Fires in the tundra destabilize the permafrost

by benwatts

Largest recorded tundra fire yields scientific surprises
[Via Eureka! Science News - Popular science news]

In 2007 the largest recorded tundra fire in the circumpolar arctic released approximately as much carbon into the atmosphere as the tundra has stored in the previous 50 years, say scientists in the July 28 issue of the journal Nature. The study of the Anaktuvuk River fire on Alaska’s North Slope revealed how rapidly a single tundra fire can offset or reverse a half-century worth of soil-stored carbon.

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As long as there is not another fire in 50 years, the area will be stabilized. But the fire exposes the permafrost to the surface, increasing the liklihood it will  melt and release more methane.

That would not be good.

The release of methane causes extinction events

by Dave Hogg

Did Methane Cause the Mass Extinction That Made Way for the Dinosaurs? [Via 80beats]

What’s the News: Two hundred million years ago, half of the Earth’s species vanished in the blink of a geological eye, clearing the way for rise of the dinosaurs in the Jurassic. The cause of that mass extinction, a new study suggests, may have been gigatons of methane released from the sea floor after a slight rise in the earth’s temperature, triggering much greater warming. And if that sounds familiar, it’s because scientists are worried the same thing will happen today.
What’s the Context:

The primary theory as to what went wrong at the end of the Triassic period, when this extinction took place, holds that tons of carbon dioxide released during the breakup of the supercontinent Pangaea ratcheted up global temperatures to deadly levels over the course of several hundreds of thousands of years. But these researchers’ work seems to indicate that the change took place even more quickly than that. In a previous study looking at limestone, which is the remains of ancient sea creatures, this team found that it disappeared from the geological record quite suddenly—a mere 20,000 years after the extinction event began.

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The researchers found a spike of carbon dioxide followed by a massive release of methane right at the boundary of the extinction event. They found warming effects in plant growth at the time and an enahnced hydrological cycle – all symptoms of global warming.

Huge amounts of methane – which is a stronger greenhouse gas than carbon dioxide – are found under the ocean’s surface under the forzen permafrost of the Northern reagions.. The structures that hold them in place break down with warming, resulting in catastrophic release of the methane into the atmosphere.

There have already been reports describing how much methane is being relased in Siberia due to warming. Now we are getting a better idea of just what can happen when all that methane is released, as what apparently happened at the Permian-Triassic extinction– the greatest extinction eent ever; 96% of all marine species gone; 70% of all terrestrial species gone; 5-6 million years before any sort of recovery and 30 million until complete recovery.

A tipping point with ocen acidification could cripple ocean ecosystems but the release of methane in such large amounts would decimate everything.

We may have very little time to solve these problems before they are on a path that can not be altered.