*UPDATE* EPA’s Massive, Downward Revision of Methane Emissions

UPDATE (4/28/2013; 6:56 pm ET): The Associated Press reports that the EPA has “dramatically lowered its estimate of how much of a potent heat-trapping gas leaks during natural gas production,” based on data in the agency’s latest GHG Inventory. The AP further notes:

The scope of the EPA’s revision was vast. In a mid-April report on greenhouse emissions, the agency now says that tighter pollution controls instituted by the industry resulted in an average annual decrease of 41.6 million metric tons of methane emissions from 1990 through 2010, or more than 850 million metric tons overall. That’s about a 20 percent reduction from previous estimates. The agency converts the methane emissions into their equivalent in carbon dioxide, following standard scientific practice.

The EPA revisions came even though natural gas production has grown by nearly 40 percent since 1990. The industry has boomed in recent years, thanks to a stunning expansion of drilling in previously untapped areas because of the use of hydraulic fracturing, or fracking, which injects sand, water and chemicals to break apart rock and free the gas inside.

Discredited Cornell professor Bob Howarth is cited in the story as saying, “I think EPA is wrong,” an ironic shift — especially considering how the Howarth/Ingraffea paper relied so heavily on data from the EPA. He also seemed puzzled that more people aren’t extrapolating larger meaning from NOAA’s research on emissions — the same research from which the Environmental Defense Fund said “conclusions should not be drawn,” and which has been categorically debunked.

Surprise, surprise. The more data that come out, the less accurate the Howarth thesis on “leakage” becomes.

Original post, April 16, 2013

One of the subjects that seems to have captivated the welter of reporters and bloggers now writing on shale, natural gas and climate on a fairly regularly basis is the infamous “methane leak” issue. Namely: How much of it is “leaking” from natural gas systems? And at what rate does natural gas lose its greenhouse gas advantages under a scenario in which fugitive emissions continue to increase?

New data from the U.S. Environmental Protection Agency may not answer all of those questions in a comprehensive fashion, but they do strongly suggest that activists’ arguments about “the methane problem” for natural gas development are without merit. They also suggest that methane emissions aren’t increasing it all. They’re decreasing, actually — even as more wells and greater production come online.

The new data come from the EPA’s latest Greenhouse Gas Inventory, which was released earlier this week. You can read EPA’s release here and the full report here. The most notable part of the Inventory – in addition to the admission that, thanks to natural gas, U.S. GHGs declined once again – was the downward, post-hoc adjustment of the agency’s previous methane emission estimates from natural gas systems.

The chart below details what EPA found with respect to methane emissions from natural gas systems in this year’s report compared to the figures it used in last year’s report:

                            1990     2007     2008     2009     2010

2012 report:      189.6    205.3    212.7    220.9    215.4
2013 report:      161.2    168.4    163.4    150.7    143.6

Diff. (raw):            28.4      36.9      49.3      70.2       71.8
Diff. (%):               15%      18%      23%     32%       33%

(All raw numbers listed in million metric tons of CO2 equivalent)

So, then: what do all these data mean? Three things jump out immediately.

The first is that EPA’s 2012 report attempted to argue that methane emissions had increased every single year from 1990 through 2009, with a slight decline in 2010.  But revised data issued in 2013 demonstrate precisely the opposite: in fact, there has been a significant and consistent decline in total methane emissions since 1990. Last year’s report suggested an increase in methane emissions of 14 percent since 1990. EPA’s new data show a decline of 11 percent.

The second is that EPA’s 2013 data show an increasing gap between agency estimates in 2012 and what it released this year – and always in the direction of fewer emissions. This suggests, at a minimum, that EPA’s original data set was deeply flawed (more on that in a moment).

The third point is that methane emissions are falling even as natural gas production continues to increase dramatically. Since 1990, U.S. natural gas production has increased by 38 percent. Since 2007, it has increased by 26 percent. There is simply no credible explanation for this divergence – more wells, greater production, fewer emissions – other than the role that significantly and consistently improving technologies continue to play in making the development process safer, cleaner and more efficient.

Indeed, for the narrative to be true that natural gas systems have a “leakage” problem in the United States, we have to exit the realm of fact-based reality and enter the world of baseless assumptions: We have to assume, for example, that the same technologies that reduced emissions by 11 percent even as production expanded by 38 percent are also somehow mysteriously leaking like uncontrolled sieves across the country. But, looking at this data, can anyone really believe that?

So, then: what explains EPA’s downward adjustment of estimated emissions?

