Global Warming

Arctic ice break raises global warming fears 30/12/2006

Researchers have confirmed that an enormous ice shelf broke away from Ellesmere Island in the Canadian Arctic last year and they warn it could be another symptom of global warming.The 66 square kilometre ice island tore away from Ellesmere, a huge strip of land in the Canadian Arctic close to Greenland.The break occurred in August 2005 and was so violent that it caused tremors that were detected by Canadian seismographs 250 kilometres away. At the time no one was able to pinpoint what had happened.The Canadian Ice Service contacted geographer Luke Copland of the University of Ottawa, who reconstructed the chain of events by piecing together data from the seismic readings and satellite images provided by Canada and the United States."This loss is the biggest in 25 years but it continues the loss that occurred within the last century," Mr Copland said.He says 90 per cent of the ice cover has been lost since the area was discovered in 1906."What is important and interesting is that it is sudden, quite large even," he said."In the past, we looked to climate change [and] thought perhaps ice shelves would just melt apart by losing a little piece day by day, but it now seems that when you reach some kind of threshold, when you reach that level, the whole thing just breaks apart."Scientific director Louis Fortier of Canadian Artic research network ArcticNet says the massive break-off signals a rise in Arctic warming."This Ellesmere ice shelf was sheltering unique ecosystems on the planet; there are freshwater lakes which were forming above and under the ice shelf," he said."The break-up of the ice cover on Ellesmere Island has been going on for 12,000 years, but it seems to have accelerated in recent years which is another indicator, among many others, of warming of the entire Arctic cryosphere."Biologist Warwick Vincent of Laval University in Quebec visited the icy waters of the Arctic to view the new island and says he has seen nothing like it in the past decade."It really is incredible," he said."People talk of endangered animals, well, these are endangered landscape features and we are losing them," he said.

http://origin.abc.net.au/nature/news/NatureNews_1819606.htm