Error on Himalayan glaciers melts UN climate panel's reputation

By Margaret Munro, Canwest News Service June 10, 2010 Comments (2)

The meltdown of the Himalayan glaciers is not going to be nearly as dire as a Nobel Prize-winning UN climate panel predicted, but it does still threaten the water and food security of 60 million people, says a new report.

Glaciers are often described as the "water towers" of the world, and the UN has warned that the glaciers feeding major Asian river basins and providing water for 1.4 billion people are fast disappearing as a result of climate change. The UN's Intergovernmental Panel on Climate Change, which co-won the 2007 Nobel Peace Prize, went so far as to say that the Himalayan glaciers could melt away by 2035 which UN officials now admit was a mistake.

A study published Friday in the journal Science shows the report got more than the 2035 date wrong. It says the 2007 IPCC report also overstated and oversimplified the impact Himalayan glaciers have on Asian rivers.

Glacier meltwater plays only a "modest role" in the several major river systems in Asia, says the study by a Dutch team that took a close look the rivers downstream from the enormous Himalayan snow and ice fields.

"Meltwater is extremely important in the Indus basin and important for the Brahmaputra basin, but plays only a modest role for the Ganges, Yangtze, and Yellow rivers," reports the team led by Walter Immerzeel at Utrecht University.

"A huge difference also exists between basins in the extent to which climate change is predicted to affect water availability and food security," the study says. "The Brahmaputra and Indus basins are most susceptible to reductions of flow, threatening the food security of an estimated 60 million people."

Though the study says global warming will lead to substantial changes in glaciers, it says the "impact will be less than anticipated" by the IPCC's 2007 report. "In that report, it was suggested that the current trends of glacier melt and potential climate change may cause the Ganges, Indus, Brahmaputra, and other rivers to become seasonal rivers in the near future," the Dutch team says. "We argue that these rivers already are seasonal rivers, because the melt and rain seasons generally coincide and a decrease in meltwater is partially compensated for by an increase in precipitation."

The study helps set the record straight, says glaciologist Graham Cogley, at Trent University, in Peterborough, Ont. "They are probably in the right ballpark," he says.

Cogley, like many scientists involved with the IPCC, was dismayed the panel's report contained the unsupported claim that Himalayan glaciers "are receding faster than in any other part of the world and, if the present rate continues, the likelihood of them disappearing by the year 2035 and perhaps sooner is very high." UN officials have acknowledged the mistake, which overstated by several hundred years when the glaciers could melt away.

"It was a first-class disaster," says Cogley, says of the mistake. He says some scientists saw the error and tried to alert senior authors, but it was "too late" to get the report corrected.

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