Are US Carbon Emissions Really Down? Methane Leaks Cause for Concern

August 26, 2014


A headline that has appeared frequently in mainstream media of late informs us that, in an unexpected turn of good news, US carbon emissions are down to 20 year lows, due to increased use of natural gas in power generation.

My uneasiness with this formulation comes from increasing evidence that the extraction of Natural gas has a a downside – largely unaccounted-for leakage in the system of wells, pipelines and processors that deliver gas to consumers.

Climate Central:

study of abandoned oil and gas wells in Pennsylvania finds that the hundreds of thousands of such wells in the state may be leaking methane, suggesting that abandoned wells across the country could be a bigger source of climate changing greenhouse gases than previously thought.

The study by Mary Kang, a Princeton University scientist, looked at 19 wells and found that these oft-forgotten wells are leaking various amounts of methane. There are hundreds of thousands of such oil and gas wells, long abandoned and plugged, in Pennsylvania alone, and countless more in oil and gas fields across the country. These wells go mostly unmonitored, and rarely, if ever, checked for such leaks.

growing list of studiesconducted over the past three years has suggested that crude oil and natural gas development, particularly in shale formations, are significant sources of methane leaks — emissions not fully included in U.S. Environmental Protection Agency greenhouse gas inventories because they are rarely monitored. Scientists say there is inadequate data available for them to know where all the leaks are and how much methane is leaking.

Methane is about 34 times as potent as a climate change-fueling greenhouse gas than carbon dioxide over a span of 100 years. Over 20 years, it’s 86 times more potent. Of all the greenhouse gases emitted by humans worldwide, methane contributes more than 40 percent of all radiative forcing, a measure of trapped heat in the atmosphere and a measuring stick of a changing climate.

Naomi Oreskes in The Nation:

Gas advocates say that while these worries might be legitimate, US greenhouse gas emissions nonetheless fell between 2008 and 2012, partly because of the way gas is replacing coal in electricity generation. This claim needs to be closely examined. In fact, it seems as if the lion’s share of that decrease was simply the result of the near global economic meltdown of 2007–08 and the Great Recession that followed. When economic activity falls, energy use falls, so emissions fall, too. Not surprisingly, preliminary data from 2013 suggest that emissions are on the rise again. Some of the rest of the 2008–12 decline was due to tighterautomobile fuel economy standards.

But how do we know what our emissions actually are? Most people would assume that we measure them, but they would be wrong. Emissions are instead calculated based on energy data—how much coal, oil and gas was bought and sold in the United States that year—multiplied by assumed rates of greenhouse gas production by those fuels. Here’s the rub: the gas calculation depends on the assumed leakage rate. If we’ve been underestimating leakage, then we’ve underestimated the emissions. Though the converse is also true, few experts think that anyone is overestimating gas leakage rates. This is not to say that emissions didn’t fall in 2008–12. They almost certainly did, again because of the recession. But the claim that there’s been a large decrease thanks to natural gas remains unproven.


Oreskes’ article is longer, packed with info,and well worth a read.




16 Responses to “Are US Carbon Emissions Really Down? Methane Leaks Cause for Concern”

  1. dumboldguy Says:

    This post is right on the money with its focus on leaks and the poor quality of the data on emissions. Oreskes article is indeed worth reading, as is everything else she has written—she gets it.

    Something else that is a “known unknown” and is not getting measured or reported on is the flaring of natural gas in the shale oil fields like the Bakken and Eagle Ford. The oil companies don’t want to try to capture it—-all that expensive equipment and pipe is bad for the bottom line—-so they just burn it and add to the GHG burden.

  2. If the scientists who are taking measurements of atmospheric methane are also separating the isotopic ratios, then maybe?? we can get a handle on how much of the methane comes from natural gas extraction. And if they have enough data globally to give a reasonably accurate value. Maybe they’re on the trail, but don’t have enough data yet?

    There are two (ok three) huge reasons I’ve never gotten on the natural gas bandwagon:

    1. Its greenhouse properties
    2. It’s still a fossil fuel, and will not take us away from the FOSSIL FUEL infrastructure
    3. Its largely un-studied effects on human health (air quality)

    I already know about the potential water issues, but the three above are even more crucial, in my opinion.

