Despite latest study, important questions continue about natural gas boom’s methane emissions

September 25, 2013 by Ken Ward Jr.

Natural Gas, fracking

We’ve written many times before here about the questions surrounding the climate change implications of the boom in natural gas production in the Marcellus Shale and other shale-gas formations around the country (see here, here, here, here and here).

Last week in the Gazette, we reported on the results of one of the most significant studies to date concerning methane emissions from natural gas drilling and production. The study is available online here, and here’s a bit of the way its results were described in the University of Texas press release:

A new study from The University of Texas at Austin reports on extensive measurements of methane emissions — including the first measurements for methane emissions taken directly at the well pad — during completion operations for hydraulically fractured wells. A team of researchers from UT Austin’s Cockrell School of Engineering and environmental testing firms URS and Aerodyne Research completed measurements at 190 natural gas production sites across the United States.

The study, a unique partnership between the Environmental Defense Fund, participating companies, an independent Scientific Advisory Panel and the study team:

— Is based on measurements made directly at 190 production sites throughout the United States, with access provided by nine participating energy companies.

— Found that the majority of hydraulically fractured well completions, which were sampled during the study, had equipment in place that reduces methane emissions by 99 percent. Because of this equipment, methane emissions from well completions are 97 percent lower than calendar year 2011 national emission estimates, released by the Environmental Protection Agency (EPA) in April 2013.

–Found that emissions from certain types of pneumatic devices are 30 percent to several times higher than current EPA estimates for this equipment; combined, emissions from pneumatics and equipment leaks account for about 40 percent of estimated national emissions of methane from natural gas production.

— Found that the total methane emissions from natural gas production, from all sources measured in the study, were comparable to the most recent EPA estimates.

In summarizing the study, The Associated Press put it this way:

Drilling and fracking for natural gas don’t seem to spew immense amounts of the greenhouse gas methane into the air, as has been feared, a new study says.

The findings bolster a big selling point for natural gas, that it’s not as bad for global warming as coal. And they undercut a major environmental argument against fracking, a process that breaks apart deep rock to recover more gas. The study, mostly funded by energy interests, doesn’t address other fracking concerns about potential air and water pollution.

And the L.A. Times put it this way:

Emissions of methane from natural gas well sites across the United States have fallen in a key part of the drilling process, despite the boom in natural gas development, according to a study published Monday.

The rise in natural gas production through hydraulic fracturing, or fracking, has stoked concerns about leakage and venting into the atmosphere of methane, a chief component. Far more carbon dioxide is emitted than methane, but methane is 72 times more potent than carbon dioxide over a 20-year period.

Researchers from the University of Texas found, however, that new equipment reduced emissions last year at 190 natural gas sites by 99% in one key step in the well-drilling process.

The Environmental Defense Fund, which helped organize the study, said this in its own press release:

The UT study, which only deals with the extraction phase of the natural gas supply chain, is the opening chapter in this broader scientific effort designed to advance the current understanding of the climate implications of methane emissions resulting from the U.S. natural gas boom. Methane, the primary component of natural gas, is a powerful greenhouse gas — 72 times more potent than carbon dioxide over a 20-year time frame. The nation’s largest single source of methane emissions is the vast network of infrastructure, including wells, pipelines and storage facilities, that supplies U.S. natural gas. Experts agree that methane leaked or vented from natural gas operations is a real concern, yet estimated emission rates vary greatly — from 1 to 8 percent of total production.

“We know that immediate methane reductions are critical to slow climate change,” said Fred Krupp, president of EDF. “But we don’t yet have a handle on how much is being emitted. We need better data, and that’s what this series of studies will deliver. As we understand the scope of what’s happening across the natural gas system, we will be able to address it. We already know enough to get started reducing emissions, and thanks to the first study, we know that new EPA regulations to reduce wellhead emissions are effective. EPA got it right.”

And here’s what the folks at the industry group Energy In Depth had to say:

For years, critics of hydraulic fracturing have alleged that “methane leaks” from development are not only astronomically high, but also make natural gas from shale a climate “disaster” and “gang-plank.” But a new, highly anticipated report from the University of Texas and the Environmental Defense Fund might put that theory to rest – at last, and for good.

In my Gazette piece, I tried to take a pretty cautious approach with this study. Here’s how that story began:

A major study out this week has provided valuable new data about the global warming pollution from natural gas production, but still leaves unanswered questions about the climate change impacts of an industry that’s booming in West Virginia.

University of Texas researchers found slightly lower overall emissions rates for the powerful greenhouse gas methane than previously estimated by the U.S. Environmental Protection Agency and other scientific studies.

Working with industry and the Environmental Defense Fund, the researchers measured actual emissions from parts of the natural-gas production process at 190 sites around the country.

