Sea levels could rocket as Arctic ice melts

Posted by Emma Woollacott

Arctic sea ice concentration was at its second-lowest ever in March, according to data from NASA.

In the past decade, says NASA's Earth Observatory, annual melting has grown more dramatic, while growth has become less so. It's released images showing Arctic sea ice concentrations for September 2010 and March 2011 showing the extent of the decline.

On September 19, 2010, Arctic sea ice reached its annual minimum, at 1.78 million square miles. The National Snow and Ice Data Center (NSIDC) declared 2010 to be the third-lowest Arctic sea ice extent in the satellite record.

And in March 2011, after a winter of growth, Arctic sea ice extent was the second lowest for March since satellite records began, in 1979. NSIDC measured it at 5.62 million square miles at its maximum, and says it's been falling by 2.7 percent per decade.

Concentrations remained below normal in both the Atlantic and Pacific sectors of the Arctic, particularly in the Labrador Sea and the Gulf of St Lawrence.

The data did show that the amount of older, thicker ice increased slightly over last year.

"Data through the third week of March shows an increase in sea ice one to two years old, and older than two years old, compared to recent years,” NSIDC says. "However, the amount of older ice remains much lower than in the mid-1980s, and there is still almost none of the oldest ice - older than four years - that used to dominate much of the Arctic Ocean.”

Meanwhile, a report from the Arctic Monitoring and Assessment Programme (AMAP), says that climate change in the Arctic could raise sea levels by a whopping 1.6 meters by the end of the century - way above most other estimates.

It says there are signs that warming is accelerating, and that the Arctic Ocean could be pretty much ice-free during summer within 30 or 40 years - again, much sooner than previous estimates.