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- Canadiske lokalstater og
/ Canadian local states and provinces
/ États locaux canadiens et les provinces
- Arctic Permafrost Melting 70 Years Sooner Than Expected.
/ : Jan Wesner Childs Countercurrents.org, June 18, 2019.
Scientists studying climate change expected layers of permafrost in
the Canadian Arctic to melt by the year 2090.
Instead, it's happening now.
A new study published this week in the journal Geophysical Research
Letters revealed that unusually warm summers in the Canadian High
Arctic between 2003 and 2016 resulted in permafrost melt up to 240%
higher than previous years.
Louise Farquharson, a researcher at the Permafrost Laboratory at
the University of Alaska Fairbanks and the study's lead author,
told weather.com the three areas of melting permafrost studied in
remote northern Canada are believed to have been frozen for
thousands of years.
"This change is unprecedented on this kind of time scale,"
She noted that while scientists had predicted the permafrost
wouldn't melt for another 70 years, those forecasts didn't take
into account the unusually warm summers that have happened in
recent years. While researchers believe all indicators point to
warmer temperatures continuing, there's no way to know for sure
just how quickly the permafrost will continue to melt.
As permafrost disappears, it creates what's known as thermokarst, a
sinking landscape often pockmarked with lakes, holes and mounds. In
one area the researchers studied, the ground sank about three feet.
"I was very surprising to just see how rapidly the landscape
changed," Farquharson said. "We started monitoring these sites back
in the early 2000s and this landscape surrounding each of our
stations was fairly flat. It was fairly easy to walk across the
The transformation was startling.
"It's pretty amazing," Farquharson said. "There are these troughs
of up to 90 centimeters (about 35 inches). It's kind of like the
elevation of a kitchen countertop. There are small ponds in many of
these troughs. It's quite a profound change."
Vegetation never before seen in the area is also creeping in.
Not only is rapidly melting permafrost a harbinger of climate
change, it exacerbates the problem by exposing thawing biological
material to the atmosphere where it decomposes and releases CO2, a
key element in global warming.
Research has also shown that loss of permafrost can wreak havoc on
everything from animal habitat, migration and diet in the wild to
agriculture and infrastructure in populated areas.
Houses are sinking into the earth in parts of Alaska, Canada and
Russia, for example, and the 92-mile road in Alaska's Denali
National Park is slowly being moved by sliding land caused by
- Klima i international lov / Climate in international law:
Canada : United Nations Framework Convention on Climate Change:
Submitted National Communication.
- Canada er medlem af / is a member of the World Meteorological
- Se også: Nordamerikansk
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