Methane is a powerful greenhouse gas, but it also has an awesome power to really get people worked up, compared to other equally frightening pieces of the climate story.
What methane are we talking about?
The largest methane pools that people are talking about are in sediments of the ocean, frozen into hydrate or clathrate deposits (Archer, 2007). The total amount of methane as ocean hydrates is poorly constrained but could rival the rest of the fossil fuels combined. Most of this is unattractive to extract for fuel, and mostly so deep in the sediment column that it would take thousands of years for anthropogenic warming to reach them. The Arctic is special in that the water column is colder than the global average, and so hydrate can be found as shallow as 200 meters water depth.
On land, there is lots of methane in the thawing Arctic, exploding lakes and what not. This methane is probably produced by decomposition of thawing organic matter. Methane could only freeze into hydrate at depths below a few hundred meters in the soil, and then only at “lithostatic pressure” rather than “hydrostatic”, meaning that the hydrate would have to be sealed from the atmosphere by some impermeable layer. The great gas reservoirs in Siberia are thought to be in part frozen, but evidence for hydrate within the permafrost soils is pretty thin (Dallimore and Collett,1995)
Is methane escaping due to global warming?
There have been observations of bubbles emanating from the sea floor in the Arctic (Shakhova, 2010; Shakhova et al., 2005) and off Norway (Westbrook, 2009). The Norwegian bubble plume coincides with the edge of the hydrate stability zone, where a bit of warming could push the surface sediments from stable to unstable. A model of the hydrates (Reagan, 2009) produces a bubble plume similar to what’s observed, in response to the observed rate of ocean water warming over the past 30 years, but with this warming rate extrapolated further back in time over the past 100 years. The response time of their model is several centuries, so pre-loading the early warming like they did makes it difficult to even guess how much of the response they model could be attributed to human-induced climate change, even if we knew how much of the last 30 years of ocean warming in that location came from human activity.
Lakes provide an escape path for the methane by creating “thaw bulbs” in the underlying soil, and lakes are everywhere appearing and disappearing in the Arctic as the permafrost melts. (Whether you get CO2 or a mixture of CO2 plus methane depends critically on water, so lakes are important for that reason also.)
So far there hasn’t been strong evidence presented for detection enhanced methane fluxes due to anthropogenic warming yet. Yet it is certainly believable for the coming century however, which brings us to the next question:
What effect would a methane release have on climate?
The climate impact of releasing methane depends on whether it is released all at once, faster than its lifetime in the atmosphere (about a decade) or in an ongoing, sustained release that lasts for longer than that.
When methane is released chronically, over decades, the concentration in the atmosphere will rise to a new equilibrium value. It won’t keep rising indefinitely, like CO2 would, because methane degrades while CO2 essentially just accumulates. Methane degrades into CO2, in fact, so in simulations I did (Archer and Buffett, 2005) the radiative forcing from the elevated methane concentration throughout a long release was about matched by the radiative forcing from the extra CO2 accumulating in the atmosphere from the methane as a carbon source. In the figure below, the dashed lines are from a simulation of a fossil fuel CO2 release, and the solid lines are the same model but with an added methane hydrate feedback. The radiative forcing from the methane combines the CH4 itself which only persists during the time of the methane release, plus the added CO2 in the atmosphere, which persists throughout the simulation of 100,000 years.
The possibility of a catastrophic release is of course what gives methane its power over the imagination (of journalists in particular it seems). A submarine landslide might release a Gigaton of carbon as methane (Archer, 2007), but the radiative effect of that would be small, about equal in magnitude (but opposite in sign) to the radiative forcing from a volcanic eruption. Detectable perhaps but probably not the end of humankind as a species.
What could happen to methane in the Arctic?
The methane bubbles coming from the Siberian shelf are part of a system that takes centuries to respond to changes in temperature. The methane from the Arctic lakes is also potentially part of a new, enhanced, chronic methane release to the atmosphere. Neither of them could release a catastrophic amount of methane (hundreds of Gtons) within a short time frame (a few years or less). There isn’t some huge bubble of methane waiting to erupt as soon as its roof melts.
And so far, the sources of methane from high latitudes are small, relative to the big player, which is wetlands in warmer climes. It is very difficult to know whether the bubbles are a brand-new methane source caused by global warming, or a response to warming that has happened over the past 100 years, or whether plumes like this happen all the time. In any event, it doesn’t matter very much unless they get 10 or 100 times larger, because high-latitude sources are small compared to the tropics.
