The UN climate change panel based claims about ice disappearing from the world's mountain peaks on a student essay and an article in a mountaineering magazine, a British newspaper reported Sunday.
The claims risk causing fresh embarrassment for the Intergovernmental Panel on Climate Change (IPCC), which had to apologise this month over inaccurate forecasts about the melting of Himalayan glaciers.
In a recent report, the IPCC stated that observed reductions in mountain ice in the Andes, Alps and Africa was caused by global warming and it referred to two papers as the source of the information.
But The Sunday Telegraph said one of the sources quoted was actually an article published in a magazine for mountaineers which was based on anecdotal evidence about the changes they were witnessing during climbs.
The newspaper said the other source was a dissertation written by a geography student who was studying for a master's degree at the University of Bern in Switzerland that quoted interviews with mountain guides in the Alps.
The IPCC rejected as "baseless and misleading" a report this month from another British newspaper, The Sunday Times, raising doubts about the evidence behind its claim that global warming is linked to worsening natural disasters.
Scientists have defended the IPCC since it admitted to errors over the Himalayan glacier claim, insisting its work is balanced and its conclusions are sound.
Explore further: Uncertainty about sea levels to last 10 more years, experts say