By David Edwards
Monday, April 11th, 2011
Shale gas, produced by “hydraulic fracturing” or “fracking,” could create as much as twice the greenhouse gasses as coal, according to a study soon to be published by Cornell University professors.
Over the past few years, the Washington D.C. consensus has been that shale gas is better for the environment than coal. President Obama has praised natural gas and given it partial credit in his proposed “clean energy standard.”
But Cornell Prof. Robert Howarth argues in the new study that making natural gas available through “fracking” contributes more to global warming than conventional gas and coal over 20 years.
“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,” a pre-publication version of the study (.pdf) — obtained by The Hill — said.
“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 out following the fracturing,” the study added.
“The footprint for shale gas is greater than that for conventional gas or oil when viewed on any time horizon, but particularly so over 20 years. Compared to coal, the footprint of shale gas is at least 20% greater and perhaps more than twice as great on the 20-year horizon and is comparable when compared over 100 years.”