They seem to show large recent increases in methane and don’t seem like nonsense, perhaps they are.
What worries me was the lack of “official” RealClimate comment on
– the undershoot of the models
– the missing feedbacks
– the observations of the methane plumes or
– the satellite images.
[Response:I'm with you on models in general, they often underpredict observations (ice sheet models, for example), often because they miss feedback, and they surely should be trumped by data where it's available. But there's so much more methane coming from the tropics that even if the high latitudes did start really pumping, they wouldn't have much impact until they start to rival the tropics, which is a ways off. David]
(I will say, though, that the discussion under the “runaway methane feedback” is much clearer if you take the time to consult the link provided–at least as far as the second point, anyway.)
[Response:I guess the information you are getting from that link is the idea of the feedback which I guess I neglected to explain. Warming causes methane release, which as a greenhouse gas drives further warming, and on and on. David]
– finding and fixing point sources — leaks in the methane/natural gas distribution pipelines, and capturing all the gas being flared off from oil wells worldwide.
– addressing surface sources in discrete locations — wetlands, rice plantations, dammed up rivers with decaying material at the bottom (those combined with chlorine produce for carcinogens in the water supply I recall)
– geoengineering the atmosphere based on claiming the problem
to address is diffuse leakage from undersea where we can’t get at it.
This makes sense of what’s been happening. Are there decent numbers on the various sources?
I recall a variety of possible approaches to agriculture to reduce methane sources.
-the satellite pictures you’ve linked to have a small range and highlight regional variations from one year to the next (in other words they don’t show large changes or a trend)
-the amounts of methane observed by Semiletov according to newspaper articles were small on a global scale (David pointed this out in general terms)
-yes, important feedbacks are poorly understood (and some may perhaps be unknown) but that’s not an excuse for baseless speculation
-no, policy makers are not lulled in a false sense of security (the IPCC reports are alarming enough), for the most part they simply have other priorities than the future of our planet (such as various power struggles)
Comment by Anonymous Coward — 4 Jan 2012 @ 3:24 PM
We will look back on this as the Great Polar Fart of 2012.
Despite the abundance of inaccurate but reassuringly conservative projections of how a multifaceted planetary response should now be unfolding due to radiative forcing from carbonic acid gas, and given certain constraining assumptions about projections, we shall soon find out how nation-states interact with the melting Arctic when floating atomic fission reactors are sent by Russia to power petroleum extraction platforms in an ice-free summer sea.
Hope a hot one doesn’t sink and discredit our calculated assumptions about the stability of hydrates. I’m sure this won’t happen, since it isn’t science (just the usual insanity).
[Response:Assumptions about heat flow probably matter more than the stability of hydrate per se. David]
I have always wondered if rising sea levels would increase hydrostatic pressure on the sub-sea methane deposits, thus tending to increase thier stability, and acting to off-set the slowly increasing ocean temperature. Anyone know if those two forces are likely to cancel each other out, or is one more likely to overwhelm the other?
#3 inline-”[Response:I guess the information you are getting from that link is the idea of the feedback which I guess I neglected to explain. Warming causes methane release, which as a greenhouse gas drives further warming, and on and on. David]”
No, I was OK with feedbacks in general. It was helpful in differentiating ‘methane runaway feedback’ specifically; I wasn’t quite sure how that was unlike other compound terms involving the word ‘runaway’–if that makes sense.
Doug O: Given the shape of the hydrate stability curve, temperature is far far more important than pressure in deep marine settings.
It is good to see a detangling of these issues, where all arctic methane was commonly ascribed to hydrates instead of the other large sources, that any and all releases were assumed to be new and not just newly-found, were all were assumed to be related to recent warming and not the much larger transgression, and the distinction between deep marine (Svalbard) and relict permafrost (ESAS) was seldom made. Thanks David.
Question, if you take an exposed shelf with permafrost and hydrates and hit it with a 15F temp change at the seafloor via transgression for 10000 years…how is it even possible that another couple degrees change in air temp could have any discernable effect?
[Response:Transgression, for the non-geological reader is flooding by rising sea level. There's permafrost, meaning soil/sediment colder than the freezing point of water, on the Siberian shelf because the air was so cold when the shelf was exposed during the last ice age. Very complicated playing field, but you're right, a bit of water warming is probably a small perturbation to the huge temperature change when it flooded, from which the permafrost is still responding. There's also frozen hydrate beneath the sea floor, because the hydrate freezing temperature is somewhat higher than the pure ice freezing point, so it doesn't rely on that extreme transgression thing to drive it. Good question. David]
Between ocean tidal changes and low/high pressure system (extreme lows being hurricanes), one can surmise that a few inches of increased sea level rise would be indiscernible. If you believe that the max/min ocean floor column pressure is already near a critical point, then sure, a slight change in seal level could tip the scale.
Here is another way of looking at it – 33′ of water column = 1 atm (14.7 psig) at say 3,000 ft, the pressure is 1,336 psi. A change of a few inches or even a few feet in seal level are not terribly significant.
You don’t mention methane from cows (which periodically gets a lot of scare story coverage). Is that totally insignificant?
[Response: No. Anthropogenic sources of methane have more than doubled atmospheric concentrations, and contribute about 0.5 W/m2 to the anthropogenic radiative forcing. There are multiple sources for this - farm animals among them (also oil and gas operations, leakage, landfills, and irrigation). David is focusing on methane feedbacks, not direct forcings. - gavin]
And why does it count it as a duplicate post when the recaptcha rejects one’s post and one tries again?
[Response: A question for the ages. Actually, if you fail recaptcha the comment is stored as 'spam' in the database and can be fished out if needed. So submitting the same comment is a duplicate - which is flagged. - gavin]
2 Geoff wrote: “Did Natalia Shakhova and Igor Semiletov really see much bigger plumes of methane this year than two years ago? If they did would be strange that 10000 year old warming should now be causing it.”
In their 2010 science paper http://www.sciencemag.org/content/327/5970/1246.full.pdf they write: “To test our hypothesis, we have undertaken annual field campaigns (August to September, 2003 to 2008; six cruises in total), one helicopter survey (September 2006), and one over-ice winter expedition (April 2007) (20, 21).”
I have not read the full article carefully but its hard to imagine how they could have characterized the variability (of the methane flux) with the 8 of trips they’ve taken.
At the other end of the geological time spectrum lies shungite, a sort of amorphous glassy carbon f forming layers thick as coal seams in the very old metamorphic rocks of Karelia and the Baltic shield.
It contains no visible microfossils, leading some to postulate that it originated as a thick marine algal mat.
Anyone know how it fits with currrent theories of bacterial methane metabolism ?
“Methane is also one of the usual suspects for the PETM, which consisted of about 100,000 years of isotopically light carbon, which is thought to be due to release of some biologically-produced carbon source, similar to the way that fossil fuel CO2 is lightening the carbon isotopes of the atmosphere today, in concert with really warm temperatures. I personally believe that the combination of the carbon isotopes and the paleotemperatures pretty much rules out methane as the original carbon source”
Don’t you then run up against some serious mass balance problems if the culprit was organic carbon?
[Response:No, since the isotopic label of organic carbon (of around -25 o/oo) is about half that of biogenic methane (-60 o/oo), it would take about twice as much organic carbon to deliver the same isotopic spike as the methane would. And the paleotemperatures indicate that it would have taken a lot of carbon to warm things up that much, unless the climate sensitivity was extremely high. Mass balance works better if it came from organic carbon. David]
“To increase the store of free gas beneath the clathrate layer, the pressure must rise to displace more water. But the pressure cannot rise too high before it will wedge open cracks through the clathrate and let gas out. Also, when the methane and water combine to make clathrate, they reject most of the salt in the water, making salty brines that are harder to freeze, until clathrate, salty water, and free gas can coexist, allowing the free gas to escape in some places by bubbling through the salty water”
I don’t see how this proves that there cannot be large pools of free methane. It is one persons thought experiment that I find rather incoherent.
Something is going on with methane over the Arctic Ocean. Perhaps it is not caused by global warming, but it will certainly contribute to it, and so it is worth taking seriously and trying to understand what is going on rather than trying to sweep it under the rug.
David, I note the turnover/replacement time for marine plankton nowadays is less than 2 weeks — which would suggest to me that the doubling time for marine plankton, and the DMS they’d produce, and the clouds _that_ would induce, might change very fast as a response to a sudden methane spike — a bloom, basically, but in response to a big input of methane. That input might be consumed within weeks of reaching the ocean, whether or not it even got into the atmosphere.
This is pure speculation, but — any thoughts on how much faster the climate sensitivity feedback might be if that were the case? What would the next limiting factor likely be?
[Response:That DMS - cloud link got people all excited when it was first proposed, the Gaians especially liked it, but I don't have the impression that it makes a huge difference in today's climate. One question is how clean the atmosphere would be particles if we didn't exist. DMS only has a large impact in air with no other cloud condensation nucleii. Might be wrong about that, not something I keep up with. But the clouds would have a cooling impact, a negative feedback, so I'm not sure I'm following the thread of your idea. David]
One thing on the “methane bubble”: I think the lack of such things at an important scale is probably true, but it is not at all clear. The natural release mechanism linked to is not real obvious and there are a few large blow-outs on arctic shelves that folks like C. Paull have attributed to more or less catastrophic releases (the pingo-like features). But these may be more geohazard, drilling issues than they are climate issues.
Anyway, I agree that hydrate methane is likely secondary to other methane even in the arctic, that arctic methane is a drop in the global methane bucket anyway, and that global methane is far secondary to Co2 in importance. So, my question is, do we see any real 1st order science issues remaining related to hydrates and climate? What we need is a way to fingerprint methane such that one can tell if or maybe even how much of it had passed through a hydrate filter?
I agree that CO2 is the prime greenhouse mover “in our lifetimes”, and of course, if the worst case scenario comes to pass, methane’s influence won’t really matter that much in the longer term Still, I would love to get a feel for how much CH4 and N20 will add to the temperature increase from a doubling of CO2. Suppose we take the best current average estimate per doubling of CO2 of about 3C. How much will the increasing methane and N20 add on top of this 3C?
[Response:Well, today methane is about 25% of total anthropogenic radiative forcing, and other gases including N2O are another 25%, but it's hard to speculate about in a warmer climate. Methane is a transient gas as described above, but N2O has a lifetime of 150 years in the atmosphere, so it has more history dependence than methane has (not as much as CO2). David]
More views by climate scientists on global warming and Arctic Methane, to add to this valuable discussion. Rates of CH4 release and short current atmospheric lifetimes do impose some constraints that can bound its climate feedback.
