What has now come to light, however, is that the scientist from whom this claim originated, Dr Syed Hasnain, has for the past two years been working as a senior employee of The Energy and Resources Institute (TERI), the Delhi-based company of which Dr Pachauri is director-general. Furthermore, the claim – now disowned by Dr Pachauri as chairman of the IPCC – has helped TERI to win a substantial share of a $500,000 grant from one of America's leading charities, along with a share in a three million euro research study funded by the EU.
To understand why the future of Himalayan glaciers should arouse such peculiar passion, one must recall why they have long been a central icon in global warming campaigners' propaganda. Everything that polar bears have been to the West, the ice of the Himalayas has been – and more – to the East. This is because, as Mr Gore emphasised in his Oscar-winning film An Inconvenient Truth, the vast Himalayan ice sheet feeds seven of the world's major river systems, thus helping to provide water to 40 per cent of the world's population.
The IPCC's shock prediction in its 2007 report that the likelihood of the glaciers "disappearing by the year 2035 and perhaps sooner is very high" thus had huge impact in India and other Asian countries, and it is precisely this statement that the IPCC has now been forced to disown.
Since this first came to light, many journalists have tried to track down how such an embarrassing error came to be included in the IPCC report, which is still widely touted as the most authoritative single document on global warming. The only researcher who has dug out the full story, however, is my colleague Dr Richard North, who on successive days last week featured prominently on India's leading English-language TV news channel discussing the issue with the two scientists at the heart of the row, Dr Hasnain and Dr Raina.
Until now it has been generally reported that the IPCC based its offending paragraph on an interview Dr Hasnain gave to the New Scientist in June 1999. This was a time when global warming researchers were busy making ever more extravagant claims in the run-up to the IPCC's 2001 report. It was in that year that Dr Michael Mann in America launched on the world his famous "hockey stick" graph, purporting to show that temperatures had risen faster in the late 20th century than ever before in the Earth's history. The graph was made the centrepiece of the IPCC's 2001 report, though it has since been comprehensively discredited.
In fact Dr Hasnain had first made his own controversial claim two months earlier, in a much longer interview with an Indian environmental magazine, Down to Earth, in April 1999. It was the wording of this interview which the IPCC was to quote almost exactly in its 2007 report.
Clearly the IPCC was aware that to cite a little Indian magazine as the reference for such a startling prediction would hardly seem sound scientific practice. But it discovered that Dr Hasnain's slightly later interview with New Scientist had been quoted in a 2005 report by the environmental campaigning group WWF. So it was this, rather oddly, which the IPCC cited as its authority – even though the words it quoted were taken directly from the earlier interview.
But even before the 2007 report was published, it now emerges, the offending claim was challenged, not least by a leading Austrian glaciologist, Dr Georg Kaser, a lead author on the 2007 report. He described Dr Hasnain's prediction of glaciers disappearing by 2035 as "so wrong that it is not even worth dismissing".
The year after the IPCC report was published, however, Dr Hasnain was recruited by Dr Pachauri to head a new glaciology unit at TERI. In a matter of months, TERI was given a share in a $500,000 dollar study of melting Himalayan glaciers funded by a US charity, the Carnegie Corporation. It is clear from Carnegie's database that a key part in winning this contract was played by Dr Hasnain's claim that most glaciers in the region "will vanish within 40 years as a result of global warming".
In May 2009 TERI was also given a share in a three million euro project funded by the EU. Citing the WWF's 2005 report, the EU set up its "High Noon" project to study the impact of melting Himalayan glaciers. It was particularly keen to foster alarm over the Himalayas as a means to win Indian support for action on climate change at last year's Copenhagen conference.
Last November, however, Dr Raina, the country's most senior glaciologist, published a report for the Indian government showing that the rate of retreat of Himalayan glaciers had not increased in the past 50 years and that the IPCC's predictions were recklessly alarmist. This provoked the furious reaction from Dr Pachauri that tarred Dr Raina's report as "arrogant" and "voodoo science". Only weeks later came the devastating revelation that the IPCC's own prediction had no scientific foundation.
Dr Pachauri's first response to these revelations was to claim that he had "absolutely no responsibility" for the blunder, that it was "the work of independent authors – they're responsible". But the IPCC's error was so blatant that last week Pachauri and other senior officials had to put out their remarkable statement, admitting that it had been due to a serious system failure.
Even more damaging now, however, will be the revelation that the source of that offending prediction was the man whom Dr Pachauri himself has been employing for two years as the head of his glaciology unit at TERI – and that TERI has won a share in two major research contracts based on a scare over the melting of Himalayan glaciers prominently promoted by the IPCC, using words drawn directly from Dr Hasnain.
This is by no means the first time that the procedures used by the IPCC to compile its 2007 report – the most alarmist so far – have been subjected to trenchant questioning. But no one, it seems, is more embarrassed by "Glaciergate" than Dr Pachauri himself, whose expanding worldwide business connections since he became chairman of the IPCC have recently been the subject of articles in these pages by Dr North and myself.
In view of the IPCC's statement last week, the very evident anger of the Indian government at his dismissal of its expert's report and now the revelation of the part played in this fiasco by a senior member of his own TERI staff, it appears that what we may soon be looking at here is not just "Glaciergate" but "Pachaurigate".