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The story of methane in our climate, in five pie charts

Filed under: — david @ 23 September 2014

106 Responses to “The story of methane in our climate, in five pie charts”

  1. 51
    Susan Anderson says:

    Jan, who is Kaiser Fung? “blogger, author, and self-proclaimed expert” is unconvincing. As someone who labors to follow the science side, I found the visualizations quite helpful. There’s been a lot of effort to put methane in proportion, and I thought this did a good job on that. Since RealClimate is “climate science from climate scientists” I feel it’s worth the effort, but the peanut gallery is already too plethoric.

    I know, one could search, but is that a useful use of time? Does he have a large audience that requires some facts inserted into their discussions?

  2. 52
    Susan Anderson says:

    “comfortable inaction–indulgence masquerading as tough-mindedness.”

    @~38 Kevin McKinney

    This is a useful way to put the problem. I watched some artists a couple of months back who pointed out that apathy and despair work out as laziness.

    Anyway, thanks.

  3. 53
    CM says:

    David @10: It looks like we could compensate for even a doubling of land (permafrost) sources, by cleaning up the Arctic fossil fuel industry.

    That’s striking. Could you please point to the source for this breakdown of Arctic methane emissions?

    [Response: I’m reviewing a report from the Arctic Monitoring and Assessment Program, that’s where I got that number. Unfortunately the report is not yet out there, but I’m sure the number could be found elsewhere. That was, indeed, one of the more interesting things in that report. David]

  4. 54
    Lawrence Coleman says:

    41: Mal adapted. You asked me a while ago to read that article. Which I did. It’s just further solidified my stance on this. Just heard now on TV of a 51% deduction of the numbers of all living things on land and at sea in just the past 2 generations. Last month I was made aware of a 45% reduction in all global invertebrates since 1980. How much research is being done as to how this catastrophic decline is affecting the global energy balance?. On the other side of the ledger we have a monoculture of 7 billion + homo-sapiens. And Yet Kevin McKinney doesn’t like my use of the term unstoppable juggernaut to describe the destabilisation of our future climatic system. I want to know where he gets his rose coloured glasses from..industrial strength!

  5. 55
    Lawrence Coleman says:

    38: Kevin McKinney. I was just made aware of a precipitous decline of 52% of our terrestrial and aquatic fauna in just two generations, this comes at the back of a report that 45% decline of our invertebrate populations since 1980. Kevin without recognising the extent of the current situation you are incapable of contributing to it’s long term reversal. Doesn’t take a genius to recognise the paramount importance of the earth’s biodiversity to our sustainable future. Just open your eyes.

  6. 56
    Hank Roberts says:

    Ten years ago:

    Research Features
    Methane: A Scientific Journey from Obscurity to Climate Super-Stardom
    By Gavin Schmidt, September 2004

    The responses of wetlands and clathrate deposits to climate change are hard to foresee, and one wild card is the extent to which the potential exploitation of the clathrate reservoir for energy production might lead to increased releases to the atmosphere. However, the technologies involved in this have yet to be fully developed and so forecasts are extremely uncertain. Research is now being conducted on reducing methane emissions from almost all the sources and that may possibly allow for relatively short term (less than 50 years) decreases in methane concentrations, and a consequent reduction in the forces driving global warming.

    Over the last 30 years, methane has gone from being a gas of no importance, to — in some researchers eyes, at least — possibly the most important greenhouse gas both for understanding climate change and as a cost-effective target for future emission reductions. Whether some of these new ideas stand up to the scrutiny of the wider climate research community remains to be seen, but one thing is certain, the scientific journey of methane is not yet complete.

  7. 57
    Hank Roberts says:

    Wili, if a rock fell on your head every time you went out the front door, would you invest in rock-proofing yourself?

    Or would you climb up and stop the guy on the roof dropping rocks on you?
    The problem is fossil fuel being burned.

    Methane is one of many bad feedbacks. It’s been studied seriously for more than a decade by the climate scientists who are telling you what’s known.

    Some feedbacks will be very bad, some will be horrible.

    For us citizens, those details don’t matter, they are a distraction.

    Seriously, the “methane monster” stuff takes attention away from the problem.

    Fix the problem.

    We can’t fix feedbacks. We can fix causes.

  8. 58
    Hank Roberts says:

    Assuming, as seems likely, that the natural seeps aren’t new — what happens to the hydrate stability zone assuming a rapid sea level rise and warming?

