Arctic Ice in “Death Spiral,” Is Near Record Low


17 Sep 2008

The Arctic Ocean’s sea ice has shrunk to its second smallest area on record, close to 2007’s record-shattering low, scientists report.

The ice is in a “death spiral” and may disappear in the summers within a couple of decades, according to Mark Serreze, an Arctic climate expert at the National Snow and Ice Data Center in Boulder, Colorado.

Each winter, sea ice fills most of the Arctic Ocean. The ice pack then melts and shrinks in the summer heat.

With additional heating due to global warming, the extent of sea ice cover has gotten smaller and smaller over the summers since the 1980s.

This has scientists concerned—and not just because the ice melt is a symptom of global warming. Sea ice has a cooling effect by reflecting sunlight back into space. So when the ice shrinks and opens up more ocean, more of the sun’s heat is soaked up by the dark sea.

This heats up the Arctic—and the planet—more than the greenhouse effect on its own, in turn melting even more ice.

“With the climate feedbacks kicking in,” Serreze said by email, “we’ll lose the summer ice cover probably by the year 2030.”

Extraordinary Melt

The 2007 melt last year smashed a previous record set in 2005.

But 2007 saw special conditions that favored melting, researchers say. “The most important factor in 2007,” Serreze said, “was an unusual pattern of atmospheric circulation in summer that brought warm, southerly winds north of eastern Siberia, promoting strong melt.”

This makes 2008’s near record all the more striking, researchers say.

“The remarkable thing about this summer is that we got all the way down to second lowest without especially favorable atmospheric patterns that would hasten melt,” Serreze said.

© 1996-2009 National Geographic Society. All rights reserved.
Photo credit: NASA/Goddard Space Flight Center Scientific Visualization Studio

bookshelf

books I've read on failure & grace

The World Without Us
The Last Oil Shock: A Survival Guide to the Imminent Extinction of Petroleum Man
Zeitoun
A Paradise Built in Hell: The Extraordinary Communities That Arise in Disaster
Hell and High Water: Global Warming--the Solution and the Politics--and What We Should Do
The Worst Hard Time: The Untold Story of Those Who Survived the Great American Dust Bowl
The Tipping Point
Three Cups of Tea: One Man's Mission to Promote Peace... One School at a Time
The Upside of Down: Catastrophe, Creativity and the Renewal of Civilization
Out of Poverty: What Works When Traditional Approaches Fail
The Little Ice Age: How Climate Made History, 1300-1850
Confessions of an Eco-Sinner: Tracking Down the Sources of My Stuff
Deep Economy: The Wealth of Communities and the Durable Future
The Geography of Bliss: One Grump's Search for the Happiest Places in the World


Mason's favorite books »

TAG CLOUD