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Climate Change Creating Novel Ecosystem In Arctic

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									CLIMATE CHANGE CREATING “NOVEL ECOSYSTEM” IN ARCTIC

                                                 If melting sea ice and glaciers
                                                 weren’t enough, now climate
                                                 change is producing what
                                                 researchers call a “structurally
                                                 novel ecosystem” in the
                                                 northwestern Eurasian tundra.

                                                  Warmer weather and
                                                  precipitation changes in the
                                                  region, which covers western
Russia into Finland, has allowed shrubs of willow and alder to grow into sparse
forests within just forty years, according to a new study in Nature Climate
Change.

The new ecosystem could have global implications as researchers say it is likely
to worsen global warming due to a decline in the region’s albedo, i.e. the
sunlight reflected back into the atmosphere due to snow cover.

“It’s a big surprise that these plants are reacting in this way,” lead author Marc
Macias-Fauria of Oxford University said in a press release. “Previously people
had thought that the tundra might be colonized by trees from the boreal forest
to the south as the Arctic climate warms, a process that would take centuries.

But what we’ve found is that the shrubs that are already there are
transforming into trees in just a few decades.”

The scientists write that the new ecosystem of tree thickets, with stands over
two meters high, may be similar to an ecosystem that once existed along the
Bering land bridge 12,000 years ago; the very same land bridge that early
humans used to cross from Asia and into the Americas for the first time.

But today that extinct ecosystem may be returning: using satellite data,
fieldwork, and on-the-ground observation by reindeer herders, the scientists
believe the open woodland ecosystem now covers about 8-15 percent of the
northwestern Eurasian tundra.

“This is just one small part of the vast Arctic tundra and an area that is already
warmer than the rest of the Arctic, probably due to the influence of warm air
from the Gulf Stream,” explains Macias-Fauria. “However, this area does seem
to be a bellwether for the rest of the region.”

One of the biggest concerns is that these sudden forests will decrease the
albedo (literally “whiteness”) of the tundra where snow cover bounces solar
radiation back into the atmosphere creating a cooling effect. But as warming
turns tundra shrubs, which can be covered by snow, into tall trees, researchers
fear that less light will be bounced back creating a feedback loop that will
worsen climate change.

Previously, scientists have estimated that if forest covered the entire Arctic
tundra it could raise global temperatures another 1 to 2 degrees Celsius (1.8 to
3.6 degrees Fahrenheit) by 2100. To date, the Earth has warmed 0.8 degrees
Celsius.

Even as shrubs becomes trees in Siberia, researchers last year reported that
boreal forests had begun shifting northward into the Alaskan tundra.



Source: controllingpollution.com

								
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