synergies described above. The committee believes that more potential benefits of these types of synergies would be realized if there were also direct coordination of some individual components of the CCSP and CCTP. The committee recommended that the CCSP assess the scientific implications of the technologies under consideration by the CCTP and develop realistic scenarios for climate and associated global changes with these technologies in mind. In addition, the program management chapter of the revised CCSP strategic plan should clearly describe mechanisms for coordinating and linking its activities with the technology development activities of the CCTP. Questions to Dr. Richard Alley Question 1. Your report was completed prior to the development of the strategic plan. Do you feel the strategic plan adequately addresses abrupt climate change issues raised in your report? Are there things that you would change? Answer. The proper balance between study of nearly-certain gradual climate change and possible, difficult-to-predict abrupt climate change may be more of a policy question than a scientific one, requiring the insights of those who are accustomed to governing in the face of uncertainty. The draft strategic plan did highlight areas of research that are relevant to abrupt climate change. However, the National Academies committee that reviewed the draft plan found that it needed a better presentation of the time scales associated with climate change, which would point to the value of paleoclimate data as descriptors of past natural variability, including past abrupt climate changes. While paleoclimate studies were noted in the draft plan, more emphasis on them would have been helpful. Just as human history helps a policymaker understand what might occur, climate history provides an essential context for present studies of forced climate change combined with natural variability. Question 2. You have mentioned that denying the likelihood or downplaying the relevance of past abrupt changes could be costly. Can you explain this point? Answer. Slow, anticipated changes allow adaptation, greatly decreasing costs in comparison to rapid, unanticipated changes. Past abrupt climate changes have been very large, and recurrence of such an event could have major consequences. Learning whether such recurrence is possible, and if so, how likely it is, thus could have value in preparing for the future. Question 2a. What might be the economic effects if abrupt climate change was happening today or within the next twenty years? Answer. A recent study on the possible impacts of climate change on U.S. agriculture suggested that an unpredicted but large shift in the strength and frequency of the El Nino/Southern Oscillation phenomenon (such a shift is one of many possible abrupt climate changes) could have annual impacts on U.S. agriculture of approximately $1 billion, but that useful forecasts could cut such damages by more than half (J. Reilly et al., 2003, Climatic Change). The possible damages clearly depend on the size, speed, and extent of the assumed climate change, but the potential magnitude of the impacts and of the value of improved knowledge are clear. Question 3. You have mentioned in your statement that the potential economic and ecological costs of disease emerging from abrupt climate change should be assessed. Can the current situation with SARS (severe acute respiratory syndrome) be used as a study case? Answer. The National Research Council report Abrupt Climate Change: Inevitable Surprises, identifies disease issues associated with climate change. I know of no evidence that emergence of SARS was linked to climate change directly; however, insofar as SARS appears to be a new disease, poses large problems for public-health officials, has already had economic impacts and may have much larger impacts, I personally believe that much can be learned from the SARS incident that would be of value in addressing any new emerging diseases, whether tied to climate change or not. The NRC produced a report in 2001 titled Under the Weather: Climate, Ecosystems, and Infectious Disease, which provides more information on the link between climate change and infectious diseases. Question 4. Your testimony highlights the importance of abrupt climate change on societies. What societies are most at risk today for abrupt climate change, and how might they be affected? Answer. Comparison of archaeological, historical and paleoclimatic records shows cases in which past settlements or civilizations "failed" in association with strong climatic stress, including abandonment of sites. Thus, the worst things that can happen are bad indeed. Climatic stress is only one of many stresses to which societies are subject. "Healthy" societies-those with assets including vigorous economies and strong political institutions are better able to deal with stresses than are "unhealthy" societies, which may aid in assessing vulnerability to climate change. In addition, those societies that rely heavily on long-lived and relatively immobile infrastructure and ecosystems, including traditional hunter-gatherer societies, may be especially vulnerable. As noted in the NRC Abrupt Climate Change report, however, little research has directly addressed this important question. Question 5. If abrupt climate change is occurring, what actions