Rajendra Pachauri, head of the Intergovernmental Panel on Climate Change (IPCC), on Wednesday admitted that its credibility was damaged by the controversy over its 2007 report, which falsely claimed that the Himalayan glaciers could melt away by 2035.

But he refused to apologise, saying he was not personally responsible for the mistake. He insisted that it was an “isolated” mistake and “totally out of character” with the panel’s rigorous standards.

“You can’t expect me to be personally responsible for every word in a 3,000 page report,” he said, pointing out that the IPCC had expressed regret over the mistake and a personal apology would be a “populist” step.

“I don’t do many populist things, that’s why I’m so unpopular with a certain section of society,” he told The Guardian.

Acknowledging that the error had undermined the IPCC’s reputation, Dr. Pachauri said: “I think this [glacier] mistake has certainly cost us dear, there’s no question about it. Everybody thought that what the IPCC brought out was the gold standard and nothing could go wrong.”

He, however, insisted that the “larger picture” in terms of the IPCC’s claims about climate change was “solid.”

“Look at the larger picture, don’t get blinded by this one mistake,” he said adding: “The larger picture is solid, it’s convincing and it’s extremely important. How can we lose sight of what climate change is going to do to this planet? What it’s already doing to this planet.”

Dr. Pachauri said that for its next report on global warming, the IPCC would make sure that its authors and reviewers checked the accuracy of their sources. Defending the IPCC’s use of “grey literature”— information which came from outside peer-reviewed journals — he said: “Our procedures are very clear on the use of grey literature. Whenever an author uses grey literature they need to double check that the source of information is authentic and defensible. Apparently in this [Himalayan glacier] case there has been a failure because authors did not follow the procedure required.”

He dismissed reports about his personal “lavish” life-style as a “bunch of lies”.