Friday, June 12, 2009
The Greenland ice sheet is melting faster
than expected according to a new study led by a University of Alaska Fairbanks
researcher and published in the journal Hydrological Processes.
Study
results indicate that the ice sheet may be responsible for nearly 25 percent of
global sea rise in the past 13 years. The study also shows that seas now are
rising by more than 3 millimeters a year—more than 50 percent faster than the
average for the 20th century.
UAF researcher Sebastian H. Mernild and
colleagues from the United States, United Kingdom and Denmark discovered that
from 1995 to 2007, overall precipitation on the ice sheet decreased while
surface ablation—the combination of evaporation, melting and calving of the ice
sheet—increased. According to Mernild's new data, since 1995 the ice sheet lost
an average of 265 cubic kilometers per year, which has contributed to about 0.7
millimeters per year in global sea level rise. These figures do not include
thermal expansion—the expansion of the ice volume in response to heat—so the
contribution could be up to twice that.
The Greenland ice sheet has been
of considerable interest to researchers over the last few years as one of the
major indicators of climate change. In late 2000/early 2001 and in 2007, major
glacier calving events sent up to 44 square miles of ice into the sea at a time.
Researchers are studying these major events as well as the less dramatic ongoing
melting of the ice sheet through runoff and surface processes.
Ice melt
from a warming Arctic has two major effects on the ocean. First, increased water
contributes to global sea-level rise, which in turn affects coastlines across
the globe. Second, fresh water from melting ice changes the salinity of the
world's oceans, which can affect ocean ecosystems and deep water mixing.
"Increasing sea level rise will be a problem in the future for people
living in coastal regions around the globe," said Mernild. "Even a small sea
level rise can be a problem for these communities. It is our hope that this
research can provide people with accurate information needed to plan for
protecting people and communities."
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University of Alaska
Fairbanks
Oh no....
don't worry, there is a counter-effect:
Originally posted by Bangulzai:don't worry, there is a counter-effect:
Oh yea.... thanks for that input.