Melting glaciers spell water crisis
Temperature changes and lack of snow are causing 90% of the world's glaciers to retreat and some to disappear completely, with potentially catastrophic consequences for communities that rely on the meltwater for irrigation, hydroelectric schemes and drinking, glaciologists agreed yesterday.
Research in Europe, Asia, Africa and the Americas all pointed to the same conclusion: that climate change is causing increasingly rapid melting of the ice.
Only Scandinavian and Alaskan glaciers are holding their own or increasing. In both cases this is due to increased snowfall, also caused by climate change.
Although it has been known for some time that glaciers are in retreat, this is the first time that such a large body of evidence has been brought together, and with such uniform results.
The loss of ice will increase sea levels worldwide.
In the Alps, where summer temperatures have risen by 2.1C since the 1970s, summer flows in glacier-fed rivers have doubled.
David Collins, professor of physical geography at the University of Salford, said this year glaciers were melting more than he had ever seen.
"Temporarily, it might be seen as good news for summer flows," he said. "After all the extra water from the glaciers this summer has meant hydroelectric dams have been topped up so they can run on maximum power.
"It helps to make up for the nuclear stations that had to close because of the heat. But in the longer term, when the glaciers disappear, there will be no meltwater at all, and it will reduce as the glaciers get smaller and survive only on the highest mountains."
But he emphasised that it was not just the higher temperatures that were causing the problem.
The increase in the number of atmospheric high pressure systems in the Alps in the winter had caused considerable a reduction in snow. As a result the glaciers were not being replenished.
In contrast, the change in track of Atlantic depressions meant that extra rain was falling in England and more snow in Scandinavia, so despite the fact that it was getting warmer there too, the glaciers were growing.
Stephan Harrison of the Oxford University school of geography and environment said in Africa most glaciers would disappear completely in 20 years.
A paper on the Ruwenzori mountain range, between Uganda and Congo, showed that the glaciers which feed the headwaters of the Nile were now so thin that they would soon disappear.
Dr Harrison's own paper, on the glaciers on Kazakhstan, which provide drinking and irrigation water to the country's largest city, Alma-Ata, show that two cubic kilometres of ice (2.6bn cubic yards) a year have disappeared from 416 glaciers in the region every year since 1955.
"They are retreating so fast they are leaving piles of rocks and debris behind that dam up the meltwater," he said.
"There is a real danger of disastrous dam bursts hurling rocks and debris on the settlements below."