Ooops. Excuse Me. Methane Leakage Underestimated by 50 Percent

February 19, 2014

Free Pizza for everyone.

Hope to have more on this soon.

Stanford University:

The first thorough comparison of evidence for natural gas system leaks confirms that organizations including the Environmental Protection Agency (EPA) have underestimated U.S. methane emissions generally, as well as those from the natural gas industry specifically.

Natural gas consists predominantly of methane. Even small leaks from the natural gas system are important because methane is a potent greenhouse gas – about 30 times more potent than carbon dioxide. A study, “Methane Leakage from North American Natural Gas Systems,” published in the Feb. 14 issue of the journalScience, synthesizes diverse findings from more than 200 studies ranging in scope from local gas processing plants to total emissions from the United States and Canada.

“People who go out and actually measure methane pretty consistently find more emissions than we expect,” said the lead author of the new analysis, Adam Brandt, an assistant professor of energy resources engineering at Stanford University. “Atmospheric tests covering the entire country indicate emissions around 50 percent more than EPA estimates,” said Brandt. “And that’s a moderate estimate.”

The standard approach to estimating total methane emissions is to multiply the amount of methane thought to be emitted by a particular kind of source, such as leaks at natural gas processing plants or belching cattle, by the number of that source type in a region or country. The products are then totaled to estimate all emissions. The EPA does not include natural methane sources, like wetlands and geologic seeps.

The national natural gas infrastructure has a combination of intentional leaks, often for safety purposes, and unintentional emissions, like faulty valves and cracks in pipelines. In the United States, the emission rates of particular gas industry components – from wells to burner tips – were established by the EPA in the 1990s.

Since then, many studies have tested gas industry components to determine whether the EPA’s emission rates are accurate, and a majority of these have found the EPA’s rates too low. The new analysis does not try to attribute percentages of the excess emissions to natural gas, oil, coal, agriculture, landfills, etc., because emission rates for most sources are so uncertain.

“People who go out and actually measure methane pretty consistently find more emissions than we expect,” said the lead author of the new analysis, Adam Brandt, an assistant professor of energy resources engineering at Stanford University. “Atmospheric tests covering the entire country indicate emissions around 50 percent more than EPA estimates,” said Brandt. “And that’s a moderate estimate.”

The standard approach to estimating total methane emissions is to multiply the amount of methane thought to be emitted by a particular kind of source, such as leaks at natural gas processing plants or belching cattle, by the number of that source type in a region or country. The products are then totaled to estimate all emissions. The EPA does not include natural methane sources, like wetlands and geologic seeps.

The national natural gas infrastructure has a combination of intentional leaks, often for safety purposes, and unintentional emissions, like faulty valves and cracks in pipelines. In the United States, the emission rates of particular gas industry components – from wells to burner tips – were established by the EPA in the 1990s.

Since then, many studies have tested gas industry components to determine whether the EPA’s emission rates are accurate, and a majority of these have found the EPA’s rates too low. The new analysis does not try to attribute percentages of the excess emissions to natural gas, oil, coal, agriculture, landfills, etc., because emission rates for most sources are so uncertain.

 

 

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34 Responses to “Ooops. Excuse Me. Methane Leakage Underestimated by 50 Percent”

  1. Jason Says:

    “Free Pizza for everyone.”

    That just made my day.

  2. daveburton Says:

    It doesn’t matter. Even if you don’t burn it, methane (CH4) in the atmosphere oxidizes fairly rapidly, changing into (negligible amounts of) harmless CO2 and water:

    CH4 + 2·O2 -> CO2 + 2·H2O

    Various sources give the half-life of methane in the atmosphere as 6 to 8 years, which would make the average lifetime 1.4427 times that (because oxidation is an exponential process, rather than linear), yielding an average lifetime for a molecule of CH4 in the atmosphere of 8.7 to 11.5 years. Page 11 of this source gives the directly-calculated atmospheric lifetime of CH4 as ~8 years, but identifies a feedback mechanism that (they say) effectively increases the atmospheric lifetime of additional CH4 to ~12 years.

    Call it 8-12 years. That’s pretty short. It means the only reason methane levels are as high as they are (about 1.8 ppm) is that methane emissions are already high. There would have to be a very large, sustained increase in methane emissions to cause much increase in long-term average atmospheric methane levels.

    Leaks & spills of natural gas do happen. A couple of months ago, I was driving through downtown Cary in the wee hours of the morning, and smelled natural gas odorant. Gas was roaring from a standpipe near the corner of Kildare Farm and SW Maynard Rds. I called it in to 9-1-1, and after a while spotted a fire truck which had quietly parked behind a building, about 100 yards from the pipe. Perhaps such things make firemen nervous.

