Natural Gas Drilling Causes Sizeable Methane Leaks, Study Says

A new study says that methane leaks from natural gas drilling, particularly hydraulic fracturing, are likely higher than previously estimated and concludes that converting vehicles from gasoline to compressed natural gas will actually produce more greenhouse gas emissions unless methane leaks are significantly reduced. The study, authored by scientists from the Environmental Defense Fund and several universities, says that replacing coal-fired power plants with natural gas-fired power plants does lead to a net reduction in greenhouse gas emissions, though not as steep a drop as gas industry advocates contend. The study, published in the Proceedings of the National Academy of Sciences, examines the “technology warming potentials” of different fossil fuels and concludes that better research needs to be undertaken to determine exactly how much methane — a far more potent but shorter-lived greenhouse gas than carbon dioxide — leaks during the cycle of natural gas drilling and transport. The U.S. government has estimated the leakage rate at 2.4 percent, but some studies suggest it is higher.