    Increasing ocean depth increases pressure — making hydrates more stable at any given depth, and does so rapidly

    By contrast, warming ocean water slowly warms sediment for that warming to propagate into hydrates.

    Has anyone projected where the top of the hydrate stability zone will be moving toward, at any particular location, a century or two from now?

    [Response: Yes, on these time scales the temperature effect is larger than the pressure. An exception to that: on geologic time, if sea level responds fully to the long CO2 forcing and changes by 10’s of meters, sea level could have a stronger impact than temperature in places where the methane now has to go through a thicker water column to reach the atmosphere, like the Siberian continental shelf. David]

    (I omit the monster earthquake/landslide/cracks/volcanic intrusion scenarios because they’d be local events — even the largest — not globally applied rapid simultaneous change the way sea level will be changing.)

    It’s worth repeating — repeatedly:

    The real Methane Monster is corporations; they have stockholders, and lawyers, and lobbyists. The real Methane Monster is the fossil fuel industry’s activities. Its little cousin, natural methane seeps, is a mouse by comparison.

  9. 59
    Hank Roberts says:

    Aside, and this is purely my opinion:

    those newish to the subject most upset and fearful seem to believe the climate scientists aren’t listening to them.

    You folks haven’t read the history of the subject. You’ve got one handful of the problem and seem to think you’ve grasped the whole thing.

    Nope. You’ve caught hold of the tail, and you’re being jerked around.

    The climate scientists have been working on this for a very long time.

    And they still are.

  10. 60
    Dan Miller says:

    Re: #34 (28 Sep 2014 @ 2:43 AM): David’s response:

    “The question is, which gas should we expend more effort on curbing, methane or CO2? My answer to your second question is in the fifth pie chart.”

    You are framing the discussion as which gas we should spend more time curbing now. But when you look at the 5th pie chart, we see that ½ of the future impacts come from the Arctic and global hydrates… all of which are out of our control (vs. the coal, oil and gas, which we do control). So I would say the point, as a climate communicator to the public, is that we should very much worry about future methane and CO2 emissions from the Arctic and the oceans. This valid concern might lead to more action to curb CO2 now. This is the opposite of the message you are conveying. It is the future scenario, that the climate system can spiral out of our control, that might — just might — get policymakers to finally take action.

    [Response: I put that chart in there to convey the point you just made, not its opposite, but only on time scales of centuries / millennia. I’ve written many times that the permafrost and hydrates could be a strong feedback on those long time scales. Just not in our century. ]

    In other words, we should be very worried about the CO2 we put in the atmosphere now because it could lead to the unstoppable release of methane and CO2 from the Arctic and oceans in the future.

    Stop for a moment and think about the emotional point you are making in addition to the scientific point. Your emotional point is “don’t worry about methane.” But that is not correct and may lead to continued inaction.

    [Response: My point is, keep your eye on the ball, which is CO2 emissions. ]

    As George Marshall says in his book “DON’T EVEN THINK ABOUT IT: Why Our Brains Are Wired to Ignore Climate Change”:

    “Ironically, one of the best proofs that information does not change people attitudes is that science communicators continue to ignore the extensive research evidence that shows that information does not change people’s attitudes.”

  11. 61
    wili says:

    Thanks for all your responses, Professor Archer. They are to me the best part among the many good parts of this blog. Surely, though, the last graph, at least, if not deceptive exactly, does not tell the most important part of the story. Most of the non-Arctic hydrate is quite deep, as I understand it, so not likely to make it into the atmosphere, or not for a very very long time.

    Furthermore, we have to hope/assume/work to make sure…that at least the hardest half of that coal to reach will never get used (and also won’t catch fire or reach the surface in some other way). So that basically cuts the ‘pie’ in half, now leaving Arctic sources as about a third, coal about the other third, and everything else the last third or so of sources likely to actually make it into the atmosphere in decade-to-centuries time spans.

    A third does not seem small relative to other sources.

    [Response: Yes, I agree, not small on long time scales. Only small on short time scales. David]

    (Frankly a source that adds up to many times all the carbon that could ever be released from oil seems not very small relative to that source, either.)

    Thanks again for great posts and responses, and let’s agree in any case (I hope) that stopping carbon emissions from coal, gas and oil must be our top priorities, no matter what may or may not be looming in the Arctic.

  12. 62
    Jan says:

    Susan: re Kaiser Fung
    As someone interested in data viz, his blog is one of a couple I’ve been following for some time. His method of critiquing real world examples is often quite instructive, even if I don’t have to agree with each of his arguments and find his know-it-all attitude distracting at times.