    I don’t know how long it took PSNC to fix it, but AFAIK it never even made the news.

    One nice thing about methane is that it is only about 62% as dense as air, so when you have a spill most of it rises pretty fast, and doesn’t concentrate at ground level.

    • dumboldguy Says:

      Dave has been busy looking things up again, and regales us with his latest non-findings, which include references to “harmless CO2”, such stunning scientific analysis as “that’s pretty short”, and the incredible “One nice thing about methane is that when you have a spill most of it rises pretty fast, and doesn’t concentrate at ground level”. That last is presumably “nice” because it rises into the atmosphere quickly so that it can “nicely” become a GHG 30 times more potent than CO2. Don’t worry, be happy, says Dave.

      Lord love a dozen ducks!

      And I would suggest Dave get out his “High School Math for Dummies” book and review the sections on significant digits and averages. “6 to 8 years” and “1.4427 times that”? How do we get from one significant digit to 5? And an “average lifetime of 8.7 to 11.5 years”? Is Dave trying to say “an average lifetime of 10.1 years with a range of 8.7 to 11.5? What?

      PS Dave’s “source” is of little relevance, and does NOT say what he says it does. He is doing a mini-Gish Gallop and mocking us with his BS. Dave offends us once again.

      • andrewfez Says:

        http://ecen.com/eee55/eee55e/growth_of%20methane_concentration_in_atmosphere.htm

        ————————————————————————————————-

        To me it looks like methane just keeps going up [Figure 1 in link]. If you look at the last 1000 years, it looks like a hockey stick.


        • Andrew-Methane has a short half life unlike CO which causes temperature rise for centuries. Unfortunately, anything like methane that raises temperature also raises CO2 by positive feed backs. It raise temperature which pushes CO out of the oceans. Then we are back to the races.

          • dumboldguy Says:

            Don’t forget that methane “decays” into CO2, so after it does its much “dirtier” GHG work for a while, it stays around as CO2.

            CH4 + 2 O2 = CO2 + 2 H2O

          • andrewfez Says:

            I’d like to read how they’re coming up with the t1/2 someday, but i’m sort of busy right now. Prof Rabbet quoted a rate constant for the limiting step of a particular schematic he posted, but he for some reason ignored the other multiple pathways that were available at that particular point, confounding the limitation. His rate constant was in a weird unit too, that seemed odd against my understanding of 0, 1st and 2nd order kinetics; could be one of those ‘cultural’ deals where a particular unit is tacit and implied for communication purposes inside a particular field. But even so, it’s obviously more complicated than just a simple ‘educational’ reaction in an undergrad class.


      • Here is some really nerdy stuff for those with insomnia, true geek status, chemists, or those who really want know.
        http://rabett.blogspot.com/2010/02/passing-gas.html
        As near as I can tell, methane has a shorter life, but much bigger effect than CO2. Reliable reference show it is a GW concern.
        http://en.wikipedia.org/wiki/Methane


    • You’ve used the square root of 2 i.e. 1.414 (1.4427?) incorrectly to derive the lifetime of the methane in the air. After 6-8 years, half the original methane remains (hence the term half-life); after another 6-8 years, one-quarter of the original methane remains; after another 6-8 years, one-eighth remains, etc.

      You’re reference to the methane’s density relative to air doesn’t apply unless the methane is in a helium-type balloon. The Kinetic Theory of Matter describes how gases spread out to occupy as large a volume as possible by means of the process of diffusion. So the “methane doesn’t concentrate at ground level” is correct but your reason is wrong.

      The reason why fireman stay a safe distance from a flammable gas leak is because the gas is well mixed with air and a spark will cause a God-awful explosion (rapid combustion). Ditto for petrol fumes which are far more flammable than the liquid petrol.

      • dumboldguy Says:

        You say Dave used the Square root of 2 = 1.414 somewhere? Don’t think so.

        The number 1.4427 is log2e, and I’m still trying to figure out why Dave used it (other than PFTA to mock us, perhaps from computer world). His “exponential versus linear process” and his use of “average” makes no sense to me but I haven’t used logarithms in a lo-o-o-ong time.

        Does anyone else know what he’s talking about and why he used 1.4427?

        • andrewfez Says:

          For whatever reason, CH4 in the atmosphere is not following a 1st order decay. A molecule exists for about 12 years +/- a year or so according to something i was reading the other day which i’ve lost track of.