By way of background, I explained:

In their push for more natural gas, drilling operators are increasingly using a process called hydraulic fracturing, or fracking, which shoots vast amounts of water, sand and chemicals deep underground to break apart rock and release the gas. More frequently, this process also involves drilling down and then turning horizontally to access more gas reserves.

In West Virginia, business and political leaders are eager to continue expanding this practice as companies seek to tap into the vast gas reserves contained in the Marcellus Shale, a formation that stretches across 95,000 square miles from Southern New York and into Eastern Ohio.

Burning coal for electricity produces about twice the carbon dioxide as burning natural gas, but some scientists remain concerned about methane emissions that leak from gas-drilling operations, in part because methane is a more potent greenhouse gas than carbon dioxide.

Two years ago, the issue gained much more attention with the publication of a study by a team of Cornell University researchers led by ecology professor Robert Howarth. That study reported that natural gas could be just as bad – or worse – than coal for global warming, especially if the issue is examined on the short time frame in which scientists believe action is needed to curb global warming.

Since then, industry officials have harshly criticized Howarth’s study, and there’s been a lively debate in scientific journals about his results and about the many variables used to estimate methane emissions from the shale-gas boom across the country.

As I also reported, Dr. Howarth had some interesting things to say about the new UT paper:

After reviewing Monday’s new study, Howarth issued a statement that called the findings “good news” and said, “it suggests that the oil and gas industry – when sufficiently motivated – can produce natural gas with modestly low emissions.”

Howarth said that the new study’s overall methane leakage rate – 0.42 percent of total gas produced – is slightly better than the low-end of the range his team published, which was 0.6 percent to 2.8 percent of total gas produced.

But Howarth cautioned that the new study was based only on measurements at sites chosen by the companies that partnered with EDF and UT researchers on the project. Other recent studies that didn’t involve industry partners and used different measurement techniques found emissions that were 10- to 20-fold higher than reported in the new paper, Howarth said.

“When measurements are made at sites the industry chooses and at times the industry allows, emissions are lower than the norm,” Howarth said. “They do better when they know they are being carefully watched.”

Howarth also noted that the UT-EDF paper looked only at “upstream” gas-production emissions, and not at other potential emissions as natural gas is transported to consumers.

Interesting discussions about these issues are ongoing on Andy Revkin’s Dot Earth blog via The New York Times, here, and Joe Romm has his take on his Climate Progress blog, in which he says:

The good news: A sample of what are probably the best fracked wells in the country finds low emissions of methane, a potent heat-trapping gas.

The bad news: The study likely missed the super-emitters, the wells that are responsible for the vast majority of methane leakage.

The ugly news: Same as ever — natural gas from even the best fracked wells is still a climate-destroying fossil fuel. If we are to avoid catastrophic warming, our natural gas consumption has to peak sometime between in the next 10 to 15 years, according to studies by both the Center for American Progress and the Union of Concerned Scientists.

Among other things, Romm points out this critique by the group Physicians, Scientists and Engineers for Healthy Energy, which says:

This new study of methane leakage appears fatally flawed. This important research bears directly on the powerful GHG/global warming effects of methane and thus the implications for regulation and continued widespread development of shale gas. But it has concluded that methane leakage at well sites, selected in time and location by industry participants, is so low as to be nearly trivial. This is a finding at odds with other researchers’ work that shows much higher rates.

The Dallas Observer and others have also reported on what appear to be undisclosed potential conflicts of interest, first identified by the Public Accountability Initiative, among some of those scientists involved in the UT study:

PAI, however, found that despite declaring “no conflict of interest,” one of the UT study’s authors, Dr. Jennifer L. Miskimins, who lists only an affiliation with the Colorado School of Mines, neglected to mention that she is also a senior engineer for a petroleum engineering firm. The author, PAI suggests, may have violated the journal PNAS conflict of interest disclosure policy.

And Allen, the study’s lead author, PAI found, reported travel sponsored by ExxonMobil, which he was advising for its “corporate strategic research program.” ExxonMobil’s natural-gas production subsidiary, XTO Energy, is a sponsor of the study.

When I inquired of UT officials yesterday about these allegations, they provided this statement:

The study on methane emissions went through a rigorous peer review process and was published by a leading scientific journal. We look forward to a robust scientific debate about the findings. We encourage the public to read the report — both with an open mind and with full knowledge about who was involved in funding and producing it.

To that end, we’ve been committed to transparency since the research began and have publicly discussed the funding sources and affiliations of study participants. As we learn of any additional affiliations that should be disclosed, we are doing so.

Critics of the study are drawing much of their information from records and documents that UT Austin has voluntarily released or posted online. We welcome such scrutiny and have full confidence in the scientific process behind this research.

And a spokesman for the Proceedings of the National Academy of Sciences told me in a separate email:

We are currently working with the authors to finalize the text for their revised disclosure statement.

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