Tuesday, January 11, 2011

Glacier shrinkage will hit European Alps hardest

Sylvia Rowley in the Guardian (UK): Glaciers in the European Alps could shrink by 75% by the end of the century, according to new research into the expected impact of global warming. The study, published in the journal Nature: Geoscience, concludes that, globally, mountain glaciers and ice caps are projected to lose 15-27% of their volume by 2100, although the extent of the damage varies widely. The analysis suggests glaciers in the Alps and New Zealand will shrink by more than 70% but shrinkage is predicted to reach about 10% in Greenland and high-mountain Asia.

The researchers argue this will result in "substantial impacts" on regional water availability, as well as a rise in sea levels. Retreating glaciers and ice caps threaten the water supplies of cities such as Kathmandu in Nepal and La Paz in Bolivia, which depend substantially on glacial meltwater for drinking and farming.

Scientists from the University of British Columbia in Vancouver, Canada, who conducted the research, predict that melting glaciers and ice caps will be responsible for increases in sea levels of 8.7-16.1cm by 2100. This broadly confirms the range projected by the UN's climate change body, the Intergovernmental Panel for Climate Change (IPCC).

"What is surprising here is the contribution to sea level rises of up to 16cm just from the melting of small glaciers and ice caps. This may still be a low estimate as we did not include ice loss from calving – when a piece of ice breaks off into the sea," said Dr Valentina Radic, who co-authored the study with Prof Regine Hock.

Total sea level rise is likely to be considerably higher, however, due to the effects of melting Greenland and Antarctic ice sheets – which make up more than 99% of the water on Earth bound up in glacier ice – and thermal expansion in the ocean….

The Aletsch Glacier in Switzerland, shot by Didier Baertschiger, Wikimedia Commons via Flickr, under the Creative Commons Attribution-Share Alike 2.0 Generic license

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