Walter Anthony et al (2012) have made a major contribution to the picture of methane emissions from thawing Arctic regions. Not a game-changer exactly, but definitely a graphics upgrade, bringing the game to life in stunningly higher resolution (/joke).
Katey Walter Anthony draws upon her previous field findings that methane emissions from the Arctic landscape tend to be focused at the intersection between frozen and thawed, in particular in rings around a peripheries of lakes. She also knew what a methane seep looks like in that landscape, leaving visible bubbles frozen into the ice or maintaining an unfrozen hole in the ice. Now she takes to the skies to produce an aerial survey of the Alaskan landscape, data that is so much more voluminous than before that it becomes different in kind.
The methane emission fluxes are higher than previous estimates, but that’s not really the most important point, because emissions from the Arctic are small relative to low-latitude wetlands, and doubling or even nearly quadrupling the Arctic fluxes (in one of their analyzed regions), they would still be small in terms of global climate forcing. And the lifetime of methane in the atmosphere is short, about 10 years, so methane doesn’t build up like CO2, SF6, and to a lesser extent N2O do.
The really interesting take-away from the new paper is how it shows that the near-surface geology and freezing state conspire to control the venting of accumulated gas dribbling up from below, and the decompostion of frozen soil carbon. They have so many methane seep observations that they are able to correlate them with (1) currently thawing permafrost, which allows fossil soil carbon deposits from the last ice age called Yedoma to decompose (Zimov et al 2006) and (2) melting ice sheets and glaciers “un-crunching” the landscape as they fade away, making cracks that vent methane from deep thermal sources. Glaciers that melted long ago no longer vent methane, showing that the methane is transiently venting from built-up pools of gas.
What these results do not do is fundamentally change the game, in my opinion. We can now see more clearly that most of the methane flux from the Arctic today are of types of emission that will respond to climate warming. But the general response time of the system is slow, decades to centuries, rather than potentially poised to release a huge pulse of methane within a few years. Earthquakes and submarine landslides are sudden events, but small individually in terms of potential methane release. The new data do not change that. Walter Anthony et al. compare an estimate the amount of methane in the Arctic, 1200 Gton C, with the 5 Gton C of methane in the atmosphere. That’s the nightmare comparison, but it’s only really relevant if the methane comes out all at once. (The Arctic estimate is for methane itself and is mostly methane hydrate, but keep in mind that there is also a comparable amount of decomposable soil carbon.)
In my opinion, the largest impact of all this methane will probably be to the long-term future evolution of climate. Avoiding a peak warming of 2 degrees C or more requires keeping the total emission of carbon down to less than about 1000 Gton C (Allen et al 2009). We have already burned about 300 Gton C, and cut about 200 Gton C. So maybe we’re 1/2 of the way there, say 500 Gton C left to go. The 1200 Gton C of Arctic methane hydrates and the permafrost carbon stack up pretty menacingly against our 500 Gton left to go, and the comparison is relevant even if the carbon is emitted slowly, or as CO2 rather than methane, or even if it is released into the ocean rather than into the air (it will still equilibrate with the atmosphere, after a few centuries, converging to the same “long tail” CO2 trajectory that would have resulted from atmospheric release).
Arctic methane, and all that frozen soil carbon, could easily play a huge role, not so much in the near-term evolution of Earth’s climate, but in the long tail of the global warming climate event.
Allen M.R., D.J. Frame, C. Huntingford, C.D. Jones, J.A. Lowe, M. Meinshausen & N. Meinshausen (2009) Warming caused by cumulative carbon emissions towards the trillionths tonne. Nature 458 doi:10.1038/nature08019
Walter Anthony, K.M., P. Anthony, G. Grosse, & J. Chanton (2012) Geologic methane seeps along boundaries of Arctic permafrost thaw and melting glaciers. Nature Geoscience doi:10.1038/NGEO1480
Zimov, S.A., Schuur, E.A.G, and F. Stuart Chapin III, F. (2006) Permafrost and the Global
Carbon Budget. Science 312: 1612-1613.
In 127 Jim Larsen says:
“…Since permafrost thaw slows down exponentially (or so) as depth increases […]”
Only true if water flow through earth is ignored, an assumption that starts to fail when we move from a time resolution in years to timeframes of decades or longer.
Hank, that was my mistake. I corrected it down thread.
Re: 151
Don’t forget that thawing surface layers tend to be a bit on the wet side, what with all that ice that has to drain away after it melts. This tends to weaken the soil, and slumping and land slips are common anywhere there is any sort of slope. (Look up “thermokarst”.) Once the surface layers are removed, more permafrost is exposed, and it will melt easily. No need to wait for the slow process of thermal diffusion to penetrate deeply when you can just move the overlying mud out of the way…
> anywhere there is any sort of slope
Per the original post: “The really interesting take-away from the new paper is how it shows that the near-surface geology and freezing state conspire to control the venting …” — and it’s a start toward quantifying how much of the area will change rapidly (due to meltwater drainage, slumping, lowering water levels and oxidation) or slowly (where meltwater remains in pools).
Re:OH- ion concentrations
are there any satellites reporting fine data around 18 micron wavelength ?
Doug Bostrom,
I am not as charitable as you about what I agree was a fair presentation of the anti-realist “side”. Rather than the usual 50:50 or worse, it was more like 20:80 and as as you said allowed them to make their usual misrepresentations for anyone with a mind open enough to see it, but compared to 2:98 or 3:97, it is still off.
