A new study suggests the Greenland Ice Sheet did not fully melt during previous periods of global warming — and that it preserved a tundra beneath it. Joshua Brown/ University of Vermont hide caption

itoggle caption Joshua Brown/ University of Vermont

Workers stand inside the gold mine in Greenland's Nulanaq mountain in 2009. The Danish territory's underground wealth was at the forefront of elections in March. Now, Greenland faces another dilemma: whether to end a zero-tolerance policy on uranium extraction. Adrian Joachim/AP hide caption

itoggle caption Adrian Joachim/AP