http://www.newyorker.com/fact/content/articles/050425fa_fact3
The Climate Of Man-I
http://www.newyorker.com/fact/content/?050502fa_fact3
The Climate Of Man-II
http://www.newyorker.com/online/content/?050425on_onlineonly01
Elizabeth Kolbert discusses climate change
--------
http://www.tompaine.com/20050505/articles/the_more_things_change_the_m
ore_things_change.php
The More Things Change, The More Things Change
I just took the time to read Elizabeth Kolbert's "The Climate Of Man
I" in the April 25 issue of The New Yorker . Oy. Kolbert provides a
real service to the community by explaining the wonky but dangerous
concept of positive feedback loops and how they're accelerating the
rate of climate change. It's really quite an accessible read, even if
it's a wee bit longer than your standard op-ed.
Here's the thesis, tucked in towards the end:
"Almost wherever you looked, temperatures in the Arctic were rising,
and at a rate that surprised even those who had expected to find
clear signs of climate change. Robert Corell, an American
oceanographer and a former assistant director at the National Science
Foundation, cošrdinated the study. In his opening remarks, he ran
through its findings-shrinking sea ice, receding glaciers, thawing
permafrost-and summed them up as follows: "The Arctic climate is
warming rapidly now, with an emphasis on now." Particularly alarming,
Corell said, were the most recent data from Greenland, which showed
the ice sheet melting much faster "than we thought possible even a
decade ago.""
Kolbert engagingly explains how global warming has triggered what
looks to be an unstoppable snowballing of changes that increase the
pace of changes-positive feedback. Sea ice (the best reflective
surface on the planet) is melting and turning into seawater (the most
heat absorbant surface), which accellerates the melting. Glaciers are
receding and dumping their fresh water rapidly into the Arctic ocean,
threatening to disrupt the Gulf Stream that heats Europe; again,
melting begets more melting.
But these two phenomena are fairly simple for the average reader. By
spending a good deal of time walking the reader through the issue of
permafrost warning, Kolbert hit her mark:
"When you walk around in the Arctic, you are stepping not on
permafrost but on something called the "active layer." The active
layer, which can be anywhere from a few inches to a few feet deep,
freezes in the winter but thaws over the summer, and it is what
supports the growth of plants-large spruce trees in places where
conditions are favorable enough and, where they aren't, shrubs and,
finally, just lichen. Life in the active layer proceeds much as it
does in more temperate regions, with one critical difference.
Temperatures are so low that when trees and grasses die they do not
fully decompose. New plants grow out of the half-rotted old ones, and
when these plants die the same thing happens all over again.
Eventually, through a process known as cryoturbation, organic matter
is pushed down beneath the active layer into the permafrost, where it
can sit for thousands of years in a botanical version of suspended
animation. (In Fairbanks, grass that is still green has been found in
permafrost dating back to the middle of the last ice age.) In this
way, much like a peat bog or, for that matter, a coal deposit,
permafrost acts as a storage unit for accumulated carbon.
"One of the risks of rising temperatures is that this storage process
can start to run in reverse. Under the right conditions, organic
material that has been frozen for millennia will break down, giving
off carbon dioxide or methane, which is an even more powerful
greenhouse gas. In parts of the Arctic, this is already happening.
Researchers in Sweden, for example, have been measuring the methane
output of a bog known as the Stordalen mire, near the town of Abisko,
for almost 35 years. As the permafrost in the area has warmed,
methane releases have increased, in some spots by up to 60 percent.
Thawing permafrost could make the active layer more hospitable to
plants, which are a sink for carbon. Even this, though, probably
wouldn't offset the release of greenhouse gases. No one knows exactly
how much carbon is stored in the world's permafrost, but estimates
run as high as 450 billion metric tons."
The message is clear. Climate change is already feeding on itself and
accelerating. The people and ecosystems of the polar regions are
getting hit hard now. But since the climate science deniers are still
in control of the White House,
<http://www.motherjones.com/news/feature/2005/05/some_like_it_hot.html
> by the time a catastrophic event wakes up the United States or the
developed world, these positive feedback loops will be in full swing,
and, as Kolbert makes clear, unstoppable.
The scary thing about positive feedback loops is that they accelerate
processes non-linearly, like those geometric curves we all studied in
high school. In a complex system, changes are normal and can be
balanced, but this time, it looks like we're in for a threshold
event. For this, Kolbert also provides a good new metaphor-the
rowboat-to those of us trying to mainstream the threat of climate
change,:
"Later, back in his office, Perovich and I talked about the long-term
prospects for the Arctic. Perovich noted that the earth's climate
system is so vast that it is not easily altered. "On the one hand,
you think, It's the earth's climate system, it's big; it's robust.
And, indeed, it has to be somewhat robust or else it would be
changing all the time." On the other hand, the climate record shows
that it would be a mistake to assume that change, when it comes, will
come slowly. Perovich offered a comparison that he had heard from a
glaciologist friend. The friend likened the climate system to a
rowboat: "You can tip and then you'll just go back. You can tip it
and just go back. And then you tip it and you get to the other stable
state, which is upside down.""
Thanks, Elizabeth. Looking forward to Part II.
--Patrick Doherty
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