The prediction was included in a 2007 UN report on global warming, in which scientists said the probability of glaciers in the Himalayas melting "by the year 2035 and perhaps sooner is very high".
The IPCC now says it took the exaggerated prediction from a 2005 report by the WWF environmental group.
The error was compounded by the accidental inversion of the date - 2035 instead of 2350.
On top of that, the WWF based its report on a single comment made by Syed Hasnian, an Indian glaciologist, in a 1999 article that appeared in the New Scientist magazine.
Speaking to Al Jazeera on Saturday, Hasnain said that he had been misquoted.
"It is a journalistic substitution. It has nothing to do with my research because it's not reflected in my research papers, it's not reflected in my reports," he told Al Jazeera.
"So how can it be an authentic thing? It can't be. I'm not as astrologer to predict the demise of the glaciers and it's not possible."
The UN panel says a team of climate change sceptics uncovered the error, which could cast a shadow over the panel's climate change research.
But Paul Johnston, the chief scientist at Greenpeace International in the UK, said irrespective of the mistake in the IPCC report, glaciers are melting.
"It's not really a question of whether they're in retreat. They definitely are," he told Al Jazeera.
"The only question that's really attached to this issue now is when they are going to finally disappear and the jury is still out on that."
The IPCC's Pachauri said that overall the conclusions reached in his group's report were "robust, appropriate, and entirely consistent with the underlying science".
"The world is on the path of unsustainable development and we will have to change our lifestyle," he said.
He admitted that the erroneous forecast that the glaciers could disappear by 2035 may have "genuinely alarmed" some people.
But he defended the panel's overall work and said there had been a benefit, in that it created a "heightened awareness about the real threat to Himalayan glaciers".