Shale gas: Gangplank to a Warm Future
ITHACA, N.Y. MANY concerned about climate change, including President Obama, have embraced hydraulic fracturing for natural gas. In his recent climate speech, the president went so far as to lump gas with renewables as clean energy.
As a longtime oil and gas engineer who helped develop shale fracking techniques for the Energy Department, I can assure you that this gas is not clean. Because of leaks of methane, the main component of natural gas, the gas extracted from shale deposits is not a bridge to a renewable energy future its a gangplank to more warming and away from clean energy investments.
Methane is a far more powerful greenhouse gas than carbon dioxide, though it doesnt last nearly as long in the atmosphere. Still, over a 20-year period, one pound of it traps as much heat as at least 72 pounds of carbon dioxide. Its potency declines, but even after a century, it is at least 25 times as powerful as carbon dioxide. When burned, natural gas emits half the carbon dioxide of coal, but methane leakage eviscerates this advantage because of its heat-trapping power.
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A 2011 study from the National Center for Atmospheric Research concluded that unless leaks can be kept below 2 percent, gas lacks any climate advantage over coal. And a study released this May by Climate Central, a group of scientists and journalists studying climate change, concluded that the 50 percent climate advantage of natural gas over coal is unlikely to be achieved over the next three to four decades. Unfortunately, we dont have that long to address climate change the next two decades are crucial.
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complete piece:
http://www.nytimes.com/2013/07/29/opinion/gangplank-to-a-warm-future.html
Anthony R. Ingraffea is a professor of civil and environmental engineering at Cornell University and the president of Physicians, Scientists and Engineers for Healthy Energy, a nonprofit group.