Tuesday, September 30, 2008

Scientists: Climate-Change 'Time Bomb' About to Go Off

There's a ticking time bomb underneath the oceans, and it's about to go off, some scientists say.

A Russian research ship trawling the Arctic off Siberia's northeastern coast has found huge amounts of methane bubbling up from the seafloor, according to reports in London's Independent newspaper and the Canadian Press wire service.

Methane is a potent greenhouse gas, trapping 20 times as much heat as carbon dioxide. While there's little of it in the atmosphere, there are gigantic frozen deposits of it, called methane clathrates, trapped in rocks in seabeds all over the world.

One of the leading global-warming doomsday scenarios involves all that methane thawing out as sea temperatures rise, then rushing to the surface and into the air, creating a runaway warming scenario.

Now there's some evidence that's beginning to happen.

"For the first time, we documented a field where the release was so intense that the methane did not have time to dissolve into the seawater but was rising as methane bubbles to the sea surface," Swedish researcher Orjan Gustafsson, aboard the Russian ship Jacob Smirnitskyi, told the Independent in an article published last week.  - fox

Methane bubbles may be the real reason for ship disappearances in the Bermuda Triangle. A large bubble can make the ocean lighter than air so a ship sinks like a stone within minutes.

Perhaps there is so much frozen methane under the ocean that it's release will cause a mass suffocation of life, by lowering the oxygen content or our air beyond our ability to survive.  This, some say, has happened before.
.. The oxygen-starved aftermath of an immense global belch of methane left land animals gasping for breath and caused the Earth's largest mass extinction, suggests new research.

Greg Retallack, an expert in ancient soils at the University of Oregon in Eugene, says his theory also explains the mysterious survival of a barrel-chested reptile that became the most common animal on the planet after the end of the Permian period, 251 million years ago.

Paleontologists have long puzzled over the mass extinction at the end of the Permian. There is no evidence for a large asteroid impact, but sharp changes in carbon isotope ratios indicate something triggered massive releases of frozen methane hydrates from under the sea floor and in permafrost. ... Bob Berner of Yale University calculated that a cascade of effects on wetlands and coral reefs would have reduced oxygen levels in the atmosphere from 35 per cent to just 12 per cent in only 20,000 years - a fleeting moment in geological time.

Retallack knows the effects of low oxygen levels all too well. "I've just about died of mountain sickness at [the equivalent of] 12 per cent oxygen" while working at high altitudes, he told New Scientist. "I know exactly what it's like."

Lungs used to higher oxygen levels strain desperately for oxygen, and fill with fluid. The lack of oxygen would have left most Permian land animals gasping for breath, suffering from nausea, headaches, and inflamed lungs. Marine life would have suffocated in the oxygen-poor water.

Yet the ungainly meter-long reptile Lystrosaurus survived because it had evolved to live in burrows, where oxygen levels are low and carbon dioxide levels high. It had developed a barrel chest, thick ribs, enlarged lungs, a muscular diaphragm and short internal nostrils to get the oxygen it needed. Retallack says Sherpas have developed some similar adaptations by living at high altitudes for generations.

While most Permian animals died gasping for breath, Lystrosaurus spread rapidly. In some areas, it accounts for 90 per cent of the fossils found after the extinction.

Oxygen depletion also could explain why coal swamps and coral reefs disappeared for millions of years after the extinction, says Retallack, as both are highly sensitive to oxygen levels....  - newsci

Massive releases of methane would eat up our oxygen creating water and carbon dioxide.

Methane and oxygen readily react to form water and carbon dioxide.
The reaction is exothermic, and CO2 and water are both at a
much more stable (lower) energy state than methane and oxygen. - anl


I've had several "end of the world" dreams. In one I'm in a room with a black hole. In another the Moon is crashing into the Earth. In another there is nuclear war. In one, fires are popping up all over the place from the ground. The methane scenario seems like it fits the last one.

But perhaps not. The wikipedia article says the latest estimates show there really isn't that much frozen methane after all. Good thing! Just in case, we should learn how to live where there is no oxygen, like the Crucian Carp pictured above.

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