The surge of ice loss from Greenland between 2005 and 2010, which drove up sea levels around the world, was not unprecedented. A similar spurt happened in the late 1980s, and possibly decades earlier as well.
The surface of Greenland has turned to slush. Satellite data shows that a warm spell earlier this month melted nearly the entire surface of the nation's ice cap. The melt is unusual: normally about half of the ice sheet melts at the surface during summer, mostly at low elevations.