[Vision2020] Permafrost Melt Poses Long-term Threat

[Ted Moffett]

http://news.yahoo.com/s/afp/20090527/sc_afp/climatewarmingpermafrost/print

This article offers important media exposure for the work of scientists
doing hard research into the implications of our CO2 emissions and other
climate change impacts of human activity... The article is rather
lame insofar as it does not expose the full implications of probable
extreme climate change scenarios induced by human activity...

It is amazing to witness the arguments that because the science behind
anthropogenic climate change posses uncertainties, that significant action
to address the problem is rash.  If you were told an airliner you were about
to board had a 50% chance of crashing, unless certain safety precautions
were taken, would you lobby to not take the precautions, because they might
raise your fare, and board the craft anyway, with your loved ones,
children?  But this comparison is minutia compared to the magnitude of what
we are potentially doing... We are facing altering the Earth's climate in
profound manner for thousands of years.... And what will future generations
think of what we are doing?
 Permafrost melt poses long-term threat, says study Wed May 27, 2:57 pm ET

PARIS (AFP) – Melting permafrost could eventually disgorge a billion tonnes
a year of greenhouse gas into the atmosphere, accelerating the threat from
climate change, scientists said Wednesday.

Their probe sought to shed light on a fiercely-debated but poorly-understood
concern: the future of organic matter that today is locked up in the frozen
soil of Alaska, Canada, northern Europe and Siberia.

The fear is that, as the land thaws, this material will be converted by
microbes into carbon dioxide, which will seep into the atmosphere, adding to
the greenhouse effect.

This in turn will stoke warming and cause more permafrost to thaw, which in
turn pushes up temperatures, and so on.

But how and when this vicious cycle could be unleashed is unclear.

Indeed, some voices have argued that it will not present a significant
threat, as plants will start to grow on the soggy, warmer earth and suck in
carbon dioxide (CO2) from the atmosphere through photosynthesis, thus
blunting the problem.

A team led by University of Florida ecology professor Ted Schuur
investigated an area of tundra at Eight Mile Lake in central Alaska, where
permafrost thaw has been monitored since 1990 but had begun to start many
years before.

Schuur's team used hand-built, automated chambers, which they deployed at
three sites that represented minimal, moderate and extensive amounts of
thaw.

>From 2004 to 2006, the chambers measured how much carbon was escaping from
the soil and how much was being absorbed by any vegetation.

In areas that had thawed for the previous 15 years, there was a net uptake
of carbon, meaning that the newly-established plants sucked up more CO2 than
was lost from the soil.

But in areas that had begun to thaw decades before, the reverse was true.

There was a net loss of CO2, the principal greenhouse gas blamed for global
warming, as older stocks of carbon were gradually released to the
atmosphere.

"At first, with the plants offsetting the carbon dioxide, it will appear
that everything is fine, but this actually conceals the initial
destabilisation of permafrost carbon," Schuur said in a press release.

"But it doesn't last, because there is so much carbon in the permafrost that
eventually the plants can't keep up."

Most of the 13 million square kilometres (five million square miles) of
permafrost remain frozen, but thawing is already under way around the
region's southern fringes and is thought likely to expand this century.

In that scenario, the permafrost could release around a billion tonnes a
year of carbon, roughly equivalent to the contribution to greenhouse
emissions each year by deforestation in the tropics, the paper said.

Even as the Arctic greens, the rising loss of older carbon "could make
permafrost a large biospheric carbon source in a warmer world," it said.

Burning fossil fuels adds about 8.5 gigatonnes of emissions each year, but
it is a process that can theoretically be controlled.

Permafrost thaw, though, would be self-reinforcing and could be almost
impossible to brake.

"It's not an option to be putting insulation on top of the tundra," Schuur
said.

"If we address our own emissions either by reducing deforestation or
controlling emissions from fossil fuels, that's the key to minimising the
changes in the permafrost carbon pool."

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Vision2020 Post: Ted Moffett
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