The claim that Himalayan glaciers could disappear by 2035 appears to have originated in a 1999 interview with Indian glaciologist Syed Hasnain, published in New Scientist magazine.

The figure then surfaced in a 2005 report by environmental group WWF - a report that is cited in the IPCC's 2007 assessment, known as AR4.

An alternative genesis lies in the misreading of a 1996 study that gave the date as 2350.

AR 4 asserted: "Glaciers in the Himalayas are receding faster than in any other part of the world... the likelihood of them disappearing by the year 2035 and perhaps sooner is very high."

Dr van Ypersele said the episode meant that the panel's reviewing procedures would have to be tightened.