Methane as past killing agent?
Mass extinctions like the end-Permean and the PETM do typically leave tantalizing spikes in the carbon isotopic records preserved in limestones and organic carbon. Methane has an isotopic signature, so any methane hijinks would be recorded in the carbon isotopic record, but so would changes in the size of the living biosphere, soil carbon pools such as peat, and dissolved organic carbon in the ocean. The end-Permean extinction is particularly mysterious, and my impression is that the killing mechanism for that is still up for grabs. 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 (Pagani et al., 2006), although Gavin draws an opposite conclusion, which we may hash out in some future post. In any case, the 100,000-year duration of the warming means that the greenhouse agent through most of the event was CO2, not methane.
Could there be a methane runaway feedback?.
The “runaway greenhouse effect” that planetary scientists and climatologists usually call by that name involves water vapor. A runaway greenhouse effect involving methane release (such as invoked here) is conceptually possible, but to get a spike of methane concentration in the air it would have to released more quickly than the 10-year lifetime of methane in the atmosphere. Otherwise what you’re talking about is elevated methane concentrations, reflecting the increased source, plus the radiative forcing of that accumulating CO2. It wouldn’t be a methane runaway greenhouse effect, it would be more akin to any other carbon release as CO2 to the atmosphere. This sounds like semantics, but it puts the methane system into the context of the CO2 system, where it belongs and where we can scale it.
So maybe by the end of the century in some reasonable scenario, perhaps 2000 Gton C could be released by human activity under some sort of business-as-usual scenario, and another 1000 Gton C could come from soil and methane hydrate release, as a worst case. We set up a model of the methane runaway greenhouse effect scenario, in which the methane hydrate inventory in the ocean responds to changing ocean temperature on some time scale, and the temperature responds to greenhouse gas concentrations in the air with another time scale (of about a millennium) (Archer and Buffett, 2005). If the hydrates released too much carbon, say two carbons from hydrates for every one carbon from fossil fuels, on a time scale that was too fast (say 1000 years instead of 10,000 years), the system could run away in the CO2 greenhouse mode described above. It wouldn’t matter too much if the carbon reached the atmosphere as methane or if it just oxidized to CO2 in the ocean and then partially degassed into the atmosphere a few centuries later.
The fact that the ice core records do not seem full of methane spikes due to high-latitude sources makes it seem like the real world is not as sensitive as we were able to set the model up to be. This is where my guess about a worst-case 1000 Gton from hydrates after 2000 Gton C from fossil fuels in the last paragraph comes from.
On the other hand, the deep ocean could ultimately (after a thousand years or so) warm up by several degrees in a business-as-usual scenario, which would make it warmer than it has been in millions of years. Since it takes millions of years to grow the hydrates, they have had time to grow in response to Earth’s relative cold of the past 10 million years or so. Also, the climate forcing from CO2 release is stronger now than it was millions of years ago when CO2 levels were higher, because of the band saturation effect of CO2 as a greenhouse gas. In short, if there was ever a good time to provoke a hydrate meltdown it would be now. But “now” in a geological sense, over thousands of years in the future, not really “now” in a human sense. The methane hydrates in the ocean, in cahoots with permafrost peats (which never get enough respect), could be a significant multiplier of the long tail of the CO2, but will probably not be a huge player in climate change in the coming century.
Could methane be a point of no return?
Actually, releasing CO2 is a point of no return if anything is. The only way back to a natural climate in anything like our lifetimes would be to anthropogenically extract CO2 from the atmosphere. The CO2 that has been absorbed into the oceans would degas back to the atmosphere to some extent, so we’d have to clean that up too. And if hydrates or peats contributed some extra carbon into the mix, that would also have to be part of the bargain, like paying interest on a loan.
It’s the CO2, friend.
