A study conducted by a Stanford University associate professor of energy resources engineering and other scientists evaluated more than 200 scientific papers relating to methane emissions in the United States and Canada. The results of the study entitled “Methane Leakage from North American Natural Gas Systems” are published in the February 14th edition of the journalScience.
According to the scientists, organizations such as the U.S. Environmental Protection Agency have underestimated methane emissions generally as well as those from the natural gas industry specifically. “Atmospheric tests covering the entire country indicate around 50% more than EPA estimates.” The study shows that a significant portion of the methane comes from leakage at conventional well sites, processing plants, storage tanks, and pipelines or other distribution centers. The scientists also found that there was no increase in methane leakage due to hydraulic fracturing.
This study concludes that the natural gas industry must maintain its equipment in order to avoid all unintentional leaks. “Reducing easily avoidable methane leaks from the natural gas system is important for domestic energy security,” according to Robert Harriss, a methane researcher at the Environmental Defense Fund and a co-author of the study.
It should be noted that a September 2013 study by the University of Texas published in the Proceedings of the National Academy of Sciences entitled “Measurements of methane emissions at natural gas production sites in the United States” found that well completion emissions were lower than previously estimated by the EPA and that estimates of total emissions were similar to the EPA’s estimates. These conclusions were reached after taking direct measurements of methane emissions at 190 onshore natural gas sites in the US.