20th century, with about half of this change occurring during the last 25 years. The year 1998 was the warmest year globally in the entire 140-year record, and the 1990's were the warmest decade.

Fluctuations in solar activity have been directly observed since the invention of the telescope 400 years ago, but accurate, direct measurements of total solar energy output have only been possible with the advent of satellite measurements in the late 1970's. These satellite data exhibit a small but definite cyclic variation over the last two decades, paralleling the 11-year solar sun spot cycle, but with little long-term difference in solar energy output contemporary with the rising global temperatures of the past two decades. Predictions of future temperature responses require atmospheric model calculations which effectively simulate the past and then are extrapolated into the future with appropriate estimates of the future changes in atmospheric greenhouse gas concentrations. These models calculate the direct temperature increases that additional greenhouse gases will cause and the further feedbacks induced by these temperature changes. One of the most prominent of these feedbacks is the change in albedo, or surface reflectivity, in the polar north. When melting ice is replaced by open water, or melting snow replaced by bare ground, less solar radiation is reflected back to space and more remains at the surface, causing a further temperature increase.

The models also assume that more water will remain in the atmosphere in response to the temperature increases, providing another positive feedback.

There is an additional possible feedback from the changes in clouds-amount, composition, altitude. In present models, the cloud feedback is assumed to be small, but data for better evaluation are very difficult to obtain.

Extrapolations for 50 or 100 years in the future necessarily include hypotheses about future societal developments, including population growth, economic activity, etc. The Intergovernmental Panel on Climate Change, or IPCC, developed a large set of scenarios about the possible course of these events over the next century, with resulting model calculations of globally averaged temperature increases for the year 2100 relative to 1990, ranging from 2.5 °F to 10.4 °F, or 1.4 °C to 5.8 °C. These results were only a small part of the three IPCC reports issued during the year 2001 about climate change. Volume I of the IPCC reports treated the scientific bases; Volume II covered impacts, adaptation, and vulnerability; and Volume III, mitigation.

The National Academy of Sciences, in response to a May 2001, request from the White House and following discussions between the Administration and the Academy over some questions raised by the former, convened an 11-member scientific panel, which issued in June a 24-page report, "Climate Change Science: An Analysis of Some Key Questions," from a select committee of atmospheric scientists. I quote the first few sentences of this report and have appended the entire represent to this testimony. Many of these words were repeated by Senator Jeffords.

"Greenhouse gases are accumulating in Earth's atmosphere as a result of human activities, causing surface air temperatures and sub-surface ocean temperatures to rise. Temperatures are, in fact,

rising. The changes observed over the last several decades are likely mostly due to human activities, but we cannot rule out that some significant part of these changes is also a reflection of natural variability."

con

The increasing global temperatures will have many sequences, often adverse in the long run. Because many of the causes of this temperature increase have their origin in the activities of mankind, actions can and should now be taken which will slow this rate of increase. I should say the last words are mine and not the Academy report. I think that we need to start taking actions that will ameliorate the problems of the greenhouse gases. Thank you.

Senator JEFFORDS. Thank you very much, Dr. Rowland.

I think we will go through all of the witnesses first before questions.

Our second witness is Roger A. Pielke, Jr., associate professor, Center for Science and Technology Policy Research at the University of Colorado/Cooperative Institute for Research in Environmental Sciences in Boulder.

Go ahead.

STATEMENT OF ROGER A. PIELKE, JR., ASSOCIATE PROFESSOR, CENTER FOR SCIENCE AND TECHNOLOGY POLICY RESEARCH, UNIVERSITY OF COLORADO/COOPERATIVE INSTITUTE FOR RESEARCH IN ENVIRONMENTAL SCIENCES, BOULDER, CO

Mr. PIELKE. Thank you. I'd like to thank Chairman Jeffords and the committee for the opportunity to offer testimony this morning. My name is Roger Pielke, Jr., and I am from the University of Colorado. On page 7 of my testimony, you'll find more details on my background.

In the time I have available, I would like to highlight the takehome points from my testimony. These are developed in greater detail in the written testimony and also in the peer-reviewed scientific papers on which they are based.

