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.
The statement got into the IPCC report by passing all the usual vetting procedures in that world.
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."
So this is the correction, restoring IPCC to scrupulous scientific standards: ask the guy who gave you bogus information if he takes it back; if he does [apparently, regardless of what experts on glaciers say] then and only then will it be removed. Keep going back to the same corrupt sources--a mere handful of people, including, it turns out, someone who churned out a brochure for the WWF using the bogus claim.
Is Murari Lal, somehow responsible for a chapter on glaciers, an expert on glaciers? Er, no.
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.
When you question the IPCC you're told: but they're real scientists, peer reviewed blah blah. Of course they're telling the truth as they know it, based on research; how could you question that? But this is one clear case where they sententiously repeated what is a piece of shoddy journalism at best. The individuals who ensured it saw the light of day were second- and third-rate popularizers of science at best, propagandists for a certain point of view at worst. And it got into the IPCC report:
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.