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Methane Leakage Not a Deal Breaker for Natural Gas

This post was co-authored by Alex Trembath, Policy Analyst at the Breakthrough Institute.

In an op-ed published in the Sunday edition of the New York Times, engineering professor Anthony Ingraffea argued that natural gas should not be part of any strategy to confront climate change. “I can assure you that this gas is not ‘clean,’” Ingraffea argued, “because of leaks in methane, the main component of natural gas, the gas extracted from shale deposits is not a ‘bridge’ to a renewable energy future.” To make his case, Ingraffea cited two studies estimating methane leakage rates from shale gas production: one study by the National Oceanic and Atmospheric Administration (NOAA), and the other study by Ingraffea and colleagues at Cornell University.

As Ingraffea pointed out, while natural gas emits about half as much carbon dioxide as coal per unit of energy, the global warming impact of methane is about 20 times more potent than coal on a 100-year basis. As a result, methane emissions have the potential to erode most or all of the CO2 emissions benefit resulting from coal-to-gas switching. According to a study from the National Center for Atmospheric Research, if methane leakage exceeds 2 percent of total production, the greenhouse gas footprint of shale gas could exceed that of coal (scientists at the Environmental Defense Fund estimated that this threshold is actually 3.2 percent, and Lawrence Cathles of Cornell University has suggested that it could be as high as 18 percent).

But the best available studies suggest that leakage rates do not exceed 2 percent. Ingraffea ignored the latest data from the US Environmental Protection Agency, which estimated nationwide fugitive methane emissions at 1.5 percent of natural gas production and indicated that leaks have been on the decline in recent years. A 2012 study published by the Joint Institute for Strategic Energy Analysis estimated leakage at 1.3 percent. Our review of estimates of fugitive methane emissions from shale gas production range from 1 percent to 7 percent, with most recent estimates in the 1–to–2 percent range (see graph below). The two leakage studies cited by Ingraffea, which both estimated leakage rates well above 2 percent, are outliers and have been faulted for selective bias and poor measurement and statistical techniques.

Methane leakage rates can and probably will be lowered substantially in the future. One study found that 70 percent of total leakage from 250 wells in Fort Worth, Texas, was occurring at only 10 percent of the wells, suggesting significant potential for low-cost, high-impact intervention. And a recent report from the World Resources Institute identified several promising options for further limiting fugitive methane emissions.

Moreover, even if methane leakage were to remain modest in some areas, long-term climate models have suggested that warming trends have less to do with the rate of methane leakage and more to do with other variables, such as the thermal efficiency of future coal plants and whether the switch to gas is permanent or a bridge to zero-carbon energy. Thus, although fugitive methane emissions reduce the short-term emissions benefit of coal-to-gas switching ­– and should be addressed for that reason – they do not limit natural gas’s potential as a bridge fuel to a low carbon future.

Not since European deployment of nuclear power in the 1970s and 1980s has any country achieved such rapid decarbonization as the United States has in the last five years thanks to cheap natural gas. Natural gas has displaced more coal than any other energy source in decades, and will prove an essential transition fuel as governments continue to support innovation in renewables, nuclear, and carbon capture technologies.

Content Discussion

David Lewis's picture
David Lewis on July 31, 2013

“…some of my colleagues have actually driven around some of these shale gas plays and they have found that lo and behold, emissions are much higher than industry reports, and higher than the EPA reports.  Well that’s not a mystery since the EPA is relying on industry estimates, a lot of the times.”

That’s what NOAA’s Lori Bruhwiler reported to the recent AGU Chapman conference on Communicating Climate Science at minute 10:50 in this video the AGU made of her talk.  There seems to be a will to believe that the discovery of abundant shale gas is reducing the climate impact of the US energy system compared to if there was no shale gas, no matter how much of it actually is leaking, and no matter that this cheap gas killed the renaissance of an industry that really can produce abundant lower climate impact energy, i.e. US nuclear.  

If the methane is still leaking, the US has not achieved any reduction in the climate impact of its energy system by starting this switch to natural gas from coal.  And there is little doubt, for those who want to take a look, that the methane is still leaking.  

Methane is what the fossil fuel industry sells.  Why is leakage still an issue?   Natural gas advocates talk as if what is theoretically possible, i.e. creating an infrastructure to use and consume all this gas without leaking enough to the atmosphere that the anticipated climate benefits are nullified, has already happened.  

The Government Accountability Office reported that the industry could make money by controlling many of these leaks, years ago and fairly recently, and yet GAO’s most recent report found that the leakage continues.  When I studied the situation at the time GAO published, what was apparent was that US fossil fuel companies don’t believe it is necessary to do anything to contribute to solving a problem they don’t believe exists, i.e. climate, so their CEOs direct fresh capital expenditure to exploring for more fossil fuel rather than to minimize methane leakage because the R.O.I. is higher.  

This industry thinks all it has to do is tell us, again and again, in their TV ads how great gas is for us than to be seen to be making an effort which they could do by making profitable investments controlling their leaks.  