Before I proceed, I want to say that everything I'll present today is consistent with the NRC report that Dr. Rowland referred to and the IPCC, so it is starting with those scientific background documents as a starting point. There is no need-I agree with some of the statements made earlier-no need to question the level of science in those reports; however, as you will hear from me momentarily, it does lead to a range of different interpretations for policy.

The take-home points:

First, weather and climate have increasing impacts on economies and people around the world. Data is scattered, hard to come by, but the picture we are able to put together, largely based on economic data, is that the impacts are growing. I think the Swiss Re report you referred to and the insurance industry would back that up.

The primary cause for that growth in impacts is the increasing vulnerability of human and environmental systems to climate variability and change, not changes in climate, per se. This is not to say that climate does not change or has not changed or will not

continue to change. This is only to say that when we look at the sensitivity of impacts to the various factors that lead to impacts, it takes both a climate event and an exposed society or exposed environment to lead to impacts.

This is shown dramatically on page 3, figure 3, of my testimony, where I show a picture of Miami Beach from 1926 and a picture of Miami Beach from near the present, near 2000. Not only does climate change, but society changes.

Taking the assumptions of the IPCC figure 6 on page 4, we compare the relative sensitivities of economic losses to tropical cyclones to society factors versus climate factors and find societal factors under the assumptions of the IPCC range from the 22-to-1 to a 60to-1 increased, larger sensitivity than the climate impacts.

Again, not to discount the possibility of climate change, but to say to understand climate change we have to put it into the context of societal change.

To address increasing vulnerability and the growing impacts that result would require a broader conception of climate policy than now dominates the debate. We could do a whole lot to energy policy and not do very much to address the growing risk of climate change, climate variability to economies, people, and the environment around the world.

Therefore, we must begin to consider adaptation to climate to be as important as matters of energy policy when we talk about response options. Present discussion all but completely neglects adaptation to climate. Increased attention to adaptation would not mean that we should ignore energy policies or reduce the intensity which we want to improve energy policies, but instead it would be a recognition of the fact that changes in energy policy are insufficient to address the primary reasons underlying the trends and the societal impacts of weather and climate.

Again, another point to emphasize is my testimony is focused on the societal and economic impacts today. It is not focused on the environmental or ecological impacts of climate.

The Nation's investments in research, which I should say are considerable in the area of climate change, in my opinion could more efficiently focused on producing usable information for decisionmakers seeking to reduce vulnerabilities to climate.

Specifically, the present research agenda is focused, in my view, improperly on prediction of the distant climate future. We can spend a lot of money on research and argue for a long time what the climate future will be 50 to 100 years from now. The real test of what the climate future will be is when we actually experience the climate of that time.

Instead, I would suggest we are neglecting what are traditionally called "no regrets adaptation and mitigation opportunities." Instead of arguing about global warming, yes or no, the degree of risk in the far-distant future, we might be better served by addressing things like the present drought that is developing in the Northeast, for which, again, energy policy will not do much to mitigate.

In closing, I would like to leave you with the thought that climate change is much too important a topic to equate solely with energy policy. The last figure in my testimony, figure 7 on page 6, illustrates schematically how we might think about energy policy

15

and climate policy, which do, indeed, have important overlaps but are not the same topic.

Thank you very much.

Senator JEFFORDS. Thank you, Doctor.

Our next witness is David Legates, a Ph.D. and C.C.M., director of the Center for Climatic Research, the University of Delaware, Newark, DE.

Please proceed.

STATEMENT OF DAVID R. LEGATES, DIRECTOR, CENTER FOR CLIMATIC RESEARCH, UNIVERSITY OF DELAWARE, NEWARK, DE

Mr. LEGATES. I would like to thank Senator Jeffords and the committee for inviting my commentary on this important topic. My basic background in research has been in precipitation, so you'll probably guess that I'm going to focus primarily on precipitation, and precipitation variability. With rain outside, it is probably a good topic to bring up today.

