Greenland and Antarctica melting faster than anyone expected

A seal swims by icebergs off the British Antarctic Survey's Rothera base in this January 23, 2009 file photo. (Alaister Doyle/Reuters)

A new study shows that the speed of the melting polar ice caps has been highly under-estimated. Led by scientists at NASA's Jet Propulsion Laboratory, the study finds that the ice sheets of Greenland and Antarctica are likely the largest contributors to the sea level rise. The Post's Brian Vastag writes:

Left unchecked, the extra water dumped into the oceans could push average global sea level six inches higher by 2050, the report finds. That would mark the ice sheets -- defined as expanses of deep, long-term ice larger than 20,000 square miles -- as the largest contributors to sea level rise, outstripping melting from Earth's other frozen reservoirs, namely mountain glaciers.

Six inches of water may not seem much -- that's just barely nipping over your heels -- but for some low-lying countries, such as the Republic of Maldives and Bangladesh, the loss of coastline could be devastating.