Opponents of natural gas production are heralding the release of a new study that finds hydraulic fracturing (fracking), the process used to break apart underground shale deposits with high pressure water and chemicals in order to release shale gas, generates at least 20% more greenhouse gases than coal.
Previously, opponents had rallied around the threat the process posed to water supplies. Some studies have found possible evidence that hydrofracking fluids can contaminate water aquifers. The industry, meanwhile, argues these findings.
The new study, conducted by scientists at Cornell University, evaluated the greenhouse gas footprint of natural gas obtained by fracking. They found that the small amounts of methane gas, a greenhouse gas with greater warming potential than carbon dioxide, escaping to the atmosphere from venting and leaks over the life of a well is 30% higher than emissions from conventional gas. Since the greatest danger of methane leaks is during the initial fracking process, the emissions are greatest in the short-term. The study found emissions to be 20% greater than coal on a 20-year comparison, but comparable to coal over 100 years. The study notes that although the uncertainty of fugitive emissions is large, it illustrates the larger need for published and consistent pollution measurement by the gas industry. So far the industry has fought such measures.
Meanwhile, critics of the Cornell study are crying foul over the uncertainties and pointing to the advantages clean-burning gas has over coal. Energy in Depth, an association of independent producers, has posted a rebuttal to the study. And Tom Zeller, Jr. has posted a thoughtful post about the debate on the New York Times’ Green Blog. With the future of nuclear power up in the air, the debate over natural gas is an important one.
You can read a PDF of the Cornell study here.