[geo] Methane - time for realism

[John Nissen]

http://www.worldchanging.com/archives/011011.html Methane Melt: The Most Important Story You Don't Follow Alex Steffen, 5 Mar 10 We've written before about the danger that climate change will lead to the thawing and release of methane frozen on the ocean floor, and indeed the worrisome news that some scientists were observing patches of Arctic sea foaming with gas bubbles from "methane chimneys" rising from the sea floor. Now, researchers in Alaska have found a similar process underway: Natalia Shakhova, a scientist at the university and a leader of the study, said it was too soon to say whether the findings suggest that a dangerous release of methane looms. In a telephone news conference, she said researchers were only beginning to track the movement of this methane into the atmosphere as the undersea permafrost that traps it degrades. But climate experts familiar with the new research reported in Friday’s issue of the journal Science that even though it does not suggest imminent climate catastrophe, it is important because of methane’s role as a greenhouse gas. Although carbon dioxide is far more abundant and persistent in the atmosphere, ton for ton atmospheric methane traps at least 25 times as much heat. Until recently, undersea permafrost has been little studied, but work so far shows it is already sending surprising amounts of methane into the atmosphere, Dr. Shakhova and other researchers are finding. Last year, scientists from Britain and Germany reported that they had detected plumes of methane rising from the Arctic seabed in the West Spitsbergen area, north of Scandinavia. At the time, they said they had begun their work hoping to gain data to predict future emissions and had not expected to find evidence that the process was under way. It is “indispensable” to keep track of methane in the region, Martin Heimann of the Max Planck Institute in Germany said in a commentary accompanying the Science report. So far, Dr. Heimann wrote, methane contributions from Arctic permafrost have been “negligible.” He added: “But will this persist into the future under sustained warming trends? We do not know.” In an e-mail message, Euan G. Nisbet of the University of London, an expert on atmospheric methane, said the situation “needs to be watched carefully.” Atmospheric concentrations of methane have more than doubled since pre-industrial times, Dr. Heimann wrote. Most of it comes from human activities including energy production, cattle raising and the cultivation of rice. But about 40 percent is natural, including the decomposition of organic materials in wetlands and frozen wetlands like permafrost. Dr. Shakhova said that permafrost in the East Siberian Arctic Shelf, peat land that flooded as sea levels rose after the last ice age, is degrading in part because runoff from rivers that feed the Arctic Ocean is warmer than in the past. She estimated that annual methane emissions from the East Siberian Arctic Shelf total about seven teragrams. (A teragram is 1.1 million tons.) By some estimates, global methane emissions total about 500 teragrams a year. Dr. Shakhova said that undersea methane ordinarily undergoes oxidation as it rises to the surface, where it is released as carbon dioxide. But because water over the shelf is at most about 50 meters deep, she said, the gas bubbles to the surface there as methane. As a result, she said, atmospheric levels of methane over the Arctic are 1.85 parts per million, almost three times as high as the global average of 0.6 or 0.7 parts per million. Concentrations over the shelf are 2 parts per million or higher. A huge release of one-frozen methane is (potentially) almost the definition of a feedback loop, perhaps even a tipping point into runaway climate change. Luckily, we're not there yet. Scientists have been very clear to say that while these field observations are surprising and disturbing, they do not yet indicate a catastrophe. We need to wait for more data to figure out if it's time to panic yet. In the meantime, we need to focus even more strongly on four solution spaces: 1) Getting to a zero net emissions economy as quickly as possible. It's very clear now that we can do this at a net gain for society, with more (and more wide-spread) prosperity for most people, and that it's largely the opposition of entrenched interests that's preventing us from making huge strides forward: this needs to change. 2) Implementing climate-adaptive ecological restoration, safeguarding ecosystem services and researching soil carbon sequestration and other practices that have multiple benefits while pulling greenhouse gasses from the air. We need to be helping the planet's natural systems heal towards resilience as much as we possibly can. 3) Engaging in a stronger and more realistic debate about geoengineering, its limits and its politics, especially since news of potential tipping points always accelerates calls for geoengineering research, even deployment. Geoengineering's main use in the climate debate at the moment is as a propaganda tool by those seeking to stall action on emissions reduction; that doesn't mean that we don't need to discuss what mega-scale answers might be possible should we find tipping points sliding past more quickly than we feared. 4) Building psychological resilience in the face of huge and alarming planetary changes. News like this is disturbing. We need to find ways, as a culture, as communities and as individuals, to understand disturbing changes without losing our balance. Psychologically wrecked people are no good to themselves, others or the planet. We need to promote the capacity to be healthy and happy despite monumental challenges. -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To post to this group, send email to geoengineer...@googlegroups.com. To unsubscribe from this group, send email to geoengineering+unsubscr...@googlegroups.com. 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