Tuesday, December 7, 2010

Glaciers in Southern South America and Alaska Melting Faster than those in Europe

UNEP: Glaciers in Patagonia, which cover parts of Argentina and Chile, followed by ones in Alaska and its coastal mountain ranges have overall been losing mass faster and for longer than glaciers in other parts of the world. These are among the findings of a new report compiled by the UN Environment Programme (UNEP) in partnership with scientists and research centres from around the world, including the Norwegian Polar Institute and Norut Alta.

The third fastest rate of loss is among glaciers in the northwest United States and southwest Canada followed by ones in the high mountains of Asia, including the Hindu Kush of the Himalayas, the Arctic and the Andes. Overall Europe's glaciers have been putting on mass since the mid-1970s but this trend was reversed around the year 2000.

While the overall trend is down, higher levels of precipitation in some places has increased the mass and in some cases the size of glaciers, including in western Norway, New Zealand's South Island and parts of the Tierra del Fuego in South America. Some mountain ranges are experiencing apparently contradictory effects. In smaller areas of the Karakoram range in Asia, for example, advancing glaciers have even over-ridden areas that have been ice-free for some 50 years.

Meanwhile, in the Tianshan and Himalayan mountain ranges, glaciers are in fact receding - and some rapidly. "Accumulation of science shows us a clear general trend of melting glaciers linked to a warming climate and perhaps other impacts, such as the deposit of soot, reducing the reflection of heat back into space", says UN Under-Secretary-General and UNEP Executive Director Achim Steiner. "This report underlines a global trend, observed over many decades now in some parts of the globe, which has short and long-term implications for considerable numbers of people in terms of water supplies and vulnerability".

"Without doubt the main driving force behind the rapid melting of Himalayan glaciers and formation of the catastrophic Glacial Lake Outburst Floods (GLOFs) is warming due to climate change. The risk to lives and livelihoods in the fragile Hindu Kush Himalayan region is high and getting higher. Immediate action by the global community on launching long-term adaptation and resilience-building programmes is urgently needed," said Madhav Karki, Deputy Director General, International Centre for Integrated Mountain Development (ICIMOD)….

This detailed astronaut photograph (from NASA) shows the merged outlet of Penguin Glacier and HPS 19 into a fjord carved into the snow-covered mountains of the southern Andes. The designation HPS stands for Hielo Patagónico Sur (Southern Patagonian Icefield) and is used to identify glaciers that have no other geographic name. Ice flowing into the fjord begins to break up at image centre, forming numerous icebergs. The largest visible in this image is approximately 2 kilometres in width. The large ice masses visible at image centre have a coarse granular appearance due to variable snow cover, and mixing and refreezing of ice fragments prior to floating free.

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