Dr. Benny Peiser 03.07.2008 21:05 +Feedback
Falscher Alarm: Grönlands Gletscher sind ok
Einige Leser werden sich vielleicht noch an die Schreckensmeldung erinnern: Schmelzwasser und ins Meer stürzende Eisbrocken lassen die Gletscher Grönlands schrumpfen - und zwar schneller als gedacht. Jetzt stellt sich offenbar heraus, die ganze Aufregung war mal wieder ein falscher Alarm: One of the most vivid symbols of global warming used by scientists and campaigners to spur society to curb climate-warming emissions is photography of gushing rivers of meltwater plunging from the surface of Greenland’s ice sheet into the depths. Recent studies have shown these natural drainpipes, called moulins, can speed up the slow seaward march of the grinding ice by lubricating the interface with bedrock below. The faster that ice flows, the faster seas rise. Now, though, a new Dutch study of 17 years of satellite measurements of ice movement in western Greenland concludes that the speedup of the ice is a transient summertime phenomenon, with the overall yearly movement of the grinding glaciers not changing, and actually dropping slightly in some places, when measured over longer time spans. The work, the authors and other experts caution, does not mean that more widespread surface melting could not eventually destabilize vast areas of the world’s second-largest ice storehouse. But for the moment, the study, which is being published in Friday’s edition of the journal Science, throws into question the notion that abrupt ice losses in Greenland are nigh. http://dotearth.blogs.nytimes.com/2008/07/03/a-tempered-view-of-greenlands-gushing-drainpipes/?ex=1215748800&en=8f674850110be7cb&ei=5070&emc=eta1
Permanenter Link | Druckversion
Kategorie(n): Wissen

