Run-off from this vast northern ice sheet – currently the biggest single source of meltwater adding to the volume of the world’s oceans – is 50% higher than pre-industrial levels and increasing exponentially as a result of manmade global warming, says the paper, published in Nature on Wednesday.
Almost all of the increase has occurred in the past two decades – a jolt upwards after several centuries of relative stability. This suggests the ice sheet becomes more sensitive as temperatures go up.
“Greenland ice is melting more in recent decades than at any point in at least the last four centuries, and probably more than at any time in the last seven to eight millennia,” said the lead author Luke Trusel, of Rowan University.
“We demonstrate that Greenland ice is more sensitive to warming today than in the past – it responds non-linearly due to positive feedbacks inherent to the system. Warming means more today than it did even just a few decades ago.”