In what may cause fresh embarrassment to the Intergovernmental Panel on Climate Change (IPCC), it has emerged that its warning about ice disappearing from the world’s mountain tops was based on a student’s thesis and an article published in a mountaineering magazine.

Earlier, the IPCC had to issue a humiliating apology over its inaccurate claim that global warming will melt most of the Himalayan glaciers by 2035, saying it was based on a “speculative” article published in New Scientist.

In its recent report, IPCC stated that observed reductions in mountain ice in the Andes, Alps and Africa was being caused by global warming, citing two papers as the source of the information.

However, it has emerged that one of the sources quoted was a feature article published in a popular magazine for climbers which was based on anecdotal evidence from mountaineers about the changes they were witnessing on the mountainsides around them, The Telegraph reports.

The other was a dissertation written by a geography student, studying for the equivalent of a master’s degree, at the University of Berne in Switzerland that quoted interviews with mountain guides in the Alps.

After the surfacing of the fact that IPCC has been using unsubstantiated claims and sources for its warnings, sceptics have cast doubt over the validity of the IPCC and have called for the panel to be disbanded.

“These are essentially a collection of anecdotes. Why did they do this? It is quite astounding. Although there have probably been no policy decisions made on the basis of this, it is illustrative of how sloppy Working Group Two has been,” Professor Richard Tol, one of the report’s authors who is based at the Economic and Social Research Institute in Dublin, said.

“There is no way current climbers and mountain guides can give anecdotal evidence back to the 1900s, so what they claim is complete nonsense,” he added.

However, scientists from around the world leapt to the defence of the IPCC, insisting that despite the errors, the majority of the science presented in the IPCC report is sound and its conclusions are unaffected.

British Climate Secretary Ed Miliband on January 31 came out in strong support of the R K Pachauri led UN panel, slamming the “siren voices” gunning for the panel over allegations of exaggeration of global warming claims.

Extending support to the IPCC, Miliband said the effects of concentration of carbon dioxide in the atmosphere, which is at highest levels in 6,000 years, were all too well known and that “we know there are observed increases in temperatures and observed effects that point to the existence of human-made climate change”.

“Mistakes and attempts to hide contradictory data had to be seen in the light of the thousands of pages of evidence in the IPCC’s four-volume report in 2007,” he said referring to the IPCC report that has been surrounded by controversies.

“It’s right that there’s rigour applied to all the reports about climate change, but I think it would be wrong that when a mistake is made it’s somehow used to undermine the overwhelming picture that’s there,” he told the Observer.

The most recent accusation against the panel’s work is that its chairman, Rajendra Pachauri, may have known before the Copenhagen summit that its assessment report had seriously exaggerated the rate of melting of the Himalayan glaciers.

However, Miliband said he believed the IPCC was on right track. “Its worth saying that no doubt when the next report comes out it will suggest there have been areas where things have been happening more dramatically than the 2007 report implied”.

Miliband said the danger of climate scepticism was that it would undermine public support for unpopular decisions needed to curb carbon emissions, including the likelihood of higher energy bills for households and issues such as the visual impact of wind turbines.

“There are a whole variety of people who are sceptical, but who they are is less important than what they are saying, and what they are saying is profoundly dangerous,” he said.

Miliband said if the UK did not invest in renewable, clean-energy, it would lose jobs and investment to other countries, have less energy security because of the dependence on oil and gas imports and contribute to damaging temperature rises for future generations.

“Everything we know about life is that we should obey the precautionary principle; to take what the sceptics say seriously would be a profound risk,” he said.

Admitting the Copenhagen summit was a “disappointment,” Miliband said there were, however, important achievements including the agreement by countries responsible for 80 per cent of emissions to set domestic carbon targets.

“There’s a message for people who take these things seriously, don’t mourn, organise,” said Miliband, who has previously called for a Make Poverty History-style mass public campaign to pressure politicians into cutting emissions.

Lord Smith, the Environment Agency chairman, said: “The Himalayan glaciers may not melt by 2035, but they are melting and there’s a serious problem that’s going to affect substantial parts of Asia over the course of the next 100 or more years”.

Meanwhile, after ‘Glaciergate’ and errors in Climate Change report spawned attacks, UN Climate Chief R K Pachauri faced demands from Britain’s chief scientific adviser for “more honest” disclosure of the uncertainty of predictions about the rate of global warming.

John Beddington also said the impact of global warming has been exaggerated by some scientists.

