Fracking Would Emit Large Quantities of Greenhouse Gases

By Mark Fischetti | Scientific American – 12 hrs ago

Add methane emissions to the growing list of environmental risks posed by fracking.

Opposition to the hydraulic fracturing of deep shales to release natural gas rose sharply last year over worries that the large volumes of chemical-laden water used in the operations could contaminate drinking water. Then, in early January, earthquakes in Ohio were blamed on the disposal of that water in deep underground structures. Yesterday, two Cornell University professors said at a press conference that fracking releases large amounts of natural gas, which consists mostly of methane, directly into the atmosphere—much more than previously thought.

Robert Howarth, an ecologist and evolutionary biologist, and Anthony Ingraffea, a civil and environmental engineer, reported that fracked wells leak 40 to 60 percent more methane than conventional natural gas wells. When water with its chemical load is forced down a well to break the shale, it flows back up and is stored in large ponds or tanks. But volumes of methane also flow back up the well at the same time and are released into the atmosphere before they can be captured for use. This giant belch of "fugitive methane" can be seen in infrared videos taken at well sites.

Molecule for molecule, methane traps 20 to 25 times more heat in the atmosphere than does carbon dioxide. The effect dissipates faster, however: airborne methane remains in the atmosphere for about 12 years before being scrubbed out by ongoing chemical reactions, whereas CO2 lasts 30 to 95 years. Nevertheless, recent data from the two Cornell scientists and others indicate that within the next 20 years, methane will contribute 44 percent of the greenhouse gas load produced by the U.S. Of that portion, 17 percent will come from all natural gas operations.

http://news.yahoo.com/fracking-emit-large-quantities-greenhouse-gases-200000721.html