The EPA recently announced new regulations for methane emissions, taking an important first step in reducing the impact of this highly potent greenhouse gas (GHG). But the rule falls short, in part because EPA has systematically underestimated methane emissions from the oil and gas industry. Emissions from conventional natural gas are likely to be at least 2- to 3-fold greater than the EPA estimates, according to several recent studies. Recent literature also suggests emissions from shale gas may be twice as much greater still, based on an observed large increase in methane in the atmosphere over recent years, with the boom in shale gas and shale oil production in the U.S.
Further, the proposed regulations neglect the existing natural gas infrastructure, which by one estimate will account for nearly 90% of methane emissions by 2018. While EPA may revisit regulating existing sources after giving industry time to achieve reductions through voluntary programs, the chances of meeting the Obama Administration goal of a 40-45% reduction in methane emissions by 2025 are low without addressing existing sources of methane.
Methane is a much more potent GHG than carbon. However, because methane stays in the atmosphere for only 12 years, its long-term influence is somewhat diminished — unless, of course, it results in a fundamental change in the climate. If current trends continue, over the next 15-35 years the Earth could reach dangerously high temperatures that represent a growing risk of a tipping point where the release of enormous stores of methane from polar ice may lead to runaway global warming. As a result, immediately decreasing methane emissions is critical.
Reducing all sources of emissions should be a priority for the Obama Administration, but, in an ongoing effort to label natural gas as a bridge fuel, they are missing the importance of properly regulating methane emissions. The global warming potency of methane must be considered in dealing with increased natural gas production, and it should be regulated accordingly.