Witnesses All Agree: Climate Science “Not Settled”

May 29, 2014

Washington, D.C. – The Committee on Science, Space, and Technology today held a hearing to evaluate the process behind the United Nations (UN) Intergovernmental Panel on Climate Change’s (IPCC) Fifth Assessment Report. A distinguished panel of experts involved in the IPCC and National Climate Assessment process unanimously stated that the science of climate change is “not settled,” as the President and others often state unequivocally.

Chairman Lamar Smith: “Both the IPCC and the White House’s documents appear to be designed to spread fear and alarm and provide cover for previously determined government policies. The President plans to announce on Monday his most costly climate regulations – new climate standards for power plants. Following the 2007 assessment, key IPCC claims about the melting of Himalayan glaciers, the decline of crop yields, and the effects of sea level rise were found to be completely erroneous and derived from non-peer reviewed sources. The Obama administration should stop trying to scare Americans and then impose costly, unnecessary regulations on them. When assessing climate change, we need to make sure that findings are driven by science, not an alarmist, partisan agenda.”

The President and others often claim that 97 percent of scientists believe that global warming is primarily driven by human activity.  However, the study they cite has been debunked. When asked today whether the science of climate change is settled or if uncertainties remain, witnesses unanimously said that the science is not settled. They also discussed concerns with the IPCC process, including lack of transparency in author and study selection, and inconsistent approaches to data quality, peer review, publication cut-off dates, and the cherry-picking of results.

Both the IPCC and White House National Climate Assessment reports acknowledge that the U.S. has achieved dramatic reductions in emissions. The National Climate Assessment recognized, for example, that “U.S. CO2 emissions from energy use…declined by around 9% between 2008 and 2012….” Further, U.S. contributions to global emissions are dwarfed by those of China, which is the world’s largest emitter of greenhouse gases. 

Witnesses also discussed how the Obama administration’s regulatory agenda will negatively impact the economy with little to no impact on global temperature.  One analysis used IPCC assumptions and found that if the U.S. stopped all carbon dioxide emissions immediately, the ultimate impact on global temperature would only be 0.08 degrees Celsius by 2050.

The following witnesses testified today before the Committee:

Dr. Richard S.J. Tol, Professor of Economics, University of Sussex

Dr. Michael Oppenheimer, Albert G. Milbank Professor of Geosciences and International Affairs, Department of Geosciences, Princeton University

Dr. Daniel Botkin, Professor Emeritus, Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara

Dr. Roger Pielke Sr., Senior Research Scientist, Cooperative Institute for Research in Environmental Sciences, and Professor Emeritus of Atmospheric Science, Colorado State University

For additional information about the hearing, including witness testimony, please visit the Science, Space, and Technology Committee website.