Friday, August 11, 2006
Something ominous may be happening beneath Greenland's vast ice sheet. For nearly 50 years, the world's second largest ice cap has inched inexorably downhill toward the ocean, but at a stable rate. Now, the sheet seems to be melting and sliding seaward much faster, and the rate seems to be accelerating--a condition that could eventually endanger coastal populations and affect Earth's climate.
When glaciers begin to melt, water works its way down to the bottom of the ice. There it lubricates the glacier, which will pick up its downhill pace. Why worry? Greenland holds about 10% of the world's ice, so if it melts completely--though an unlikely prospect--it would raise global sea level about 6.5 meters. That's enough to flood all of the planet's coastal cities and displace billions of people.>