EPA will not reverse CO2 “endangerment” finding, denies petitions

Posted on July 29, 2010


The following is the fact sheet released July 29th by the Environment Protection Agency upholding its finding that CO2 is a gas dangerous to the public health.  Attacks on EPA’s finding were based on the so-called “climategate” e-mails and various right-wing conspiracy theories.

Fact Sheet:  EPA’s Denial of Petitions to Reconsider EPA’s Greenhouse Gas Endangerment Findings



After several months of careful review, on July 29, 2010, EPA denied 10 petitions to reconsider the 2009 Endangerment and Cause or Contribute Findings for Greenhouse Gases under Section 202(a) of the Clean Air Act (the “Endangerment Finding”).

With this decision, EPA decided there was no scientific or other basis to change its 2009 finding that climate change caused by emissions of greenhouse gases threatens public health and the environment.  The science remains strong and has been reinforced by recent additional major science assessments and individual studies.

The petitioners argued that the science underlying EPA’s determination is flawed or that the review process has been corrupted.  EPA finds that the evidence provided does not support these claims.

EPA received petitions from Coalition for Responsible Regulation, Commonwealth of Virginia, Competitive Enterprise Institute, Ohio Coal Association, Pacific Legal Foundation, Peabody Energy Company, Southeastern Legal Foundation, State of Texas, U.S. Chamber of Commerce, and one private citizen.


The primary information provided by the petitioners to back their arguments includes a set of disclosed private e-mail communications among several scientists associated with the temperature record from the Climatic Research Unit (CRU) at the University of East Anglia in the United Kingdom; a small number of actual or alleged errors in the voluminous 3,000-page Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report; and a limited number of new studies that have been published in the literature.

Climate Change Science and Data

Petitioners questioned the reliability of the global temperature record and the finding that observed recent warming is unusual and based on increasing levels of greenhouse gases.  However, three global temperature records—including CRU’s—indicate increasing temperatures, and there are other lines of evidence, such as rising sea levels, linking recent global warming to human activities.  Petitioners’ criticisms of the CRU record are unfounded.

Petitioners asserted that some scientists’ discussion in private CRU e-mails undermines the credibility of the temperature record.  After careful review of all of the e-mail statements (not just the ones highlighted by petitioners), EPA finds nothing in the e-mails that calls into question the validity of the data or of CRU’s analysis.  To the contrary, analysis of the e-mails shows scientists working through the problems involved in compiling large datasets.

Petitioners asserted that warming has slowed or stopped over the last decade, contrary to scientists’ expectations, and in spite of increasing greenhouse gases in the atmosphere.  In reality, the last decade was warmer than the previous decade, and warming has not stopped.  Climate change is a long-term phenomenon, unlike day-to-day variations in weather.  Thus, climate change trends should be discussed over the long term, as opposed to on a year-by-year basis.

Petitioners also challenged the temperature records of the National Oceanic and Atmospheric Administration (NOAA) and the National Aeronautics and Space Administration (NASA).  The truth is that NOAA’s and NASA’s data are fully transparent, accessible, and peer reviewed.  EPA’s confidence in the quality of the NOAA, NASA, and CRU temperature records is further strengthened by the fact that all three datasets show similar results despite the fact that they are prepared independently and with different methods.

Petitioners claim that new studies not previously considered contradict key conclusions in the Endangerment Finding.  EPA examined each of these new studies and documented that they neither undermine the key scientific findings nor change the scientific basis for the Endangerment Finding.

Use of IPCC Information and EPA’s Approach to Developing the Findings

Petitioners claimed that recently found and alleged errors in IPCC’s Fourth Assessment Report undermine IPCC’s credibility, and by extension, EPA’s use of the report as a reference document.  EPA has carefully reviewed each of the alleged errors.  Collectively, they are minor and have no bearing on the Endangerment Finding, are not relied on by EPA to support the Finding, and most are not even errors.  The two factual errors in a document the size of IPCC’s 3,000-page Fourth Assessment Report do not substantiate petitioners’ claim that IPCC science, as a whole, is not credible.

Petitioners asserted that the IPCC has a policy agenda and is not an objective scientific body, but this assertion is not backed up by credible evidence.  The Agency has carefully examined the extensive process used by IPCC as well as the U.S. government’s approach to approving IPCC documents, and found that they are well grounded and based on science rather than policy considerations.

Petitioners claimed that the scientific assessments of the U.S. Global Change Research Program and the National Academy of Sciences are not separate and independent assessments from IPCC.  This is not correct.  Each of these organizations is separately administered and relies on its own scientific processes and collaborating scientists.  That similar and consistent conclusions are reached by each body does not substantiate the petitioners’ claim. To the contrary, when independent institutions reach similar findings, it strengthens confidence in those findings.

Petitioners suggested that EPA’s process to develop scientific support for the Findings was not rigorous.  This is not the case.  EPA thoroughly reviewed the scientific literature and summarized it in the Technical Support Document (http://www.epa.gov/climatechange/endangerment.html#tsd).  EPA invited public comment on both the Technical Support Document and the proposed Endangerment Findings.  Before finalizing the Findings, EPA carefully and comprehensively responded to all comments, reviewed additional science, and considered issues raised by commenters.  EPA’s detailed responses are provided in a comprehensive, 11-volume Response to Comments document (http://www.epa.gov/climatechange/endangerment.html#comments).

Petitioners asserted that improper data sharing, peer review, and editorial practices biased the underlying scientific literature used by the major assessments.  Petitioners’ assertions of an extensive, concerted effort to manipulate peer-reviewed literature are unsupported.  The CRU e-mails, for example, show a small group of scientists privately discussing their scientific views of a handful of papers.  The petitioners raised concerns that certain research papers were kept out of the IPCC Fourth Assessment Report, but these concerns are unfounded; the papers did appear in the IPCC assessment.

Results of Recent and External Inquiries Into the CRU E-mails

Several independent committees have examined many of the same allegations brought forward by the petitioners as a result of the disclosure of the private CRU e-mails.  Their conclusions are consistent with EPA’s review and analysis.  The independent inquiries have found no evidence of intentional data manipulation or any lack of scientific integrity and rigor on the part of the climate researchers associated with the e-mails.  A list of the inquiries completed to date is available here:


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