R. Gates #28
The main effect of CH4 in the long run is to increase the amount of CO2 (see David’s post). Rather than affecting the warming per doubling, it mainly affects the timeline of the doubling.
What you perhaps wanted to ask is how much would CH4 increase the expected warming per teraton of fossil carbon released in the atmosphere. I would be interested in expert guesstimates on the matter as well. This is especially pertinent since Matthews, in a paper promoting this metric (discussed on RC in 2010), assumed that CH4 would be offset by aerosols(!).
Comment by Anonymous Coward — 5 Jan 2012 @ 2:53 AM
David Archer @ 23 – I understand the reasoning that the greater amount of organic carbon required, gets one closer to the inferred paleotemps, but it’s a long way short (to say the least). And in what form could the organic carbon possible have been? The suggestions thus far are on even shakier ground than the methane hydrate capacitor idea.
Isn’t it more likely that the Earth’s climate was in fact more sensitive back then? Have you seen these papers?:
The ridiculously large organic carbon releases required, to match the isotope excursion, surely relegates itself to the bottom of the pile on that basis alone.
[Response:It could have been peat, or sedimentary organic carbon that suddenly degrades. The release time was ~10,000 years, they say, so time isn't a problem. It's certainly easier to imagine a smaller release of methane than a larger release of carbon from organics, but the proposed higher climate sensitivity of that time is hard to imagine too, given that it was a world with no ice albedo feedback. The situation forces us to believe at least one "impossible" thing before breakfast. Choose your poison, I guess. David]
I’m with you on models in general, they often underpredict observations (ice sheet models, for example), often because they miss feedback, and they surely should be trumped by data where it’s available.
I wish you could point this out to policy makers. I stopped Chris Huhne, the UK Secretary of State for Energy and Climate Change last year: He thought the missing Arctic feedbacks were now in the climate models.
I subsequently asked Kevin Schaefer of the NSIDC to send me a quote. He said:
If I were given the opportunity to talk to Chris Huhne, I would say
1. We must reduce total, global fossil fuel emissions.
2. None of the IPCC AR5 projections include the permafrost carbon feedback.
3. We must allocate 15% of total allowed global emissions to account for the permafrost carbon feedback.
4. The Department of Energy and Climate Change should definitely look into the permafrost carbon feedback because it implies a 15% greater reduction in fossil fuel consumption.
I understand Kevin was referring only to CO2 not methane – any methane would enhance this effect.
I have found that statements such as yours above very difficult to extract and I don’t remember any climate scientist volunteering this opinion. Is that due to climate scientist solidarity? If so we have a problem of trust.
Do you agree that “None of the IPCC AR5 projections include the permafrost carbon feedback.”?
[Hope you're reading this Chris. Did you like my article in Challenge?]
[Response:If I see any policymakers today I'll be sure to mention. Paleoclimate modeling generally finds that the model simulations of, say, abrupt climate changes are generally good, in the right direction, but muted compared to the reconstructed data. Richard Alley made this point in an AGU talk I heard him give, I don't think it's a secret. And ice sheet models are widely recognized to be limited in their responses, the whole field is working feverishly to make them better. The permafrost feedback is a carbon source, and generally the model are run with some prescribed atmospheric CO2 trajectory, sort of subsuming that and any other carbon cycle feedbacks. It would amplify the fossil fuel CO2 forcing. On the other hand, the land biosphere today is taking carbon out of the atmosphere. So it's hard to model, exactly, makes more sense for now to sort of include that possibility in the forcing. It's speculative. David]
Interesting post – thanks, David. Like many I have been looking into this issue recently. However, it seems to me that with respect to the East Siberian Arctic Shelf we are talking about a relatively data-poor area (until recently, very data-poor). That makes the reports from the area relatively difficult to interpret, despite the obvious problems with finding a mechanism for a large abrupt methane release and the lack of evidence in ice-cores for same to have occurred in any of the geologically recent deglaciations.
On the point that methane decays to CO2: in the long run I can see that as being the case, but could a very large methane event rapidly speed up other feedbacks like ice loss? That may be hard to discern in the resolution of the geological record, but could make a very big difference to the biosphere.
[Response:Sure, fast-responding things like sea ice would probably respond within the decadal time scale of a methane spike. David]
I took the trouble to read Raypierre’s Principles of Planetary Climate and that cleared up one big mystery for me: why methane is supposed to be a much stronger greenhouse gas than CO2: there’s so much less of it that the stronger absorbing parts of the spectrum aren’t yet saturated. I explain some of this on my blog, though Raypierre’s book is really the place to go if you want it explained properly.
“It’s the CO2, friend” is essentially a semantic argument. Those of us who are, yes, alarmed by the Semiletov/Shakhova evidence are quite aware that methane degrades into CO2, adding substantial amounts of carbon dioxide to our atmospheric thermal blanket.
What Archer’s post did not address is the recent 1km wide methane plumes that have been observed in the Arctic, or the enormous measured increase of methane concentrations in Arctic water and atmosphere. These plumes, along with Walter’s work, indicate unusual and rapid releases.
The data you cited assumes that a modest increase in methane/CO2 will still be less than our annual 7Gt and up AGW CO2 emissions. Even if this is true, accelerated methane releases in response to Arctic warming could be the early stages of a process that carries its own feedback loops.
Finally, scientists, including on this blog, appear to be awaiting catastrophic bursts prior to validating the danger. Humans instead need to act cautiously and preemptively in light of recent events in the Arctic. Otherwise, black swans could kill us all, partly because scientists were afraid to be wrong, or called the new “liberal”, (horrors!), “alarmist”.
It’s a little complicated to address the methane releases in the context of things like burning coal and gas and destroying forests. This is what scientists have to do, and forcefully. Gavin gets this, but some of the other contributors here err on the side of caution. Journalists are on the sidelines, and politicians are bought.
James Hansen published a paper a few years ago on methane which I found very illuminating. If I remember correctly, he essentially said that yes, the CO2 is the problem, but because methane has a much higher short term impact, you get more bang for your buck reducing methane emissions than CO2 emissions.
He noted that it will take a long time for us to switch from CO2 intensive sources of energy to less/minimally intensive sources, but that reducing emissions of trace gases like methane might be easier and quicker.
The notion that “journalists” have been scaring people with stories about methane is kind of absurd. Very few Americans have heard anything about methane in the media, as mainstream outlets have ignored it. Climate blogs only address a very small sliver of our society, as the rest of us belch merrily along.
The permafrost feedback is a carbon source, and generally the model are run with some prescribed atmospheric CO2 trajectory, sort of subsuming that and any other carbon cycle feedbacks. It would amplify the fossil fuel CO2 forcing.
Do you expect these feedbacks lag behind the forcing. If so, is there much in the pipeline?
[Response:Sure the feedbacks lag. Even the warming lags the forcing, then it takes decades, even centuries to melt permafrost etc. David]
To make rational policy decisions don’t we have to speculate and make a best guess?
The title chosen is an interesting inference. It is one whose import—and technical accuracy—is lost on all but the most fluent in the specificity of the language of science. The blue collar worker in me senses something is off with this choice relative to our condition. Is there is a bit of professional jealousy functioning as a muse for this Shakespearian allusion? With methane appearing to get the attention which (as is rightly noted) CO2 should be getting, such a feeling would be ‘reasonable’—if not fully reasoned.
Drawing on my knowledge gained in blue collar work regarding insulation, a political message is sacrificed to “theological” purity with the title equating the observed exponential increase in East Siberian continental shelf methane out gassing with “nothing” relative to CO2′s importance. Is the exponential nature of the impact insulation has relative to heat transfer via conduction not being modeled accurately for the Arctic? While greenhouse gases are primarily considered relative to their radiant heat transfer dynamics, does the consequenced increased Arctic cloud cover and types represent a poorly understood (and modeled) conduction force? Also, don’t these two forces invoke the third factor in heat transfer, that of convection, which may also be different in the Arctic than what is understood for the tropics?
Consider: the relative density of cold air, in conjunction with the Coriolis Effect affects the troposphere at the poles. It is less thick. What if that difference functions—if only simplistically—as a multiplier in terms of modeling factors? If such was proportional, and an enhancing factor, what is perceived as happening in small ways might need to be increased by 140% to have meaningful parity with what is currently thought to be of greater importance and the tropics. In addition, any bets that the impact might only be proportional, if such is the case. Career biasses can blind.
In relative terms, there is a lot that is known about the tropics and how it drives the climate. Is this because the poles are a bit less comfortable to hang out at and gather data from? Between the Coriolis Effect and the tilt of the earth’s axis, a lot forces can be observed and modeled to be center in the equatorial zone in terms of such being primary factors. However, to what degree might such also be a consequence of observer bias? Is climate change in the Ferrel Cell “the sound of one hand clapping” or integral to a less well understood Polar Cell with unique dynamics? Last winter (northern hemisphere), didn’t the polar jet move so as to all but subsume the Ferrel Cell for the Eastern US and Europe? What multiplier is necessary for that observation to be modeled relative to the dynamics of the climate—as assumed—in the Polar Cell? Would 140% cover it?
Anyway, there should be much ado about CO2, and politically, in the United States, there isn’t (except for a due diligence to pursue the BAU track and ‘recover’ a collapsed economic paradigm; i.e. rally around trusted delusional thinking). The technical definition of abrupt climate change, in some ways, justifies this reminder that it is CO2, not CH4, that is capitalism changing the climate (stuck accelerator & broken breaks metaphor in “Its All About Me(thane)” post a couple of years ago)—though I still think my rocket with liquid fuel first stage engines and solid fuel second stage ones whose ignition is tripped by an uncalibrated altitude switch, is a better one.
In terms of policy making here in the US (& to the degree rationality currently informs public policy), tipping points, which are the “altitude switch” at which the fuse of the methane time bomb is lit, are of public interest and policy concern. Don’t observations in the face of know uncertainty (and know unknowns—unknown unknowns withstanding)—make the concept of tipping points that which needs a language, both in popular and scientific rhetoric . . . and is something this essay has missed an opportunity to engage in?
