New Efforts to Predict When Polar Ice Will Melt (CSM, via AlterNet)

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New Efforts to Predict When Polar Ice Will Melt

By Gregory M. Lamb, Christian Science Monitor. Posted March 28, 2007.



A new study finds that as Arctic warming accelerates, polar waters could become ice-free by the turn of the century, or, under one scenario, as early as 2040.

The loss of sea ice in the Arctic may have reached a "tipping point" that could "trigger a cascade of climate change" reaching much farther south. As Arctic warming accelerates, polar waters could become ice-free by the turn of the century, or, under one scenario, as early as 2040.

These are among the conclusions of a new study published March 16 in the journal Science. The area of the Arctic covered by sea ice has been shrinking at least since 1979, when regular satellite observations began.

The report attributes the loss of ice, averaging about 38,000 square miles annually (an area about the size of Maine), to rising concentrations of greenhouse gases in the atmosphere, as well as to natural variability.

Says Mark Serreze, a senior research scientist at the University of Colorado's National Snow and Ice Data Center and the lead researcher on the report:

"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."

The effects could be felt widely around the world and could include drought in the American West and increased winter rains over Western and Southern Europe, notes a story in Britain's Telegraph. Dr. Serreze told the newspaper: ......(more)

The complete piece is at: http://www.alternet.org/envirohealth/49820/