    Thank you for your detailed responses to Fung’s critique. I’ve been trying to follow the scientific debate on climate change since the 90ies. Being a scientist myself, I value your efforts in trying to inform the public about the state of science very much.

    However, while I’m with you content-wise, I feel you’re being a bit too lighthearted in rejecting his formal critique. As someone who doesn’t follow your blog on a daily basis, I too had a very hard time understanding your post. As this blog’s goal is to address the interested public, I think Fung’s critique could be quite informative in improving towards that goal, whatever his views on the issues might be.

  13. 63
    Sean says:

    @49 PS – Peter Ward added 30th Sept

    “I do not know what the hell they were trying to say. No idea. Bizarre”

  14. 64
    Sean says:

    It does not matter where CO2 originates from, and that includes Methane as a source. All sources of increasing CO2 levels are critically important because they all add up to the total.

    And it is the polar regions where the temperatures are rising faster then anywhere else on the planet right now. And those rising temperatures there are having an effect upon everything, long before a scientists is able to notice it or measure it, and then write a paper about it.

    OK, so what is the difference between a flood basalt, methane hydrates, a volcano, and a Volvo?


    Carbon Dioxide, is Carbon Dioxide, is Carbon Dioxide!

    And that is the greatest problem that deep time tells us.

    The volcanoes did it, but something else is doing it now.


  15. 65
    Sean says:

    @60 Dan Miller

    Hear hear! You got it down perfectly.

    If only more scientists would listen to and then act on this proven cognitive scientific knowledge – “information does not change people’s attitudes”

    George Lakoff says the exact same things – has been for over a decade now.

    Why don’t the scientists listen to other scientists who have already presented the evidence which proves their work and their conclusions are 100% correct???

    As I mentioned before: How Brains Think

    and 01/07/2010 Communicating science to the public and engaging in outreach [end of Peter Ward video]

  16. 66


    Kevin without recognising the extent of the current situation you are incapable of contributing to it’s long term reversal… Just open your eyes.”

    – See more at:

    My eyes are quite open, thank you. But in my world, and the dictionary, you don’t ‘reverse’ the unstoppable.

    Please choose your words carefully.

  17. 67
    MartinJB says:

    RE Lawrence Coleman (54 & 55): Can you point us to where you’re getting those rather large numbers describing lose of vertebrate and invertebrate populations? Without the context, it’s rather hard to interpret just what they mean.


  18. 68
    David Miller says:

    David, in #36 you say:

    [Response: The warming, as indicated by the oxygen-18, persisted for long after the time period of the carbon release stopped (when the 13-C stopped rising). This is why I conclude that CO2 was the warming agent, not methane itself (which goes away in 10 years after the emission stops). David

    …. and I have to ask about the “goes away in 10 years” part….

    My understanding is that methane is primarily broken down into CO2 + H2O through oxidation with the OH- radical. I also understand that the amount of OH- radicals produced globally is relatively fixed.

    Why, then, is it safe to assume that methane will all (substantially) decay after a decade regardless of concentration? If we have 10x or 100x the methane concentrations of today it seems to me the residence time is going to increase substantially. Probably not linearly – nothing in the atmosphere is that simple – but substantially.

    Where am I going wrong?

    On a related note, I see methane dismissed because it decays into CO2 in a decade, but rarely if every any mention of the H2O. I know what happens to H2O vapor in the troposphere (it quickly precipitates), but doesn’t it reside much longer in the stratosphere where a substantial portion of the methane breaks down?

    [Response: Your intuition is correct, that if the source flux of methane were higher, the lifetime would increase somewhat. You can see the effect in my on-line CO2 vs. methane slug model (Slugulator). But it’s not a huge effect, compared with the huge lifetime of a CO2-driven climate perturbation. It doesn’t rain from the stratosphere so the lifetime of water vapor up there is probably order a few years or a decade (which is my recollection of the circulation time of air through the stratosphere). ]

  19. 69
    wili says:

    Hank wrote: “Reality will be what it is, as it works out.
    Many models, but one actual planet and climate evolving.”

    “details don’t matter”

    A major reason I’m here is to try to understand what science is telling us that our reality is, including the details, whichever way that points. I hope that is still an appropriate goal here.

    “It’s been studied seriously for more than a decade by the climate scientists who are telling you what’s known.”