I note this was the summary of Keith Kvenvolden’s 1988 summary paper in Glob Bio Cycles…
Present evidences suggest that global warming is under way, with its effects already noticeable in the Arctic. This warming likely results, in part, from the greenhouse effect, due to the ever increasing amounts of atmospheric carbon dioxide. The amount of atmospheric methane is increasing more rapidly than that of carbon dioxide, but the current greenhouse effect of methane is almost an order of magnitude less than that of carbon dioxide. Global warming will eventually penetrate the surface of the Earth and in the process destabilize gas hydrates. This destabilization will likely occur first and most intensely in the very shallow, nearshore regions of the Arctic Ocean where offshore permafrost exists. The processes of offshore permafrost warming and methane release may already be in progress, but the amount of methane presently being released and to be released during global warming in the 21st century is probably not particularly large and will contribute minimal positive feedback to the global-warming phenomenon.
A denialist blogger wrote this; is there anything to it, does he mean that released CH4 from hydrates would have no warming effect at all:
Since methane hydrate decomposition is an endothermic reaction [ absorbing heat ] it is self-quenching. This should have been a question that was asked and answered when it was first proposed. It’s a testament to the lack of scientific knowledge that the AGW’ ers bring to the discussion.
[Response: Complete nonsense. The role of methane being discussed here is as a greenhouse gas, nothing to do with the heat generated or used in chemical reactions. It is in fact a testament to the lack of scientific knowledge that the skeptics bring to the discussion. - gavin]
[Response:I presumed the person was arguing that the heat absorbed in the dehydration would be a negative feedback to that process, thereby preventing or slowing down CH4 release. The second sentence is the giveaway that an agenda drives the argument.--Jim]
[Response:It is true however that the rate of hydrate "decomposition" (melting) is limited by how quickly heat can diffuse down there. So it takes time for hydrates to melt just like it takes time for peat to decompose. Perhaps that was what was meant. In which case it would be like the old trick of "revealing" the band band saturation effect of greenhouse gases as though this wasn't already in the textbook on the subject. David]
Comment by Lynn Vincentnathan — 5 Jan 2012 @ 10:57 AM
Interesting and informative article, thanks. Is the rate of warming significant in this discussion? I’ve read that we are warming up the global climate at least ten times faster than the fastest known events of the past (e.g. the PETM). If there are no analogues in the palaeoclimate record for today’s rapid warming event, then perhaps that would make it difficult to predict future climate trajectories from the palaeoclimate evidence. Are the outcomes dependent upon the rate of warming, or do we just get to the same place but sooner?
[Response:There is an effect which they call the "efficacy" of ocean heat uptake. As the oceans absorb heat (the transient) that process somehow scrambles the atmosphere to vent a bit heat as well to space, something like that. For ocean acidification, a faster transition like ours has less time to be buffered by the CaCO3 cycle in the ocean (time scale between 1-10 kyr) and so the pH spike will be much more intense than if it took 10,000 years like the PETM. As far as the methane cycle is concerned, if methane release is able to respond quickly, the resulting elevated methane concentration would go up as the time scale got quicker. Lots of time dependence. David]
> to anthropogenically extract CO2 from the atmosphere.
One method is already underway — increased consumption by, and reproduction of, bacteria and algae in the ocean. Search for:
jackson “rise of slime”
for much about that. It’s already underway.
It’s not an -intentional- choice and it’s not a -human-friendly- route.
We’ve kicked off this process far faster than nature would have.
“… In many places — the atolls of the Pacific, the shrimp beds of the Eastern Seaboard, the fiords of Norway — some of the most advanced forms of ocean life are struggling to survive while the most primitive are thriving and spreading. Fish, corals and marine mammals are dying while algae, bacteria and jellyfish are growing unchecked. Where this pattern is most pronounced, scientists evoke a scenario of evolution running in reverse, returning to the primeval seas of hundreds of millions of years ago.
ARCTpolar2010.11._AIRS_CH4_400.jpg and ARCTpolar2011.11._AIRS_CH4_400.jpg
–a potential feedback has been proposed that once emissions of seabed methane start to increase significantly, they will create conditions (through warming, sea ice melt, disruption of sea bed…) that will essentially guarantee that all of the seabed methane will be released.
–many models have represented seabed methane as including clathrate caps over pools of free methane
These are among the reasons that some of us have expressed concerns about the recent reports of increased methane emissions.
The main counterpoint presented here seems to be that the methane will likely not be released quickly enough to have a global warming potential of much greater than CO2.
How certainly do we know this? Even if there is little good evidence of sudden release in the paleo-record, we are now increasing GHG concentrations in the atmosphere faster than at any time in the history of the earth, iirc. This is a new experiment we are conducting, and the exact degree to which and speed at which things will unravel cannot be known with certainty.
The other point that is constantly made is that right now emissions from this source are ‘small potatoes’ compared to other sources. Of course. But if we are seeing the beginning of an exponential increase in this source, it won’t take long for it to be a very major contributor indeed.
Of course, the main thing all this should tell us is that we need to decrease our GHG emissions–CO2 and CH4 and the others–to below zero very quickly indeed. Unfortunately, we seem to be doing the opposite–the global civilization seems to have something of a death wish.
I do appreciate the discussion of this important topic here. I would also point out that Shakhova did not say that the recent increase in emissions were the result of GW, and she specifically emphasized that they had not made this claim. So we can hope that whatever the cause of the recent increase in emissions this summer and fall is self limiting or cyclical in some way, rather than the beginning of an exponential increase.
Even if that is not correct, we have a situation where the ESAS is getting hit by (a) retreating sea ice causing a near albedo flip in the Arctic, heating up the sea exactly in the area in question (open water there right now), (b) increasingly warm oceans waters flowing in from both the Pacific and the Atlantic, (c ) rapidly rising sea-surface temperatures, and (d) increasing positive feedback from anthropogenic aerosols hanging over the Arctic Sea from pollution arriving from Asia.
#43–Just guessing, but I took it the same way Jim did.
It seems a poorly-thought-out meme, even by the usual standards.
Setting aside the vast over-simplification involved, I’d think that if asked whether a given endo- or exo-thermic reaction would become more likely under warming, you would pick the endothermic: The warmer temps supply more energy, and energy to drive the reaction is the postulated limiting factor.
But then I’ve seen “IR absorption” re-characterized to be the functional equivalent of reflection (in order to argue against albedo feedbacks) so this shouldn’t surprise. Just more of the same ‘sciency’ stuff.
Whilst methane is a powerful GHG it occupies a narrow, partially saturated spectrum which it shares with Nitrous Oxide (see http://www.climatedata.info/Forcing/Emissions/introduction.html) and the figure based on Kiehl and Trenberth). Not only is its spectrum narrower than for CO2 it is in part of the IR wavelength where the potential forcing effect is more limited than for CO2. This also seems to suggest that the impact of large increase in methane emissions would be limited.
“… we have conducted [more than] 200 point measurements of methane emission and ecosystem respiration rates on the Arctic coastal tundra within the Barrow Environmental Observatory. These measures reveal that methane emission rates are log-normally distributed, but ecosystem respiration rates are normally distributed. The contrast in frequency distributions indicates that methane and carbon dioxide emission rates respond in a qualitatively different way to their environmental drivers: while ecosystem respiration rates rise linearly with increasing temperature and soil moisture, methane emissions increase exponentially….”
Could that biological change be happening in the ocean as well as on land?
You always have to look at the big picture and look on the capacities of earth natural carbon sinks (input/output). The natural sinks it seems, are over loaded and degrade from all kinds of anthro involvements. And then there are feedback mechanismic which are not accounted for too. For instance the Jenkinson effect.
The big picture is also that we are on path to an ice free planetary state, thus the entire hydrocyle is put on steroids. Hence why extreme weather, especially with increased precipitation is the new normal.
Sure, we know when topsoil dies it produces lots of CO2 (as does anything that dies if not promptly eaten by something).
My impression was that screwed up Biosphere II — I recall they rushed closure, didn’t bring in mineral soil below a layer of topsoil and duff; instead, they used all topsoil. Of course that part buried too deep died.
Of course CO2 went way up.
So we _know_ that already.
Would we be so stupid …
Thanks for pointing out that the methane spike has now been scrubbed from the Barrow, Hank. Usually don’t they replace the aberrant orange dots with little green crosses? This time they seem to have been left out completely. Is that a usual practice, as far as you know?
I would really like to hear what people are thinking of Semiletov and Shakhova. It seems to me that we either have to say, in spite of their impressive credentials and experience in the area, that they are essentially delusional, or that they are right but that the monitoring stations and some other sources are faulty. Is it possible that large quantities of methane would not have made it to monitoring stations hundreds of miles away by now? Or is there some super sink that could have gobbled up all the methane that S&S (and others) report seeing bubbling from the ocean? Could it be that something else was bubbling up?
In short, should we really just ignore the statements of these experienced scientists? Do they have a reputation for making things up that we should know about?
[Response:I think they're doing important, necessary work and I'm grateful to them. David]
Relating to #4 and #18. Some may be aware that there is a lot of debate on the topic of having municipalities separate organics from non organic in the waste stream (separate collection from households and businesses). Millions are being spent or are being considered.
There are lots of components to these debates. The one I want to raise (and that is always included) is that organics sent to landfills generate methane (ignore capture, since it is so inefficient) and this is significantly worse than separating them so they can be composted which would produce CO2-and compost.
Does the short half life of methane fatally weaken this argument?
[Response:No, since methane is more powerful than CO2 it would have a stronger climate impact until it decays to CO2. The main fear of CO2, though, is that it will build up and cause much more severe problems in the decades ahead. Methane vs. CO2 is less relevant to that concern. David]
Comment by George Spiegelman — 5 Jan 2012 @ 6:45 PM
It took just hours to get back to methane alarmism. But nice try David.
To George @ 58–I think it is still a cogent argument. Even over the period of a century, methane has global warming potential 35 times CO2. It also argues for slow composting with less turning since this leaves more of the carbon in the compost (and produces more compost).
Our landfills have been a way that we have very temporarily and ineffectively been sequestering carbon, but that carbon has been and will be coming back to us in the very powerful form of methane.
Your point reminds me of another issue–any large burst of methane in the next few years and decades is especially bad since it makes it that much more likely that other feedback loops will be kicked off or kicked into high gear before we have started reducing CO2 emissions and bringing down CO2 levels.
Again, even a remote possibility that significant amounts of methane could come from the Arctic sea and land should be a spur to set us on an emergency path to drastically reduce GHG emissions. Actual findings that certainly parts of the tundra and reportedly parts of the ocean are starting to release increasingly large amounts of GHGs should not be minimized or swept under the rug, but shut set policy makers hair on fire to find every remotely reasonable way to reduce our own emissions. But instead we have the very weak tea that is the results of the Durban talks. Very sad for ourselves and for our progeny.
#58 George Spiegelman:
“Does the short half life of methane fatally weaken this argument?”
