Climate Change

Myths vs. Facts: Denial of Petitions for Reconsideration of the Endangerment and Cause or Contribute Findings for Greenhouse Gases under Section 202(a) of the Clean Air Act

Myth: The University of East Anglia's Climatic Research Unit (CRU) emails prove that temperature data and trends were manipulated.

Fact: Not true. Petitioners say that emails disclosed from CRU provide evidence of a conspiracy to manipulate data. The media coverage after the emails were released was based on email statements quoted out of context and on unsubstantiated theories of conspiracy. The CRU emails do not show either that the science is flawed or that the scientific process has been compromised. EPA carefully reviewed the CRU emails and found no indication of improper data manipulation or misrepresentation of results.

Myth: The jury is still out on climate change and CRU emails undermine the credibility of climate change science overall.

Fact: Climate change is real and it is happening now. The U.S. Global Change Research Program, the National Academy of Sciences, and the Intergovernmental Panel on Climate Change (IPCC) have each independently concluded that warming of the climate system in recent decades is "unequivocal." This conclusion is not drawn from any one source of data but is based on multiple lines of evidence, including three worldwide temperature datasets showing nearly identical warming trends as well as numerous other independent indicators of global warming (e.g., rising sea levels, shrinking Arctic sea ice). Some people have "cherry-picked" a limited selection of CRU email statements to draw broad, unsubstantiated conclusions about the validity of all climate science.

Myth: The CRU emails and several errors found in the most recent IPCC report undermine the credibility of the IPCC Fourth Assessment Report.

Fact: The IPCC's primary conclusions are based on an assessment of thousands of individual studies and collective insights from the comprehensive climate science literature. Although many errors were alleged, EPA confirmed only two errors. The small number of documented errors are not central to IPCC's main conclusions or to EPA's Endangerment Finding. In a report of such magnitude, a few errors do not undermine the credibility of the entire work of the IPCC. The process used by the IPCC stands as one of the most comprehensive, rigorous, and transparent ever conducted on a complex set of scientific issues.

Myth: EPA misstepped when it did not do its own scientific analysis of climate change to inform the Endangerment Finding and instead relied on existing scientific assessments.

Fact: EPA relied on major scientific assessments, including reports from the U.S. Global Change Research Program, National Academy of Sciences, and IPCC, because they represent the best available information to determine the state of climate change science. These assessments are designed to address the breadth and scope of all published literature and undergo multiple levels of rigorous review. This approach ensures that EPA benefits from the depth and strength of thousands of climate scientists.

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