Alaska’s role in sea-level rise vastly underestimated
Scientists at the University of Alaska have found that the country contributes around half of global glacial meltwater, even though it only contains about 13 per cent of the world’s mountain glaciers.
The researchers measured volume and area changes on 67 glaciers in Alaska and neighbouring Canada using an airborne laser technique. The depletion of these glaciers follows a global trend of accelerated melting since 1998, and it is likely that other large Alaskan glaciers will have the same characteristics.
“These recent losses are nearly double the estimate annual loss from the entire Greenland ice sheet… and are much larger than previously published loss estimates for Alaska glaciers,” say the authors. “They form the largest glaciological contribution to rising sea level yet measured.”
Glaciers around the Gulf of Alaska include some of the largest outside Greenland and Antarctica, and produce as much as 4000mm of water every year. But previous climatic models have not included data from Alaskan glaciers, meaning that the resulting projections of global sea-level rise may have been seriously underestimated.
The authors stress that although their observations are consistent with recent climate warming, rapid melting of the Alaskan glaciers is unlikely to be the result of climate change alone.
© SciDev.Net 2002