Greenland Is Going to Be OK

According to the government's Global Change Research Program, the oceans will rise three to four feet [i] by the year 2100.  Ice-covered Greenland is the top candidate to supply the water.  The big ice sheets in Antarctica are too cold, and the mountain glaciers aren't big enough to realistically add that much water to the oceans.It became possible to get a good handle on the melting of Greenland only when the GRACE satellites were launched in 2002.  These satellites measure changes in the Earth's gravity and are able to measure changes in the mass of the Greenland ice sheet.An ice sheet has a dynamic balance.  Snow falls on the ice, and as it stacks higher, that snow turns into more ice.  The great mass of ice, thousands of feet thick, flows like plastic toward the sea at a speed measured in feet per year.  At the edge of the Greenland ice sheet, the altitude is lower, and temperatures during the summer are high enough to melt ice.  Some of the ice...(Read Full Article)