The House Committee on Science, Space, and Technology held a hearing on the process used to compile the most recent United Nations Intergovernmental Panel on Climate Change (IPCC) report. The hearing focused on the IPCC Working Group II report, a subset of the 2014 report, which addresses the impacts of climate change.

Witnesses discussed possible bias in the process used to choose scientists to review the report and potential lack of rigor in the review process.­ Richard Tol, Professor of Economics at the University of Sussex, believes that scientists who disagreed with parts of the report were marginalized. He also believes that the IPCC Summary for Policymakers contains inaccuracies, and expressed doubt that the summary was indeed policy neutral and faithful to the science. Michael Oppenheimer, Professor of Geosciences and International Affairs at Princeton University disagreed, arguing that two rounds of peer editing ensure the document’s accuracy and relevance.

Both witnesses agreed, however, that the IPCC report would benefit from more transparency and a change in format to shorter documents released more frequently. Dr. Oppenheimer recommended publishing a record of divergent viewpoints along with the IPCC report.

Witnesses and members of Congress discussed whether there is a scientific consensus regarding climate change. Ranking member Eddie Bernice Johnson (D-TX) remarked that clear consensus exists that humans impact climate change, a view echoed by Dr. Oppenheimer and Dr. Tol. Representative Paul Broun (R-GA) and others took issue with the concept of “settled science,” saying that rigorous science requires healthy debate. Witness Daniel Botkin, Professor Emeritus in the Department of Ecology, Evolution, and Marine Biology at the University of California Santa Barbara, argued warming is neither unusual nor irreversible and Roger Pielke Sr., Professor Emeritus of Atmospheric Science at Colorado State University, warned that the models being used to predict regional weather events and form policy are unreliable.

Sources: Intergovernmental Panel on Climate Change, House Committee on Science, Space, and Technology