Tuesday, August 5, 2014

Don' Worry, Be Happy - It's Only the Arctic So Who Cares?

You know when you've eaten something dodgy and you get that rumbling in your guts that tells you this is no time to go too far from the throne? Well, that's sort of what may be going on in the Arctic right now. There's a definite rumbling across the far North that portends potentially explosive outcomes in the near future. From Scientific American

It's not just craters purportedly dug by aliens in Russia, it's also megaslumps, ice that burns and drunken trees. The ongoing meltdown of the permanently frozen ground that covers nearly a quarter of land in the Northern Hemisphere has caused a host of surprising arctic phenomena.

...The most likely explanation for the newly discovered craters in Russia is an accumulation of methane over centuries or more that then burst out of the thawing ground sometime in the last few years. "High pressure built up and [the ground] literally popped open," explains biogeochemist Kevin Schaefer of the U.S. National Snow and Ice Data Center. "If it is indeed caused by melting methane ice, we should expect to see more."

These craters will then become lakes, which further thaw the permafrost around and beneath them as the water traps yet more heat from the sun. Similar new lakes are forming in depressions in the newly thawing lumpy landscape across the Arctic known as thermokarst. Such thermokarst lakes and surrounding marshes create the muddy conditions favoring microbes that break dead plant material down into methane. That methane then bubbles out of the lakes and ground and, where concentrated, can even be lit on fire, leading to cases of flames dancing above the ice.

Even more widespread than blast craters or burning ice are drunken trees. When permafrost thaws, soil that was once as solid as concrete becomes mud, due to the fact that ice makes up as much as 80 percent of the ground in some parts of the Arctic. And because ice takes up more space than water, the ground subsides, causing trees that grew upright to lean as the ground liquefies beneath them. Whole forests have listed like an army of drunkards as a result. This is also bad news for modern infrastructure in the Arctic as well: Roads, pipelines and building foundations sink into mud and crack or entire landscapes subside. "Long term, there are huge economic and social impacts to permafrost degrading," Schaefer notes.

Where the ground slopes, even worse can occur: slumps, which are like slow-moving mudslides that can undermine areas of 40 hectares or more and stretch more than a kilometer across. The largest megaslumps can eat into the landscape at rates of a kilometer per decade and seem to show no signs of stopping. One slump in Russia that has mystified scientists extends more than 70 meters deep into the permafrost and is still growing after starting in the 1970s.

Perhaps the biggest concern of thawing permafrost is a massive and sudden release of methane from the Arctic Ocean and/or permafrost. Methane traps at least eight times more heat than carbon dioxide over decades, driving global warming even faster. The bad news on the belch front are noticeable upticks in the amount of methane produced in the Arctic—an increase of roughly 8 percent over 30 years at the Canada’s Alert Station in the Northwest Territories. And ocean expeditions have observed methane bubbling out of methane ice at the bottom of the Arctic Ocean.

By mid-century, computer simulations predict that as much as a third of the permafrost area in Alaska could thaw, at least at the surface, with similar amounts in Canada and Siberia. Once the melt has kicked in—and the frozen dead plants that make up the top three meters or so of the permafrost become food for microbes that release CO2—the process is irreversible. "You can't refreeze it," Schaefer says. "Once the decay turns on you can't turn it off, and it persists for centuries."

The permafrost already holds vast stores of carbon, as much as 1.7 trillion metric tons according to estimates—or more than twice as much as is currently in the atmosphere today. Not all of that will thaw in the near future—some areas of permafrost extend 700 meters deep—but as much as 120 billion metric tons could be released by 2100. That's enough to raise global average temperatures by nearly a third of a degree Celsius. "These are big numbers," Schaefer notes. But "they are in fact small when compared to those projected from burning coal and oil and natural gas. Those emissions are just immense."

MoS, the Disaffected Lib

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