    In this case, various scientists are saying various things about the nature of the risk. I hope it is allowed to try to come to a clearer understanding here of the nature of those differences of viewpoint.

    Certainly we can all agree that reducing human emissions as deeply and as rapidly as possible is of utmost importance, including educating others–something I have been working at diligently for nearly three decades now individually, in my family and social circles, in the organizations institutions I work for and interact with, and as an active citizen in my neighborhood, city, state and country, risking and sometimes losing important relationships and jobs in the process.

    I guess I don’t see trying to understand the details of the science (to the best of my limited ability and time) as a distraction from those pursuits. But of course opinions can differ.

  20. 70
  21. 71
    Hank Roberts says:

    Wili, just saying, be skeptical.

    Look it up.

  22. 72
    Hank Roberts says:

    Has anyone tried improving the “bathtub model” to include methane?

    As described here by Nat. Geographic, even MIT students don’t understand Dr. Archer’s point about the lifetime of these gases in the atmosphere.

    Improving the bathtub model, to illustrate the way methane works, would be a real challenge — but might help. Viz:

    A fundamental human flaw, says John Sterman, impedes action on global warming. Sterman is not talking about greed, selfishness, or some other vice. He’s talking about a cognitive limitation, “an important and pervasive problem in human reasoning” that he has documented by testing graduate students at the MIT Sloan School of Management. Sterman teaches system dynamics, and he says his students, though very bright and schooled in calculus, lack an intuitive grasp of a simple, crucial system: a bathtub.

    Interactive Climate Change Simulator

    … as climatologist David Archer explains in his book The Long Thaw, those drains are slow. It’s going to take them hundreds of years to remove most of the CO2; that humans are pouring into the tub and hundreds of thousands of years to remove it all. Stopping the rise of CO2; will thus require huge cuts in emissions from cars, power plants, and factories, until inflow no longer exceeds outflow.

    Most of Sterman’s students—and his results have been replicated at other universities—didn’t understand that, at least not when the problem was described in the usual climate jargon. Most thought that simply stopping emissions from rising would stop the rise of CO2; in the atmosphere— as if a tap running steadily but rapidly would not eventually overflow the tub. If MIT graduate students don’t get it, most politicians and voters probably don’t either. “And that means they think it’s easier to stabilize greenhouse gases and stop warming than it is,” Sterman says.

    I’d bet that failing to understand the size and duration of these factors also explains why people focus on the short rather than long term effects, although the short-lived effects, as well as those of us now living, will be history soon. The long-lived effects will remain real for a very long time.

  23. 73
    wili says:

    OK, Hank. Thanks. I confess, though, that I tend to be more skeptical of scientists who tell me not to worry than those who tell me _to_ worry. But I understand that this can be an unfair bias, and I strive to listen carefully to all sides.

  24. 74
    Geoff Beacon says:

    Give future generations a chance

    Much earlier David’s response:

    Trying to balance carbon emission today vs. methane emission today, which is worse? Methane emitted today will be gone soon. Methane emitted 20 years from now is a different question.

    “quite soon” may be “too late”. Would reducing the continuing methane emissions from (say) cattle reduce the chance of tipping points?

    Have we reached a situation where CO2 has to be extracted from the atmosphere? After we stop flying, driving cars and burning fossil fuel for electricity, atmospheric CO2 levels will still be too high so the next generation may wish to extract it to give the world a better chance of survival.

    Why not increase their chances by cutting methane emissions. Wouldn’t that act quickly and reduce the dangers of dangerous feedbacks?

    I suspect that the climate scientists at RealClimate are not willing to argue for a negative carbon life-style – and that is what we should be aiming for.

    Cutting methane emissions by removing most ruminants from the Earth, removing rice produced from paddy fields, covering land-fills with more soil, stopping fracking … is an emergency measure that would be easier to implement that tackling CO2.

    This might just give the next generation or two a slightly better chance and tackle atmospheric CO2 levels.

  25. 75
    Rafael Molina Navas, Madrid says:

    “What caused the other extinctions was sudden volcanism (flood basalt flows) extruding CO2 and the world warmed by 10 degrees centigrade over 50,000 years and this warming produced hydrogen sulphide”
    As far as I know, before the warming due to CO2 huge increase there was also a huge but transient (in geological time) cooling due to increased albedo … at least partly due to volcanic SO2.
    But your statement is what said in the youtube video … I can´t understand why Peter Ward put it so.