    • I’m not sure the isotope ratios are going to help too much.  Both natural gas and methane from thawing permafrost are biogenic and should have similar 12C-13C ratios, and as they’re also both pretty old 14C won’t be very useful either.  This is going to take work, going around and measuring the actual plumes from areas and point sources.

      • But I would imagine the time involved, aka decay rate, would have something to do with the isotopic signature. Unless I’m forgetting something. So the methane in the ground was made a long time ago (don’t know how long, if it’s the same as with oil but I imagine it’s not too different??), and the carbon in it has been sitting there for millions of years, decaying. That from the active cycle would not have been decaying (it’s generated in the upper atmosphere in a reaction with nitrogen atoms and cosmic rays) so I would imagine atmospheric (active carbon cycle) carbon would have a much higher ratio of C^14 than the stuff coming out of the ground.

      • I think it likely, to reply to your point about permafrost, that a lot of the methane coming out of the permafrost hasn’t been trapped as long as the methane from natural gas.

        • Even 1 14-C half-life would lead you to underestimate the contribution by a factor of 2 compared to e.g. anaerobic decay of much more recent material.

          • dumboldguy Says:

            You and CL are chasing your tails a bit with this train of thought. Yes, C isotope measurement might give some clues, and yes, those clues may not mean much. It doesn’t matter much where the methane is coming from—what matters is that it IS being released in ever-larger quantities and the “methane bomb” from clathrates and permafrost becomes ever more likely as we leak more methane from oil and gas production and also allow CO2 to keep climbing. As O’Reilly might say, “CO2 increases, Temp goes up, Things melt, Methane comes out”.

            It looks like we are approaching the tipping point, and just like the East Antarctic ice sheet, it will be irreversible (and a huge positive feedback mechanism when it happens). The fossil fuel interests simply don’t want to know how much methane is being released and from where. I’ll say it again—-bad for the bottom line. We need to seriously start looking at methane, and soon.

            PS Regarding the methane from permafrost and natural gas both being “pretty old”, the natural gas took many millions of years to form (hundreds of millions actually), while the methane in permafrost is an ice-age phenomenon—hundreds of thousands of years at most.

          • I would agree with dumboldguy on the point that it doesn’t matter (to warming anyway) where the CH4 came from. I would argue that it does matter if we can determine where, from a prevention and/or mitigation standpoint. And from a regulation of the fracking industry standpoint too. And for a better scientific understanding of methane in the atmosphere. The fingerprint change over time could probably help with determining the major sources of methane. For example, the belching in the Arctic (clathrates) might cause a rapid change in the fingerprint, if it starts to go up exponentially, in which case we know we’ve pushed past the tipping point. Better to be armed with the knowledge, if it’s possible (or feasible) to determine and track.

          • It doesn’t just matter where the methane is coming from, it’s crucial.  If it’s leaking from wells, we need to clamp down on wells (maybe installing flare stacks even at plugged wells).  If it’s coming from permafrost, we need to go to full crisis mode and consider measures like geoengineering to drop temperatures immediately to halt the rise.

          • dumboldguy Says:

            I don’t disagree with what E-Pot and CL have said. Perhaps I wasn’t clear, but my point is that right now we don’t seem to WANT to know where the methane is coming from and how much is being released. It’s just another can being kicked down the road so that the fossil fuel interests can extract every last penny of profit before the SHTF.

            Yes, it’s leaking from wells, both new and old. Yes, it’s leaking from distribution systems. Those are things we can and should do something about, and we don’t need isotope analysis to see that is happening—-a paint brush and some bubble solution wielded by a high-school dropout is enough. And it’s ironic that flaring at all those well sites could be a solution—-yep, convert that methane to CO2 because CO2 is a less potent GHG short-term—-but wait, isn’t long-term buildup of CO2 the main problem?—-I get so confused sometimes.

            From the limited research that has been done, we know that methane is bubbling out of the seabed all along the Arctic coast of Russia (and the latest news is now all along the Atlantic seaboard as well). We know that it’s being released by melting permafrost everywhere (and how ’bout them craters that are opening up in Siberia and what’s coming out of them?—-are we looking at them closely?).

