evidence: Over a third of the Antarctic's ice shelf area may be at risk of collapsing into the sea if global temperatures reach four degrees Celsius above pre-industrial levels, according to a study. The research, published in the Geophysical Research Letters journal, found that 34 % of the area of all Antarctic ice shelves – around half a million square kilometers – including 67 % of ice shelf area on the Antarctic Peninsula, would be at risk of destabilisation under such a warming scenario. [...] The researchers identified the Larsen C, Shackleton, Pine Island and Wilkins ice shelves as most at-risk under four degrees Celsius of warming, due to their geography and the significant runoff predicted in those areas.