Greenland ice sheet melted at unprecedented rate during July

The Greenland ice sheet melted at a faster rate this month than at any other time in recorded history, with virtually the entire ice sheet showing signs of thaw. The rapid melting over just four days was captured by three satellites. It has stunned and alarmed scientists, and deepened fears about the pace and future consequences of climate change. In a statement posted on Nasa's website on Tuesday, scientists admitted the satellite data was so striking they thought at first there had to be a mistake. The set of images released by Nasa on Tuesday show a rapid thaw between 8 July and 12 July. Within that four-day period, measurements from three satellites showed a swift expansion of the area of melting ice, from about 40% of the ice sheet surface to 97%. Scientists attributed the sudden melt to a heat dome, or a burst of unusually warm air, which hovered over Greenland from 8 July until 16 July. Greenland had returned to more typical summer conditions by 21 or 22 July, Mote told the Guardian...more