...Dr Pachauri blamed Dr Lal, saying his team had failed to apply IPCC procedures.

It was an accusation rebutted angrily by Dr Lal. 'We as authors followed them to the letter,' he said. 'Had we received information that undermined the claim, we would have included it.'

However, an analysis of those 500-plus formal review comments, to be published tomorrow by the Global Warming Policy Foundation (GWPF), the new body founded by former Chancellor Nigel Lawson, suggests that when reviewers did raise issues that called the claim into question, Dr Lal and his colleagues simply ignored them.>

For example, Hayley Fowler of Newcastle University, suggested that their draft did not mention that Himalayan glaciers in the Karakoram range are growing rapidly, citing a paper published in the influential journal Nature.

In their response, the IPCC authors said, bizarrely, that they were 'unable to get hold of the suggested references', but would 'consider' this in their final version. They failed to do so.

The Japanese government commented that the draft did not clarify what it meant by stating that the likelihood of the glaciers disappearing by 2035 was 'very high'. 'What is the confidence level?' it asked.

The authors' response said 'appropriate revisions and editing made'. But the final version was identical to their draft.

Last week, Professor Georg Kaser, a glacier expert from Austria, who was lead author of a different chapter in the IPCC report, said when he became aware of the 2035 claim a few months before the report was published, he wrote to Dr Lal, urging him to withdraw it as patently untrue.

Dr Lal claimed he never received this letter. 'He didn't contact me or any of the other authors of the chapter,' he said.

The damage to the IPCC's reputation, already tarnished by last year's 'Warmergate' leaked email scandal, is likely to be considerable.

Benny Peiser, the GWPF's director, said the affair suggested the IPCC review process was 'skewed by a bias towards alarmist assessments'.

Environmentalist Alton Byers said the panel's credibility had been damaged. 'They've done sloppy work,' he said. 'We need better research on the ground, not unreliable predictions derived from computer models.'