Dramatic Arctic & Antarctic Changes Over Last Two Decades

Melting permafrost sets up dangerous climate
scenario, says Polar scientist Michael Gooseff.
The Pennsylvania State University hydrologist works in remote regions of
the Arctic and Antarctic, where ice and frozen ground are thawing. Permafrost
itself holds about twice as much carbon as we currently have in the atmosphere.
Melt from this
frozen precipitation, as well as from older snowpack and glacier ice, is
happening faster and is more widespread than a decade ago.

August 12, 2011

Polar Scientist Charts Melting Caused by
Climate Change

Expects accelerated thawing to continue
unless greenhouse-gas emissions are reduced

Rosanne Skirble | Washington, D.C.

Voice of America

Photo: Michael Gooseff

Sparse snow patches in Taylor Valley
Antarctica may be an important source of moisture for soil ecosystems in this
extreme environment. .

Michael Gooseff follows water to the end of
the earth. The Pennsylvania State University hydrologist works in remote
regions of the Arctic and Antarctic, where ice and frozen ground are thawing.
He expects polar warming and melting to continue at an accelerating pace if no
significant reductions are made in climate-changing greenhouse-gas emissions.

At the annual convention of the Ecological
Society of America in Austin, Texas this week he posed this question: “How are
those polar systems responding to climate change?”

The answer is based on his on-going research
into how water crosses landscapes and what happens to it above and below
ground.

“In the northern regions, of course, we have
sea ice, but a smaller surface area than in the Antarctic where we have very
large ice sheets. And that actually plays into the differences in climate
change responses that we’re seeing at both of those places.”

According to Gooseff, the two regions also
differ widely geologically and ecologically. He says the Antarctic McMurdo Dry
Valleys station where he’s based “appears like a polar desert system with open
exposed soils, with no vascular plants at the surface and with glaciers coming
down from the mountains, whereas in northern Alaska, we have a lot of plants.
The tundra is actually dense with vegetation and very green.”

Michael Gooseff

Thawing permafrost creates a formation called
a thermokarst, which sends an overload of sediment and nutrients into streams
in the Western Brooks Range of Alaska.

Gooseff is documenting change over time, by
observing patterns in polar rivers, streams and lakes. He recalls a 2003 visit
to Alaska’s North Slope, when his team charted the course of an unusual muddy
stream.

“We
follow this up and finally we found a big gash in the hill slope essentially,
and all of this mud pouring out from underneath it.”

Here’s what had happened: A massive ice wedge
under the surface had melted, thawing the permafrost and causing the soil above
it to collapse. That created a deep gully in the hillside.

A study of historic aerial photos of the area
revealed that this dramatic change, as well as similar warming-induced changes
to 25 other landscape features, had occurred over just two decades.

Gooseff explains that as water moves through
these altered formations, it picks up sediment and nutrients normally locked up
in the permafrost. As that flows into rivers, it could affect fisheries and
coastal oceans.

The Toolik River thermokarst gully that
Michael Gooseff and colleagues discovered just after its formation in 2003.

Gooseff says the melting permafrost sets up
another dangerous climate scenario.  “As
we warm, we release more carbon, that carbon goes into the atmosphere,
contributes to more warming, contributes to more permafrost degradation and the
cycle sort of continues. In fact, permafrost itself is expected to hold about
twice as much carbon as we currently have in the atmosphere.”

At the opposite end of the earth, near the
McMurdo Dry Valleys station, Gooseff studies snow patches. Not much snow falls
in Antarctica, but what little there is collects in cool shady spots, behind
rocks and hills. These patches insulate the soil and may provide small amounts
of moisture for microbes below.

Gooseff says the melt from this frozen
precipitation, as well as from older snowpack and glacier ice, is happening
faster and is more widespread than a decade ago. The remote sensing devices his
research team has deployed are helping to track how that water moves across the
land.

“We expect that there are going to be
patterns in both time and space that will be somewhat predictable.”

Gooseff hopes his research of climate change
at the poles underscores the regions’ interconnectedness with a global climate
system that affects everyone on the planet.

Source: www.voanews.com