The answer lies in a fact sheet that EPA released yesterday summarizing its latest report. Among other things, EPA cites a study from URS Corporation released last year as having better data for the “liquids unloading” stage. From the fact sheet:

“The [URS] study data show that there is more widespread use of emissions control technologies than had been assumed in the previous Inventory. It also demonstrated that duration of emissions from liquids unloading activities is shorter than had been assumed in the previous Inventory.” (emphasis added)

So, in essence, updated and more accurate data reveal significantly smaller amounts of methane being emitted by natural gas systems.

But wait, there’s more.

The URS Corporation study that EPA cited as having better data than its own prior estimates is the same study that Cornell activists Robert Howarth and Anthony Ingraffea trashed as “fatally flawed.” Howarth and Ingraffea said the study was “almost useless,” but clearly the U.S. EPA disagrees.

So, to whom should we ascribe more credibility: two activists whose funding comes from an entity trying to “fuel an army” to oppose fracking (and whose research has been debunked throughout the academic community), or the U.S. Environmental Protection Agency?

Of course, Howarth and Ingraffea also leaned heavily on EPA’s prior data in an attempt to validate their own research as it was continuously being called into question by their peers. In their response to Cornell colleague Lawrence Cathles, who comprehensively debunked their report, Howarth and Ingraffea cited EPA’s 2011 Greenhouse Gas Inventory as having data that fell “within our estimated range” of methane emissions from shale gas. Howarth and Ingraffea also admitted: “Our high-end methane estimates for both conventional gas and shale gas are substantially higher than EPA,” comparing once again their results to EPA’s 2011 inventory.

EPA’s 2011 estimates for methane emissions from natural gas systems were almost identical to the numbers released in the 2012 Inventory – the same numbers that EPA has now dramatically revised downward based on better data. That means Howarth and Ingraffea’s emissions estimates have been even further marginalized, if such a thing is even possible.

And remember: Howarth said that NOAA’s leakage estimates (from a study conducted last year) “are coming in very close to ours, maybe a little higher.” If that’s the case, then Michael Levi’s critique of the NOAA study is at the very least supported – if not entirely validated – by EPA’s latest Inventory.

What this all boils down to is both simple and significant: the “scholarly” argument against the climate benefits of natural gas – which was always premised on the Howarth and Ingraffea research, and then supposedly supplemented by NOAA’s findings – has now been rejected by EPA. And as technologies continue to improve, it’s hard to imagine those methane numbers going anywhere but down as we eagerly await the next installment of this EPA report.

Comments

  1. Karl Schwartz says:

    Nature | News

    Air sampling reveals high emissions from gas field

    Methane leaks during production may offset climate benefits of natural gas.
    Jeff Tollefson

    07 February 2012

    snip:
    The team analysed the ratios of various pollutants in the air samples and then tied that chemical fingerprint back to emissions from gas-storage tanks built to hold liquid petroleum gases before shipment. In doing so, they were able to work out the local emissions that would be necessary to explain the concentrations that they were seeing in the atmosphere (see ‘A losing battle’). Some of the emissions come from the storage tanks, says Pétron, “but a big part of it is just raw gas that is leaking from the infrastructure”. Their range of 2.3–7.7% loss, with a best guess of 4%, is slightly higher than Corn­ell’s estimate of 2.2–3.8% for shale-gas drilling and production. It is also higher than calculations by the EPA, which revised its methodology last year and roughly doubled the official US inventory of emissions from the natural-gas industry over the past decade. Howarth says the EPA methodology translates to a 2.8% loss.

    • Steve, EID Spokesman says:

      Thanks for commenting Karl.

      I would recommend you read what the Environmental Defense Fund said about that NOAA study (and its followup, which looked at a field in Utah), specifically this:

      “While the Colorado and Utah studies offer valuable snapshots of a specific place on a specific day, neither is a systematic measurement across geographies and extended time periods and that is what’s necessary to accurately scope the dimensions of the fugitive methane problem. For this reason, conclusions should not be drawn about total leakage based on these preliminary, localized reports. Drawing conclusions from such results would be like trying to draw an elephant after touching two small sections of the animal’s skin: the picture is unlikely to be accurate.”

      SOURCE: http://blogs.edf.org/energyexchange/2013/01/04/measuring-fugitive-methane-emissions/

      Michael Levi, an energy and climate change expert at the Council on Foreign Relations, has also completely debunked the NOAA research in a peer-reviewed journal. Read more here: http://www.energyindepth.org/four-key-facts-on-the-noaa-shale-study/

      Again, thanks for reading!

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