CLIMATE CHANGE: THE STATE OF THE SCIENCE WEDNESDAY, MARCH 14, 2001 HOUSE OF REPRESENTATIVES, COMMITTEE ON SCIENCE, The Committee met, pursuant to call, at 10:10 a.m., in Room 2318 of the Rayburn House Office Building, Hon. Sherwood L. Boehlert (Chairman of the Committee) presiding. COMMITTEE ON SCIENCE U.S. HOUSE OF REPRESENTATIVES WASHINGTON, DC 20515 CLIMATE CHANGE: THE STATE OF THE SCIENCE Wednesday, March 14, 2001 WITNESS LIST Dr. Daniel L. Albritton Director, Aeronomy Lab, National Oceanic and Atmospheric Administration Dr. Charles Kennel Chairman, Committee on Global Change Research, National Research Council Dr. Berrien Moore Director, Institute for the Study of Earth, Oceans, and Space University of New Hampshire Section 210 of the Congressional Accountability Act of 1995, applies the rights and protections covered under the Americans with Disabilities Act of 1990 to the United States Congress. Accordingly, the Committee on Science strives to accommodate/ meet the needs of those requiring special assistance. If you need special accommodation, please contact the Committee on Science in advance of the scheduled event (three days requested) at (202) 225–6371 or FAX (202) 225-0891. Should you need Committee materials in alternative formats, please contact the Committee as noted above. HEARING CHARTER Climate Change: The State of the Science Wednesday, March 14, 2001 1. PURPOSE The purpose of this hearing is to examine: (1) the state of our understanding of climate science, (2) the gaps in our understanding that limit our ability to detect, attribute, and predict climate change, and (3) the adequacy of the federal government's approach to filling these gaps. Testifying before the Committee are three witnesses: (1) Dr. Daniel L. Albritton, Director, Aeronomy Lab, National Oceanic and Atmospheric Administration, (2) Dr. Berrien Moore, Director, Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, and (3) Dr. Charles Kennel, Director, Scripps Institution of Oceanography. 2. THE U.S. GLOBAL CHANGE RESEARCH PROGRAM In 1990, the House Science Committee passed the National Global Change Research Act, which later became law and created the U.S. Global Change Research Program (USGCRP), a multi-agency program coordinated through the President's National Science and Technology Council to focus U.S. research efforts on climate change and other global environmental changes, such as deforestation and ozone depletion. Agencies participating in the program include the National Aeronautics and Space Administration (NASA), the National Science Foundation (NSF), the Department of Energy (DOE), the National Oceanic and Atmospheric Administration (NOAA), the Department of Agriculture (USDA), the Department of Interior, and the Environmental Protection Agency (EPA). Total funding for the program for the last two years averaged about $1.67 billion. The program funds research by both government and non-government researchers, and has the following goals: • To observe and document changes in the Earth system • To understand why these changes are occurring • To improve predictions of future global changes • To analyze the environmental, socioeconomic, and health consequences of global change • To support state-of-the-science assessments of global environmental change issues. The USGCRP has achieved "an impressive array of scientific accomplishments," according to a 1998 report by the National Academy of Sciences (NAS). It has helped predict the 1997-1998 El Niño weather phenomena, improved our understanding of stratospheric ozone loss, helped decipher ice cores providing evidence of past changes in the Earth's environment, helped develop large-scale climate models, and helped us better understand how terrestrial and marine ecosystems affect the carbon cycle. However, the NAS also criticized the program. In the 1998 report entitled Global Environmental Change: Research Pathways for the Next Decade, the Academy leveled several criticisms at the program and recommended improvements. For example, the report criticized the under-funding of critical research priorities for which the program was created, blaming the lack of coordination between agencies participating in the USGCRP and too heavy an emphasis on expensive space-based observational systems. It also faulted the program for failing to make a serious commitment to maintaining the long-term continuity of climate data-collection systems, which are critical to understanding changes in the climate over time. The Academy report urged the USGCRP to take a new approach with a more sharply focused scientific strategy. Specifically the Academy urged the USGCRP to, among other things: • Secure more powerful computers needed to run the larger, more complex and more useful models currently under development. The Academy emphasized that the U.S. is no longer the leader in this critical field. • Tie its decisions regarding what research to fund and what kinds of observation systems to build more closely to answering a list compiled by the report of over 200 "unanswered scientific questions" in six major areas of global change research. • Shift funds from larger, space-based observing systems to more agile and responsive systems, taking advantage of recent technological advances in small satellite systems, robotics and microelectronics. 