evidence: A new study published in Nature suggests there may be more wiggle room left for the ice sheet before it sets on an irreversible decline. Even if human-driven climate change pushes global temperatures above that 2C threshold, an increasingly likely possibility, the Greenland ice sheet could avoid full collapse if temperatures come back down relatively quickly, the study says. "The Greenland ice sheet is more resilient than we thought," says Nils Bochow, a researcher at the Arctic University of Norway and the lead author of the paper. [...] Since 2002, the Greenland ice sheet has contributed about 20% of the extra water that's pushed global sea levels up. "And the proportion is increasing over time," says Helene Seroussi, a glaciologist at Dartmouth University who was not involved in the study. More concerning, she says, is that "over the last few years, we have been seeing that Greenland is responding more rapidly than the models predict."