Ancient Canadian Arctic ice sheets go bye-bye

Arctic ice sheets as old as 4,000 years old are disappearing. Researchers say Canada’s portion of the Arctic lost one-quarter of its ice this summer:

The entire Markham ice shelf broke away in early August and is now adrift in the Arctic Ocean, carving away 50 square kilometres. Two large sections of the Serson ice shelf also broke off, shrinking it by 122 square kilometres or about 60 per cent. The Ward Hunt ice shelf lost 22 square kilometres.

These ice shelves in the area of Ellesmere Island are are up to 4,500 years old, and as much as 40 metres thick. So, that’s a significant “heat sink” loss.

“These substantial calving events underscore the rapidity of changes taking place in the Arctic,” said Dr. Derek Mueller, who has been studying the shelves at Trent University, in a statement. “These changes are irreversible under the present climate and indicate that the environmental conditions that have kept these ice shelves in balance for thousands of years are no longer present… .”

“The extent of their loss this season is significant,” said Dr. Warwick Vincent, director of Laval University's Centre for Northern Studies, who collaborated on the study. "Unique ecosystems that depend on this ice are on the brink of extinction.”

Oh, and for the global warming denialists, the famed “hockey stick” is back, better and more accurate than ever.