3. THE INTERGOVERNMENTAL PANEL ON CLIMATE CHANGE In 1988, the Intergovernmental Panel on Climate Change (IPCC), composed of hundreds of scientists from more than 50 countries, assembled to conduct periodic assessments on climate change and its consequences. To date, the IPCC has released three major reports describing the climate system, the extent to which the climate has changed, and projections of future change. The IPCC issued its third assessment earlier this year. Among the most recent report's findings were that the levels of greenhouse gases in the atmosphere have risen, the temperature of the Earth's surface has grown warmer, sea level has risen and the oceans have also warmed, and some aspects of climate, such as global precipitation patterns, have changed. The IPCC based these findings both on direct observations of climate data and on such indirect observations of temperature as tree rings, corals, and ice cores. The IPCC also concluded that "there is new and stronger evidence that most of the warming observed over the last 50 years is attributable to human activities." The IPCC based this conclusion partly on results from global climate models and partly on the unique nature of the recent temperature rise when compared with new data showing that the climate has been relatively stable extending as far back as the past 1000 years. Finally, the IPCC projected that in the future greenhouse gases would continue to rise, accompanied by additional warming, sea level rise, and climate change. The group projected that by the end of 2100 the global average temperature of the Earth could rise by 1.5 to 5.8 degrees Celsius. The IPCC's "Summary for Policymakers" is attached. 4. THE RESPONSE TO THE IPCC Some have criticized the IPCC, charging that its "Summary for Policymakers" does not accurately reflect the underlying scientific report, having selectively left out information that undercuts the group's more worrisome climate predictions. Some disagree that climate change can be attributed to human activities at all, citing the many areas of uncertainty that remain important research topics such as the response of the oceans to rising temperatures, the effect of aerosols on cloud formation, and the feedback relationship between the climate and the biogeochemical cycles, such as the carbon and water cycles. Others have criticized the IPCC's reliance on computer simulations to forecast possible future climates and its use of so-called proxy data, such as tree rings, to give an accurate reflection of the temperature of past climates. Still others have disputed IPCC's finding that the temperature of the Earth has increased, pointing to satellite records collected since 1979 that show, if anything, a much smaller warming pattern.1 5. QUESTIONS TO THE WITNESSES Witnesses were asked to address the following questions (not every one was posed to each witness): • What evidence do we have that the Earth's climate is changing, and how reliable is that evidence? To what degree is climate change attributable to anthropogenic activities, what evidence supports this assertion, and how reliable is that evidence? • What factors limit our ability to detect, attribute, and understand current climate change and to project what future climate change may be? • How should the government prioritize its efforts to overcome these limiting factors, and what steps should the government take to overcome them? • What are the most important areas of climate science in which we must improve our understanding in order to detect and attribute climate change? 1 Last year, however, the National Academy of Sciences issued a report concluding that measurements taken at the Earth's surface do in fact show that the temperature of the surface of the Earth is rising, and that satellites, which measure the temperature of the lower to mid-troposphere (the layer of air up to 8 kilometers above the Earth), do not necessarily contradict those surface measurements. The Academy suggested that the actual layer of the troposphere measured by the satellites may be warming less than the surface of the planet, but recommended further research to better determine if this is in fact the case. |