It urged the US government to reject the treaty and said: "The proposed limits on greenhouse gases would harm the environment, hinder the advance of science and technology, and damage the health and welfare of mankind."

It added: "There is no convincing scientific evidence that human release of ... greenhouse gases is causing or will, in the forseeable future, cause catastrophic heating of the Earth’s atmosphere and disruption of the Earth’s climate. Moreover, there is substantial scientific evidence that increases in atmospheric carbon dioxide produce many beneficial effects upon the natural plant and animal environments."

The petition was reissued last year by the Oregon Institute of Science and Medicine, an independent research group, partly in response to Al Gore’s film on climate change, An Inconvenient Truth.

Its president, Arthur Robinson, said: "If this many American scientists will sign this petition, you certainly can’t continue to contend that there is a consensus on this subject."

One of the signatories, Frank Nuttall, a professor of medicine, said he believed the Earth was becoming warmer, despite his signature.

"This issue is whether the major reason for this is from human activities. I consider that inconclusive at the present time," he said.

A spokesman for the Royal Society, Britain’s national academy of science, said: “The world’s leading climate experts at the Nobel Prize-winning Intergovernmental Panel on Climate Change believe that it is greater than 90 per cent likely that human activity is responsible for most of the observed warming in recent decades. That is a pretty strong consensus.

“The science has come a long way since 1998 and it continues to point in one direction - the need to reduce greenhouse gas emissions to avert dangerous climate change.”