http://arstechnica.com/science/news/...n-expected.arsUh-oh. Greenland and Antarctica melting faster than expected
By Tim De Chant | Last updated about 5 hours ago
The rate of melting by the ice sheets covering Greenland and Antarctica may throw existing projections for sea level rise out the window. Unfortunately for Maldivians and other idyllic, but altitude-challenged islands, the ice sheets are melting faster than anyone expected.
Sea levels have been rising nearly unabated since the late 19th century, but rates have been increasing in recent years. The bulk of the change has been attributed to water expanding due to rising ocean temperatures, while melting ice in Greenland and Antarctica was considered to contribute a relatively small amount. But a new study published in Geophysical Research Letters reports the ice sheets may be contributing to sea level rise at a rate three times that which was previously suspected. The result? Sea levels could reach predicted heights 50 years earlier than experts thought, and total sea level rise may exceed previous estimates.
Ice is primarily lost from the Greenland and Antarctic sheets when it calves into the ocean. When ice sheets move faster toward the ocean, they shuck more ice into the water. And if snowfall over the ice sheets fails to replenish the amount lost, the sheet shrinks in size over time, transferring the water it once held into the ocean.