For reference – a bit more on what NOAA’s Bruhwiler said at the recent AGU conference.  She introduced herself at the recent AGU conference by saying this:  

“I’m from the NOAA Earth system research laboratory… global monitoring division.  We’re the people who, along with our global collaborators, brought you the “400 ppm CO2” [were the source for the widely reported news story] recently.  However today… I want to focus on methane….

[ moving along to minute 10:20 ]  “…another issue I want to talk about: what the frack is going on with fugitive emissions from fossil fuel production?  [ commenting that the news is full of reports that leakage is low ] The EPA… has recently revised their estimates of emissions of methane from fossil fuel exploration and they decreased it…  

[ However, at 10:50 ] some of my colleagues have actually driven around some of these shale gas plays and they have found that lo and behold, emissions are much higher than industry reports, and higher than the EPA reports.  Well that’s not a mystery since the EPA is relying on industry estimates, a lot of the times.  [technical discussion]  the network data in the assimilation product also suggests that something is going on.  If you look at… North America fossil fuel emissions [ measurements of methane in the air over fossil fuel production regions ] and furthermore you look in the winter when the biogenic sources are small… [blah blah blah]  ...this suggests that fossil fuel emissions from temperate North America are actually much larger, [more techspeak] and if you go and look to see what sites are producing this kind of difference you can see that for example this site Southern Great Plains in Oklahoma as time goes on it becomes progressively harder to fit our first guess to what the emissions are…. [concludes] this is support for the idea that emissions from the current oil and gas boom are probably underreported.  

And an interesting question is, what happens when this technology spreads throughout the world? I’ve seen some economic analyses that suggest that there’s not enough of this shale gas to really make a dent in our long term fossil fuel cumulative emissions, however, I think it remains to be seen whether that ends up to be true.  Just recently there were reports that Poland was going to start using hydrofracking.  I think emissions all over the world are going to start increasing in this kind of a manner.  [i.e. initial enthusiastic denial that so much is leaking until scientists catch up with published peer reviewed studies showing the actual measurements]. 

Sage Radachowsky's picture
Sage Radachowsky on August 1, 2013

I spent some time looking at how the EPA figured the methane emissions.  I found it in section 3.5 of Annex 3 of the report:

I find that they rely on the industry estimates and data quite a lot, and use a theoretical model. As i recall, the NOAA study used empirical data, i.e. measurements at a fracking site.  I propose a study with gastight domes around fracking sites, as well as roaming sniffers, to test how much gas may be migrating through the soil.  The story is not immediate, as well. Gas diffusion through cracked bedrock can take many years. Diffusion does not stop when a well is capped. What explains methane seen bubbling from stream beds around fracking sites. This may be a problem that is not going to show its full force for a while.

Lewis Perelman's picture
Lewis Perelman on August 1, 2013

Some 70% of natural gas emissions come from sources other than the natural gas and petroleum industries. Coal mining contributes some 11%. See:

Various efforts are underway to contain, and utilize, methane emissions from these other sources. There is no obvious reason to presume that methane emissions from fracking or other natural gas production/distribution processes cannot or will not be successfully contained and recuperated.

For the most part, solar, wind, and other renewable energy sources are not currently cost-effective substitutes for fossil fuels in power generation or most other applications. Nor can they offer the same chemical, material, fertilizer, etc. applications. For practical purposes, the main alternative to expanded use of natural gas is continued or expanded use of coal.

Even if the climate impact of natural gas development were on a par with the use of coal, natural gas’s overall environmental, health, and safety impacts are so much less than coal’s that the replacement of coal by gas still would be desirable.

Robert "Bob" Mitchell's picture
Robert "Bob" Mitchell on August 2, 2013

Hog wash!  If wishes were fishes, we’d all have a giant fish fry!

The fact of the matter is that gas leaks!  Recent studies have shown that methane shows up in the drinking at a much higher rate the closer you are to a well site.  This is indicative of leakage that would be very difficult to measure and is not accounted for in your 1.3% figure because it’s not leaking out of the well itself.

Also, how objective are the people doing the measuring?

When you add up all of the potential disadvantages of fracking and weigh them against the benefits of the technology, it’s simply not worth the risk unless you happen to be an oil or gas company.  Hell, the gas companies are already starting to screw the landowners out of their royalties..imagine that???


Bob “The Clean Energy Guy” Mitchell

Lewis Perelman's picture
Lewis Perelman on August 2, 2013

Benefits not worth the risk? Business Week reports that $100 billion is being invested in new chemical manufacturing facilities in the US, to take advantage of cheap natural gas:

Nationwide, chemical producers added 11,800 jobs in the 12 months through June, according to the U.S. Bureau of Labor Statistics, the biggest 12-month gain since 1988. The industry will need 46,000 more workers by decade’s end, according to the ACC. Investments by chemical companies will generate an additional 1.7 million jobs in construction and other industries.”