I'd hate to run into one of these on a dark night:
http://www.ens-newswire.com/ens/dec2005/20051220_sinkhole.jpg>
Mike Neuman
---------- Forwarded Message ----------
Permafrost Meltdown Across the Arctic
<http://www.ens-newswire.com/ens/dec2005/2005-12-20-03.asp>
BOULDER, Colorado, December 20, 2005 (ENS) - Permafrost is losing its
permanence across the Northern Hemisphere, altering ecosystems and
damaging roads and buildings across Alaska, Canada, and Russia.
Government scientists warned today that over half the area covered by
this topmost layer of permafrost could thaw by 2050 and as much as 90
percent by 2100.
New climate simulations from the National Center for Atmospheric
Research (NCAR) in Boulder show that global warming may melt the top
10 feet (3 meters) or more of the frozen soil.
<http://www.ens-newswire.com/ens/dec2005/20051220_lawrencedavid2.jpg>
Dr. David Lawrence is with the NCAR Climate and Global Dynamics
Division. (Photo courtesy NCAR)
"People have used models to study permafrost before, but not within a
fully interactive climate system model," says NCAR's David Lawrence,
the lead author. The coauthor is Andrew Slater of the University of
Colorado's National Snow and Ice Data Center.
The scientists predict the thawing permafrost will increase runoff to
the Arctic Ocean and release vast amounts of carbon dioxide into the
atmosphere, increasing the greenhouse effect.
Permafrost occurs under about 85 percent of Alaska's surface area,
and patches of permafrost can be found as far south as Anchorage.
Recent warming has degraded large sections of permafrost across
central Alaska, with pockets of soil collapsing as the ice within it
melts. The results include buckled highways, destabilized houses, and
"drunken forests," trees that lean at wild angles, the authors say.
In Siberia, some industrial facilities have reported significant
damage. Further loss of permafrost could threaten migration patterns
of animals such as reindeer and caribou.
<http://www.ens-newswire.com/ens/dec2005/20051220_permafrostmap.jpg>
On this permafrost projection map, the light blue shows the extent of
permafrost in 1999. The dark blue indicates the permafrost remaining
in 2099 under the business as usual scenario. (Photo courtesy NCAR)
The study is the first to examine the state of permafrost in a global
model that includes interactions among the atmosphere, ocean, land,
and sea ice as well as a soil model that depicts freezing and thawing.
The scientists used the Community Climate System Model (CCSM) based at NCAR.
The CCSM simulations are based on high and low projections of
greenhouse gas emissions for the 21st century, as constructed by the
Intergovernmental Panel on Climate Change. In both cases, the CCSM
determined which land areas would retain permafrost at each of 10
soil depths extending down to 11.2 feet (3.43 meters).
Results appear online in the December 17 issue of "Geophysical
Research Letters." The study was funded by the National Science
Foundation, which is NCAR'S primary sponsor, and the U.S. Department
of Energy.
About a quarter of the Northern Hemisphere's land contains
permafrost, defined as soil that remains below 32 degrees F (0
degrees C) for at least two years.
Permafrost has an active surface layer, extending anywhere from a few
centimeters to several meters deep, which thaws during the summer and
refreezes during the winter. The deeper permafrost layer remains
frozen.
<http://www.ens-newswire.com/ens/dec2005/20051220_sinkhole.jpg>
This sinkhole near Fairbanks, Alaska, formed due to the melting of an
ice pocket within permafrost that is thawing as temperatures warm.
(Photo courtesy Vladimir Romanovsky, Geophysical Institute,
University of Alaska Fairbanks)
The active layer responds to changes in climate, expanding downward
as surface air temperatures rise. Deeper permafrost has not thawed
since the last ice age, over 10,000 years ago, and will be largely
unaffected by global warming in the coming century, says Lawrence.
For the high emission scenario, the area with permafrost in any of
these layers shrinks from four million to just over one million
square miles by the year 2050 and decreases further to about 400,000
square miles (one million square kilometers) by 2100.
In the low emission scenario, which assumes major advances in
conservation and alternative energy, the permafrost area shrinks to
about 1.5 million square miles by 2100.
"Thawing permafrost could send considerable amounts of water to the
oceans," says Slater, who notes that runoff to the Arctic has
increased about seven percent since the 1930s.
In the high-emission simulation, runoff grows by another 28 percent
by the year 2100. That increase includes contributions from enhanced
rainfall and snowfall as well as the water from ice melting within
soil.
The new study highlights concern about emissions of greenhouse gases
from thawing soils. Permafrost may hold 30 percent or more of all the
carbon stored in soils worldwide. As the permafrost thaws, it could
lead to large-scale emissions of methane or carbon dioxide beyond
those produced by fossil fuels.
"There's a lot of carbon stored in the soil," says Lawrence. "If the
permafrost does thaw, as our model predicts, it could have a major
influence on climate."
To address this and other questions, Lawrence and colleagues are now
working to develop a more advanced model with interactive carbon.
<http://www.ens-newswire.com/ens/dec2005/20051220_kipnuk.jpg>
Kipnuk, Alaska, a coastal Inuit village located about 100 miles west
of Bethel, is home to 500 people. Kipnuk elders and University of
Alaska scientists say the village is sinking because it sits atop
thawing permafrost. (Photo courtesy Lower Kuskokwim NEA)
If this widespread permafrost thaw comes about, "It will change the
face of southern Alaska," says Tom Osterkamp. A professor of physics
at the University of Alaska Fairbanks Geophysical Institute,
Osterkamp has studied Alaska's permafrost for 25 years.
Osterkamp monitors the temperature of permafrost with a network of
one-inch holes drilled in permafrost throughout the state. The holes,
located near Fairbanks, Anchorage, Bethel, Glennallen, Eagle, and
other towns and villages, have all been telling the same story. Since
1989, each time Osterkamp has checked the temperatures of permafrost
at depths from 10 to 25 meters, the permafrost has crept closer to
the melting point.
Osterkamp's recent measurements show that all permafrost south of the
Yukon River is warming, and in most cases there isn't one degree left
between ice and water.
In addition to creating roller coaster roads and tilting buildings,
Osterkamp says, thawing permafrost often causes large sections of
forest to collapse, killing trees and other vegetation that live on a
foundation of permafrost.
Posted by Tim
AustinTex
--
<http://groundtruthinvestigations.com/>
Global warming, let's do something about it. Our heart should be where our home is. <http://www.groundtruthinvestigations.com/>
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