"As natural gas production in the United States hits an all-time high, a major unanswered question looms: What does growing hydraulic fracturing mean for climate change?"
"The Obama administration lists natural gas as one of the 'clean energy sources' it wants to expand. When burned, natural gas emits about half the heat-trapping carbon dioxide as coal. Yet natural gas production can result in releases of methane into the atmosphere.
Methane, the primary component of natural gas, is 25 times more potent as a greenhouse gas than carbon dioxide. Methane can enter the atmosphere when gas is stored or transported, but it's particularly a concern with shale gas production during flowback -- when fracking fluids, water and gases flow out of a well after drilling but before the gas is put into pipelines.
Companies often burn or capture the methane during flowback. How extensively or effectively that's done overall, however, isn't clear."
Renee Schoof reports for McClatchy Newspapers March 18, 2012.
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