In my written testimony, I discuss some of the problems associated with determining climate change from both climate models and observations. In my limited presentation here, I'm going to examine an issue, which I feel focuses on an important environmental risk that we face-human-induced changes in climatic extremes-droughts, floods, and storminess.

Do climate models well represent the Earth's climate? Well, on three separate occasions, I have reviewed the ability of state-of-theart climate models to simulate regional scale precipitation. The models poorly reproduce the observed precipitation, and that character of the models had not substantially changed over time. But, more importantly, climate models simply do not exhibit the observed variability. Both air temperature and precipitation exhibit little year-to-year fluctuation, which is quite unlike what we presently experience. This is crucial, because climatic extremes and not their mean values have the largest economic and environmental impacts.

Simply put, climate models cannot address issues associated with changes in the frequency of extreme events because they fail to simulate storm scale systems or to exhibit the observed variability. Moreover, many extreme weather events are so uncommon that we simply cannot determine their statistical frequency from the observed record, let alone determine how that frequency has changed over time. Determining anthropogenic changes in extreme weather events, either from modeling or observational standpoints, therefore, is nearly impossible.

Furthermore, it is unclear how much should be attributed to anthropogenic increases in atmospheric trace gases and how much will be simply a result of natural variability or measurement bi

ases.

So I ask: is there a cause for concern that anthropogenic warming will lead to more occurrences of floods, droughts, and storminess? I point to the latest Intergovernmental Panel on Climate Change, the IPCC, Summary for Policymakers, which states that, "Global warming is likely to lead to greater extremes of drying and heavy rainfall and increase the risk of droughts and floods."

The mainstream media has frequently echoed this enhanced hydrologic cycle scenario; however, if one carefully reads the IPCC Technical Summary, you will find an admission that, "There is no compelling evidence to indicate that the characteristics of tropical and extra-tropical storms have changed. Recent analysis of changes in severe local weather do not provide compelling evidence to suggest long-term changes. In general, trends in severe weather events are notoriously difficult to detect because of their relatively rare occurrence and large spatial variability."

The IPCC further goes on to state that areas experiencing severe drought to severe wetness increased only to a small degree over the entire 20th century. Tom Karl and Richard Knight have concluded that as the climate has warmed, precipitation variability actually has decreased across much of the Northern hemisphere's mid-latitudes. Bruce Hayden, writing for the Water Sector of U.S. National Assessment, argues that little can or should be said about change in storminess in carbon-dioxide-enriched years.

Sinclair and Watterson recently noted that increased levels of atmospheric trace gases generally leads to a marked decrease in the occurrence of intense mid-latitude storms.

Clearly, claims that a warmer world will lead to more occurrences of droughts, floods, and storms are exaggerated.

So what should we do? I feel first we must continue to develop and preserve efforts at climate monitoring and climate change detection. Efforts to establish new global climate observing systems are useful, but we must preserve the stations that we presently have. There simply is no surrogate for a long-term climate record taken with the same instrumentation and located in essentially the same environmental conditions.

However, given that oceans cover nearly three-quarters of the Earth's surface, we must further develop satellite methods for monitoring the Earth's climate. We also need to better utilize a national network of WSR-88D, Nexrad weather radars to monitor precipitation and its variability.

But foremost we must focus on developing methods and policy that can directly save lives and can mitigate the economic devastation that often is associated with specific weather-related events.

Climate change discussions usually focus on increases in mean air temperatures or percentage changes in mean precipitation, but it is not changes in the mean fields on which we need to place our efforts. Loss of life and adverse economic and environmental impact occurs not when conditions are normal, but rather they occur as a result of extreme climatic events-floods, droughts, storms at all spatial scales. One thing I can guarantee is that, regardless of what impact anthropogenic increases in atmospheric trace gases will have, extreme weather events will continue to be a part of our life and they will continue to cause the most weather-related deaths and have the largest weather-related economic impacts.

Thus, we must focus on providing real-time monitoring of environmental conditions, which will yield to important benefits. First, it will provide immediate data to allow decisionmakers to make informed choices to protect citizens faced with these extreme weather events, and, if installed and maintained properly, it will assist with our long-term climate monitoring goals.