IPCC’s Fourth Assessment Report in 2007, which has been the main reference point for climate-change science, cited a 2005 World Wildlife Fund (WWF) report to say that the Himalayan glaciers would disappear entirely by 2035 — “perhaps sooner” — if current trends in global warming continued.

That WWF report itself was based on an interview of Syed Iqbal Hasnain, an Indian researcher honoured with Padma Shri last year, published in the New Scientist in 1999.

WWF today admitted that its 2005 report “contained erroneous information”. “Although scientists remain deeply concerned about glacier retreat in that region, this particular prediction has subsequently proved to be incorrect,” the WWF said in a statement.

There were reports that Hasnain — who is working with the Pachauri-led The Energy and Resources Institute (TERI) since last year — had himself admitted that the 2035 reference in his 1999 interview was nothing more than “speculation” but he was not available today for comment.

The IPCC is already under scrutiny following the emergence of some leaked emails of its scientists some months ago, the contents of which revealed attempts to exaggerate the scientific evidence on global warming. Pachauri himself has come in for criticism for using his position for commercial gains, allegations that he has denied.

But the latest episode is a shot in the arm for Environment Minister Jairam Ramesh who has been deeply suspicious of the “alarming” projections made in IPCC report on glacier melt and has insisted that many more studies required to be done to say anything with conclusive evidence.

In fact, just before the Copenhagen conference, his ministry came out with a “discussion paper,” authored by a former deputy head at the Geological Survey of India V K Raina, which made the same point.

“It is premature to make a statement that glaciers in the Himalayas are retreating abnormally because of global warming. A glacier is affected by a range of physical features and a complex interplay of climatic factors. It is, therefore, unlikely that the snout movement of any glacier can be claimed to be a result of periodic climate variation until many centuries of observations become available. While glacier movements are primarily due to climate and snowfall, snout movements appear to be peculiar to each particular glacier,” Raina had said in that report.

The revelations are an indictment of IPCC’s claims that all conclusions in its assessment reports are put through extremely vigorous peer review by scientists all over the world.

Pachauri said the IPCC would verify all the information and would come out with the facts in the next few days. “There is no doubt that the glaciers are retreating. What has come to be questioned is the 2035 date. We will find out the source of that number,” he said.

Murali Lal, one of the authors of the chapter on glaciers in the fourth assessment report, admitted that this particular finding did not get extensive peer review.

He said a couple of years before the fourth assessment report was published, the IPCC rules were changed to allow the authors to include “grey literature” while making their conclusions.

“Authors of the IPCC reports are mandated to go through all available literature, including some grey literature that has gone through limited peer review, while formulating their conclusions. WWF reports come under the definition of such grey literature,” he told The Indian Express.

Murari Lal lambasted Hasnain for making speculative statements. “Such scientists should be banned from getting government funding,” he said.