First came Climategate, the row over leaked emails that raised doubts about data used to confirm global warming by the influential United Nations panel on climate change.

Then this week the controversy dubbed Glaciergate has again dealt a blow to the credibility of the Intergovernmental Panel on Climate Change, the IPCC. Or has it?

At this early stage the jury is out though both sides of this heated debate say little has altered to change their views: climate change sceptics say the IPCC's ludicrous conclusion that Himalayan glaciers could be gone by 2035 - just 25 years away - serves as a reminder of its poor science and dangerous tendency to exaggerate .

Not so, insists the climate change camp. All that the rather large mistake reveals are inadequate review processes at the IPCC, whose reports summarise climate research for policy makers around the world.

Still, the row has forced the Nobel-prize winning panel to re-examine the flawed glacier claims.

It now admits the assertion was unfounded, saying that its "clear and well-established standards of evidence" were not properly applied.

Besides the global climate community, there are vast numbers with a stake in the outcome of this dispute. Meltwater from the Himalayas supports tens of millions of people in China and India. Clearly they would benefit from accurate early warnings about risks to such great rivers as the Ganges, Mekong and Yangtze.

The claim about melting Himalayan glaciers - the 2007 IPCC document said they were receding faster than in any other part of the world ... and "the likelihood of them disappearing by the year 2035 and perhaps sooner is very high if the Earth keeps warming at the current rate" - appeared in a 2005 report by the environmental group World Wildlife Fund.

WWF in turn got the date from a story that ran in the New Scientist magazine as far back as 1999. That story included an interview with an Indian climate scientist Syed Iqbal Hasnain who predicted the central and eastern Himalayan glaciers could disappear by 2035.

Hasnain has since admitted the claim was "speculation" and not supported by deeper research. He also insists he was misquoted.

Last November the Indian Government got in on the act when it attacked the IPCC glacier claim at the release of its own discussion paper by geologist Vijay Kumar Raina.

Raina agreed that some glaciers were retreating but insisted it was "nothing to suggest, as some have said, that they will disappear."

A mountaineer, Raina observed that some glaciers were retreating and others were stable. He wanted to know, if global warming was causing them to melt, why were they not all retreating at the same time?

India's environment minister Jairam Ramesh subsequently accused the IPCC of being alarmist. "Glaciers are a serious issue," Ramesh said. "But to derive the conclusion that glaciers are melting rapidly and will disappear is alarmist and not necessarily based on facts."

This upset IPCC chairman Rajendra Pachauri who criticised Raina's "voodoo science" and accused the Indian Government of "arrogance" for questioning the IPCC claims.

Pachauri, who runs an institute in India where Hasnain is employed, has this week tempered his language and said the melting claim would be reviewed. The Indian Government for its part plans a comprehensive study of high altitude Himalayan glaciers.

Pachauri told Bloomberg: "The science doesn't change: Glaciers are melting across the globe and those in the Himalayas are no different."

The Zurich-based World Glacier Monitoring Service would appear to agree, though says it is difficult to state precisely when they might vanish.

A report issued jointly by the service and the UN Environment Programme in 2008 warned: "There is mounting evidence that climate change is triggering a shrinking and thinning of many glaciers world-wide which may eventually put at risk water supplies for hundreds of millions - if not billions - of people.

"Data gaps exist in some vulnerable parts of the globe undermining the ability to provide precise early warning for countries and populations at risk."

The service identified Central Asia - the Himalayan region - as a critical area where detailed information was lacking. The report, which detailed the latest fluctuations of glaciers and ice caps and underlines the overall trend of glaciers' retreat, confirmed that the average annual melting rate of glaciers appeared to have doubled after the start of 2000, with record losses in 2006.

It also emerged this week that that the IPCC - or at least some of its scientists - knew as far back as 2006 that the glacier conclusion was wrong. Georg Kaser, an Austrian glaciologist and IPCC contributor, found the section absurd and alerted the IPCC. Problems he detected in a section on glaciers in Africa were dealt with - those in the chapter on Asia were overlooked.

Kaser and several other scientists wrote in the journal Science this week that the IPCC had made a "a bad error. It was a really bad paragraph, and poses a legitimate question about how to improve IPCC's review process."

They added, perhaps anticipating the fallout: "It was not a conspiracy. The error does not compromise the IPCC Fourth Assessment, which for the most part was well reviewed and is highly accurate."

In New Zealand two scientists with close interests in climate change draw different conclusions about the

glacier dispute. Andrew Mackintosh, senior lecturer in geology and geography at Victoria University, said: "I'm astonished that there aren't more errors like this to be frank." He described the mistake as "unfortunate", but said it was wrong to suggest this meant the whole IPCC process was wrong. He was in no doubt that overall, glaciers were in retreat: "We need to remember that even if scientists make mistakes glaciers are telling us the truth."

Dr Mackintosh said he was independent and not part of the IPCC but regarded its reports as an "incredible resource."

Auckland University's school of Environment associate professor Chris de Freitas argues the glacier row further undermines the IPCC's credibility. He says there is uncertainty around climate science, but IPCC reports have, in his view, an unwarranted authority.

"This is not the sort of thing you'd expect from a UN body driving very expensive global economic policy.

"For a long time there's been a view that the IPCC is right and everyone else can go home. But what is being revealed now is the opposite - it's the IPCC that has been misleading people."