"In July 2012, a spate of warm weather caused nearly the entire surface of the Greenland ice sheet to begin melting, an event with no precedent in the satellite record. A new study shows this massive melt-out wasn’t just an anomaly compared with the last 40 years, but the last 350. Unfortunately, the study also suggests 2012 could be a harbinger of our new normal.
Published today in Nature, the research finds that rates of melting at Greenland’s surface have skyrocketed in recent decades and are now far out of bounds of what was considered natural variability over the last few centuries. The rapid rise in surface melting over the last two decades in particular suggests a ‘non-linear’ response to rising temperatures, meaning as global warming progresses this melting could greatly accelerate, contributing more and more to rising sea levels.
“The real take home message is it’s just in the last two decades we’ve seen this unprecedented increase in runoff,” Sarah Das, a glaciologist at Woods Hole Oceanographic Institution and co-author on the study, told Earther."