The 30-kilometre Gangotri glacier is steadily retreating (Image: Jesse Allen/Earth Observatory/Aster Science Team/NASA)

Glaciologists are this week arguing over how a highly contentious claim about the speed at which glaciers are melting came to be included in the latest report of the Intergovernmental Panel on Climate Change.

In 1999 New Scientist reported a comment by the leading Indian glaciologist Syed Hasnain, who said in an email interview with this author that all the glaciers in the central and eastern Himalayas could disappear by 2035.

Hasnain, of Jawaharlal Nehru University in Delhi, who was then chairman of the International Commission on Snow and Ice’s working group on Himalayan glaciology, has never repeated the prediction in a peer-reviewed journal. He now says the comment was “speculative”.


Despite the 10-year-old New Scientist report being the only source, the claim found its way into the IPCC fourth assessment report published in 2007. Moreover the claim was extrapolated to include all glaciers in the Himalayas.

High probability

Chapter 10 of the report says: “Glaciers in the Himalaya are receding faster than in any other part of the world.”

The inclusion of this statement has angered many glaciologists, who regard it as unjustified. Vijay Raina, a leading Indian glaciologist, wrote in a discussion paper published by the Indian government in November that there is no sign of “abnormal” retreat in Himalayan glaciers. India’s environment minister, Jairam Ramesh, accused the IPCC of being “alarmist”.

The IPCC’s chairman, Rajendra Pachauri, has hit back, denouncing the Indian government report as “voodoo science” lacking peer review. He adds that “we have a very clear idea of what is happening” in the Himalayas.

‘Disturbing’ prediction

The IPCC report sources the prediction to a document published by the environment group WWF in 2005; this document quotes the New Scientist article as its source. The WWF report describes the prediction as “disturbing”, without specifically endorsing it.

Nonetheless, the IPCC report goes further, concluding without citing further evidence that the prediction is “very likely” – a term that it says means a likelihood of greater than 90 per cent.

Graham Cogley, a geographer from Trent University in Peterborough, Ontario, Canada, says the 2035 date is extremely unlikely. “At current melting rates it might take up to 10 times longer,” he says.

Grey literature

However, the lead author of the IPCC chapter, Indian glaciologist Murari Lal, told New Scientist he “outright rejected” the notion that the IPCC was off the mark on Himalayan glaciers. “The IPCC authors did exactly what was expected from them,” he says.

“We relied rather heavily on grey [not peer-reviewed] literature, including the WWF report,” Lal says. “The error, if any, lies with Dr Hasnain’s assertion and not with the IPCC authors.”

But Hasnain rejects that. He blames the IPCC for misusing a remark he made to a journalist. “The magic number of 2035 has not [been] mentioned in any research papers written by me, as no peer-reviewed journal will accept speculative figures,” he told New Scientist.

“It is not proper for IPCC to include references from popular magazines or newspapers,” Hasnain adds.