Arrhenius’ ideas about feedback effects— mentioned in the March 23 post— were generally ignored, since he wasn’t predicting calamity and he’d made some mistakes. But the substance of his work was dismissed mainly because the idea of humanity affecting the Great Cycles of Nature was out of the question.
It's not about the glove, it's about the bubbles.
In 1896 global population was 1 billion people, and despite the sooty air in coal-burning cities like London, global emissions were relatively low. No cars, no CFCs, far less deforestation. Urban dwellers were still a minority, and most people lived in conditions similar to those of the 14th century. It was a tough sell asking a scientist like Arrhenius to believe that human-caused pollution could, within a century, screw up the biosphere.
What Arrhenius didn’t have data on were the wild cards. Two such factors are embedded carbon dioxide and methane – greenhouse gases locked by ice into glaciers, the sea-floor, Arctic permafrost and undersea shelves.
As glaciers retreat, and sea-ice disappears—and permafrost melts— both of these gases enter the atmosphere. This in turn raises temperature, which in turn melts permafrost and glaciers more quickly. This is not your parents’ feedback, not Jimi on a Marshall amp. This is bad feedback. An Earth-size headache.
This may be Mr. Semiletov. Click for source.
The amount of carbon dioxide trapped in the world’s thawing tundra and northern taiga landscapes is estimated at 1.5 trillion tons, more than twice what is currently in the atmosphere. As for methane, it’s a greenhouse gas 20 times as potent as carbon dioxide in trapping solar heat in the short term (over a twenty-year period it’s 72 times as potent).
Igor Semiletov and Natalia Shakhova, two Russian scientists with the International Arctic Research Center, have studied the increasing release of methane from a submerged land mass known as the East Siberian Arctic Shelf (ESAS). As temperatures rise in the Arctic and sea-ice disappears, the global warming picture is quickly changing.
“The amount of methane currently coming out of the East Siberian Arctic Shelf is comparable to the amount coming out of the entire world’s oceans,” said Shakhova in a National Science Foundation (NSF) press release. “Subsea permafrost is losing its ability to be an impermeable cap.” The amount of methane stored in the shelf is estimated at 2,000 gigatons, equal to 250 years of carbon emissions at our current industrial levels of output.
If just one percent of ESAS methane escapes its crystal prison, Semiletov suggested at a geophysical conference in 2008, it might push total methane to 6 parts per million. Some researchers consider this is a tipping point towards ‘runaway climate change.’ If that term doesn’t summon up an image, you can take NASA scientist James Hansen’s suggestion of an “ice-free state” where the Greenland and Antarctic ice sheets melt entirely, raising global sea level by over 200 feet.
“It is high time to warn people,” Semiletov told the conference attendees, but then took a pause, and offered an apologetic smile before adding: “We can do nothing about it, of course.”
Courtesy the NSF. Click for article.
The usually staid NSF recently backed up Semiletov in a press release. “Permafrost under the East Siberian Arctic Shelf, long thought to be an impermeable barrier sealing in methane, is perforated and is starting to leak large amounts of methane into the atmosphere. Release of even a fraction of the methane stored in the shelf could trigger abrupt climate warming.”
This idea of a methane “time bomb” is the global warming equivalent of Dr. Strangelove’s Doomsday Machine, that apotheosis of Mutual Assured Destruction that once initiated, can’t be turned off. Even Kennedy and Khrushchev could come to detente during the Cuban Missile Crisis and agree to take their fingers off their red buttons. But you can’t reason with a frozen gas bubble.