Weaken, yes. Fatally, no.
The lifetime of methane in the atmosphere is already taken into account in most accounts of the importance of methane as a GHG. But these accounts depend critically on the timeframe being considered.
Lower methane emissions would yield less methane in the atmosphere (everything else being equal). That would allow more heat to reach outrespace, which would of course be welcome.
But, strategically, you’ve got to wonder if millions should be spent going after methane at this stage…
If one were solely concerned about the next few years, going after methane would make sense. But, if you take the long view, any harm that methane could do in 10 years, CO2 will do in 30 years anyway (arbitrary numbers for illustration only).
Deep cuts in CO2 emissions would not stop warming immediately because the implied loss of aerosols. In my opinion, that’s the point at which it would make the most sense to play all available cards. That’s the point at which one could start talking about avoidable warming.
As long as CO2 is being emitted at anything like the current pace, I fear schemes to reduce methane emissions driven by arbitrary and short-sighted CO2e values effectively amount to yet another excuse for inactivism on the central issue.
But that’s just my opinion. The fact of the matter is that reducing methane emission would have a positive impact.
Comment by Anonymous Coward — 5 Jan 2012 @ 7:46 PM
Methane is too spooky for many scientists to wrap their heads around. It’s one thing to talk about adding 2 ppm CO2 per year and +.3C per decade, it’s quite another to talk about strangely behaving chemical monsters from the deep. Methane has stimulated more cautious and even wrong scientific opinion from quality scientists than any topic I’ve observed in the last decade.
In any case, we will all have to await Shakhova and Semilitov’s paper, due sometime around April, last I heard. Whatever it says, or at least that which survives peer review, could lead to the conclusion that emergency measures are called for. This will require government action, something dreaded by the Kochs and Boyces and now, thanks to their media massaging, much of the public as well.
All I ask is that Gavin et al keep an open mind, something that was not apparent in Archer’s piece. Many of us depend on you. And yes, the Arctic measurements taken so far were done with state of the art instruments, by an international team of supremely qualified scientists. Preemptive attacks and pooh poohing are uncalled for, and belong on Fox News, not here.
Here’s another comment from that skeptic — could you answer this, David?
I wrote: A portion of CO2 can remain in the atmosphere up to 100,000 years.
His comment: Your knowledge of CO2 is flawed. You keep repeating this claim – I keep asking you for your evidence.
[I provided links to some articles and books by D. Archer for him.]
His comment: CO2 is heavier than the atmosphere. CO2 is much heavier than Methane.
CO2′s Molar mass [ molecular weight ] is 44.0096 g/mol. It has a net atmospheric lifetime of about 5 years.
Methane’s [ CH4 ] Molecular weight : 16.043 g/mol. It has a net atmospheric lifetime of about 10 years.
I responded: That’s an interesting point, but I’m thinking it is not the weight, but the fact that CH4 is less stable and degrades for why it stays in the atmosphere a much shorter time than CO2.
I’ll ask David Archer about it….
[Response:He thinks that gases settle out of the atmosphere, so heavy ones have a shorter lifetime than light ones? That's a new one. You are spending time reading this person's wisdom, why? The five year lifetime for CO2 he quotes could be an exchange time scale, how long an individual CO2 molecule stays in the air before it moves into a plant or the ocean. But exchange fluxes don't affect atmospheric CO2, only net uptake fluxes. David]
Comment by Lynn Vincentnathan — 5 Jan 2012 @ 8:52 PM
> … capture, … so inefficient
numbers? what’s done is done and needs to be checked; are there new designs that successfully make clean enough methane an output?
As in organic chemicals, not organic farming
I’m much happier getting compost made from household food and yard waste that’s been piled and turned (by bulldozers admittedly) so it stays aerated, doesn’t make methane, and gives back a fairly clean compost product.
If there weren’t cities collecting food and yard waste, what alternate source of compost would likely be used on at least the public lands — sewage biosludge?
It’s happening. And that seems less than good practice from the results so far.
#57–”Is it possible that large quantities of methane would not have made it to monitoring stations hundreds of miles away by now?”
Sure. If the methane were to disperse uniformly (and remain in a ‘flat’ layer), concentrations would drop as the square of those ‘hundreds of miles.’ If not, it’s quite likely the wind wouldn’t blowing in quite the right direction–there’s many more vectors that don’t lead to the monitoring station than ones that do.
IIRC, S & S were unsurprised that their plumes weren’t being detected at large distances.
[Response:The air mixes longitudinally fairly quickly, so if there is an ongoing new large source in the high latitudes, going for more than a few months I guess, it would be detectable in the interhemispheric gradient of methane. David]
#58–Also, there has been and is a lot of work on using “landfill gas”–about 50% methane. In the US, according to the source linked below, about 20% of landfills are already harvesting energy from LFG, with roughly another 20% as good candidates for the utilization of this technology.
I like this essay except it doesn’t show where the methane sources are on a map. I know only about the Beaufort sea . I would say dominant wind direction causing an El-Nino like warming of the more open coastal Arctic ocean should have been modeled, otherwise the time scales proposed here are very conservative. I would caution anyone coming to absolute conclusions without a model simulating current Arctic sea ice melts as well.
Lynn Vincentnathan @64 — Carbon dioxide is a well mixed gas in the atmosphere (with a mixing time of about 2+ years between the northern and southern hemisphere). In other words, even carbon dioxide is sufficiently light that a combination of Brownian motion, turbulence and simple convection keeps it aloft and well, but not perfectly, mixed.
Furthermore, at water surfaces it quickly equalizes the partial pressures of dissolved in the water and free in the air. So while a tracked molecule of carbon dioxide in the atmosphere will eventually dissolve in watr another molecule will ‘evaporate’ to replace it.
David Archer’s “The Long Thaw” has rest of the carbonate story; its not such easy chemistry.
Comment by David B. Benson — 5 Jan 2012 @ 11:45 PM
On slime, until recently I did a lot of painting at the shore (wind on water, waves in motion, hence current fascination with water vapor maps, and you could add in chaos and celtic etc. imagery if you like that kind of thing). It got discouraging as rocks began to be covered regularly with black and green slime, making the light dark and unappealing; there was a similar deterioration in England’s west country, and they’ve had a good few floods as well.
A variety of Earth Observatory satellite images show various blooms; I’ve even adopted one labeled Ostrov Kolguyev for my desktop. I may be imagining things, but news of these does seem to be on the increase. It fits with land-based observations of more insect pests as seasons lengthen.
It does seem that even a smaller temporary amplification of polar methane, accompanied as you say by a larger effect closer to the equator, cannot be good news.
In any case, a very informative article and discussion for which I thank you all, yet again.
@Wayne, you can see the levels at 400 mb for the Northern Hemisphere for the month of November for years 2011, 2010 and 2002, on my blog, where I put them up so people can compare. The difference between 2002 and 2011 is pretty large:
Thank you Wili, Hank and Tenney Naumer. You have summarised the present situation enough for me to wait a bit before I hassle the policy makers I can contact – probably until I hear more about what Shakova and Semiletov saw and measured.
Another side of the methane discussion is it’s role as a short(er) term forcing agent. Anna #37 mentioned one of Hansen’s papers but the paper avoids mentioning the difficult issue of beef. Does anyone give any credibility to Livestock and Climate Change by the World Watch Institute. The authors, Robert Goodland and Jeff Anhang, say
Livestock are already well-known to contribute to GHG emissions.
Livestock’s Long Shadow, the widely-cited 2006 report by the United Nations Food and Agriculture Organization (FAO), estimates that 7,516 million metric tons per year of CO2 equivalents (CO2e), or 18 percent of annual worldwide GHG emissions, are attributable to cattle, buffalo, sheep, goats, camels, horses, pigs, and poultry.
That amount would easily qualify livestock for a hard look indeed in the search for ways to address climate change. But our analysis shows that livestock and their by products actually account for at least 32,564 million tons of CO2e per year, or 51 percent of annual worldwide GHG emissions.
A very large component of their GHG emissions is methane.
[Response: there are many errors in this report which ends up greatly overstating the role of methane. That is not to say methane is negligible, but rather it has to be seen in context - the ipcc report is much better than this. - gavin]
Lynn @ 64, I see that David has given a very good straightforward
answer. I want to add: Your knowledge of co2 is not flawed. It may be limited but that’s a different thing. The other party’s knowledge is flawed, or in other words the problem is what he knows that isn’t so, or in other words he’s an idiot. Is he really one oft those people who thinks co2 falls out of the sky because of it’s molecular weight?
Those are both short books. Archer’s is more technical.
Finally, the evidence that when the CO2 fraction is elevated, it stays elevated for a long time comes from paleo-studies of CO2 concentration. Ask your “skeptic” what takes CO2 out of the air. Just ask him and see what he says. That’s enough for now.
Comment by Pete Dunkelberg — 6 Jan 2012 @ 10:29 AM
#79 (Geoff Beacon and Gavin)
On environmental blogs like Grist the FAO report came up.
Environmentalists who are vegetarians/vegans said the equivalent of “we told you so” and urged all environmental groups to push meat free diets. As a meat-eating environmentalist I wondered how robust the arguments for livestock’s contribution to AGW in the FAO report were.
I have a question about Gavin’s reply. Which report has many errors, the FAO report or the World Watch Report? What are the errors?
Any light that could be shed on this issue would be greatly appreciated.
[Response: the worldwatch report is the one with the problems. This came up a few years ago when it was published, and the errors involve double counting, including things that are actually carbon neutral, and some large over-estimates of individual terms. But in any attribution excercise, there are many different ways of slicing things and many of the comparisons that are made are down using inconsistent accountings (ie using full life cycle analysis vs not), and so many of the headlines are a little misleading at face value. - gavin]
Comment by Joseph O'Sullivan — 6 Jan 2012 @ 10:31 AM
Gavin, if and when time permits, I would love to see a RealClimate analysis of both the FAO and the WorldWatch studies of GHG emissions attributable to animal agriculture a.k.a. livestock production.
The FAO study attributed nearly 20 percent of anthropogenic GHG emissions to animal agriculture. Even though that’s less than half of what the WorldWatch study found, it is still comparable to the transport sector — which gets a lot more attention.
Looking at the issue another way, there was a study a few years back (I’ll try to find a link later) that compared the GHG footprint of the average American diet to that of a vegan diet, and found that the reduction in GHG footprint from switching from a conventional American meat-heavy diet to a vegan diet was comparable to the reduction from replacing a conventional gasoline-fueled car with a Prius.
