Glaciers have survived through a delicate balance of gain and loss. A new study shows just how much the scale has tipped.

like water does. Different substances have different melting points and boiling points. For example, sodium chloride (table salt) has a melting point of 801 °C and a boiling point of 1465 °C ...

The images are murky at first. Sediment sweeps past the camera as Icefin, a bright yellow remotely operated robot submarine, moves tentatively forward under the ice. Then the waters begin to clear.

Their analysis found that because water has a high heat content ... "There's a simple threshold, the melting point, and when the temperature goes above that you get rain instead of snow," he ...

Polar Portal points out ... the sheet were to melt entirely. Greenland together with Antarctica have the only permanent ice sheets and hold some 70% of the world's fresh water.