- D. Archer, "Methane hydrate stability and anthropogenic climate change", Biogeosciences, vol. 4, pp. 521-544, 2007. http://dx.doi.org/10.5194/bg-4-521-2007
- N. Shakhova, I. Semiletov, I. Leifer, A. Salyuk, P. Rekant, and D. Kosmach, "Geochemical and geophysical evidence of methane release over the East Siberian Arctic Shelf", Journal of Geophysical Research, vol. 115, 2010. http://dx.doi.org/10.1029/2009JC005602
- N. Shakhova, "The distribution of methane on the Siberian Arctic shelves: Implications for the marine methane cycle", Geophysical Research Letters, vol. 32, 2005. http://dx.doi.org/10.1029/2005GL022751
- G.K. Westbrook, K.E. Thatcher, E.J. Rohling, A.M. Piotrowski, H. Pälike, A.H. Osborne, E.G. Nisbet, T.A. Minshull, M. Lanoisellé, R.H. James, V. Hühnerbach, D. Green, R.E. Fisher, A.J. Crocker, A. Chabert, C. Bolton, A. Beszczynska-Möller, C. Berndt, and A. Aquilina, "Escape of methane gas from the seabed along the West Spitsbergen continental margin", Geophysical Research Letters, vol. 36, pp. n/a-n/a, 2009. http://dx.doi.org/10.1029/2009GL039191
- M.T. Reagan, and G.J. Moridis, "Large-scale simulation of methane hydrate dissociation along the West Spitsbergen Margin", Geophysical Research Letters, vol. 36, 2009. http://dx.doi.org/10.1029/2009GL041332
- D. Archer, and B. Buffett, "Time-dependent response of the global ocean clathrate reservoir to climatic and anthropogenic forcing", Geochemistry, Geophysics, Geosystems, vol. 6, pp. n/a-n/a, 2005. http://dx.doi.org/10.1029/2004GC000854
- M. Pagani, K. Caldeira, D. Archer, and J.C. Zachos, "An Ancient Carbon Mystery", Science, vol. 314, pp. 1556-1557, 2006. http://dx.doi.org/10.1126/science.1136110
148 Responses to "Much ado about methane"
Tenney Naumer says
@Wayne, the link to the Northern Hemisphere files is from wili: ftp://asl.umbc.edu/pub/yurganov/methane/MAPS/NH/
go back to the parent directory to see the Southern Hemisphere
Martin Manning says
In response to #95 from Anonymous Coward,
The web pages for the “Greenhouse Gases and Related Measurement Techniques” conference are at:
and a PDF of my slides is currently at:
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!
Geoff Beacon says
The index page for these images is
So far I’ve downloaded the 2002 to 2011 images for each November. They show interesting patterns.
Thanks to wili and Tenney for pointing them out.
Geoff Beacon says
… but why didn’t we know about these before?
How do they compare with flask measurements?
Greg Robie says
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.
Chris G says
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.”
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.
For perspective, look at figure 6.1 at
(Pick CO2, H2O, and CH4 as species.)
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.
Tenney Naumer says
@Geoff, re: #104
There seem to be only 3 locations that measure via flask in the Arctic – Barrow, Alert, and Zeppelin, as Shakhova states — all far from the ESAS.
See post by The Tracker here:
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.
John E. Pearson says
Do undersea methane clathrates and permafrost thaw into gloppy muck or into liquid?
Steve Albers says
Interesting to see how methane at Barrow fluctuates hourly as can be selected for 2011 with in-situ observations. Much more sampling frequency compared with the weekly flasks.
Martin Manning says
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.
Hank Roberts says
GEOPHYSICAL RESEARCH LETTERS, VOL. 39, L01401, 4 PP., 2012
Extreme organic carbon burial fuels intense methane bubbling in a temperate reservoir
Greg Robie says
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..
Hank Roberts says
> clathrates and permafrost thaw into gloppy muck or into liquid?
Clathrates don’t; the definition of a clathrate explains that it’s a gas trapped in a lattice. Thaw it and gas bubbles out.
Permafrost — thawed peat is still peat, but unfrozen it gets exposed to air and changes: http://scholar.google.com/scholar?q=permafrost+melt
David Lewis says
#93 Martin Manning –
regarding your point about some new possible “highly non-linear atmospheric chemistry” in your comment that mentioned an “ozone hole” in the equatorial troposphere.
I’ve found an abstract that lists Markus Rex as a participant in a 2011 NDACC symposium “Is there a Hole in the Global OH Shield over the Tropical Western Pacific Warm Pool?” http://ndacc2011.univ-reunion.fr/fileadmin/documents/Abstracts_and_documents/abstracts/Abstracts_Session_5.pdf
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?