  26. 76
    Lawrence Coleman says:

    67: MartinJB. In the latest report by the WWF for 2014. ‘2014 Living Planet Report’. With re: to invertebrates you can google that one, it likewise comes from an exceeding reputable source.

  27. 77
    Geoff Beacon says:

    Much earlier David’s response:

    Trying to balance carbon emission today vs. methane emission today, which is worse? Methane emitted today will be gone soon. Methane emitted 20 years from now is a different question.

    Will “quite soon” be “too late”? Would reducing the continuing methane emissions from (say) cattle reduce the chance of tipping points?

    Have we reached a situation where CO2 has to be extracted from the atmosphere? After we stop flying, driving cars and burning fossil fuel for electricity, will atmospheric CO2 levels still be too high to avoid disaster? If so the next generation may wish to extract it to give the world a better chance of survival.

    Why not increase their chances by cutting methane emissions. Wouldn’t that act quickly and reduce the dangers of dangerous tipping points from positive feedbacks?

    I suspect that the climate scientists at RealClimate are not willing to argue for a negative carbon life-style – and that is what we should be aiming for. Is this true?

    Methane emissions could quickly be cut by removing most ruminants from the Earth, removing paddy fields, covering land-fills with more soil, stopping fracking. Is this an emergency measure that would be easier to implement than cutting CO2 from flying, driving cars &etc?

    Would this give the next generation or two a slightly better chance to tackle atmospheric CO2 levels and survive.

  28. 78

    “methane will just peter out in a few decades”… What if the short-term worry is destabilising a major ice sheet?

  29. 79
    David Miller says:

    David (I presume) kindly responded to my question of increased residence time of methane due to greater atmospheric concentrations like so:

    Your intuition is correct, that if the source flux of methane were higher, the lifetime would increase somewhat. You can see the effect in my on-line CO2 vs. methane slug model (Slugulator). But it’s not a huge effect…..

    Nice tool, the slugulator. According to it the effect certainly isn’t huge.

    A 1 Gton pulse of methane peaks at 2ppm and decays to (background level?) 1.6 in just over 20 years. 10 Gton peaks at ~6 ppm and decays to 1.6 in maybe 30.

    1000 Gton peaks at a bit over 450 and decays to background in maybe 55 years.

    What’s the math behind this? One (OK, *I*) would find it very easy to intuit that with OH- produced by breaking down ozone, and ozone production limited to lightning strikes, that 1000 Gton would take a lot more than a couple of extra decades to break down. 2-3 times as long to break down 1000 times as much methane?

    One also has to wonder what happens to the ozone concentration under such conditions and what effect its decrease would have on UV hitting the surface.

    I’m not suggesting a 1000 Gton pulse is even possible, never mind likely. I’m just trying to understand the physics.

    [Response: It’s chemistry, not physics. We discussed this in our 2003 paper on the PETM, and there is some online code associated with that you can use to estimate the effect. It probably needs updating but it’s still a reasonable estimate. – gavin]

  30. 80
    David Miller says:

    Hank pointed me to

    Thanks Hank – nice text, very accessible to the layman like me. If I read it right, OH- is produced by photolytic breakdown of ozone and the interaction with a water molecule to make 2 OH-. The vast majority of oxygen atoms split off an ozone molecule recombine with another O2 molecule to make ozone. Surely this is because O2 is so much more prevalent in the stratosphere than water molecules; perhaps extra H2O in the stratosphere from methane oxidation will make formation of additional OH- radicals.

    Some homework for me: find a) amount of ozone in the stratosphere and b) production rates of ozone in the upper atmosphere. Over the long run it’s not apparent how methane breakdown could exceed (b), and the ability to deal with a pulse depends on (a).

  31. 81
    Hank Roberts says:

    > scientists telling me not to worry

    I don’t recall any climate scientist saying not to worry.
    I see them saying: understand what’s known that we can control and where’s the leverage.
    I see drilling gas hydrates to “depressurize” as excusing business already underway.…/charting-mankinds-expressway-to-extinctio…
    Aug 12, 2012 – The exponential increase in the Arctic atmospheric methane derived from the … Unless immediate and concerted action is taken by governments and oil companies to depressurize …”

    Check the claims. There’s no exponential increase. The measured increases come from land.

    “Current methane growth in the Arctic is gradual …
    If a sudden venting (bubbling) of methane would happen due to hydrates destruction, IASI would be able to detect it.”
    (also at )

    That’s from Yurganov, often cited for his concerns this _might_ become a problem, if we go on warming the planet. You have to look at the originals, not the enthusiasts’ scary stories.

