20070922 Arctic sea ice 'melts to all-time low'

clipped from www.telegraph.co.uk Photographs taken in September 2005 and 2007 Sea ice in the Arctic shrank to the smallest area on record this summer, prompting fears it could melt completely within decades and speed up global warming. The ice, which melts in summer months and regrows in the winter cold, shrank so much this year that the route became fully navigable for around five weeks. Sea ice reflects most of the sunlight that strikes it. However, once it melts, the dark ocean surface, which absorbs sunlight, becomes exposed. This causes waters to warm and increases the melt rate. If the sea ice were to disappear, the Earth would absorb more solar energy, which could accelerate global warming. Wildlife in the Arctic would also suffer, particularly polar bears which cross ice floes in search of food. scientists at the NSIDC warned that, at current rates, the Arctic could be ice-free in the summer by 2030 and blamed climate change for the record melting.