World's Worst Gas Leak: Methane Released as Permafrost Melts
Debate has erupted in the scientific community as a study puts the economic cost of a mega-burst of methane that could be emitted by melting Siberian permafrost over the next decade or two at $60 trillion—about equal to the entire world’s economic output in 2012.
The study, published on July 25 in the journal Nature, based its economic price tag on the assumption that a 50-gigatonne reservoir of methane on the East Siberian Arctic Shelf “is likely to be emitted as the seabed warms, either steadily over 50 years or suddenly,” the paper said. This will lead to higher atmospheric concentrations of methane, which will accelerate global warming as well as Arctic ice melt, wrote the three authors, Gail Whiteman, Chris Hope and Peter Wadhams.
“The ramifications will be felt far from the poles,” they said. Further, the article made the point that the business opportunities being slavered over by oil and resource companies to the tune of $100 billion are dwarfed by this potential cost.
At issue, besides the question of whether we can expect such a methane “pulse,” is how quickly the permafrost will melt relative to how long the methane—which does not stick around as long as carbon dioxide—will last in the atmosphere. Those critiquing the study say that the greenhouse gas will not build up faster than methane dissipates, which takes about two years. In contrast, carbon dioxide, the other potent greenhouse gas, can linger for centuries, a recent study found. And melting permafrost has also been a concern in Alaska.
Regardless of how much the dollar amount is, said co-author Wadhams, who heads the Polar ocean physics group at Cambridge University, in a rebuttal to the initial critique in the Washington Post, “the planetary cost of Arctic warming far outstrips the benefits (from shipping and oil exploration) that have been talked about so confidently by some politicians.”
The naysayer, Jason Samenow, set off a chain reaction of sorts as expert after expert came forward to concur that the methane-belch scenario is not that probable.
"The paper says that their scenario is 'likely.' I strongly disagree," said Gavin Schmidt, a climate scientist at the NASA Goddard Institute for Space Studies in New York, to LiveScience.com. He explained that summer sea ice has nearly disappeared before, during previous warm geological eras, and did not result in the melting of methane hydrates trapped in permafrost as predicted by Wadhams and his team.
However, Wadhams said that today’s factors are different.
"The mechanism which is causing the observed mass of rising methane plumes in the East Siberian Sea is itself unprecedented, and the scientists who dismissed the idea of extensive methane release in earlier research were simply not aware of the new mechanism that is causing it," wrote Wadhams, an oceanographer at the University of Cambridge in the United Kingdom. "But once the ice disappears, as it has done, the temperature of the water can rise significantly, and the heat content reaching the seabed can melt the frozen sediments at a rate that was never before possible."
Either way, the current models being used to calculate climate change may be missing some key variables, simply because they cannot be known until they happen. A rash of recent studies have shown how aspects of climate change influence other factors that compound and cloud the issue.
“What is missing from the equation is a worldwide perspective on Arctic change,” wrote the paper’s three authors. “More modeling is needed to understand which regions and parts of the world economy will be most vulnerable.”
The Antarctic is not immune from such melt either. As this debate erupted, the Los Angeles Times was reporting on another study, this one published in the journal Nature Scientific Reports, that found melt rates of buried ice in the Garwood Valley “that shifted from a creeping annual rate of about 40,000 cubic feet per year over six milleniums, to more than 402,000 cubic feet last year alone,” the newspaper reported on July 24.
“We think what we’re seeing here is sort of a crystal ball of what coastal Antarctica is going to experience,” said geologist Joseph Levy, of the University of Texas, lead author of the study, to the Los Angeles Times. “When you start warming buried ice and other permafrost in the dry valley, it’s going to start to melt and it’s going to start melting in a style that’s consistent with permafrost thaw in the Arctic.”
Regardless of how much the melting permafrost will cost economically, other manifestations of climate change are already being felt, especially by Indigenous Peoples. Even if methane does suddenly get unleashed into the atmosphere, could damage be mitigated if we were to harness it for energy?