    Every scientist can tell you what they find worrisome about warming the planet.
    There’s plenty to worry about.

    The drilling is underway; the pipelines are being laid; the gas sales are contracted.
    They did that part already. Claiming that’s the path to _protecting_ the climate is bogus.

  32. 82
    Hank Roberts says:

    Wili, I don’t think any scientist you’ve heard from has told you not to worry.

    I’m saying watch for the people, nonscientists, who know the answer (“depressurize”) and build their argument by worrying only about what leads to their chosen answer.

    This is their chosen answer, by the way, buried deep after all the stuff above it:

    Got that? They want to provoke circulation of warm water down into the stable hydrates to get them to melt now.

    And the thing is, they’re already doing that. The gas development was already contracted for and underway several years ago.

    The claim that it will save the climate — what you see there — is the excuse. Pretty poor excuse, turning the big control knob the wrong way.

  33. 83
    Rafael Molina Navas, Madrid says:

    “What caused the other extinctions was sudden volcanism (flood basalt flows) extruding CO2 and the world warmed by 10 degrees centigrade over 50,000 years and this warming produced hydrogen sulphide”.
    Before the warmings the opposite happened: a cooling (5 or 6 ºC, if I remember well), due to albedo increase, with huge increase in ice cover … That albedo increase was at least partially due to SO2, also extruded by the volcanos.
    Much much higher persistence of extruded CO2 produced eventually the warming …
    I can´t understand why Peter Ward put it differently.

  34. 84
    GlenFergus says:

    Just a thought on pie charts in general … I’m far from the only one who thinks they’re hard to assimilate, but apparently the difference is not always clear-cut:

  35. 85
    Rafael Molina Navas, Madrid says:

    #81 and others
    What you link from artic-news isn´t actually “new” … RealClimate stance could be “right”. But there is recent artic-news:

    ANY COMMENTS would be appreciated …

  36. 86
    wili says:

    Thanks Hank. I don’t put much store in that AMEG source too much: too many times they have put out stuff that is just wrong on the face of it. And as you say their agenda is, well, questionable at best. Still, I don’t think it automatically disqualifies everything that any individual who has been associated with them says or publishes.

    In other news (apologies if this was already linked and I missed it, and thanks to ASLR at Arctic sea ice forum for the link):

    The linked reference finds that degrading permafrost will produce more methane and less carbon dioxide that current Earth System Models assume; which when corrected will significantly increase projections of Arctic amplification:

    Zhaosheng Fan, Jason C. Neff, Mark P. Waldrop, Ashley P. Ballantyne, Merritt R. Turetsky, (2014), “Transport of oxygen in soil pore-water systems: implications for modeling emissions of carbon dioxide and methane from peatlands”, Biogeochemistry, doi:10.1007/s1053-014-0012-0.

    Abstract: “Peatlands store vast amounts of soil carbon and are significant sources of greenhouse gases, including carbon dioxide (CO2) and methane (CH4) emissions. The traditional approach in biogeochemical model simulations of peatland emissions is to simply divide the soil domain into an aerobic zone above and an anaerobic zone below the water table (WT) and then calculate CO2 and CH4 emissions based on the assumed properties of these two discrete zones. However, there are major potential drawbacks associated with the traditional WT-based approach, because aerobic or anaerobic environments are ultimately determined by oxygen (O2) concentration rather than water content directly. Variations in O2 content above and below the WT can be large and thus may play an important role in partitioning of carbon fluxes between CO2 and CH4. In this paper, we propose an oxygen-based approach, which simulates the vertical and radial components of O2 movement and consumption through the soil aerobic and anaerobic environments. We then use both our oxygen-based and the traditional WT-based approaches to simulate CO2 and CH4 emissions from an Alaskan fen peatland. The results of model calibration and validation suggest that our physically realistic approach (i.e., oxygen-based approach) cause less biases on the simulated flux of CO2 and CH4. The results of model simulations also suggest that the traditional WT-based approach might substantially under-estimate CH4 emissions and over-estimate CO2 emissions from the fen due to the presence of anaerobic zones in unsaturated soil. Our oxygen-based approach can be easily incorporated into existing ecosystem or earth system models but will require additional validation with more extensive field observations to be implemented within biogeochemical models to improve simulations of soil C fluxes at regional or global scale.”

    One of the uncertainties is how much of Arctic carbon is going to emerge as methane. It doesn’t change the amount of carbon, but it does change the global warming impact, at least in the short- to mid-term, doesn’t it?

