New Study: EPA Seriously Underestimates Methane Emissions
An important new study measures actual methane levels in the U.S. atmosphere. 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 yesterday’s New York Times article, “New study finds U.S. has underestimated methane levels in the atmosphere,” also co-wrote a key analysis four years ago in the New York Times, revealing how serious the EPA’s 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, methane’s importance cannot be overstated. But the EPA has yet to re-vamp its estimates. Yesterday’s headline is eerily reminiscent of another headline just over two months ago after the results of another new study in Utah came out: “Something in the Air: Latest Research Finds Methane Leaks from Gas, Oil Production Much Higher than EPA Estimates.”
From yesterday’s 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, “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.
Revkin refers back to the EPA’s own admission four years ago that they were seriously under-reporting methane emissions from gas wells:
As early as 2009, as I explained in a front-page article co-written with Clifford Krauss, the E.P.A. was acknowledging that its estimates for methane leaks from gas wells at that time were likely far too low:
An E.P.A. review of methane emissions from gas wells in the United States strongly implies that all of these figures may be too low. In its analysis, the E.P.A. concluded that the amount emitted by routine operations at gas wells … is 12 times the agency’s longtime estimate of nine billion cubic feet. In heat-trapping potential, that new estimate equals the carbon dioxide emitted annually by eight million cars.
It’s important to note that the new study is a snapshot of conditions in 2007 and 2008, before concerns increased about the need for tighter standards for gas and oil drilling operations.
Ruminating about Methane Spike in South-Central U.S.
In the Harvard press release, the lead author comments on the high methane levels in the south-central U.S.:
“The bottom-up and top-down approaches give us very different answers about the level of methane gas emissions,” notes lead author Scot M. Miller, a doctoral student in Earth and Planetary Sciences through the Harvard Graduate School of Arts and Sciences. “Most strikingly, our results are higher by a factor of 2.7 over the south-central United States, which we know is a key region for fossil-fuel extraction and refining.
Some may speculate that the methane emissions in the south-central U.S. may be due as much to dairy farms full of ruminants, particularly cows, which produce a lot of methane, as well as from oil and gas extraction and refining in general and life-cycle impacts from shale gas fracking, in particular.
However, the devil’s in the details: these scientists measured not only methane, but also propane, which is produced by gas wells but not by cows. This “suggests,” in science-speak, that gas drilling and fossil fuel operations are predominantly responsible for the methane spike in the south-central United States. Revkin explains:
In addition, they drew correlations between methane levels and other gases that were observed at the time. For example, a high correlation between levels of methane and propane in the south-central region suggests a significant role for fossil fuels there.
The study’s findings are considered to be “robust,” because of the technology used and the collaborative approach among multiple institutions. Harvard’s Miller and Wofsy, along with colleagues at the Carnegie Institution for Science, the National Oceanic and Atmospheric Administration (NOAA), and five other institutions, used a combination of observation and modeling to conduct their analysis.
Finally, Revkin took the time to email several scientists inviting them to comment on the findings. Cornell climatologist Bob Howarth sent in an eloquent response summing up the policy implications of these findings, in combination with other findings. Howarth wrote:
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.
When you add up that there is more methane being emitted than E.P.A. has estimated, that methane is responsible for up to half of all the greenhouse gas emissions for the entire US, and that each unit of methane emitted is far more important in causing global climate change over the critical few decades ahead, it should be clear that bridge-fuel argument just doesn’t hold up. And the oil and gas industry is the major source of these methane emissions.
Human — and Animal — Toll from Methane Emissions
Lest we forget what all this seemingly dry science, with its corrolary — debates over data and policy implications — really means, we need look no further than the faces of survivors of Typhoon Haiyan. Methane continuing to spike means rapidly escalating global warming. Ocean temperature rises fast, and as oceans warm, warmer air picks up more moisture, feeding the weather patterns that create more ferocious, devastating storms more frequently.
Look into the eyes of a Haiyan survivor… and then head to your nearest resistance movement to head off fracking exports, resist the next pipeline, change public opinion, or block trucks at a fracking waste re-injection site, as two protesters were arrested for doing two days ago in Ohio. Those protesters held up a banner saying “Fracking Hurts Communities,” which is broadly true: from the Maldives to the Philippines, from Flower Mound, Texas to Houston, Pennsylvania — home of the heavily polluting MarkWest processing plant for natural gas liquids — different communities are hurt in different ways and on different timelines. Feel the hurt — and work to stop it.