Rain fell at Greenland's summit over the weekend—the first time in recorded history that precipitation there came in the form of rain rather than snow. Temperatures at the summit of the ice sheet, about two miles above sea level, rose above freezing for the fourth time in 32 years—three of those times having occurred since less than a decade ago—and 7 billion tons of water fell on the ice sheet, the heaviest rainfall on the books since record keeping began. Historic it may be, but good news it's not: Greenland experienced what the Washington Post calls a "major melting event," and the amount of ice mass lost on Sunday was seven times the daily average for this time of year.
An expert tells CNN this is evidence of "unprecedented" rapidity in Greenland's climate warming up. Rain fell from Greenland's southeast coast all the way to the National Science Foundation's Summit Station at the ice sheet's highest point at 10,551 feet elevation. An NSF program officer says that means the station will need to start preparing for weather events it's never had to deal with before. Weather events once considered abnormal have been occurring with increasing frequency over the past decade, she says. (Read more Greenland stories.)