  37. 87
  38. 88
    Hank Roberts says:

    > AMEG … many times they have put out stuff that is just wrong ….
    > Still, I don’t think it automatically disqualifies everything
    > that any individual who has been associated with them says or publishes.

    When it’s someone who’s reblogged misinformation in the past, better not to trust they’ve somehow become qualified to report the science accurately now.

    Look up the primary source, read that critically, search for a reliable science blogger’s discussion, link to the original and to good discussion..

    For an example of bad behavior “on the other side” look at the site formerly known as CO2Science:

  39. 89
    larsjaeger says:

    I stopped reading comments on most websites about a year ago. The very few who add to the conversation are drowned out by conspiracy theorists and trolls.

  40. 90
    chris says:

    On the bottom line, we need to curb CO2 in order to prevent CH4, which accelerates AGW.

    Related, a compilation i made last year.

    Estimating northern polar CH4 flux

  41. 91
    chris says:

    AMEG is calling for climate engineering. However, study conclusions from this year give many engineering attempts a bad taste and without addressing these findings and calling for large scale efforts is not very scientific nor wise.

    A study from 2014 investigated the most common climate engineering methods and concluded they are either ineffective or have potentially severe side effects and cannot be stopped without causing rapid climate change

  42. 92
    Geoff Beacon says:


    Financial engineering would drive climate engineering and a reduction in greenhouse emmissions &etc.

    The abstract of the paper you mention has

    Here we use an Earth system model to compare the effectiveness and side effects of afforestation, artificial ocean upwelling, ocean iron fertilization, ocean alkalinization and solar radiation management during a high carbon dioxide-emission scenario.

    I can think of a few others e.g. biomass burning with carbon capture. There are simpler ones: sinking biomass in the deep ocean, peroditite weathering &etc.

    The Nature study just investigates cheap options. A decent carbon tax ($1000 per tonne CO2) would make many more options available.

  43. 93
    Hank Roberts says:

    Chris Machens, you quote Schmidt and Shindell (2003) for “plausible emission rates (1500 Gt carbon over 500–20,000 years)” and after that, you have a couple of paragraphs verbatim from Ch. 2 of the methane article from Environmental Change Institute, University of Oxford, about exhausting OH in the atmosphere. That chapter ends with an argument for focus on aggressive control of short-lived greenhouse gases.

    I look for support of the claim claim about pollution overwhelming atmospheric OH levels, what I find is, e.g., — which doesn’t support that argument. How confident are you of your, or their, conclusion?

  44. 94
    Mal Adapted says:

    Geoff Beacon:

    The Nature study just investigates cheap options. A decent carbon tax ($1000 per tonne CO2) would make many more options available.

    …and if imposed soon enough, would render talk of geo-engineering moot, by driving a rapid transition to non-fossil energy sources.

  45. 95

    I don’t want to, er, ‘endorse’ the quote I give below; the source is not all that reputable, being a slightly shady investment advice outfit that is effectively impossible to unsubscribe from, once they’ve got your email addy. That said, however, there are intriguing things that get bandied there, and I thought this is one relative to the current post:

    Based on new data released by the Environmental Defense Fund (EDF), there seems to be a huge opportunity for companies to profit from regulations that could mandate oil and gas companies limit methane leaks from wells, valves, and pipelines.

    EDF data show the oil and gas industry can cut methane emissions by 40% at an average annual cost of less than one penny per thousand cubic feet of natural gas by adopting available emissions-control technologies and practices.

    And here’s the rub…

    If the full economic value of recovered natural gas is taken into account, the 40% reduction is achievable while saving the U.S. economy and consumers over $100 million a year, and the most cost-effective methane reduction opportunities would create over $164 million in net savings for operators.

    The bottom line is that oil and gas producers know these mandates are coming, so they’re trying to get in front of regulations — which, by the way, aren’t limited to the United States.

    In fact, just last month, six major oil companies including Statoil, Pemex, and the BG Group agreed to cut methane leaks from their operations. As a result, we’re now seeing a move on companies that provide solutions to mitigating methane leaks.

    It’d be interesting to know how big a bite this would (or could) take out of the ‘everything else’ slice in chart #3 above. (I’m sure I could find an answer, but lack the time just now.)

  46. 96
    Hank Roberts says:

    P.S. for Chris Machens — OH is toxic to phytoplankton — so we’re fortunate that methane isn’t affecting the amount of OH.