Given that adopting a vegan diet costs far less than buying a Prius (and in fact most likely will save you money), and that it also benefits your health, reduces your contribution to other very serious environmental impacts of meat production, and addresses animal welfare concerns as well, it certainly seems like an appealing option for anyone who wants to take personal action on global warming.
And yet, for some reason, many environmentalists seem to really get their hackles up when this is suggested.
#81 Joseph O’Sullivan,
About livestock, the methane issue is a distraction (for the time being anyway). It’s carbon neutral and the impact goes away as soon as the methane degrades to CO2 in the atmosphere.
The main issue with livestock is that raising grain-fed beef (and similar species) has a significant carbon footprint, in part because fossil fuels are used for inputs and operations in the farms which raise the grain. It takes a lot of grain to get a little meat on your table and you would get a lot more nutrition out of the grain if you ate it directly. The impact of the extra fossil fuel combustion isn’t going away because a fraction of the CO2 is likely to remain in the atmosphere a very long time…
Livestock which simply roams the countryside for food does not have that problem.
Comment by Anonymous Coward — 6 Jan 2012 @ 3:23 PM
“comparable to the reduction from replacing a conventional gasoline-fueled car with a Prius”
There are conventional cars which consume less (depending on the test) than a Prius, a very heavy car. The Prius’ efficiency in traffic jams can’t be beaten by conventional cars however.
Comment by Anonymous Coward — 6 Jan 2012 @ 3:42 PM
Maybe I missed it, but how is bio-activity accounted for; whereby melting of permafrost initiates biological activity, heating the surrounding permafrost, causing deeper melting and composting, etc.? Intuition (which is not the best way to analyze things) makes me thing that these types of runaways would not have such a long lag.
[Response:Interesting question. I tend to think of soils in the active (seasonally melted) zone of permafrost or around Arctic lakes as just plain cold, but I've never actually been to the Arctic, what do I know? David]
David wrote: “The only way back to a natural climate in anything like our lifetimes would be to anthropogenically extract CO2 from the atmosphere.”
I’d love to see an RC thread on this.
[Response:Good idea, watch this space. David]
Please be good enough to include the much saner, easier, healthier and more sustainable methods that have nothing to do with extracting more fossil fuels. I’ve posted them many times. Let me know if you need the links, David.
Quick hit: Geo-engineering based in technology is a Very Bad Idea. unintended consequences and all that… nature-mimicking solutions much preferred.
I am quite prepared to accept that the World Watch report has problems but the authors do have certain plausible arguments for increasing the CO2e footprint of livestock-related activity set out in the FAO report.
I’m surprised that you did not comment on the FAO report’s choice of GWP for methane as 23 – the Kyoto figure was 21. The excellent paper by Shindell, Schmidt et al., Improved Attribution of Climate Forcing to Emissions gives a value of GWP100 for methane of 33. Measured over 20 years this paper gives methane a GWP of 105 times carbon dioxide. The GWP20 of methane here is thus five times the Kyoto figure of 21 and almost five times that used in the FAO report.
I was surprised to reread the World Watch report again and find
The Intergovernmental Panel on Climate Change supports using a 20-year timeframe for methane.
Is that correct?
Should we then use a methane GWP of 105 for policy purposes?
The World Watch authors only used 72. Would the use of a higher figure of 101 cancel some of their “over-estimates of individual terms”?
[Response: No. GWP estimates, which as you note, are being revised upwards due to the indirect impacts of methane on atmospheric chemistry and aerosols, are all for comparing the integrated effects of a future emission of a kilo of CH4 compared to a kilo of CO2. The claim in the WW report was related to forcings today (which are the net effect of many past emissions), so they aren't really comparable. In the Shindell et al (2009) paper we look at both attribution and GWP, but the conclusions on attribution would need to be further broken down by full lifecycle sector-by-sector emissions to get at the FAO claim. I haven't done that, but my reading of the FAO claim is that is a reasonable estimate. The WW claim is not, nor is their claim of IPCC backing for an exclusive use of the 20 year timescale - IPCC gives those numbers but also those for 100 year timescales. - gavin]
Beef: The issue with raising beef has some to do with how you raise them. When they are grass fed and part of whole system designs in which they are used in healthy land management, they produce less methane themselves and help sequester more via the greater biological biomass of the healthier, balanced systems.
#68 inline–”[Response:The air mixes longitudinally fairly quickly, so if there is an ongoing new large source in the high latitudes, going for more than a few months I guess, it would be detectable in the interhemispheric gradient of methane. David]”
Thanks, that is helpful. After opining to willi, I did a very rough-and-dirty back of the envelope calculation, which suggested that concentration excursions comparable to the annual cycle amplitude would be quite conceivable. (Yeah, I should have done that first!)
Do we have an idea roughly how large would “large” have to be in order to affect the interhemispheric gradient?
[Response:I'm not sure how big an event or new degassing source would have to be before you could see it. If it were in were near the equator you'd never see it. David]
RE #64, thanks, David, and others who made suggestions. I posted all your comments about CH4 & CO2 (minus certain phrases) on that site. I’m not writing it for the skeptic — I don’t think anything could convince him — but for other readers who might be bamboozled by him. Catholic Answers Forum is a huge forum with over 500,000 threads, over 9 million posts, and over 300,000 members (not that a whole lot would be reading that particular thread on “Radical Environmentalism: Now Global Warming Causes Prostitution?”).
Another of my pet projects is the Catholic TV channel, EWTN, which reaches some 1.5 million homes. It has had a number of skeptic and denialist comments and screeds (despite 21 years of the popes writing that it’s everyone’s duty to mitigate climate change). I got another top climate scientist to help me with their weekly news program, The World Over, where they sometimes have as guest-speaker Fr. Sirico, head of the Exxon & Koch-funded Acton Institute for the Study of Religion and Liberty. At least that program is no longer promoting climate change skepticism anymore, and that environmentalists are a bunch of neopagan-pantheistic-atheist-communist-totalitarian-genocidal maniacs out to destroy the world.
And we thought too much CO2 and CH4 in the atmosphere was was bad.
Comment by Lynn Vincentnathan — 6 Jan 2012 @ 5:05 PM
Lynn on long lasting CO2 again –
1. Contrary to what I said earlier the studies on how long some fraction of fossil fuel CO2 will last are model studies, not paleo studies. Of course the paleo record does show that once CO2 is raised it does not come back down quickly.
2. Note that only some of our CO2 stays in the air out to 100 K years. It may be less than 10 percent.
I’m not ashamed to say that I didn’t quite follow the middle section of your comment. I do find GWP an odd concept to use for policy decisions but it is embodied in international treaties. I see the choice of a time frame for GWP as what economists call revealed preference. You didn’t reveal yours. Might I guess your preference is nearer to 100 years rather than 20 years?
I understand that greenhouse gasses and particulates we are emitting change the Earth’s radiation balance and this perturbs our climate in a dangerous way. We (the human race?) are grappling with strategies to avert the disasters that climate scientists such as yourself predict and other climate scientists may already be measuring.
I also understand that in discussing “attribution” – the measure of how emissions should be judged – depends both on “science” and “strategy”: the strategy that we (or following generations) might follow. For me the key question is the balance between short-term and long-term forcing.
I have come across two trains of thought.
The first says the effect of long term forcing over many decades is the most important because we are building up to a situation that cannot be retrieved.
The second thinks that because we are so near the danger zone we have to reduce short term forcing very quickly because the climate system is already too dangerous. This second view thinks we must hold the fort waiting for the cavalry to arrive.
I am sure you know just what I am talking about and I expect you could express this better.
My impression is that you are in the first train. Do you believe that
1. That the “missing feedbacks” in the underpowered climate models are not large enough to affect their message – that we must concentrate on reducing our emissions of long-term forcing agents (mostly CO2)? (We cannot afford to worry too much about shorter term forcing agents, which dissipate.)
2. That it will be practically impossible (for scientific and political reasons) to have geo-engineering solutions e.g. extraction of CO2 from the atmosphere.
My gut feel is that we are in imminent danger – at least the poor in the world are. We should slow warming by all means possible in the short term, while we wait for the biochar, olivine or other cavalry.
I believe reducing forcing this year is much more important than a projected reduction in 50 years time.
Comparing methane with CO2 often gets oversimplified and so I would like to make some comments.
After only small changes for about 7 years, methane started increasing around September 2006 and we still do not know why! When I showed my summary of the ESRL/CMDL methane data at the “Greenhouse Gases and Related Measurement Techniques” meeting in Wellington last October, Ed Dlugokencky, who leads that programme, agreed with me that this recent methane increase seems to have started in the southern hemisphere. A running 12-month mean shows a high degree of consistency for a large number of different flask sampling stations, so this is not just some local effect – and it does not seem to have started in the Arctic.
We do not know nearly as much about the methane budget as we do about the CO2 one. For the last IPCC assessment there was no simple way of producing a break down into the different sources and sinks that was consistent with all the data and model analyses. For example, most of the atmospheric chemistry models ignore removal of methane by reaction with chlorine, despite this being the only way of explaining the seasonal cycle in isotopic data in the southern hemisphere. So the budget for methane is complex and still raising some significant questions.
Next, methane is predominantly removed by the hydroxyl radical and that removal rate is now more than twice what it was during the preindustrial period – whereas for CO2 the gross removal rate is only ~3% higher. Because the Montreal Protocol has caused a switch to more use of HCFCs and HFCs that now means we are becoming increasingly dependent on this tropospheric chemistry. So it should be recognised that it does more to reduce climate forcing than all of the combined ocean and biospheric uptake of CO2 – see Manning & Reisinger, Phil Trans Roy Soc 369:1891-1905, 2011.
Recent work led by Markus Rex from the Alfred Wegener Institute is now showing evidence for a tropospheric “ozone hole” in the equatorial Western Pacific, but we don’t know if it was always there or is some recent development. So the argument that CO2 emissions will make long lasting changes in our environment is absolutely right – but it also has to be recognised that further perturbation of highly non-linear atmospheric chemistry could trigger some significant transition like the Antarctic Ozone hole.
Global Warming Potentials are not the right way to compare methane with CO2 because they just raise major issues about the time horizon and the range of processes and feedbacks that should be included. Even more seriously, they are based on a simplified linear perturbation approach to cover what are becoming significant changes in a complex system. We don’t require the medical profession to come up with a single number to compare heart attacks and lung cancer, so climate science should start adopting a much broader perspective when comparing quite different types of global environmental stress.
“The Intergovernmental Panel on Climate Change supports using a 20-year timeframe for methane.”