should be taken to mitigate its effects? Answer. Better-foreseen changes are less damaging, so improvement in knowledge of what changes are possible, what changes are likely, and when changes are likely will reduce damages. Some uncertainty will always be attached to projections of abrupt climate changes, so actions that increase the resiliency and adaptability of society in the face of large, unexpected changes would be valuable. In addition, research into "no regrets" policies is needed to help inform decision makers about available options. Some ideas are listed in the Abrupt Climate Change report, but actual policy recommendations were beyond the charge of that NRC committee that prepared that report. RESPONSE TO WRITTEN QUESTIONS SUBMITTED BY HON. OLYMPIA J. SNOWE TO DR. THOMAS E. GRAEDEL, DR. ANTHONY C. JANETOS, DR. DIANA M. LIVERMAN, DR. ANDREW SOLOW, AND DR. RICHARD ALLEY Question 1. There has been an ongoing argument in Congress as to whether global climate change is actually occurring. I understand the task of the November 2002 Strategic Plan for the Climate Change Science Program was to map out the scientific uncertainties. But, there are many published certainties from the Intergovernmental Panel on Climate change (the IPCC), from the National Research Council, and from the President's U.S. Climate Action Report-2002, to the United Nations, which state that there is a strong degree of certainty that global warming is occurring. As renowned scientists, is it your belief that the Earth is experiencing climate change over and above that which would occur with natural variability because of anthropogenic fossil fuel emissions? Answer. As is explained in the 2001 National Academies Report Climate Change Science, there is wide scientific consensus that climate is indeed changing. Greenhouse gases are accumulating in Earth's atmosphere as a result of human activities, causing surface air temperatures and subsurface ocean temperatures to rise. This conclusion is based on instrumental records from land stations and ships, which indicate that global mean surface air temperature warmed about 0.4-0.8 °C (0.7-1.5 °F) during the 20th century. The ocean, which represents the largest reservoir of heat in the climate system, has warmed by about 0.05 °C (0.09 °F) averaged over the layer extending from the surface down to 10,000 feet, since the 1950s. In addition to these direct measurements, proxy records-which can be derived from ice cores, tree rings, and corals—indicate that today's levels of carbon dioxide (CO2), a key greenhouse gas, are at their highest levels of the last 400,000 years. The proxy records indicated that recent warming is anomalous and that the observed change in temperature is consistent with our understanding of how Earth responds to greenhouse gases present in the atmosphere. Dr. Thomas E. Graedel: Yes, I believe that the Earth is experiencing climate change over and above that which would occur with natural variability because of anthropogenic fossil fuel emissions. Dr. Anthony C. Janetos: Yes, I believe that the Earth is experiencing climate change over and above that which would occur with natural variability because of anthropogenic fossil fuel emissions. Dr. Diana M. Liverman: Yes, I believe that the Earth is experiencing climate change over and above that which would occur with natural variability because of anthropogenic fossil fuel emissions. Dr. Andrew Solow: Yes, I believe that the Earth is experiencing climate change over and above that which would occur with natural variability because of anthropogenic fossil fuel emissions. Dr. Richard Alley: Yes, I believe that the Earth is experiencing climate change over and above that which would occur with natural variability because of anthropogenic fossil fuel emissions. Question 2. Do you believe that decision making for climate change mitigation and adaptation should occur even in the face of scientific uncertainties? Should Congress wait until these uncertainties are resolved or should Congress be acting now with measures to decrease the emissions of carbon dioxide and other greenhouse gases? I would appreciate it if you would answer individually. Answer. All important decisions are made under conditions of uncertainty. Indeed, uncertainty will never be resolved fully. The draft strategic plan agrees with this point of view, stating that "All of science, and all decisionmaking, involves uncertainty. Uncertainty need not be a basis for inaction; however, scientific uncertainty should be carefully described in CCSP reports as an aid to the public and decisionmakers" (CCSP, 2002, p. 11). At the same time, there are many aspects of climate change that are well-understood, and it is equally important for scientists to communicate to decision makers the degree to which they are certain about findings and predictions. Dr. Anthony C. Janetos: It is my own belief that decision making must occur, even in the face of uncertainties, and that Congress should begin to act. I have two primary reasons for this. One is that all decision making, and all decision makers must live with uncertainties, even while they attempt to have them reduced. This is true for all manner of choices that we make every day. The other is that there are some things we do know: the concentration of greenhouse gases is rising due to human influence, and is