    … experiments demonstrated a tight negative relationship between phytoplankton abundance and the concentration of OH in surface seawater, with acute cell death during afternoon atmospheric OH influx events. The effect of OH radical was higher for picophytoplankton organisms, with Prochlorococcus showing the highest decay rate and the shortest half-life among the phytoplankton populations habiting the ocean surface layers. Our results provide evidence for a high toxicity of atmospheric-derived OH radical to phytoplankton of the surface layer of the ocean.

  47. 97
    Hank Roberts says:

    forgot the proper cite, which is:

    Transference of Atmospheric Hydroxyl Radical to the Ocean Surface Induces High Phytoplankton Cell Death
    DOI: 10.1111/j.1751-1097.2012.01184.x
    Photochemistry and Photobiology
    Volume 88, Issue 6, pages 1473–1479, November/December 2012

    (as always, look up citing papers to see what’s become of this idea)

  48. 98
    chris says:

    Hank, methane is indeed affecting the amount of OH, overall four ways of methane reactions are identified (AR4: indirect radiative effects of CH4 emissions have been identified).

    Four indirect radiative effects of CH4 emissions have been identified (see Prather et al., 2001; Ramaswamy et al., 2001). Methane enhances its own lifetime through changes in the OH concentration: it leads to changes in tropospheric ozone, enhances stratospheric water vapour levels, and produces CO2

    See also

    Methane increases also the amount of water vapor, thus contributing to precipitation and affecting evapotransporation patterns.

    Preindustrial to present-day changes in tropospheric hydroxyl radical and methane lifetime from the Atmospheric Chemistry and Climate Model Intercomparison Project (ACCMIP)

    The large inter-model diversity in the sign and magnitude of preindustrial to present-day OH changes (ranging from a decrease of 12.7% to an increase of 14.6%) indicate that uncertainty remains in our understanding of the long-term trends in OH and methane lifetime. We show that this diversity is largely explained by the different ratio of the change in global mean tropospheric CO and NOx burdens (ΔCO/ΔNOx, approximately represents changes in OH sinks versus changes in OH sources) in the models, pointing to a need for better constraints on natural precursor emissions and on the chemical mechanisms in the current generation of chemistry-climate models. For the 1980 to 2000 period, we find that climate warming and a slight increase in mean OH (3.5 ± 2.2%) leads to a 4.3 ± 1.9% decrease in the methane lifetime.

    Analysing sensitivity simulations performed by 10 models, we find that preindustrial to present-day climate change decreased the methane lifetime by about four months, representing a negative feedback on the climate system. Further, we analysed attribution experiments performed by a subset of models relative to 2000 conditions with only one precursor at a time set to 1860 levels. We find that global mean OH increased by 46.4 ± 12.2% in response to preindustrial to present-day anthropogenic NOx emission increases, and decreased by 17.3 ± 2.3%, 7.6 ± 1.5%, and 3.1 ± 3.0% due to methane burden, and anthropogenic CO, and NMVOC emissions increases, respectively.

    Emission of methane is affecting its own lifetime by reducing OH. Currently the enhancement factor is approximately 40%. For large future emissions the feedback factor will increase (Prather et al. 2001)

  49. 99
    chris says:

    Holocene variations in peatland methane cycling associated with the Asian summer monsoon system

    The close coupling between precipitation and methanogenesis is validated by climate simulations, which also suggest a regionally widespread impact

  50. 100

    Getting back to my earlier comment on the purportedly cost-effective mitigation of industrial CH4 leaks, Miller et al (2013) found US anthropogenic emissions of methane to be ~33.4 TgC/yr, of a global budget of “∼395–427 teragrams of carbon per year (TgC⋅y)−1”.

    So, the back of the envelope would indicate that, if as the original quote claimed, methane leak controls could decrease emissions by 40%, then full implementation would cut global fluxes by 4%, which would seem to be significant. Presumably similar initiatives could be undertaken globally, cutting global fluxes by several multiples more.

    Eyeballing Chart #4, non-anthropogenic fluxes look to be in the 25-30% range. If so, a 40% reduction in Arctic anthro emissions should more than compensate. Presumably, then, folks worried about methane have a possible policy option: push for adoption of these leakage control measures. (That’s in addition, one would presume, to continuing to push for mitigation of CO2 emissions, upon which we all pretty much agree.)

    “And so to work.” If I get a chance, I’ll see if I can find something more solid about the original quote, either to substantiate or rebut it.