The massive West Antarctic ice sheet is melting, and its complete disappearance could be inevitable, according to new research. Its collapse would raise sea levels around the world by between 15 and 20ft, more than enough to swamp many coastal countries and leave holiday islands such as the Seychelles under water.
The ice sheet is thousands of yards thick in places and covers an area more than 11 times the size of Ireland. Yet its future stability is in doubt, and even concerted action to limit the effects of global warming might have no impact at all, according to Dr Howard Conway of the University of Washington.
He and colleagues from the University of Maine this morning publish new research on the demise of the West Antarctic ice sheet in the journal, Science. The immense chunk of ice rests uneasily on the bedrock of Antarctica. It has been in retreat for the past 10,000 years but is becoming increasingly unstable, they claim.
Much of the sheet sits below sea level, making it particularly susceptible to rising seas. The ice used to reach far out into the surrounding ocean, sitting heavily on the seabed up to 800 miles from the coast. It has retreated by about 400ft per year for the past 7,600 years and now barely reaches beyond the coastline.
The researchers used radar imaging and carbon-14 dating to study ice cover reaching back 20,000 years. They now believe the retreat may be part of a natural process which will continue no matter what we might do to slow global warming.
It might be a bit too soon, however, to up stakes and move to higher ground. If the ice continues to disappear at its current rate complete disintegration will take another 7,000 years, more than enough time to complete the last boat-loan repayment.