Another top British scientist Mike Hulme raised questions whether Pachauri of India should continue to head the Intergovernmental Panel on Climate Change (IPCC).

In the wake of an admission by IPCC that it grossly overstated the rate at which Himalayan glaciers were receding, Beddington told ‘The Times’ that climate scientists should be less hostile to sceptics who questioned man-made global warming.

He also condemned scientists who refused to publish the data underpinning their reports.

Beddington said that public confidence in climate science would be improved if there were more openness about its uncertainties, even if that meant admitting that sceptics had been right on some hotly-disputed issues.

Pachauri’s ‘voodoo science’ remark to slam India’s Environment ministry over the Himalayan glacier issue drew more flak from another scientist.

Hulme, Professor of Climate Change at the University of East Anglia, criticised Pachauri for his dismissive response last November to research by an Indian group suggesting that the UN body had overstated the threat to the glaciers.

Pachauri described it as “voodoo science”. “Pachauris choice of words has not been good. The question of whether he is the right person to lead the IPCC is for the 193 countries who make up its governing body. It’s a political decision.” Prof Hulme said.

Beddington said that the false claim in the IPCCs 2007 report that the glaciers would disappear by 2035 had exposed a wider problem with the way that some evidence was presented.

“I dont think its healthy to dismiss proper scepticism. Science grows and improves in the light of criticism. There is a fundamental uncertainty about climate change prediction that cant be changed,” said.

“Certain unqualified statements have been unfortunate. We have a problem in communicating uncertainty. There’s definitely an issue there. If there wasnt, there wouldnt be the level of scepticism. All of these predictions have to be caveated by saying, Theres a level of uncertainty about that.”

Beddington said that particular caution was needed when communicating predictions about climate change made with the help of computer models.

“Its unchallengeable that Carbon Dioxide traps heat and warms the Earth and that burning fossil fuels shoves billions of tonnes of Carbon Dioxide into the atmosphere. But where you can get challenges is on the speed of change.

When you get into large-scale climate modelling there are quite substantial uncertainties. On the rate of change and the local effects, there are uncertainties both in terms of empirical evidence and the climate models themselves.”

He said that it was wrong for scientists to refuse to disclose their data to their critics: “I think, wherever possible, we should try to ensure there is openness and that source material is available for the whole scientific community.”

He added: “There is a danger that people can manipulate the data, but the benefits from being open far outweigh that danger.”

A UN warning that Himalayan glaciers may melt by 2035 appears not to be backed up by scientific evidence, an American scientist says – an admission that could energise climate change critics. In a 2007 report, the UN Intergovernmental Panel on Climate Change said the Himalayan glaciers are very likely to disappear within three decades if the present melting rate continues. But a key member of the panel now says the source for that claim is unclear.

The statement, made within the group’s voluminous, Nobel-winning report, was little noticed until ‘The Sunday Times’ said the projection seemed to be based on a news report.

“The origin of that material has not been traced through to its source with a high level of confidence,” said Chris Field, a co-chair of an IPCC working group. “Based on the evidence we’ve seen, the estimated data comes from reports that are more like news reports rather than from a primary scientific literature.”

The leaders of the panel are investigating how the forecast got into the report, Field said. “There are people in various blog postings and in the media who have pointed out that the text on which that conclusion is based is not a primary scientific source,” Field said. “That appears to be correct as far as we can ascertain.”

Field, director of the ecology department at the Washington-based Carneige Institution for Science, has published numerous articles on climate change. He is also a professor of biology and environmental earth science and an FSI Senior Fellow at Stanford University.

India’s Environment Minister Jairam Ramesh repeated his previous criticism of the panel’s assessment of the Himalayan glaciers.

“The health of the glaciers is a cause of grave concern, but the IPCC’s alarmist position that they would melt by 2035 was not based on an iota of scientific evidence,” Ramesh was quoted as saying by ‘The Times of India’.

The IPCC’s Fourth Assessment Report of 2007 said the Himalayan glaciers were receding faster than any other place in the world. “The likelihood of them disappearing by the year 2035 and perhaps sooner is very high if the Earth keeps warming at the current rate,” it said.

But, in a confusing note, the report added the glacier’s total area “will likely shrink from the present 500,000 to 100,000 square kilometres by the year 2035.”

IPPC chairman Rajendra Pachauri could not be immediately reached for comment.

The IPCC shared the Nobel Peace Prize with former US Vice President Al Gore in 2007 after a series of reports documenting scientific evidence of climate change.