An important new study measures actual methane levels in the U.S. atmosphere. Â This is a case where the total is definitely more than the previously imagined sum of its parts. The study, soon to be published in the Proceedings of the Natural Academy of Sciences (PNAS), found, in particular, that the EPA continues to greatly under-estimate methane emissions from shale gas production, as well as from fossil fuel extraction and processing in general.
Andrew Revkin, who wrote yesterdayâs New York Times article, âNew study finds U.S. has underestimated methane levels in the atmosphere,â also co-wrote a key analysis four years ago in the New York Times, revealing how serious the EPAâs under-estimation of methane emissions from gas wells was at that time.
Since methane is responsible for up to half of the total U.S. contribution to global greenhouse gasses, methaneâs importance cannot be overstated. But the EPA has yet to re-vamp its estimates. Yesterdayâs headline is eerily reminiscent of another headline just over two months ago after the results of another new study in Utah came out: âSomething in the Air: Latest Research Finds Methane Leaks from Gas, Oil Production Much Higher than EPA Estimates.â
From yesterdayâs New York Times (November 25th, 2013):
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, âAnthropogenic emissions of methane in the United States,â 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 âtop downâ look so far at methane levels over the United States, providing a vital check on âbottom upâ approaches, which have tallied estimates for releases from a host of sources â ranging from livestock operations to gas wells.