.S. agriculture is even more com-            considered as adaptive strategies are designed
plicated. We have already seen how the compe-           and implemented. Failure to do so can lead to
tition for water may make it more difficult for         ineffective outcomes, maladaptation, and reduc-
farmers to rely upon irrigation as their sole           tions in social well being. Decision makers
means of adapting to a warmer world. If                 should not be cavalier about how effective
climate becomes more variable as the hydro-             adaptation will be.

                                                                  APPENDIX 1: INVITED TALKS

Many opportunities to adapt already exist. Ex-
amples include the development of improved
monitoring and surveillance systems to protect
public health, establishment of markets to effi-
ciently allocate water, requirement of setbacks
and rolling easements to protect coastal zones
against sea level rise, development of heat-re-
sistant crops for agriculture and seed banks to
facilitate the movement of managed forests, and
establishment of migration corridors for wild-

Effective adaptation is necessary and possible.
But a lot of research about adaptation still needs
to be done to ensure that policy makers and re-
source managers are able to make intelligent and
informed decisions.
 Joel Scheraga is the Director of the Global Change
Research Program in EPA’s Office of Research and
Development. The views expressed are the author’s own and
do not represent official EPA policy.



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