Large Methane Releases From Arctic Soils Likely - Vienna EGU Conference

[hatrack]

VIENNA, Austria, April 4, 2006 (EN'S) - Large amounts of the greenhouse gas methane will be released into the atmosphere in the near future, according to a Dutch scientist speaking today at the European Geosciences Union (EGU 2006) meeting in Vienna. He said global warming could lead to melting of the arctic tundras, setting free large volumes of methane, which would in its turn increase global warming.

Methane is a much stronger greenhouse gas than carbon dioxide said Dr. J. (Ko) van Huissteden of Vrije Universiteit in Amsterdam. He explained that methane fluxes from the arctic permafrost areas attract scientific attention because the release of this powerful greenhouse gas may act as a positive feedback to climate warming.

Methane release is enhanced by increasing the metabolic activity of methane bacteria in warmer arctic soils, or by the release of methane from melting permafrost.

Van Huissteden's research in the tundra of northeast Siberia, conducted in cooperation with the Yakut Institute of Biology, shows that the floodplains of arctic lowland rivers are major methane sources, where methane fluxes may be five times as high as in non-flooded tundra bogs. Moreover, he said, these fluxes are very sensitive to river discharge fluctuations and the incidence of river floods. Currently, both air temperatures and river discharges are rising significantly in the Arctic.

EDIT

http://www.ens-newswire.com/ens/apr2006/2006/04-04-04.asp

(Subscription service - link may not work)

[villager]

1. ergo, we're pretty much sunk

How do you sequester methane?

[Spinzonner]

2. Next step in our Venus-forming experiment

[skooooo]

3. maybe i'm being morbid..

...but i keep hoping i die before things get really bad, because i think they will in another 20 - 30 years.

[Ilsa]

5. I wish we hadn't had kids when I read this stuff.

IT'll be difficult keeping it all together and surviving.

[MsKandice01]

4. Downward spiral, here we come!! n/t

[Minnesota Libra]

6. So in other words, thanks to us humans, it's a toss up whether.........

....the planet is going to hell in a hand basket quick or at break neck speed? Great!! Aren't we proud of ourselves now?? :sarcasm:

[phantom power]

7. Yes, we now get to choose between bad, very bad, or very very bad.

Because here in America, we're all about consumer choice.

[meatloaf]

8. Damn, made me blow diet coke out my nose, that burns.

[Sinti]

9. Ignore it and it will go away

Don't worry, and you can be like Wiley Coyote doesn't fall out of the sky because he hasn't learned about gravity yet. Of course, this could also lead to a mass-extinction event. So pop some popcorn, it's better than shock and awe. :banghead:

[Odin2005]

10. Not only will methane be a problem...

...but increased CO2 levles will weaken the "Rainforests make thier own rain" effect, causing the African rain forests and the interior parts of the amazon to dry out, releasing CO2 into the atmosphere that was once biomass or soil organic matter. The Amazon may loose 78% of it's biomass and 72% of soil carbon, sending CO@ levels zooming to 1000ppm.

[skids]

11. A possible counter-feedback mechanism.

We may not be totally sunk by this:

Although the atmospheric concentration of methane - the second most important trace-gas contributor to global warming next to CO2 - has more than doubled since pre-industrial times, its rate of increase has slowed considerably over the last few decades (Steele et al., 1992). Prinn et al. (1992) suggest that one of the major causes of the slowdown is the increasing magnitude of methane oxidation by methanotrophic bacteria in the aerobic zones of soils, the magnitude of which phenomenon is believed to be equivalent to the annual input of methane to the atmosphere (Watson et al., 1992). Hence, as Tamai et al. note, "this biological sink plays an important role in modulating global warming."

http://www.co2science.org/scripts/CO2ScienceB2C/articles/V6/N38/B2.jsp

Not to say that this mechanism will necessarily work fast enough. A sudden shot of large volumes of methane could very likely overwhelm this system. But there is some hope here that the impact will be lessened a bit.



(One could take a wild-ass-guess from the above chart that at abput 1992 the population of the bacteria caught up with rising methane levels, and the exponential-looking period from 92 through 2000 is influenced by a population growth curve in an ample supply environment, with the flat period being the point at which the methane "food supply" became a limit on the population.)

Of course, what happens when populations of these bacterium become large over the long term, biospheres adjust to their population size and come to rely on them in other capacities, and then methane concentrations fall precipitously as the supply "runs out" is another matter entirely.

Of course, we won't find many of these bacteria in desert "soil" which is another worry as deserts grow. The article says forests do this job the best.

[bemildred]

12. That's interesting.

I was just discussing the notion that biological sequestration was a best bet for managing the problem, because it can scale exponentially (in the right situation), and has the potential to be self-adjusting.

On the other hand, it reinforces the idea that we really have only the crudest sort of grasp of what will happen as time goes on.