        • andrewfez Says:

          Oh, I might have an idea why: because there is a natural background baseline that’s around 0.7 ppm, according to the graph in my link above. Probably because of this natural baseline which is around half of present values, any expellation of methane into the atmosphere only needs to decay enough to reach this baseline before it’s considered ‘gone’. Thusly the 1/2 life and the ‘atmospheric lifetime’ would be fairly similar numbers.

          *Disclosure: that’s my own speculation; the real story is probably more complicated.


    • daveburton wrote:
      “It doesn’t matter. Even if you don’t burn it, methane (CH4) in the atmosphere oxidizes fairly rapidly, changing into (negligible amounts of) harmless CO2 and water.”

      Except that CO2 is a greenhouse gas whose residence time in the atmosphere is much longer than methane’s. Not “harmless”. Since the ratio (as your chemical formula indicates) is 1:1, the oxidation of methane is only “negligible” to the extent that methane is present in the atmosphere.

      daveburton wrote:
      “There would have to be a very large, sustained increase in methane emissions to cause much increase in long-term average atmospheric methane levels.”

      Or rather, there would have to be a very large, sustained increase in methane emissions to cause a very large increase in long-term average atmospheric methane levels – if by “sustained” you mean “continuing”, as seems probable.

      And in fact the concentration of atmospheric methane is about 2.5 times the pre-industrial concentration, which would certainly qualify as “a very large increase in long-term average atmospheric methane levels.”

      daveburton wrote:
      “Call it 8-12 years. That’s pretty short. It means the only reason methane levels are as high as they are (about 1.8 ppm) is that methane emissions are already high.”

      Meaning human emissions, I take it? Well, we should certainly cut back. But the real danger lies elsewhere: the precipitous warming of the last two generations is thawing the northern tundras, which will release massive amounts of methane. We do not now have the capability to stop that from happening, and the positive feedback from it would overwhelm any gains made by our plodding transition away from fossil fuels.

      These methane stores, by the way, are distinct from the undersea methane hydrates (aka clathrates) that will be released from a warming Arctic Ocean – but there appears to be doubt about whether that methane would make it into the atmosphere in any quantity. I would be glad to know of any recent research into methane hydrates, but the real risk appears to be methane sequestered in frozen tundra.


      • Dave Burton’s understanding of the consequences of methane emissions places him on the level of my state Congressman, John Boehner, who famously remarked on a Sunday talk show that methane is harmless since it’s what cows fart.

        “Who are you who know so much of the world of SCIENCE?”

  3. Johan Rebel Says:

    Though negligble, it is still an addition to the CO² burden which will presumably be around hundreds of years, all else being equal.

    You fail to mention that in its short lifetime it will cause 27-100 times as much enhanced forcing as does the same amount of CO² molecules. I don’t know the proportion in comparison to other methane sources, but it is still addition.

    (27-100 depending on whose figures you take, largely dependant on variables such as presumed period of time, altitude at which the effect is being measured or presumed, etc etc)

    • Gingerbaker Says:

      daveburton denies the laws of physics when it comes to CO2 and the greenhouse effect. He also denies the copious data on the acceleration of sea level rise. These things are inconvenient to his argument, so they do not exist.

      Behold the splendor of daveworld. Kneel before its benevolent and erudite leader.


    • Heat, Mr. Speaker, is a natural by-product of nature. Heat is natural. It occurs in Earth. Heat is portrayed as harmful. But there isn’t even one study that can be produced that shows that heat is a harmful energy. There isn’t one such study because heat is not a harmful energy. It is a harmless energy. (Homage to Michelle Bachmann)

      • dumboldguy Says:

        And to think, many members of a major political party thought she was qualified to be president of the United States. And her opponents were little better (except for Huntsman, who was overwhelmed by the clowns very early). We are doomed.


        • The only Republican whose campaign I’ve ever donated to is Huntsman’s. I would have voted for Obama, but was hoping, against all odds, for a sane opponent.

          • kanspaugh Says:

            Didn’t Huntsman eventually also bite the bullet and recant his earlier expression of belief in AGW? Held out longer than did Newt and Mitt on that score, but still caved. The conventional wisdom, apparently, is that you can’t be the Republican nominee without being stupid.

          • dumboldguy Says:

            Yes, he did waffle and “unwaffle” on the issue as the tides of craziness brought on by the “circus of clowns” swept around him. He finally proved he was the most intelligent of the Republican candidates by dropping out of the race.


      • Too much oxygen will kills us – either by poisoning us, or by spontaneously combustion.

        Too much water will kill us.

        Too much sugar will kill us.

