Wednesday, September 13, 2006

Simply melting away

While the world’s major powers go about their daily business of exploiting the planet and waging wars on several fronts, there is more dire news about the impact of climate change. Scientists from the University of Colorado’s National Snow and Ice Data Centre (NSIDC) report that this year’s retreat of Arctic sea ice could be the most extreme since monitoring of the polar ice cap began in 1979.

The loss of permanent sea ice is "the most irrefutable evidence" that global warming is affecting the environment, says Ted Scambos, lead scientist with NSIDC.

In 2005 - the warmest year ever recorded, according to scientists - the summer extent of Arctic sea ice hit a record low, covering an area 20 percent less than the average minimum of 7 million square kilometres between 1979 and 2000. The 2006 retreat, which peaks in September, is expected to be even greater. By the end of July, Arctic sea ice covered only 8.7 million square kilometres, down from 9.1 million in 2005 and 10.1 million on average for the 1979–2000 period.

Recent satellite data shows that melting of Greenland’s massive land-based ice sheet has accelerated as well. Measurements by a US space agency NASA satellite suggest that some 239 cubic kilometres of ice is being lost per year, almost a three fold increase in melting from the 2002 to 2004 average.

Unlike melting sea ice, which floats on the surface of the water, loss of land-based ice could lead to rising sea levels with catastrophic effects, including greater risks from severe storm surges and permanent submergence of low-lying areas. Experts estimate that each millimetre increase in sea level results in shoreline retreats of approximately 1.5 metres; if Greenland’s ice sheet were to melt completely, global sea levels would rise 6.5 metres. UN experts predict that rising sea levels and environmental deterioration will displace as many as 50 million people by 2010. And that’s only the start. Meanwhile, in Iraq and Afghanistan…

Paul Feldman, communications editor

No comments: