Arctic Council Scientists Scrambling For Answers On Greenland's Glaciers By 2009 - IHT

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The ancient frozen dome cloaking Greenland is so vast that pilots have crashed into what they thought was a cloud bank spanning the horizon. Flying over it, one can scarcely imagine that this ice could erode fast enough to raise sea levels dangerously any time soon. Along the flanks in spring and summer, however, the picture is very different. For a lengthening string of warm years, a lacework of blue lakes and rivulets of meltwater have been spreading ever higher on the ice cap. The melting surface darkens, absorbing up to four times as much energy from the sun as unmelted snow, which reflects sunlight. Natural drainpipes, called moulins, carry water from the surface into the depths, in some places reaching bedrock. The process slightly, but measurably, lubricates and accelerates the grinding passage of ice toward the sea.

Most important, many glaciologists say, is the breakup of huge semi-submerged clots of ice where some large Greenland glaciers, particularly along the west coast, squeeze through fjords as they meet the warming ocean. As these passages have cleared, this has sharply accelerated the flow of many of these creeping, corrugated, frozen rivers. All of these changes have many glaciologists "a little nervous these days - shell-shocked," said Ted Scambos, the lead scientist at the National Snow and Ice Data Center in Boulder, Colorado, and a veteran of both Greenland and Antarctic studies.

Some say they fear that the rise in seas in a warming world could be much greater than the upper estimate of about two feet in this century made last year by the Intergovernmental Panel on Climate Change. (Seas rose less than a foot, or 30 centimeters, in the 20th century.) The panel's assessment did not include factors known to contribute to ice flows but not understood well enough to estimate with confidence. All the panel could say was, "Larger values cannot be excluded."

A scientific scramble is under way to clarify whether the erosion of the world's most vulnerable ice sheets, in Greenland and West Antarctica, can continue to accelerate. The effort involves field and satellite analyses and sifting for clues from past warm periods, including the last warm span between ice ages, which peaked about 125,000 years ago and had sea levels 12 to 16 feet higher than today's. The Arctic Council, representing countries with Arctic territory, has commissioned a report on Greenland's ice trends, to be completed before the 2009 round of climate-treaty talks in Copenhagen, at which the world's nations have pledged to settle on a long-term plan for limiting human-caused global warming.

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http://www.iht.com/articles/2008/01/07/healthscience/ice.php