No one quite knows why glaciers and ice shelves are melting so fast, or how a meltwater lake on the Greenland ice sheet covering six square kilometres could drain away in 24 hours, as it did in 2006.

• 没有人明白为什么冰川和冰架正如此快地在融化，或者方圆六平方公里的格陵兰岛冰盾上的融水湖怎么会在二十小时内枯竭，这是发生在2006年的事情。