Moreover, that sentence is self-inconsistent. It doesn’t make sense to use one timeframe for one gas, and another timeframe for another gas, and then claim that the two calculations are comparable. Either use 20 year GWPs for all gases, or 100 year for all gases (personally, I’d prefer the latter as coming closer to a reasonable balance between short-term and long-term effects), but using a 20 year GWP for methane and a 100 year GWP for, for example, N2O, and then trading them is just not a supportable approach – though some people keep suggesting it.
#93 Martin Manning,
Thanks for your insightful comment.
Would you have a reference for the analysis of “a large number of different flask sampling stations” attributing a recent global change in methane concentrations to the southern hemisphere? Even if it’s only your slides, I think it could be helpful.
Comment by Anonymous Coward — 6 Jan 2012 @ 9:01 PM
#76 Tenney, impressive data, can you display a full year? like does 2011.1 mean version 1 or January?
Curious to know the details on the model and observations differences in lower latitudes discussed behind the pay-wall. The authors noting discrepancies in Southeast Asia and central Africa with the term “such as” leaves the Amazon Basin hanging? These seem to be the prime non anthropogenic methane emitting areas. The available observation network is absent there, with that absence being a part of the orbiting instrument’s rational.
Also wonder if anyone plans to “proof” the bird aginst the far northern TCCON observatories Spitzbergen at 79º N and Eureka on Ellesmere Island at 80º N. (Strange there’s no barrow – and per Canadian PM Harper, soon no Eureka?)
Hank Roberts and # 21, John Reisman, 4 Jan, 7:24 PM
And ’yall might extend thanks to the TCCON observation net run out of CalTech with sponsorship from NASA, and stuff like
Sorry, those numbers will appear in full if you click on the images. All the images are from November data from the 3 years presented. Links to the originals are provided. They are from Yurganov’s ftp files.
If anyone can give help on deciphering the colors on these images from the Arctic, I would be forever grateful:
Maybe I missed it, but how is bio-activity accounted for; whereby melting of permafrost initiates biological activity, heating the surrounding permafrost, causing deeper melting and composting, etc.? Intuition (which is not the best way to analyze things) makes me thing that these types of runaways would not have such a long lag.
[Response:Interesting question. I tend to think of soils in the active (seasonally melted) zone of permafrost or around Arctic lakes as just plain cold, but I've never actually been to the Arctic, what do I know? David]
If I recall correctly, there was a recent paper claiming 50% of methane would convert to CO2 via biogenesis in permafrost. I found that optimistic, but hoped it was true.
“To answer this question, the researchers looked at the proportions of different forms of oxygen in bubbles of air trapped in ice during these time periods.
“There are different forms of oxygen, and as that oxygen in the carbon dioxide molecules is being moved around between different sources, you get different proportions of those different forms,” Harrison says. “You can use that change to tell you where the carbon dioxide is coming from.”
Combining this information with climate models, the researchers concluded that the extra carbon dioxide was being released from vegetation, particularly tundra and cold steppes, which are very rich in carbon.
“These plants were stocking carbon in the soil, and when the climate started warming at the end of the glacial period, that carbon was released into the atmosphere,” Harrison says.
Scientists know that there is carbon locked up in permafrost and permafrost soils at high northern latitudes today. They also expect that as the climate warms in the future, that carbon is going to be released and increase the amount of carbon dioxide in the atmosphere.
But without being able to explain exactly the natural carbon dioxide changes in the past, they have been hesitant about projecting exactly what the impact might be. “You do wonder if there are things you don’t understand about the system,” Harrison says.
“Essentially what this paper is saying is that we now have a much better understanding of what was happening in the past through the use of these modelling tools and these measurements.”
The new findings will help scientists develop more accurate models of what will happen to atmospheric carbon levels as the permafrost melts.”
But note that this was deliberately a very wide ranging talk and so my summary of the methane changes by latitude bands is just on slides 23/24.
The ESRL data is at ftp://ftp.cmdl.noaa.gov/ccg/ch4/flask/ and I have done several compilations which suggest that the methane increase started in August 2006 at about 10oS. The 12-month running average values had been flat or decreasing slightly over most of the Southern hemisphere since early 2000, and then that seemed to change quite sharply. Any detailed explanations will be gratefully received!
Martin Manning, #93, I question your and Dlugokencky’s assumptions regarding the southern hemisphere being the likely source of the atmospheric methane’s renewed increase. This observed increase could, just as easily, be Arctic methane finally showing up in a relatively pristine atmosphere where in can be observed, measured, and quantified.
The speculated causes of the tabling of atmospheric methane include agriculture practices (new rice species), landfill capping (for Kyoto carbon credit value), and a significant effort in the oil and gas industry to capture methane at well heads and in the transport and distribution systems. With the northern temperate zone being an ongoing primary source of methane, these reductions could be expected to hide a small and growing increase in Arctic methane from being measurable until the atmospheric transport of methane gets it to the relatively pristine atmosphere of the southern hemisphere. Isn’t the “delay” these observations, and their characteristics roughly in agreement with such a scenario?
Right now, it seems that satellite-based data is providing us with a view of changes in Arctic methane that surface air sampling stations are not seeing as clearly. Might we simply be at a time in the Arctic growing role in atmospheric methane where the consequences of limited investing in a robust Arctic atmospheric sampling network means that those with that expertise are going to be confirming, not identifying, the initial stages of important changes? If so, humility may be both required, and scientifically relevant as observations continue to confound previous assumptions and modeling.
BTW, the ozone hole you mention evidence pointing to over the western Pacific adds some credence to the speculation I made in my earlier comment (#41) about the difference the headroom the atmosphere provides for atmospheric chemistry and heat transfer dynamics concerning the relative importance of equatorial and polar zones. A forty year lag could be attributed, in part, to the frequency with which various molecules would tend to bump into each other in a more compressed/dense atmosphere. Whether a 40 year head start is a consequence of a 140% multiplier, or another amount—or at all—is, for me, secondary to the possibility that observer/career bias is at the root of the current contention regarding when and why, not if, tipping points happen. That medical metaphor is well considered.
Thanks David, this is a welcome perspective on things. Basically, yes, there is a lot of feedback potential in methane clathrates, but the release is unlikely to be very fast.
Re: 64 Lynn Vincentnathan
Actually, I have seen this ill-informed opinion before. To me, it just illustrates that a little knowledge can be dangerous. Others have explained it well enough, but I thought a picture or two might help get the point across.
Easy counter: Measurements show that CO2 does not vary much with altitude; how can you reconcile that with your idea that its molecular weight causes it to sink?
“The observed CO2 concentration is generally high in low altitude and low in high altitude. High CO2 concentration relative to the average CO2 distribution is sometimes observed during the flights. Its difference is about 8 ppmv at most.” http://adsabs.harvard.edu//abs/2002AGUFM.A62B0151W
The first part actually agrees with the other guy, but 8 ppm/400 ppm is well within my definition of ‘not much’ (2% over the entire measurement range), and that is the maximum difference they found.
Thank you greatly, Martin, for your very informative posts. I particularly liked your comparison of different sources of GHGs to differences in different anatomical organs. Reducing everything to numbers can give a false sense of equivalence among systems with very different dynamics, apparently.
You mentioned Cl as an under-appreciated sink for methane. Some of us here have been struggling to reconcile the eye-witness reports from experts (and others) of vastly expanded methane plumes in the Arctic Ocean on the one hand with the apparent lack of instrumental measures of correspondingly large increases in atmospheric methane concentrations in the region.
So the question is, could Cl in the newly exposed ocean surface and the relatively new so still salty ice over much of the Arctic ocean be providing a potent sink for all this methane that has been observed bubbling from the deep but has mostly not shown up at monitoring stations? IIRC, methane can be held close to the surface in this area by inversions of very cold air, so this may perhaps facilitate such sea- and ice-surface reactions of atmospheric methane with Cl, I suppose. I realize that only direct measurements, careful experiments, etc., can actually determine whether some such thing is occurring. I’m just wondering if on the fact of it such a thing is worth considering.
My other question is whether the new methane source in the SH in ’06 could be from Antarctica. I am quite ignorant about the nature of the land and soils there, so I have no idea if any such thing is possible. But there have been some fairly large temperature anomalies down there at various times. Are there tundra like features there? Or vast fields of frozen penguin guano that might be starting to melt…? On another tack, is there any evidence of marine methanogens whose populations may have swelled under conditions of warming oceans?
Thanks again for your informative comments and all your other important work.
Last spring, we extracted a 53-meter-long core sample from the East Siberian Arctic Shelf, to validate our conclusions about the current state of subsea permafrost. We found that the temperatures of the sediments were from 1.2 to 0.6 degrees below zero, Celsius, yet they were completely thawed. The model in the Dmitrenko paper assumed a thaw point of zero degrees. Our observations show that the cornerstone assumption taken in their modeling was wrong.
In response to Greg Robie’s #105:
The changes that I mentioned were for concentrations and not for identifiable sources. But there are other times when some increase in methane is seen in one latitude band and then appears some months later in the adjacent ones in a way that can be linked to a change in the sources. So even though you are right, that trends can be easier to see in the well mixed and relatively clean extra-tropical southern hemisphere, it does not seem easy to explain this fairly abrupt change in the southern hemisphere as being caused by sources in the Arctic.
And in response to Wili’s #107:
Chlorine seems responsible for removing about 5% of methane but it has a larger effect on the isotope ratios. References for more details are:
- Allan, W., Struthers, H., and Lowe, D.C., 2007: Methane carbon isotope effects caused by atomic chlorine in the marine boundary layer: Global model results compared with Southern Hemisphere measurements. J. Geophys. Res, 112, D04306, doi:10.1029/2006JD007369.
- Allan, W., Struthers, H., Lowe, D.C., and Mikaloff Fletcher, S.E., 2010: Modeling the effects of methane source changes on the seasonal cycles of methane mixing ratio and δ13C in Southern Hemisphere mid-latitudes. J. Geophys. Res, 115, doi:10.1029/2009JD012924.
- and another recent study showing that we might still need to know more about atmospheric chemistry relevant for methane removal in different places is at … Thornton, J.A., et al., 2010: A large atomic chlorine source inferred from mid-continental reactive nitrogen chemistry Nature, 464, 271-274.
