Climate change worries deepen

The dramatic decline in polar ice is being increasingly documented and a new study reveals how biological systems are responding to Arctic climate change. Meanwhile tourists are heading in, adding to the pressure on these fragile regions. In the past few months researchers discovered that an enormous ice shelf had broken free of an island in Canada’s Arctic in 2005. The piece of ice is larger than Manhattan and could prove a major problem if it moves into shipping lanes or towards oil rigs this summer. When it was discovered it was trapped in sea ice, but as this melts “the large island can then move itself around off the coast and one potential path for it is to make its way westwards towards the Beaufort Sea where there is lots of oil and gas exploration, oil rigs and shipping,” says Luke Copeland, at the University of Ottawa. And the BBC sent a crew to the ice shelf to film from it, further raising both awareness and curiosity about the polar regions. This slab of ice deepens concerns about the pace of global warming at higher latitudes. One of the problems for researchers in this region is the lack of data. Now long-term satellite images of the seasonal ice coverage are providing detailed information about changes. The ice break was initially undetected due to the remoteness of the northern coast of Ellesmere Island, but satellite images showed the 15 km crack, then the ice floating about one kilometre from the coast within about an hour. A combination of low accumulations of sea ice around the edges of the ice mass, as well as the Arctic’s warmest temperatures on record, contributed to the break, says Copeland. Ice shelves in Canada’s far north have shrunk by as much as 90 per cent over the last century. “It’s hard to tie one event to climate change, but when you look at the longer-term trend, the bigger picture, we’ve lost ice shelves on northern Ellesmere in the past