            We are just NOT trying to learn all we can about all of this, and if we wait until the SHTF and we have to resort to crisis-level “geoengineering”, we are likely doomed. We are already proving that the fossil fuel experiment we have been conducting for the past 200 years is a failure, and “geoengineering” always makes me think of the Law of Unintended Consequences and “unknown unknowns”.

            I will say it again—-if the methane bomb explodes, the positive feedback loop may be so powerful that it overwhelms our ability to combat it. As Dr. Box has said (and other scientists have been too cautious about saying), if methane goes bad, “We’re F**K-ed”.

  3. First off, welcome back Peter. I’ve also been absent for a few weeks, not just from this blog but others, because I’m really busy trying to get a house (currently under construction) finished. With luck, will move in by mid-September. I’m trying to make it reasonably green.

    Secondly, good post. Indeed, the first post you’ve had in awhile where I’m in full agreement. I’ve been saying for a good long while that the all crowing about how US CO2 emissions are falling has had more to do with recession and the natural gas fracking boom than the green energy boom.

    About methane leaks… Ever since I saw the first Gasland movie, I’ve been very concerned about that. Although I don’t recall that Josh Fox (the producer) actually talked about how methane leaks were a problem in greenhouse terms, he showed clearly that methane was bubbling up through a creek bed in an area that was fracked. He put a traffic cone in the water and lit the end of it with a match, resulting in a visible flame. You can see the bubbles where there’s water, but in most of the land where fracking is going on, you don’t see the methane though it’s certainly there. No attempt is being made by either the gas drillers or the EPA to measure this. They just don’t want to know, and they certainly don’t want the public to know.

    Add to that the fact that natural gas obtained from fracking is rapidly depleted, with wells only producing for maybe two years before going dry. So what we are likely to see is a big boom/bust in drilling – thus the “fracking solution” is destined to be a short-lived phenomena. Right now this is hidden by the fact the gas producers just move on to another field when one goes dry, and they can continue to do that only as long as there are unexploited fields to drill. Although I hesitate to make predictions, I’ll make a wild guess that maybe we’ve got a decade to play this game before the fracking industry dies, at least in the USA. Of course, the drillers will be looking overseas to extend the boom/bust cycle as long as it remains profitable.

    As you’ve mentioned, there are just thousands of capped wells out there. Although they no longer produce a usable quantity of gas, the leaks continue for many years thereafter even if the cap itself is perfect. Gas leaks up through the soil once an area has been fracked, and there is no way to contain that.

    In terms of green power, one of the implications of the gas fracking boom/bust is that by the time we’ve got a generous supply of gas turbines (to serve as backup for wind and solar), we may not have a sufficient affordable gas supply to run them. Something to think about.

  4. Whoops, before I hit the “send” button, I forgot to add that besides recession and gas fracking, another reason for falling US emissions of CO2 has a lot to do with the USA sending its dirty industries off to China. Now China has surpassed the USA in terms of CO2 emissions, it allows Americans to point the finger elsewhere and say “Why should we cut our CO2 emissions when the Chinese just keep increasing there’s?”

    Such a convenient excuse for inaction.

  5. Peter – Subsidies. I found a high quality link.

    Peter’s link to Pennsylvania shows almost a million wells in that state. 100s of thousands indeed. Oil was discovered here long ago. Any oil well or coal mine can leak methane. One other thing. I read a link that says methane is 40% of forcing, but I need to find the link to get it right. It might be more significant than most realize.

  6. […] keeping the carbon accelerator jammed to the floorboards.Instead of the deep, urgent reductions in carbon emissions urged by frightened scientists, drowning polar bears, still homeless Katrina survivors. […]

    • dumboldguy Says:

      How did some spam about “Custom Tyvek Wristbands” sneak in here? Along with some chemtrail conspiracy crap?

      Take a look at “rainbow lady” for your laugh of the day regarding the chemtrail conspiracy.

      PS I will again boost the new book THE BOOM, which is the WSJ’s energy reporter’s take on how wonderful fracking is (and why it is likely to be causing methane leaks for many years). A great read, just as is Atomic Accidents.

      PPS Does the lead-in pic for this post make anyone else as angry as it does me? Every time I see it, I get an urge to shoot something or someone. It looks like that used to be “where the antelope roam” country, and now it’s a sacrifice zone. Mankind is truly unworthy.

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