"The collapse of Antarctic ice shelves is largely thought to be caused by warming of the atmosphere, but it appears that changes in sea temperature and ice-shelf structure are also important, " said Prof Glasser.

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That breathing space would be useful if something really bad, such as the collapse into the sea of part of the Greenland ice-shelf, was in imminent danger of happening, and the realisation of the danger led to a political agreement that climate change had to be stopped rapidly.

ECONOMIST: Global warming

"Reduced sea-ice conditions and unusually high air temperatures have facilitated the ice shelf losses this summer, " said Dr Luke Copland from the University of Ottawa.

BBC: Major ice-shelf loss for Canada