Martin Manning, #111: the clarification regarding concentration and sources is important and appreciated. The point that an increase in atmosphere methane can both be associated with a source shift, and also not so associated, makes explaining the dynamics that are in play anything but easy. To do so relative to a small, if exponentially growing source, that is three zones remove from an unexpected shift in what is observed, but is not identifiable with a source, is a case where such a challenge is an understatement. Changes that are occurring in parts per billion against a backdrop of northern temperate zone reductions in the rate of emissions and equatorial variations due to increasingly variable precipitation patterns and their commensurate impact on wetland methane generation in the Hadley Cells—and an increase in atmospheric turbulence everywhere (not to mention less-than-well understood saturation issues regarding atmospheric chemistry and the breakdown of methane)—makes finding hens teeth an easier task! ;)
Given the time stamps of your posts, you must be the bloke with your name working out of Wellington. Interdisciplinary climate change research has never been more needed, so my best wishes for your endeavors. The specialized education-centric approach to research and the current funding paradigm, which dominate the fields of climate change sciences, are not serving us well.
Anyway, Ed Dlugokencky’s comparative analysis of 2007 and 2008 surface air samples (2009) did identify the tropics and wetlands as a primary source of the increase in atmospheric methane. Anthony Bloom used satellite data to associate an increase in Arctic methane, which Dlugokencky missed—averaged away?—with Arctic wetlands (2010). Do both approaches to studying methane in the atmosphere contribute to what is being observed in the southern hemisphere?
Only one of the six Arctic stations used in Dlugokencky’s comparison study had an increase in methane between the two years of the study. If the Arctic is a source of a southern hemisphere methane increase, such is yet a variable source. And a growing contribution from the Arctic may yet be small enough that not only is a trusted analysis metric averaging it away, but any clear fingerprint of the Arctic as a source of southern hemisphere atmospheric methane may be getting muddied in the transit south.
With the passage of time, which policy makers do not have, all this will be sorted out, but in the meantime a better interdisciplinary understanding of tipping points, including how darn hard they are to see within the constraints of any specific scientific discipline (until it is way too late to be of value to the news media and policy makers), might be able to quantify the likelihood of the Arctic NOT being a contributing factor to what is being observe elsewhere using a process of elimination. To the degree a formula could be developed, through an interdisciplinary approach to climate change study, that uses information from zones about which more is known, what is not as well known about the Arctic could be deduced and certainty quantified. The changes in that certainty over time could give a current insight into what is otherwise among the known unknowns of the Arctic. Given the threat the loss of the sequestered Arctic carbon represents to climate change dynamics—once its release is tipped (if such has not already happened), filling in the gap in what we should already have the means to collect data and monitor change about is of upmost importance . . . to any would would wish to call themselves sapient..
The “hole” they were talking about is if we imagine OH as a layer in the troposphere providing essential service in the climate and/or ozone/UV radiation shield department, it may be that a sudden new “hole” has developed in it.
They say tropospheric OH abundance is closely related to tropospheric O3 abundance and because they can’t even measure O3 it was so low where they were attempting to measure it they believe OH is low. Their ship launched ozonesondes couldn’t find O3 “throughout” the troposphere in an area “well correlated with the region where most of the vertical transport of air into the stratosphere occurs”. They are calling for more and better data. Their concern is that this inferred “hole” in the OH layer, if it is new, could be allowing “organic species” to increase in abundance in the stratosphere as tropospheric OH normally oxidizes these molecules before they get there.
If so, they say, there would be unspecified but presumably significant changes for climate, and possibly for the ozone layer. The way they are referring to this, i.e. is there a “hole” in the “OH shield”, and the way you refer to this it seems you believe it might prove to be as significant as when Farman published his observations of the Antarctic hole. Can you refer me to more information?
To further assess and quantify the
contribution of the ESAS to the regional and global carbon
cycle, we plan to obtain new data to answer the following
(1) How does the contribution of the ESAS affect the role of
the Arctic Ocean in influencing the regional CO2 balance?
(2) How do processes of terrestrial OM decay in the ESAS
water contribute to Arctic Ocean acidification?
(3) How much CH4 could be released to the atmosphere from
the ESAS due to degradation of sub-sea permafrost and
decay of seabed deposits? What is the current state and
projected future dynamics of sub-sea permafrost?
To answer these questions we call for extended
international cooperation in studying the ESAS. Such study
will require multiple year-round exploration campaigns,
including drilling of sub-sea permafrost to evaluate the
sediment CH4 potential and comprehensive atmospheric
measurements to assess the ESAS strength as a greenhouse
gas source. International effort should also be joined in
order to quantitatively assess future changes in greenhouse
gas emissions in response to ongoing climate change by
establishing and developing regional numerical models with
the aim of incorporating them into global climate models.
Semiletov et al.’s new paper is a very helpful review of the types of data collected and how it is analyzed, the sources 9ncluding a lot of river runoff and direct coastal erosion as well as seabed clathrates, and fates of carbon from these sources. But when it comes to the bottom line – how much CO2 and CH4 are being released to the atmosphere, they use only old data. I hope this paper is just a prelude to another one with the latest results.
Inline above (??) – by reproducing the “shocking conclusion” I meant to draw attention to the opposite.
Comment by Pete Dunkelberg — 9 Jan 2012 @ 10:43 PM
This is kind of a nice chapter which among other things addresses some of the physical characteristics of undersea methane.
Comment by John E. Pearson — 9 Jan 2012 @ 10:45 PM
On #113 by Greg Robie:
Yes, I was the inaugural director of the NZ Climate Change Research Institute in Wellington, although have now stepped back from that and am trying to finish some papers. Interdisciplinary research is steadily becoming more important and it is not easy. We are working with social psychologists who can point at evidence for structural inertia being caused by traditional views that get locked in to the way that people think. In science we have to be careful to avoid falling into the same trap and my concern about atmospheric chemistry is because the more you dig into it the more you realise that we do not know enough about how it can change. This is not meant be alarmist, but the chemical composition of our atmosphere has never been the way that it is now, so the past records are of limited value, and early identification of potential transitions is very important. I have just reviewed a research proposal by someone in the UK to work on a better analysis of potential tipping points by combining different types of data, and I strongly recommended that.
On #115 by David Lewis:
The NDACC 2011 talk by Markus Rex seems very similar to the one he also gave in Melbourne last year. And no, sorry, but I don’t yet have anything else to add to these points about potential changes in methane removal rate. But am trying to finish another paper on 14C in carbon monoxide which both Paul Crutzen and Sherry Rowland (Chemistry Nobel prize laureates) have said was currently the best way of tracking changes in OH. In NZ we have the longest records for this tracer and so far it looks like there is no obvious trend, but we have to make sure we are dealing with changes in 14CO production rate due to the unusual solar cycle. The biggest fluctuation in our record still seems to be one caused by the Indonesian fires that started in late 1997. Our data is consistent with Steve Montzka’s paper in Science last January which summarised other tracers of oxidation rates but 14CO should be more sensitive to regional changes because it has a shorter lifetime. By coincidence we have some 14CO data from ship sampling going through the region that Markus Rex now calls a tropospheric ozone hole – but I still do not know if we have enough data to say if this appears to have affected OH. Ironically a steadily tightening budget for this sort of work means that our ship sampling has now been stopped!
What about the underestimates identified in forecasts (e.g., http://www.global-warming-forecasts.com/underestimates.php )? What about the conclusions of Nobel Laureate Dr. Kirk R. Smith who argues that dismissing methane as insignificant or underestimating the impact of its GWP could engender the undesirable result of “spending more money to protect people thousands of years into the future and ignoring the needs of ourselves and our children”?
Salmon #120: scientists have underestimated many things because they don’t like to be alarmist and also because of the cacophony of denialist voices that accuse climate scientists as a group of being alarmist. I don’t think underestimating the impacts of methane is at the top of the list. A rapid decrease of land ice (given that so it takes so much longer to replace long-term ice than to build it up) worries me a lot more. That’s not to say methane predictions may be wrong on the safe side but a lot goes wrong before that concern comes into play.
On the other side, the “anti-alarmist” camp is pretty quiet of late. Look at how the satellite data that used to be one of their core security blankets is not looking so conservative any more.
AIRS is one of the satellites; discussion at this blog references RC, Neven, and the AGU presentation
“… I’m busy reading up on the subject. In the meantime Dr Leonid Yurganov has been kind enough to give permission for me to put some of his satellite images into videos. The images are derived from NASA’s Atmospheric Infra-red Sounder (AIRS), info and data. Version 5 of the retrieval algorithm is used. … Those interested may want to read Dr Yurganov’s presentation to a London symposium on Arctic methane (pdf – right click and ‘save as’), it’s informative and well worth spending time on.
There are 12 videos each covering the full set of data for one month. Due to the large intra-annual variability this seemed the best approach. I’ll be referring to these in due course ….
Bear in mind that these show methane at 400mbar height so any large surface fluxes will be mixed unless plumed up into the atmosphere. For example the AIRS website has a graphic of a plume of methane at 200mbar implying signifcantly higher concentrations at the surface. That page also states AIRS is most sensitive around 200mbar with an accuracy of 1.2 to 1.5%….”
#121–”On the other side, the “anti-alarmist” camp is pretty quiet of late.” Yes, I’ve noticed that; cynically, I think it’s because there’s not much happening with COP at present; the denialists think they’ve won, and that now us ‘scammers’ will go away. And, insofar as institutional action is grossly inadequate so far, they have in fact won–or rather, they’ve been winning so far.
On the other hand, I’m confident that they are in for multiple surprises–though at a fundamental level I’d like it better if they actually were right. I’d go back to just making music (and writing about it.) Little chance, though.
“During the last decade, the southeastern Bering Sea shelf has undergone a warming of ∼3 °C that is closely associated with a marked decrease of sea ice over the area. This shift in the physical environment of the shelf can be attributed to a combination of …. four mechanisms have served to temporally and spatially limit ice during the 5-year period (2001–2005). “
concludes that there has not been any change in the climate pattern, and going “back to a natural climate” is not possible when there is no evidence of man made climate change in the data: the observed warming of 0.6 deg C per century existed BEFORE mid 20th century, before widespread use of fossil fuels.
I dearly hope people try to solve real problems like poverty now than the fictitious AGW problem.
Tropospheric ozone and black carbon (BC) contribute to both degraded air quality and global warming. We considered ~400 emission control measures to reduce these pollutants by using current technology and experience. We identified 14 measures targeting methane and BC emissions that reduce projected global mean warming ~0.5°C by 2050. This strategy avoids 0.7 to 4.7 million annual premature deaths from outdoor air pollution and increases annual crop yields by 30 to 135 million metric tons due to ozone reductions in 2030 and beyond. Benefits of methane emissions reductions are valued at $700 to $5000 per metric ton, which is well above typical marginal abatement costs (less than $250). The selected controls target different sources and influence climate on shorter time scales than those of carbon dioxide-reduction measures. Implementing both substantially reduces the risks of crossing the 2°C threshold.
