New Study Finds U.S. Has Greatly Underestimated Methane Emissions

Overall, according to the new study, total methane emissions in the United States appear to be 1.5 times and 1.7 times higher than the amounts previously estimated by the U.S. Environmental Protection Agency (E.P.A.) and the international Emissions Database for Global Atmospheric Research (EDGAR) [link], respectively.

It seems the desire for methane to be a clean replacement for coal keeps running up against the emissions issue.

New Study Finds U.S. Has Greatly Underestimated Methane Emissions - NYTimes.com:

A comprehensive new study of atmospheric levels of methane, an important greenhouse gas released by leaky oil and gas operations and livestock, has found much higher levels over the United States than those estimated by the Environmental Protection Agency and an international greenhouse gas monitoring effort. The paper, “Anthropogenic emissions of methane in the United States,” is being published in the Proceedings of the National Academy of Sciences.
The study, combining ground and aerial sampling of the gas with computer modeling, is the most comprehensive “top down” look so far at methane levels over the United States, providing a vital check on “bottom up” approaches, which have tallied estimates for releases from a host of sources — ranging from livestock operations to gas wells.

The research seems to support previous findings of Robert Howarth, and Andrew Revkin's column includes this comment from Howarth [I've added emphasis]:

Using this new information as well as other independent studies on methane emissions published since 2011, and the latest information on the climate influence of methane compared to carbon dioxide from the latest synthesis report from the Intergovernmental Panel on Climate Change released in September of this year, it is clear that natural gas is no bridge fuel. When used to generate electricity, natural gas likely has a greenhouse gas footprint similar to that for coal. However, when used for domestic heating of water, the greenhouse gas footprint of natural gas is at least two-times larger than that of using modern electric-driven heat pumps.

Society should move as quickly as possible away from using natural gas for water heating and domestic and commercial space heating – uses which are equal to the use of gas to generate electricity in the US. This is the low-hanging fruit for reducing the total greenhouse gas emissions from the United States.