"The whole tissue of argument that makes climate change into the greatest problem facing humanity is based on a long series of improbabilities," he said.

The Competitive Enterprise Institute has received $1.5m from Esso since 1998 (see www.exxonsecrets.org). Esso is the world's biggest oil company and funds a series of front groups that spread doubt about climate science and advise Republican politicians on global warming. The CEI is one of the biggest of these groups.

Mr Ebell claimed that Britain's chief scientist, Sir David King, "knows nothing about climate science." He said Sir David is an "alarmist" who is "promoting this ridiculous claim."

Greenpeace campaigner Anita Goldsmith said:

"It is terrifying that this man is advising the White House on the gravest threat this planet faces. It just goes to show what was at stake on Tuesday, and what was lost. Mr Ebell might as well be claiming that Elvis is alive and well and living in Croydon or that the Earth is flat. The world's best climate scientists agree the threat is real and growing. Mr Ebell is a mouthpiece for Esso and should not be taken seriously, but his views are policy in the oval office."

Liberal Democrat environment spokesman Norman Baker is tabling an Early Day Motion in parliament, condemning Mr Ebell for his comments (see below).

Mr Ebell did not accept the suggestion that the world's temperature has risen more quickly than at any time in recorded history. Asked whether European countries were 'not out to save the world, but out to get America,' Mr Ebell replied, 'I think that is pretty obviously and explicitly the programme of the EU Commission, yes.'

Anita Goldsmith added: "This kind of idiocy would be a mere distraction if it were not for the fact that Bush believes this nonsense. If Tony Blair really regards global warming as a huge threat, like he says he does, he needs to give the President a dose of straight talking the next time they meet."

For more call Greenpeace on 0207 865 8255.

Norman Baker EDM reads:

THE US GOVERNMENT AND CLIMATE CHANGE - This House deplores in the strongest possible terms the unfounded and insulting criticism of Sir David King, the government's Chief Scientist, by Myron Ebell, advisor to US President George W Bush on climate change; notes that Mr Ebell is a director of global warming at the Competitive Enterprise Institute in Washington, an organisation bankrolled by, amongst others, ExxonMobil and the American Petroleum Institute; fervently hopes that Mr Ebell's comments do not represent official US policy; congratulates Sir David King on the work he has done to raise the issue of global warming both at home and abroad; believes that the planet cannot afford another four years of inaction and denial from the US administration; and calls on the Prime Minister and Foreign Secretary to do everything possible to get President Bush to accept the need to take climate change seriously and ensure the US plays its part internationally in reducing greenhouse gas emissions.