Pete Dunkelberg says
On carbon transport and fate in the East Siberian Arctic land–shelf–atmosphere system – Semiletov et al. (2012)
The shocking conclusion:
Pete Dunkelberg says
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.
John E. Pearson says
This is kind of a nice chapter which among other things addresses some of the physical characteristics of undersea methane.
Martin Manning says
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”?
Philip Machanick says
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.
Hank Roberts says
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%….”
Kevin McKinney says
#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.
#122–Thanks once again, Hank!
Hank Roberts says
hm, Bering Sea shelf 3 degrees C warmer: http://www.sciencedirect.com/science/article/pii/S0967064507002020
“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). “
The only way back to a natural climate in anything like our lifetimes would be to anthropogenically extract CO2 from the atmosphere.
Any one who has seen the following data
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.
Ray Ladbury says
Girma, what I see is that if you blow up your y-axis sufficiently, your glaring errors will not be so obvious.
Brian Dodge says
@Ray Ladbury — 14 Jan 2012 @ 1:35 PM Re Girma’s graph [scaled to hide the incline]
“I still believe that BEST represents a very good effort, and that all parties on both sides of the debate should look at it carefully…” – Anthony Watts
Pete Dunkelberg says
Shindell et al 2012 and misleading press:
AP Headline & first paragraphs:
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.
Pete Dunkelberg says
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.
Another news headline & top of report:
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:
which is a lie. In their eagerness to find excuses to keep on burning carbon journalists insist on misinterpreting the research.
Kevin McKinney says
#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.
Hank Roberts says
It must be happening, you can buy the T-shirt:
“curtailed, askeyz” says ReCaptcha
Hank Roberts “It must be happening, you can buy the T-shirt..”
Ha, Haaa :F
When we go down, then let’s size opportunities :) Seriously, what better way to start a decent discussion?
ps. there is more http://climateforce.net/2012/01/17/climate-action-tshirts-eu-usa/
Hank Roberts says
This should be current as I post:
But I’m some guy on a blog. Check the actual source for yourself:
change “Parameter” to methane (CH4)
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 says
> i run climateforce
But who are you? What connection to the “geo-engineering” blog with the stuff about upcoming planetary alignments, earthquakes, and total extinction?
Some of what link to is science. Some is speculation. Some is stuff from the outer limits.
How do you tell them apart?
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 http://www.skepticalscience.com/arctic-methane-outgassing-e-siberian-shelf-part2.html
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
Hank Roberts says
This one, linked on your main page:
“Thermal Expansion of the Earth’s Crust Necessitates Geo-engineering October 7, 2011”
Seriously — if you’re associated with Climate Progress as your page indicates, someone there can give you a physics sanity check.
As a reader of science sites — yours isn’t. It could be, with work.
Speculation is fine but when you mix science, speculation, and -stuff- it means someone has to check everything before recommending your site.
You can do better. Get someone to review the content and sort it out so the science is clearly distinguished from the -stuff-.
Hank Roberts, you seem to conflict “me” (prokaryotes) which i run climateforce.net, with another blog, i do not administrate.
[Response: Your URL link goes to climateprogress – is that not what you want? – gavin]
[Response: Your URL link goes to climateprogress – is that not what you want? – gavin]
Yes, and ClimateProgress.net is yet “another” website, which i recently set up and which i link from my blog at http://climatefore.net
What Hank is referring to, is this blog, from Sam Carana http://geo-engineering.blogspot.com/2011/10/thermal-expansion-of-earths-crust.html
Since we hijacked somewhat the discussion, let me add [edit – no, not here]
Hank Roberts says
http://dotearth.blogs.nytimes.com/2011/03/23/the-dread-to-risk-ratio-on-radiation-and-other-discontents/ may be helpful, though not encouraging.
“I wish there were an easy way to graph the high ‘dread to risk ratio’ attending debates over a host of environmental and public health questions. …
Would it matter to have a clearer view of the difference between perceived and actual hazards related to a host of issues …?
Quite a bit of social science research would imply that the answer is no.”
Hank Roberts says
Update, including interview transcript:
Stuart Poss says
“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.
Hank Roberts says
If anyone’s tracking, this looks like another website with basically the same methane emergency information, reformatted a bit and somewhat rearranged:
I wonder if an image search can track the spread of this stuff …
Hank Roberts says
uh, yep, here’s another:
[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):
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.”