[Mb-civic] ticking time bomb?

[ean at sbcglobal.net]

Here's another piece on global warming indicating that "National 
Security" concerns around terrorism are a joke compared to the 
potential devestation to our national (and world) security...and 
survival...from global warming.  Time for some "pre-emptive" action 
where it really makes sense....


http://www.commondreams.org/views04/1215-24.htm

Is 400 gigatons of methane locked in the frozen arctic tundraa 
ticking time bomb?
By John Atcheson for the Baltimore Sun 
December 15, 2004
 
The Arctic Council's recent report on the effects of global warming 
in the far north paints a grim picture: global floods, extinction of 
polar bears and other marine mammals, collapsed fisheries. But it 
ignored a ticking time bomb buried in the Arctic tundra. 

There are enormous quantities of naturally occurring greenhouse 
gasses trapped in ice-like structures in the cold northern muds and 
at the bottom of the seas. These ices, called clathrates, contain 
3,000 times as much methane as is in the atmosphere. Methane is 
more than 20 times as strong a greenhouse gas as carbon dioxide. 

Now here's the scary part. A temperature increase of merely a few 
degrees would cause these gases to volatilize and "burp" into the 
atmosphere, which would further raise temperatures, which would 
release yet more methane, heating the Earth and seas further, and 
so on. There's 400 gigatons of methane locked in the frozen arctic 
tundra - enough to start this chain reaction - and the kind of 
warming the Arctic Council predicts is sufficient to melt the 
clathrates and release these greenhouse gases into the atmosphere. 

Once triggered, this cycle could result in runaway global warming 
the likes of which even the most pessimistic doomsayers aren't 
talking about. 

An apocalyptic fantasy concocted by hysterical environmentalists? 
Unfortunately, no. Strong geologic evidence suggests something 
similar has happened at least twice before. 

The most recent of these catastrophes occurred about 55 million 
years ago in what geologists call the Paleocene-Eocene Thermal 
Maximum (PETM), when methane burps caused rapid warming and 
massive die-offs, disrupting the climate for more than 100,000 
years. 

The granddaddy of these catastrophes occurred 251 million years 
ago, at the end of the Permian period, when a series of methane 
burps came close to wiping out all life on Earth. 

More than 94 percent of the marine species present in the fossil 
record disappeared suddenly as oxygen levels plummeted and life 
teetered on the verge of extinction. Over the ensuing 500,000 years, 
a few species struggled to gain a foothold in the hostile 
environment. It took 20 million to 30 million years for even 
rudimentary coral reefs to re-establish themselves and for forests to 
regrow. In some areas, it took more than 100 million years for 
ecosystems to reach their former healthy diversity. 

Geologist Michael J. Benton lays out the scientific evidence for this 
epochal tragedy in a recent book, When Life Nearly Died: The 
Greatest Mass Extinction of All Time. As with the PETM, 
greenhouse gases, mostly carbon dioxide from increased volcanic 
activity, warmed the earth and seas enough to release massive 
amounts of methane from these sensitive clathrates, setting off a 
runaway greenhouse effect. 

The cause of all this havoc? 

In both cases, a temperature increase of about 10.8 degrees 
Fahrenheit, about the upper range for the average global increase 
today's models predict can be expected from burning fossil fuels by 
2100. But these models could be the tail wagging the dog since they 
don't add in the effect of burps from warming gas hydrates. Worse, 
as the Arctic Council found, the highest temperature increases from 
human greenhouse gas emissions will occur in the arctic regions - 
an area rich in these unstable clathrates. 

If we trigger this runaway release of methane, there's no turning 
back. No do-overs. Once it starts, it's likely to play out all the way. 

Humans appear to be capable of emitting carbon dioxide in 
quantities comparable to the volcanic activity that started these 
chain reactions. According to the U.S. Geological Survey, burning 
fossil fuels releases more than 150 times the amount of carbon 
dioxide emitted by volcanoes - the equivalent of nearly 17,000 
additional volcanoes the size of Hawaii's Kilauea. 

And that is the time bomb the Arctic Council ignored. 

How likely is it that humans will cause methane burps by burning 
fossil fuels? No one knows. But it is somewhere between possible 
and likely at this point, and it becomes more likely with each passing 
year that we fail to act. 

So forget rising sea levels, melting ice caps, more intense storms, 
more floods, destruction of habitats and the extinction of polar 
bears. Forget warnings that global warming might turn some of the 
world's major agricultural areas into deserts and increase the range 
of tropical diseases, even though this is the stuff we're pretty sure 
will happen. 

Instead, let's just get with the Bush administration's policy of pre-
emption. We can't afford to have the first sign of a failed energy 
policy be the mass extinction of life on Earth. We have to act now. 

John Atcheson, a geologist, has held a variety of policy positions in 
several federal government agencies. 

© 2004 Baltimore Sun



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Action is the antidote to despair.  ----Joan Baez
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