        Too much food will kill us.

  4. Wes Says:

    This natural methane is in addition to the much vaster quantities spewing from the hydrates in the Arctic, which are enormous and which are poorly measured because they are so widespread. They constitute a major positive feedback to Arctic and planetary warming.

  5. redskylite Says:

    Ignorantia juris non excusat

    Yet another hockey stick showing mankind’s casual use of Earth’s stratosphere/atmosphere as a free trash bin and upsetting natural balances.

    Even if CH4 has a short lifetime and breaks down into water and CO2, if we are continually the adding the gas faster than it breaks down, we are impacting the climate and increasing blocked radiation. Never mind about awakening the sleeping giants (the reservoirs of methane hydrates in our polar regions).

    Is our shared atmosphere really a “commons” that we can dump anything we like without penalty ?

    Source: Encyclopaedia of Earth
    Figure 4. The following graph illustrates the rise in atmospheric methane from 1008 to 2001. Note that the increase in methane’s concentration in the atmosphere is exponential in nature. An extrapolation into the immediate future would suggest continued annual increases. (Image Copyright: Michael Pidwirny, Data Source: D.M. Etheridge, L.P. Steele, R.J. Francey, and R.L. Langenfelds. 2002. Historical CH4 Records Since About 1000 A.D. From Ice Core Data. In Trends: A Compendium of Data on Global Change. Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tenn., USA and Steele, L. P., P. B. Krummel and R. L. Langenfelds. 2002. Atmospheric CH4 concentrations from sites in the CSIRO Atmospheric Research GASLAB air sampling network (October 2002 version). In Trends: A Compendium of Data on Global Change, Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, TN, USA.).

    • dumboldguy Says:

      Dang! Another hockey stick! How many does that make now? And will certain folks ever notice?

      • kanspaugh Says:

        “Will certain folks ever listen?” Not, dumboldguy, until they personally are repeatedly victimized by high sticking, i.e., extreme weather events. Even then many, lying dazed and bleeding on the ice, will refuse to admit that hockey sticks exist.

        • dumboldguy Says:

          Excellent metaphor. Can we work in a hockey pucks analogy along with the hockey sticks? As in “they are as dense as Dave Burton’s skull and and unthinking as his brain”?

          Or is that a simile? I get so confused sometimes. You’re the English guy. I’m a science guy who took English with Dr. Blackburn, a proper British spinster whose life’s mission was to deal with “non-majors” and punish us.

          • kanspaugh Says:

            Comedian Don Rickles favorite putdown is to refer to someone as a “hockey puck,” so sterling precedent for referring to denialists as such. As in “Jesus saves, but Mann rebounds and scores!”

            Sounds like Dr. Blackburn had the right idea. Make them all suffer for their impertinence!


      • It’s for bashing Dave with.

        • dumboldguy Says:

          See kanspaugh’s comment. Dave will likely not even notice, or in his religious zeal and delusional state, he will imagine that he is just doing a bit of self-flagellation.

          (Using whips made from cables from his computer shop attached to stakes from NC-20 “real estate for sale” signs, of course. And chanting as he does so—–“Sea level rise is not accelerating, the whole world is crazy except for meeeeeeeeeee!”).

  6. rayduray Says:

    The Real Climate blog has done good work over the past few years on the issue of methane and global warming.

    Here’s the latest:

    http://www.realclimate.org/index.php/archives/2013/11/arctic-and-american-methane-in-context/

    The take-away message is that of the total atmospheric concentration of methane, that about 5% of it can be ascribed to the Arctic and another 5% to America. Most methane is of tropical origin. And on the list of things that might cause a disastrous tipping point in our global climate, methane is not all that high on the list.

    ***
    I find Real Climate more scientifically grounded than the Arctic Methane Emergency Group. EMEG is something I’ll recommend to those of you who fret about not having enough nightmares.

    http://ameg.me/


  7. I have to take issue with something mentioned in the video – methane from cattle is not the normal thing. We feed them things we grow with fertilizers and pesticides, and since they are evolved to eat grass, this food makes them sick. So they get indigestion and they pass a lot of gas; mostly in belches, actually.

    If they ate grass like they are “supposed” to – first of all they would not be passing nearly as much gas. And more importantly, that gas would not be adding anything to the atmosphere. Grass grows by pulling carbon from the air, so the cows eating it *will not* change the balance in the air.

    The biggest problem comes from us pouring chemical fertilizer onto corn and soybeans, etc. – fertilizer made from natural gas. THIS is what is adding carbon to the atmosphere; not the cows themselves, per se.


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