Gas From Fracking Dirtier Than Coal?

Hydraulic fracturing, in pursuit of shale gas, can cause serious groundwater problems, which are sometimes excused on the ground that the climate needs natural gas to displace coal. It's therefore shocking to learn that shale gas could have worse GHG emissions than coal, according to a Cornell study published in the May issue of Climatic Change Letters (105:5):

"We evaluate the greenhouse gas footprint of natural gas obtained by high- volume hydraulic fracturing from shale formations, focusing on methane emissions. Natural gas is composed largely of methane, and 3.6% to 7.9% of the methane from shale-gas production escapes to the atmosphere in venting and leaks over the life- time of a well. These methane emissions are at least 30% more than and perhaps more than twice as great as those from conventional gas. The higher emissions from shale gas occur at the time wells are hydraulically fractured—as methane escapes from flow-back return fluids—and during drill