The House Science, Space, and Technology Committee held a hearing on May 29 to evaluate the process that the United Nations used in producing an Intergovernmental Panel on Climate Change (IPCC) Assessment Report. The Members of the committee were divided along party lines on issues including data analysis, data quality, transparency in author and study selection and whether the report provided biased information. The hearing preceded President Obama’s announcement of new greenhouse gas emission standards for power plants.
Chairman Lamar Smith (R-TX) began the hearing by discussing the economic impact of climate regulations. He was concerned that regulations will “hit workers and families hard but have no discernible impact on global temperature.” He was concerned about whether the report uses “inconsistent approaches to data quality, peer review, publication cut-off dates, and the cherry-picking of results.” Smith also noted that “U.S. contributions to global emissions are dwarfed by those of China, the world’s largest emitter of greenhouse gases.”
Ranking Member Eddie Bernice Johnson (D-TX) expressed her concern “that the real objective of this hearing is to try to undercut the IPCC and to cast doubt on the validity of climate change research.” She countered Smith’s remarks about the IPCC assessment stating that it “is unprecedented in its scope and inclusiveness” highlighting that the United States and 194 other nations used a “rigorous and open process that yields the most comprehensive and objective assessments of the scientific literature relevant to understanding climate change and its associated risks.” Regarding the Chairman’s remarks questioning the consensus of the scientific community on climate change, Ranking Member Johnson responded that “the IPCC process of developing a consensus arguably results in a summary with more conservative estimates than some scientists believe are warranted -- estimates that understate the impacts of climate change.”
Four witnesses testified. Richard Tol, Professor of Economics at the University of Sussex discussed his work as a member of Working Group II of the IPCC. He described the nomination process for researchers who participate in the Working Group and outlined his concerns with the Summary for Policy Makers section of the IPCC report. Tol supported recommendations made by an InterAcademy Council to improve the process for IPCC producing reports.
Michael Oppenheimer, Albert G. Milbank Professor of Geosciences and International Affairs in the Department of Geosciences at Princeton University outlined the IPCC structure and the development of assessments. He also described the aim for the Summary for Policy Makers section of the IPCC report as “policy relevant but not policy prescriptive.” Oppenheimer offered recommendation for changes to the IPCC procedure including “more frequent but briefer reports,” “increase transparency,” “make the intergovernmental part of the process more accessible,” and “experiment with more formal approaches to assessment.”
Daniel Botkin, Professor Emeritus in the Department of Ecology, Evolution, and Marine Biology at the University of California Santa Barbara outlined his concerns about what he thought were speculative and incomplete conclusions. He agreed “we have been living through a warming trend” but that the climate has always undergone changes. He thought that the report presents “extreme overemphasis on human induced global warming” and that “has taken our attention away from many environmental issues.”
Roger Pielke Sr., Senior Research Scientist at the Cooperative Institute for Research in Environmental Sciences and Professor Emeritus of Atmospheric Science at Colorado State University described some of the difficulty of predicting changes in atmospheric circulation using models. He noted the limitations of weather predictions using models and commented on whether the limitations are accurately available in peer reviewed literature. Pielke also noted that the predictions based on climate models may not “accurately quantify their reliability.” He offered a statement on “Human Impacts on Climate” as a part of his written testimony.
Following the witnesses opening statements, Smith asked Tol to discuss the impact of climate change on agriculture. Smith also asked Botkin to comment on whether extreme weather it is influenced by human-induced climate change. Botkin responded by arguing that one “cannot use short term weather changes as an index of climate change.” Smith was also interested to hear witnesses comment on the impact of cutting greenhouse gas emissions.
Ranking Member Johnson was interested in the review process for the report and the role of review editors. Oppenheimer commented that scientists have the option of holding up the completion of a chapter if they believe “not all comments have been adequately addressed.” She also wanted to hear about how authors are selected for the study.
Rep. Dana Rohrabacher (R-CA) commented on the tone of broader climate science discussions stating that there is a tendency for one side to dismiss the viewpoints of the other. Oppenheimer commented that scientists discuss the viewpoints of the whole community adding that “everyone should be listened to, but in the end governments have to act on evidence that the large majority of the scientific community believes while not dismissing the fringes.”
Rep. Suzanne Bonamici (D-OR) asked Oppenheimer to comment on the importance of and current state of climate models. Oppenheimer stated that even in the absence of climate models from previous centuries, there is evidence that the Earth’s climate is changing. He noted that scientists have a good understanding of paleoclimates and that “even without the evidence of models we know that large periods of warming have been associated with changes in levels of carbon dioxide.” Bonamici asked about the IPCC rules to address uncertainty and the potential risks of inaction. Oppenheimer responded by describing the long term effects of carbon dioxide in the atmosphere.
Rep. Randy Neugebauer (R-TX) asked about the timeframe of recorded data for climate models, noting that the proportion of climate history in which scientists have recorded data is small. He questioned the accuracy of climate models and what is a more accurate way to measure the impacts of climate change. Pielke commented that the levels of carbon dioxide and nitrogen are increasing but that the models are “misleading.”
Rep. Eric Swalwell (D-CA) asked Tol to describe how he was involved in the IPCC process and how he became a member of the working group. Swalwell also discussed carbon emissions and their impact on society.
The tone of the hearing highlighted the highly partisan debate about climate change. Members’ questions were representative of many issues commonly discussed in the broad national context and debates between Members and witnesses certainly reflected the tension surrounding this issue.