Alaska's glaciers are melting at more than twice the rate previously assumed because of warming temperatures, a disturbing phenomenon that is dramatically altering the majestic contours of the state and driving up sea levels, according to a new study.
Scientists using highly precise airborne laser measurements of 67 Alaskan glaciers from the mid 1950s to the mid 1990s discovered that the glaciers are melting an average of six feet a year - and in some cases a couple hundred feet - and that the rate has accelerated in the past seven or eight years.
As one measure of the severity of the problem, the researchers calculated that the glaciers are generating nearly twice the annual meltage of the Greenland Ice Sheet, which is the largest ice mass in the Northern Hemisphere and second only to the Antarctic. That would mean the Alaskan melt is adding about two-tenths of a millimeter a year to the sea levels - an unprecedented development that could have long-term implications for flooding on Pacific islands and along coastal areas, the researchers concluded.
The study by a team of researchers from the University of Alaska in Fairbanks, published in Friday's issue of the journal Science, offers a vivid and troubling picture of the potential adverse impact of climate change on the United States and the rest of the world.
"The change we are seeing is more rapid than any climate change that has happened in the last 10 to 20 centuries," said Keith A. Echelmeyer, one of the five researchers who prepared the study.
Scientists can't say whether the extraordinary melting is the result of man-induced global warming, the slow natural advance and rapid retreat of the glaciers, or dramatic but natural variations in weather patterns. But the effects are illustrative of what some scientists and environmentalists predict will happen at home and abroad unless the United States and the rest of the world undertakes a more aggressive effort to reduce carbon dioxide and other heat-trapping gases.
full piece at: http://www.washingtonpost.com/wp-dyn/articles/A25660-2002Jul18.htm l