Washington DC

A prominent climate-change scientist has resigned from a US government panel, saying that colleagues tried to suppress his views.

Roger Pielke claims his views were edited out.

Roger Pielke, of Colorado State University in Fort Collins, stepped down from the US Climate Change Science Program (CCSP) on 13 August. He says he quit in part because other panel members were trying to rewrite a report chapter he was charged with overseeing. “I was being prevented from including my views,” he says.

Pielke is well known for his stance that other factors as well as carbon dioxide emissions cause climate change. The report is on temperature trends in the lower atmosphere, the first of 21 overviews commissioned by the CCSP. The group was set up by President George W. Bush to provide comprehensive reports on climate-change science for policy-makers.

Last month, some of the panel published papers in Science previewing parts of the report (see Nature 436, 896; 2005). The three papers suggest that observational problems are to blame for inconsistent measurements of atmospheric warming.

Pielke doesn't disagree with the published findings, but says that they narrow the remit of the report too much. “The CCSP charge was much broader than these three papers,” he contends. The chapter was edited to bolster this narrowed view, he says.

Thomas Karl, who oversees the 22-member panel, admits that Pielke's chapter was edited. But he plays down the changes: “The new version was based on what had already been done — the changes were just an effort to push the process forward.”

Pielke's departure is “unfortunate”, says outgoing CCSP director James Mahoney, but his views will still be partly expressed in the final version. Pielke plans to submit detailed points during a public-comment period after the report is released later this autumn.

The resignation could have adverse effects, says John Holdren, an environmental-policy expert at Harvard University. “On a politically controversial issue like climate change, each little hiccough makes people wonder whether everything is in doubt,” Holdren warns. “That perception can only be offset by a chorus of scientific voices saying that the findings are robust.”