The Associated Press reports:

The fields of rippling ice 500 feet below the NASA plane give way to the blue-green of water dotted with irregular chunks of bleached-white ice, some the size of battleships, some as tall as 15-story buildings.

Like nearly every other glacier on Greenland, the massive Kangerlussuaq is melting. In fact, the giant frozen island has seen one of its biggest melts on record this year. NASA scientist Josh Willis is now closely studying the phenomenon in hopes of figuring out precisely how global warming is eating away at Greenland’s ice.

Specifically, he wants to know whether the melting is being caused more by warm air or warm seawater. The answer could be crucial to Earth’s future.

Water brings more heat to something frozen faster than air does, as anyone who has ever defrosted a steak under the faucet knows.

If Willis’ theory that much of the damage is from the water turns out to be correct, he said, “there’s a lot higher potential for Greenland to melt more quickly than we thought.” And that means seas rising faster and coastal communities being inundated more.

Greenland contains enough ice to make world sea levels rise by 20 feet if it were all to melt. In a single day this month, it lost a record 13.7 billion tons (12.5 billion metric tons) by one estimate. [Continue reading…]