On Thursday May 30, the House Science Committee invited a panel of climate change researchers to discuss the United Nation’s Intergovernmental Panel on Climate Change (IPCC) reports, with Republicans citing concerns about inappropriate political influences and a lack of independent and dissenting voices in the process.
The panelists included Dr. Richard Tol, a professor of economics from the University of Sussex; Dr. Michael Oppenheimer, a professor of geosciences and international affairs at Princeton; Dr. Daniel Botkin, a professor emeritus of ecology at UC Santa Barbara; and Dr. Roger Pielke Sr., a researcher at the Cooperative Institute for Research in Environmental Sciences (CIRES). Tol participated in the production of the IPCC report but recently stepped down as lead author of a chapter on the economics of climate change, citing concerns over the exclusion of dissenting views. Oppenheimer was a lead author on the fourth IPCC report and is a coordinating lead author of the fifth report, and has long championed efforts to understand the impacts of global climate change. Botkin and Pielke were not involved as authors, but both expressed concerns with the report’s conclusions and review process.
Several of the committee members focused their questions on how the IPCC process could be improved, with Rep. Johnson (D-TX) inquiring about the consideration of minority views in the review/revision process and how the IPCC selects authors, Rep. Bonamici (D-WA) asking about the role uncertainty plays in how the report’s conclusions are decided on, and Rep. Schweikert (R-AZ) wanting to know how ‘noisy’ data is accounted for in the research used for the report. Oppenheimer defended the rigor of the IPCC’s methods resolving disagreements across working groups who are building scientific background for the report, saying that the open review process is “very painful” and that not addressing comments can hold up the publication of entire chapters. However, much of the rest of the hearing was devoted to discussing the reliability of models used to draw conclusions in the IPCC reports, with Reps. Rohrabacher (R-CA) and Broun (R-GA ) objecting vehemently to the idea of ‘settled science’ and expressing concerns that dissenting views were being quashed entirely.
Chairman Smith (R-TX) called both the IPCC reports and recently released National Climate Assessment overly alarmist and a clear cover for political agendas, citing a “serious concern” about the transparency of the IPCC process. All of the witnesses suggested that the process of review and comment involved in producing IPCC reports could be made clearer and that it was valuable to publish dissenting opinions, although Oppenheimer stood against the other witnesses in suggesting that the process actually produced overly conservative results rather than alarmist statements. Botkin repeatedly stressed his belief that current climate change is neither unusual nor the most pressing environmental issue policymakers should be addressing; Pielke chose to call into question whether IPCC climate models were adequately tested and decried any attempts at forecasting on multi-decadal timescales.
Democrats in general expressed their displeasure with the hearing, with Rep. Johnson (D-TX) saying in her opening statement that she was “concerned that the real objective of this hearing is to undercut science” and that she hoped the process hearing would be followed by one focusing on the science itself. Reps. Swalwell (D-CA) and Kennedy (D-MA) also went on the offensive; Swalwell pointed out that Tol was still chosen to be a lead author on the IPCC despite his “dissenting voice” and tried to get a waffling Pielke to answer a question about whether cutting carbon emissions was beneficial, while Kennedy needled Botkin about why he didn’t believe it was a priority to mitigate the effects of climate change.
The two-hour hearing ended with little concrete discussion about methods for improving the IPCC report process, although both Oppenheimer and Tol advocated for publishing reports more frequently and Oppenheimer suggested that the review process could benefit from more independent participants.