The glaciers of the Himalayas, suppliers of fresh water to more than a billion people, are undoubtedly retreating because of global warming, the head of the UN's climate change body reaffirmed yesterday – two years after he was embroiled in an international political row about similar forecasts.
Raj Pachauri, the Indian chairman of the Intergovernmental Panel on Climate Change (IPCC), became a controversial figure around the world in December 2009 after a claim in the IPCC's last report, about Himalayan glacier meltback, said that the likelihood of the glaciers disappearing by the year 2035 "is very high". Many scientists criticised this as ridiculous.
Dr Pauchauri at first attacked critics, accusing one of producing "voodoo science" and provoking a widespread controversy which became known as "Glaciergate". He was later forced to apologise and correct the claim in the IPCC report. Yesterday, however, Dr Pachauri reasserted that the glaciers in general were melting back, after the publication of the most authoritative report produced on those in the Himalayan-Hindu Kush region.
The report, from the Kathmandu-based International Centre for Integrated Mountain Development (ICIMOD), used satellite data to establish the geography of the snow cover, revealing for the first time that the number of glaciers in the region is in excess of 54,000.
Only 10 of them, it says, have been closely studied for change in "mass balance" – the shifting volume of the ice which can indicate is a glacier is growing, shrinking or stable. But in these 10, the rate of ice loss has roughly doubled between 1980 and 2005. In the Everest area, the data show a marked acceleration in the loss of glacial mass between 2002 and 2005, the report says.
One of the key implications of the melting is that the glaciers provide the headwaters of the major river systems which come off the Himalayas and provide water for more than a billion people. On the question of a timescale for the glaciers melting completely, Dr Pauchauri said: "It's very difficult, that's something which we have to get much more scientific evidence on."