Arctic sea ice decline may trigger climate change even in temperate zones

Malaysia Sun
Friday 16th March, 2007 
(ANI)

Washington, Mar 16 : Arctic sea ice that has been dwindling for several decades may have reached a tipping point that could trigger a cascade of climate change reaching into Earth's temperate regions, a new University of Colorado at Boulder study has said.

Mark Serreze, a senior research scientist at CU-Boulder's National Snow and Ice Data Center who led the study synthesizing results from recent research, said the Arctic sea-ice extent trend has been negative in every month since 1979, when concerted satellite record keeping efforts began. 

He said the loss of ice, about 38,000 square miles annually as measured each September, was due to rising concentrations of greenhouse gases and strong natural variability in Arctic sea ice.

"When the ice thins to a vulnerable state, the bottom will drop out and we may quickly move into a new, seasonally ice-free state of the Arctic. I think there is some evidence that we may have reached that tipping point, and the impacts will not be confined to the Arctic region," said Serreze.

Serreze said the decline in Arctic sea ice besides negatively affecting wildlife like polar bears and increasing erosion of coastlines in Alaska and Siberia, could also cause reduced rainfall in the American West or increased precipitation over western and southern Europe.

It could impact western states like Colorado, by reducing the severity of Arctic cold fronts dropping into the West and reducing snowfall, thereby impacting agriculture as well as the ski industry, he said. 

"Just how things will pan out is unclear, but the bottom line is that Arctic sea ice matters globally," said Serreze.

"While the Arctic is losing a great deal of ice in the summer months, it now seems that it is also regenerating less ice in the winter. With this increasing vulnerability, a kick to the system just from natural climate fluctuations could send it into a tailspin.

"This ice-flushing event could be a small-scale analog of the sort of kick that could invoke rapid collapse, or it could have been the kick itself. At this point, I don't think we really know," he said.

The paper by Serreze and Julienne Stroeve of CU-Boulder's NSIDC and Marika Holland of the National Center for Atmospheric Research, titled "Perspectives on the Arctic's Shrinking Sea Ice Cover" appears in the March 16 issue of Science.