A WARNING that climate change will melt most of the Himalayan glaciers by 2035 is likely to be retracted after a series of scientific blunders by the United Nations body that issued it.
Two years ago the Intergovernmental Panel on Climate Change (IPCC) issued a benchmark report that was claimed to incorporate the latest and most detailed research into the impact of global warming. A central claim was the world's glaciers were melting so fast that those in the Himalayas could vanish by 2035.
In the past few days the scientists behind the warning have admitted that it was based on a news story in the New Scientist, a popular science journal, published eight years before the IPCC's 2007 report.
It has also emerged that the New Scientist report was itself based on a short telephone interview with Syed Hasnain, a little-known Indian scientist then based at Jawaharlal Nehru University in Delhi.
Hasnain has since admitted that the claim was "speculation" and was not supported by any formal research. If confirmed it would be one of the most serious failures yet seen in climate research. The IPCC was set up precisely to ensure that world leaders had the best possible scientific advice on climate change.
Professor Murari Lal, who oversaw the chapter on glaciers in the IPCC report, said he would recommend that the claim about glaciers be dropped: "If Hasnain says officially that he never asserted this, or that it is a wrong presumption, than I will recommend that the assertion about Himalayan glaciers be removed from future IPCC assessments."
The IPCC's reliance on Hasnain's 1999 interview has been highlighted by Fred Pearce, the journalist who carried out the original interview for the New Scientist. Pearce said he rang Hasnain in India in 1999 after spotting his claims in an Indian magazine. Pearce said: "Hasnain told me then that he was bringing a report containing those numbers to Britain. The report had not been peer reviewed or formally published in a scientific journal and it had no formal status so I reported his work on that basis.
"Since then I have obtained a copy and it does not say what Hasnain said. In other words it does not mention 2035 as a date by which any Himalayan glaciers will melt. However, he did make clear that his comments related only to part of the Himalayan glaciers. not the whole massif."
The New Scientist report was apparently forgotten until 2005 when WWF cited it in a report called An Overview of Glaciers, Glacier Retreat, and Subsequent Impacts in Nepal, India and China. The report credited Hasnain's 1999 interview with the New Scientist. But it was a campaigning report rather than an academic paper so it was not subjected to any formal scientific review. Despite this it rapidly became a key source for the IPCC when Lal and his colleagues came to write the section on the Himalayas.
When finally published, the IPCC report did give its source as the WWF study but went further, suggesting the likelihood of the glaciers melting was "very high". The IPCC defines this as having a probability of greater than 90%.
The report read: "Glaciers in the Himalaya are receding faster than in any other part of the world and, if the present rate continues, the likelihood of them disappearing by the year 2035 and perhaps sooner is very high if the Earth keeps warming at the current rate."
However, glaciologists find such figures inherently ludicrous, pointing out that most Himalayan glaciers are hundreds of feet thick and could not melt fast enough to vanish by 2035 unless there was a huge global temperature rise. The maximum rate of decline in thickness seen in glaciers at the moment is 2-3 feet a year and most are far lower.
Professor Julian Dowdeswell, director of the Scott Polar Research Institute at Cambridge University, said: "Even a small glacier such as the Dokriani glacier is up to 120 metres [394ft] thick. A big one would be several hundred metres thick and tens of kilometres long. The average is 300 metres thick so to melt one even at 5 metres a year would take 60 years. That is a lot faster than anything we are seeing now so the idea of losing it all by 2035 is unrealistically high.”
Some scientists have questioned how the IPCC could have allowed such a mistake into print. Perhaps the most likely reason was lack of expertise. Lal himself admits he knows little about glaciers. "I am not an expert on glaciers.and I have not visited the region so I have to rely on credible published research. The comments in the WWF report were made by a respected Indian scientist and it was reasonable to assume he knew what he was talking about," he said.
Rajendra Pachauri, the IPCC chairman, has previously dismissed criticism of the Himalayas claim as "voodoo science".
Last week the IPCC refused to comment so it has yet to explain how someone who admits to little expertise on glaciers was overseeing such a report. Perhaps its one consolation is that the blunder was spotted by climate scientists who quickly made it public.
The lead role in that process was played by Graham Cogley, a geographer from Trent University in Ontario, Canada, who had long been unhappy with the IPCC's finding.
He traced the IPCC claim back to the New Scientist and then contacted Pearce. Pearce then re-interviewed Hasnain, who confirmed that his 1999 comments had been "speculative", and published the update in the New Scientist.
Cogley said: "The reality, that the glaciers are wasting away, is bad enough. But they are not wasting away at the rate suggested by this speculative remark and the IPCC report. The problem is that nobody who studied this material bothered chasing the trail back to the original point when the claim first arose. It is ultimately a trail that leads back to a magazine article and that is not the sort of thing you want to end up in an IPCC report.”
Pearce said the IPCC's reliance on the WWF was "immensely lazy" and the organisation need to explain itself or back up its prediction with another scientific source. Hasnain could not be reached for comment.
The revelation is the latest crack to appear in the scientific concensus over climate change. It follows the so-called climate-gate scandal, where British scientists apparently tried to prevent other researchers from accessing key date. Last week another row broke out when the Met Office criticised suggestions that sea levels were likely to rise 1.9m by 2100, suggesting much lower increases were likely.