NASA Reaches for Muzzle as Renowned Climate Scientist Speaks Out

NOTE: The following is one of a series of case studies produced by the Union of Concerned Scientists' Scientific Integrity Program between 2004 and 2010 to document the abuses highlighted in our 2004 report, Scientific Integrity in Policy Making.


Dr. James E. Hansen, the top climate scientist at the National Aeronautics and Space Administration (NASA), believes that the world has little time to waste in reversing its current trend toward global warming. In late 2005, however, Dr. Hansen's ability to voice his concerns about global warming was severely compromised by NASA public affairs officials. After he called on the United States to reduce greenhouse gas emissions in a December 2005 lecture, Dr. Hansen found that NASA officials began reviewing and filtering public statements and press interviews in an effort to limit his ability (as well as that of other government scientists) to publicly express scientific opinions that clashed with the Bush administration’s views on global warming.

While Dr. Hansen's scientific standing is unquestionable—he was described by CBS' 60 Minutes as "arguably the world's leading researcher on global warming"¹—administration officials found some of his conclusions politically inconvenient. In a lecture at the December 2005 meeting of the American Geophysical Union, Dr. Hansen argued that the earth will become "a different planet" without U.S. leadership in cutting global greenhouse gas emissions.² This position conflicted with the Bush administration's policy of opposing mandatory reductions in greenhouse gas emissions. In January 2006, NASA publicized data showing that 2005 was likely the warmest year in over a century.³

In January 2006, Dr. Hansen told Andrew Revkin of the New York Times that he was warned of "dire consequences" if he continued to make similar statements. Revkin reported that George Deutsch, a public affairs officer appointed by the White House, denied a request from National Public Radio to interview Dr. Hansen, calling NPR the country's "most liberal" media outlet and arguing that his job was "to make the president look good."4 Mr. Deutsch later resigned after it was revealed that he had fabricated his own academic credentials.5

Arguing that his loyalty was to NASA's mission statement, which then read in part "to understand and protect our home planet," Dr. Hansen refused to be silenced. ''Communicating with the public seems to be essential,'' the Times reported him as saying, ''because public concern is probably the only thing capable of overcoming the special interests that have obfuscated the topic."6  

Dr. Hansen's public stand helped to bring about reforms of NASA's public relations policy. In February 2006, after the widely publicized allegations of censorship, NASA Administrator Michael Griffin issued an agency-wide statement clarifying that the role of public affairs officers was not "to alter, filter or adjust engineering or scientific material produced by NASA's technical staff."7  This statement was followed, on March 30, by an official new NASA media policy, which supports principles of openness.8

However in February 2006, the phrase "to understand and protect our home planet" was deleted from NASA's mission statement without any notification to agency scientists. The replacement mission statement, which reads "to pioneer the future in space exploration, scientific discovery and aeronautics research," represented the first time that knowledge of Earth was not explicitly stated as part of NASA's mission.9

Dr. Hansen pointed out that Bush administration attempts to control scientific information on climate change were not limited to NASA, and that colleagues at NOAA have told him that conditions there are, in general, much worse.10 Said Hansen, "In my thirty-some years of experience in government, I've never seen control to the degree that it's occurring now. I think that it's very harmful to the way that a democracy works. We need to inform the public if they are to make the right decisions and influence policy makers."11


1. “Rewriting the Science,” 60 Minutes, March 19, 2006, transcript accessed December 7, 2006.

2. James E. Hansen, “Is There Still Time to Avoid ‘Dangerous Anthropogenic Interference’ with Global Climate? A Tribute to Charles David Keeling,” December 6, 2005, talk at the American Geophysical Union meeting, accessed December 7, 2006.

3. NASA, “2005 Warmest Year in Over a Century,” January 24, 2006, accessed December 7, 2006.

4. Revkin, Andrew C. “Climate Expert Says NASA Tried to Silence Him.” New York Times, January 29, 2006, accessed December 7, 2006.

5.  Revkin, Andrew C. “A Young Bush Appointee Resigns His Post at NASA,” New York Times, February 8, 2006, accessed December 7, 2006.

6. Revkin, January 29, 2006.

7. Griffin, Michael “Statement on Scientific Openness,” February 4, 2006, National Aeronautics and Space Administration, accessed December 7, 2006.

8. “NASA Policy on the Release of Information to News and Information Media,” March 30, 2006, accessed December 7, 2006.

9. Revkin, Andrew C., “NASA’s Goals Delete Mention of Home Planet,” New York Times, July 22, 2006, accessed December 7, 2006.

10.  Farrell, Bryan, “Political Science,” The Nation, February 13, 2006, accessed December 7, 2006.

11. “A Conversation With Dr. James Hansen,” New York Times video interview, accessed December 7, 2006.

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