Dramatically greener Arctic predicted in coming decades
ARCTIC: Rising temperatures will lead to a massive greening,
or increase in plant cover, in the Arctic, a new research has predicted.
Rising temperatures will lead to a massive greening, or increase in
plant cover, in the Arctic, a new research has predicted. Scientists
have revealed new models projecting that wooded areas in the Arctic
could increase by as much as 50 percent over the next few decades. The
researchers also showed that this dramatic greening would accelerate
climate warming at a rate greater than previously expected.
“Such widespread redistribution of Arctic vegetation would have
impacts that reverberate through the global ecosystem,” said Richard
Pearson, lead author on the study and a research scientist at the
American Museum of Natural History’s Center for Biodiversity and
Conservation.
Plant growth in Arctic ecosystems has increased over the past few
decades, a trend that coincides with increases in temperatures, which
are rising at about twice the global rate.
The research team—which includes scientists from the Museum, AT ‘n’ T
Labs-Research, Woods Hole Research Center, Colgate University, Cornell
University, and the University of York—used climate scenarios for the
2050s to explore how this trend is likely to continue in the future.
The scientists developed models that statistically predict the types
of plants that could grow under certain temperatures and precipitation.
Although it comes with some uncertainty, this type of modelling is a
robust way to study the Arctic because the harsh climate limits the
range of plants that can grow, making this system simpler to model
compared to other regions such as the tropics.
The models reveal the potential for massive redistribution of
vegetation across the Arctic under future climate, with about half of
all vegetation switching to a different class and a massive increase in
tree cover. What might this look like? In Siberia, for instance, trees
could grow hundreds of miles north of the present tree line.
“These impacts would extend far beyond the Arctic region. For
example, some species of birds seasonally migrate from lower latitudes
and rely on finding particular polar habitats, such as open space for
ground-nesting,” Pearson said.
In addition, the researchers investigated the multiple climate change
feedbacks that greening would produce. They found that a phenomenon
called the albedo effect, based on the reflectivity of the Earth’s
surface, would have the greatest impact on the Arctic’s climate. When
the sun hits snow, most of the radiation is reflected back to space. But
when it hits an area that’s “dark,” or covered in trees or shrubs, more
sunlight is absorbed in the area and temperature increases.
This has a positive feedback to climate warming: the more vegetation
there is, the more warming will occur. “By incorporating observed
relationships between plants and albedo, we show that vegetation
distribution shifts will result in an overall positive feedback to
climate that is likely to cause greater warming than has previously been
predicted,” said co-author Scott Goetz, of the Woods Hole Research
Center The research has just been published in Nature Climate Change.
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