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Climate change: is the US Congress bullying experts?

Climate chief Rajendra Pachauri responds to US demands for information.

Last week, US Congressman Joe Barton, head of the House of Representatives' energy and commerce committee, wrote to three leading climate researchers, the head of the National Science Foundation and Rajendra Pachauri, chairman of the Intergovernmental Panel on Climate Change (IPCC). Barton asked for extensive information about their careers, funding and research.

The letters focused on a 1998 finding by Michael Mann of the University of Virginia, Charlottesville, that has been dubbed the ‘hockey stick’ graph because of its shape. Mann's study created headlines around the world when it suggested that the twentieth century was the warmest of the past millennium, and the 1990s was the warmest decade. The finding is central to the IPCC's most recent assessment of climate change.

Scientists have called the aggressive tone of the letters disturbing and dangerous (see Climate of distrust). They have accused Barton of attempting to bully climate researchers with whom he does not agree. Nature asked Pachauri for his reaction, and found him undaunted.

What was your first thought when you read the letter?

I was very surprised. This is the first time I have received a letter of this nature.

Do you feel obliged to respond?

I will first consult my colleagues in the IPCC. Over the next days we will decide whether and how to react. We might not do anything at all.

What kind of information would you consider providing?

I would not hesitate, out of courtesy, to provide basic information about how the IPCC functions and about the manner in which we choose our authors. This is a well established and absolutely transparent process. The only criteria are scientific merit and integrity. I don't think we need to provide more information than that. I guess it will be sufficient to mention the processes and procedures of the IPCC and to refer the committee to our website.

Climate chief Rajendra Pachauri was surprised to receive a letter from a US House committee. Credit: N. PISARENKO/AP

Is it appropriate for a US House committee to make these demands?

Yes, we're living in a democracy. But I don't know how anyone outside the scientific community would be able to make use of the information — it would take weeks or months to process all the information that is requested.

Was it unwise to give Mann's ‘hockey stick’ so much prominence in the IPCC's summary for policy-makers?

No. It is no exaggeration and it doesn't contradict the rest of the IPCC assessment. Of course you can always argue about details. But we assess all the available literature, and we found the hockey stick was consistent with that.

Do you think individual scientists such as Mann need to be better protected against pressure from politicians?

The IPCC cannot do that. But Mann and his colleagues are distinguished, independent scientists who are able to explain their points of view. These letters don't curb their independence. And the recipients don't need to provide all the information requested. By and large, I don't regard this as a threat to the scientific community.

Interview by Quirin Schiermeier

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Climate change: is the US Congress bullying experts?. Nature 436, 7 (2005).

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