Interviewer – Sarah Crespi
Well, you talked about carbon dioxide reductions a little bit. And how do these pollutants fit in with plans for carbon dioxide reduction?
Interviewee – Drew Shindell
Well, these are largely separate and complimentary to reductions in carbon dioxide. Given their fairly short lifetimes in the atmosphere of these pollutants, they don’t have such a drawn out impact the way CO2 does. And that’s what gives them powerful leverage in the near term when you don’t have powerful leverage from CO2 reductions. But that means in the long term what happens to climate is really going to be a function of CO2. Reductions from CO2 are primarily from things like power plants – things like that that are extremely efficient combustion and therefore don’t emit lots of black carbon. So they’re really independent sources, and they have effects on independent time scales.
An international team of scientists says it’s figured out how to slow global warming in the short run and prevent millions of deaths from dirty air: Stop focusing so much on carbon dioxide.
They say the key is to reduce emissions of two powerful and fast-acting causes of global warming — methane and soot.
Carbon dioxide is the chief greenhouse gas and the one world leaders have spent the most time talking about controlling. Scientists say carbon dioxide from fossil fuels like coal and oil is a bigger overall cause of global warming, but reducing methane and soot offers quicker fixes.
Soot also is a big health problem, so dramatically cutting it with existing technology would save between 700,000 and 4.7 million lives each year, according to the team’s research published online Thursday in the journal Science. Since soot causes rainfall patterns to shift, reducing it would cut down on droughts in southern Europe and parts of Africa and ease monsoon problems in Asia, the study says.
I don’t have the full paper but the abstract clearly and correctly says do both: cut CO2 and other bad things. I seriously doubt that the paper says at any point to do less about CO2.
Comment by Pete Dunkelberg — 14 Jan 2012 @ 9:12 PM
Re Shindell et al. 2012 again
Shindell, D., J.C.I. Kuylenstierna, E. Vignati, R. van Dingenen, M. Amann, Z. Klimont, S.C. Anenberg, N. Muller, G. Janssens-Maenhout, F. Raes, J. Schwartz, G. Faluvegi, L. Pozzoli, K. Kupiainen, L. Höglund-Isaksson, L. Emberson, D. Streets, V. Ramanathan, K. Hicks, N.T.K. Oanh, G. Milly, M. Williams, V. Demkine, and D. Fowler, 2012:
Simultaneously mitigating near-term climate change and improving human health and food security. Science, 335, 183-189, doi:10.1126/science.1210026.
In battle against climate change, NASA scientists call for curbing methane, soot
So far so good. Who doesn’t want to reduce pollution.
But then the article continues:
In the battle against global warming, scientists say they (sic) some of the world’s largest emitters should adjust their focus from reducing emissions of carbon dioxide to curbing the emissions of soot and methane.
which is a lie. In their eagerness to find excuses to keep on burning carbon journalists insist on misinterpreting the research.
Comment by Pete Dunkelberg — 14 Jan 2012 @ 10:07 PM
#125–The really funny thing is that the attempt to ‘hide the incline’ doesn’t even work. It’s still quite clear that the temps are warming.
Who is “climateforce”?
Who is “http://geo-engineering.blogspot.com/”?
climateforce links to these at the “geo-engineering” blog:
“The potential for methane releases in the Arctic to cause runaway global warming January 11, 2012
Thermal Expansion of the Earth’s Crust Necessitates Geo-engineering October 7, 2011″ which says:
“Extrapolation of the data points at Total Extinction Zones during which all organic life on Earth risks going extinct, due to accelerating release of methane from Arctic hydrates destabilized by Gakkel Ridge earthquake activity.”
This needs a sanity check or a better filter by whoever runs the blogl.
So does the reference collection. For example on methane
The same image is used on both blogs — the same one from last December that got posted at RC earlier by someone in comments. This one:
I always caution people — when any blogger posts a copy of an image instead of linking to the actual source, look very hard and find the original. Check whether the explanation clarifies what’s being shown there.
If it was omitted, ask why the blogger left off the explanation.
For the methane chart the explanation — which people should go read at the site — includes:
“Circle Symbols are thought to be regionally representative of a remote, well-mixed troposphere. + Symbols are thought to be not indicative of background conditions, and represent poorly mixed air masses influenced by local or regional anthropogenic sources or strong local biospheric sources or sinks. A smooth curve and long-term trend may be fitted to the representative measurements when sufficient data exist. Data shown in ORANGE are preliminary…..” along with a caution about checking with the site’s manager before using the preliminary data for any purpose.
Hank Roberts, thanks for the input, though the author name of the article is written on top of the posting and i run climateforce ^^(as you can guess when reading the actual poster name, stated beside the post date). I added the latest plotting..
Not sure if this was posted before but here is a quick recent paper about the “Antarctic enigma” ( methane anomaly appears in West Antarctica every October-November and disappers in austral autumn) and Methane long-term behavior, among other measurements and findings, by Leonid Yurganov. Interesting is the Correlation between methane and permafrost
..after 2007 new growing source(s) caused a new growth of CH4. The nature of these sources is a matter of debates.
The current rate of CH4 increase (~ 20 Tg per year for the global troposphere) seems to be constant between 2007 and September, 2011. This increase does not look catastrophic: in early 1980 methane was increasing with a rate 40-50 Tg/year and the rate decreased to zero by 2000. A permanent monitoring is necessary to detect a potential large surge as promptly as possible. ftp://asl.umbc.edu/pub/yurganov/methane/Yurganov_LondonCH4.pdf
Hank Roberts, i think it is quiet clear that i reposted a blog post from Sam Canara, about the topic of methane release. If you have input as you did, than we can talk about it. And if you personally have issues with other content he or others on his blog might publish then i do not share these setiments.
Arctic methane outgassing on the E Siberian Shelf part 2 – an interview with Dr Natalia Shakhova
SkS: With respect to future events, in your EGU 2008 abstract it is stated that “we consider release of up to 50Gt of predicted amount of hydrate storage as highly possible for abrupt release at any time”. This represents a colossal quantity of gas. How quickly could such a release occur and what would be the most likely mechanism?
NS: I believe that the non-gradual (massive, abrupt) emission mode exists for a variety of reasons. First, wherever in the World Ocean such methane outgassing releases from decaying hydrates occur, they appear to be torch-like with emission rates that change by orders of magnitude within just a few minutes. Note that there was no additional seal such as permafrost to restrict emissions for hundreds of thousands of years anywhere in the World Ocean. Imagine what quantity of methane has been stored beneath sub-sea permafrost if even now, when the permeability of permafrost is still limited, the amount of methane annually escaping from the ESAS is equal to that escaping from the entire World Ocean. Another important factor is that conversion of hydrates to free gas leads to a significant increase in the gas pressure. This highly-pressurized gas exerts a geological power that creates its own gas migration pathways (so-called “chimneys” within sediments). It is even more important to understand that the nature of the permafrost transition from frozen to unfrozen is such that this physical process is not always gradual: the phase transition itself appears to be a relatively short, abrupt transformation, like opening a valve. Remember that the gas “pipeline” is highly pressurized. There could be several different triggers for massive releases: a seismic or tectonic event, endogenous seismicity caused by sediments subsiding pursuant to hydrate decay, or sediment sliding on the shelf break; the shelf slope is very steep, and the sedimentation rates are among the highest in the ESAS. As for the amount that could possibly be released, this estimate represents only a small fraction of the total amount of methane believed to be stored in the ESAS (3.5% of 1400 Gt). Because these emissions occur from extremely shallow water, methane could reach the atmosphere with almost no alteration; the time scale of such releases would largely depend on the spatial distribution and capacity of the gas migration pathways. http://www.skepticalscience.com/arctic-methane-outgassing-e-siberian-shelf-part2.html
“But there’s so much more methane coming from the tropics that even if the high latitudes did start really pumping, they wouldn’t have much impact until they start to rival the tropics, which is a ways off. ”
Above said in response to #2.
What evidence is there that tropical methane mixes with high arctic air sufficiently quickly to assume that the exogenous tropical methane component rather than the endogenous increasing arctic component is what may be driving the discrepancy between carbon dioxide model predictions ignoring arctic methane production and observed arctic warming?
At least from my reading so far, the rate as well as the distribution and extent at which methane outgasing has occurred in the near or distant past is not that well known, much less the rate at which it might be increasing relative to that of relevance to high latitude warming, especially given that the size of the hydrate reserves are only rough estimates. All functions look linear when one only has one or a few data points all close together.
Recent field workers seem to speak in terms of surprise at rate at which permafrost in generating methane, suggesting that the phenomena could be just becoming noticeable. Given the inertia in these systems, it seems quite conceivable that waiting too long to detect and then verify a very slight deviation from linearity might be a mistake science could only make once.
I can’t speak directly on the geophysical data, but my incidental reading of zoogeographic and ecological faunal changes suggests to me that things are probably happening at a frighteningly rapid clip as compared to the pre-human baseline. We may soon see more transfers of Pacific and Atlantic faunal elements via the high arctic.
Seems as if more discussion couched in quantitative terms is needed as opposed to assertions based on a few data snapshots, regardless of how interpreted. Lacking tabular data to examine, one can only wonder just how ill-conditioned some of these data sets are and to what extent they are sufficiently constrained to realistically speak in terms of coupling causal phenomena.
[methane] “it must rise upwards into the middle troposphere along a gradual curve the trend of which will be determined by Corioli’s force …”
Ah, yes, Corioli … and his force …
“… The Arctic Ocean floor sourced methane must be sucked up into the stratosphere by these two giant tornado systems that are rotating anticlockwise in sympathy with the Earth. …
See this animation on NASA 2011 (6.59 MB download): http://earthobservatory.nasa.gov/images/imagerecords/36000/36972/npole_gmao_200901-02.mov
long term gradients and the estimated Arctic temperature trends from Gakkel Ridge earthquake frequency data are compared to estimated Giss temperature trends …. and indicate that a large (yellow region) total extinction zone has already started with the massive Arctic methane emissions in 2010, on schedule to reach its climax in the 2040′s to 2050′s….
… methane in the Arctic can be linked to seismic activity. As temperatures of deep waters of the Arctic Ocean keep rising, further seismic activity can be expected to trigger further releases of methane from hydrates that are likely to make the planet uninhabitable within decades.”