copyright - New York TimesPoor old George. One week he tries to paint himself green, and manages to mention climate change for the first time in his State of the Union address.

The next week, his administration is accused of systemic tampering with the work of government climate scientists to eliminate politically inconvenient material about global warming.

At a hearing yesterday in Congress, scientists and advocacy groups described a campaign by the White House to remove references to global warming from scientific reports and limit public mention of the topic to avoid pressure on an administration opposed to mandatory controls on greenhouse gas emissions.

Yesterday’s hearings, overseen by the new Democratic chair of the House committee on oversight and government reform, Congressman Henry Waxman, follow years of complaints by scientists that the Bush administration was seeking to put its own spin on scientific research at government agencies. They also complain of a reduction in funding for climate research since the 1990s.

The committee was warned that the campaign by the Bush administration discouraged free academic inquiry. “If you know what you are writing has to go through a White House clearance before it is to be published, people start writing for the class,” said Rick Piltz, a former senior associate at the US Climate Change Science Programme. “An anticipatory kind of self-censorship sets in.”

“There were a very large number of edits that came at the 12th hour after all the earlier science people had signed off,” said Mr Piltz, who eventually resigned from his job because of such pressure. In one such case, a White House appointee, Phil Cooney, demanded 400 last-minute changes which significantly changed the meaning and tone of the report.

Cooney now works for Exxon Mobil, which says it all really.

Pity that George is refusing to cooperate with the inquiry.