already past the realm of natural variability over the past several hundred thousand years. All the available, credible science that has been done on the sensitivities of natural resources and ecosystems to climate variability and change, and on the potential impacts due to reasonable scenarios of change in the future, suggest that there are potential consequences that one might want to avoid. The main uncertainties are the absolute magnitude of climate change and its regional basis, and therefore the absolute magnitude, regional location, and timing of potential consequences. While these are serious issues, and must be addressed, they should not be reason enough to delay beginning to reduce the emissions of greenhouse gases with sensible policies. Dr. Diana M. Liverman: Yes I do believe that decision making should occur in the face of scientific uncertainties because we do not need to be certain to act, because effective decisions about many other important issues (e.g., economic and health policy) have been made under conditions of considerable uncertainty, and because research has developed a number of useful tools for making such decisions. My personal opinion is that it is possible to make decisions to mitigate and adapt to climate change that will reduce the risks of serious climate change and can provide side benefits (e.g., by reducing other risks such as those of air pollution and natural climate variability, by saving consumer energy costs through conservation) to many sectors of society. Dr. Andrew Solow: I do not believe that Congress should delay acting until the scientific uncertainties are resolved. However, by the same token, I do not believe that Congress should ignore these uncertainties in its decision making. Dr. Richard Alley: Change will occur. The existence of abrupt climate change ensures that detailed projections of climate change will always be somewhat uncertain. Just as one cannot predict exactly when a leaning person will flip a canoe on a wave-tossed lake, so it is difficult to tell exactly when a threshold will be crossed that alters the way the climate behaves. If policymakers had to wait for all scientific uncertainty to be resolved before considering appropriate policy, they would wait forever. Question 3. The Global Change Research Act of 1990, Section 106, calls for an assessment to be prepared and submitted to the President that analyzes, for instance, the effects of global change on the natural environment, agriculture, energy production and use, land and water resources, transportation, human health and welfare, human social systems, and biological diversity. A national assessment, Climate Change Impacts on the United States, of which you were one of the team members, was published in 2001, addressing the potential consequences of climate variability and change. Do you know why there is no mention of this 2001 National Assessment in the draft Strategic Plan, especially as was developed by a great number of regional and local stakeholders and scientific experts? Answer. Dr. Anthony C. Janetos: I do not know why the U.S. National Assessment of the Potential Impacts of Climate Variability and Change was not mentioned in the draft CCSP strategic plan. Our committee concluded that the draft strategic plan did not adequately use many prior assessments and consensus reports that have provided scientific information to decision makers, including the U.S. National Assessment. This is especially unfortunate in several respects. One is that the National Assessment, through its sectoral and regional studies, involved literally thousands of citizens and hundreds of scientists in its workshops and many published products. Another is that the national reports of the Assessment were the subject of extensive scientific and public review, and contrary to some assertions, have not been discredited in the scientific community. In fact, the main conclusions from the Overview document (appended below) are quite balanced, and should continue to provide guidance for future research activities, as is also documented in the peerreviewed literature (Parson, Edward A., Robert W. Corell, Eric J. Barron, Virginia Burkett, Dr. Anthony C. Janetos, Linda Joyce, Thomas R. Karl, Michael C. MacCracken, Jerry Melillo, M. Granger Morgan, David S. Schimel, and Thomas Wilbanks, 2003. Understanding Climatic Impacts, Vulnerabilities, and Adaptation in the United States: Building a Capacity for Assessment. Climatic Change 57: 942). The CCSP would also do well to learn not only the substantive lessons of the results of the National Assessment, but also the operational complexities inherent in attempting such a large-scale, national effort to engage both scientists and stakeholders in a dialogue of national importance. KEY FINDINGS 1. Increased warming Assuming continued growth in world greenhouse gas emissions, the primary climate models used in this Question to Dr. Richard Alley Model Projected Question 1. In your book, Abrupt Climate Change: Inevitable Surprises, you mention that there is no federal plan for improving our understanding of abrupt climate change. I would like to know what you think of my request to establish a NOAA Joint Institute that will involve universities carrying on abrupt climate change research such as yours at Penn State and Dr. George Denton's at the University of |