It is clear from the comments that the truth about threats and violence rolled off the backs of people who didn’t want to admit it, or worse, felt it was justified. There are far too many anti-realists out there, and not all of them are on the fringe. We are so accustomed to thinking about things and checking sources that we fail to imagine people who simply believe what they are told if they approve of the source, and automatically disbelieve anything that contradicts that. That’s close to 50% of the population, with an error bar of as much or more than 20%. It’s a growth and education problem, with a lot of arrested development out there, and teachers are under attack too for “corrupting” the precious children (though most children I’ve met are not necessarily particularly nice until they learn tolerance and acceptance of complexity and contradiction comes even later).
As to what’s next – escalation, and blaming the victims. So what else is new?
The local nanny-bot kept rejecting my post as “spam.”
Rather than waste any more time trying to decipher the problem, I will just post a link to my blog.
Oceanic mixing times from archaeological radiocarbon.
http://stonesnbones.blogspot.com/2012/06/i-dont-want-to-get-sucked-into-global.html
Susan: It is clear from the comments that the truth about threats and violence rolled off the backs of people who didn’t want to admit it, or worse, felt it was justified.
Susan, of course that’s true. The very presence of those gibberish comments confirms that their authors are essentially beyond reach; if one can’t get a grip on the relatively simple basic reasoning behind AGW then increasingly complicated and elaborate explanations are not likely to work.
Most people don’t run red lights at intersections. The few that do are disproportionately influential not only in a material way via accidents but also in our perceptions; a person running a red light is highly conspicuous and thus occupies a big space in our thinking compared to all the people who sensibly obey rules.
Similarly a person who follows a scofflaw to the next intersection and then engages in an altercation is also quite unusual. Guess what? You’re one of them. :-)
Most people inconspicuously obey traffic signals because there’s a reasonable case for so doing, not because it’s a statutory requirement. The arguments presented in the PopSci piece are at an accessible level and will be folded into the thinking of a large number of persons who will never be noticed by we of the few and the loud. Some of those arguments are reasonable and some are fairly plainly not. People reading the article will draw conclusions from seeing the juxtaposition between science and fiction plainly illustrated and I think it’s safe to say that the net effect of the contrast will be positive. We’ll never hear from the beneficiaries.
I don’t think there’s benefit to be gained from pretending that nobody is arguing for wrong conclusions. Accepting that, simply repeating “they’re wrong” without any cues as to why isn’t effective. “Inhofe is wrong but I can’t tell you how or why because I don’t wish to refer to what he says.” How effective is that? At then end of the day the most plainly inaccurate telling will come from the very lips of the wrong themselves.
Thanks for the interesting discussion on CH4, which I still think is the bomb with CO2 the trigger. Also, please tell me why there is no discussion on human overpopulation of the earth since Global Warming is anthropogenic? Or, why no mention of inexpensive, time-buying solutions such as a law that all roofs and cars be white to regain some of the albedo that we have lost.?snsys
Sharon
…there is no discussion on human overpopulation of the earth
In respect to that one, might I suggest that you give Hans Rosling 15 minutes of your time – it won’t be wasted
http://www.ted.com/talks/lang/en/hans_rosling_on_global_population_growth.html
Having watched that, you may feel like re-phrasing your question a little.
Sharon,
Realclimate has made its niche the provision of reliable synopses of the science that can be understood by intelligent laymen. Neither overpopulation (nor for that matter overconsumption) nor time-buying solutions fit well with that. What is more, it seems that every discussion of solutions eventually bets bogged down in nukes vs no nukes or some other distraction. And if you sought to legislate roof color, there is no doubt some idiot glibertarian would equate it with fascism and the end of human civilization.
Susan wrote: “we fail to imagine people who simply believe what they are told if they approve of the source, and automatically disbelieve anything that contradicts that. ”
Worth repeating. I find it mind-boggling what people repeat without question.
Re- Comment by Sharon Black Hawkins-Fauster—2 Jul 2012 @ 7:23 AM:
Overpopulation is the big elephant in everybody’s room. The solution is conceptually simple but expensive, and there appears to be no will to do anything about it. This board is for discussions of climate and it seems to me that if the CO2 problem is not solved there will be no chance at all of addressing overpopulation and big mama nature will take care of it in her usual direct and callous manner.
As for house and car roof albedo, the area is so small that any change in temperature would not be detectable and could easily be surpassed by using more carbon efficient transportation or insulating ones roof. Also, changing albedo is a onetime thing, while CO2 is the gift that keeps giving.
Steve
For Sharon (follow up to the July open thread once it, er, opens)
http://scholar.google.com/scholar?as_ylo=2012&q=white+roof+anthropogenic+warming&hl=en&as_sdt=0,5
(The IOPScience articles are both worth reading)
As for house and car roof albedo, the area is so small that any change in temperature would not be detectable…
Frequently misunderstood. The point of these is to reduce cooling load by making any given level of roof insulation have to isolate less transmitted heat into the interior of buildings as well as reduce “heat island” effect.
The benefit comes from less demand on generating capacity hence less combustion.
It’s a technique that is proven to be effective.
I’m afraid to say it but I think space based solar irradiance reduction and modification is going to be the only way we can get out of this dilemma.
It’s the future anyways, embrace artificial weather! That would give us time to naturally reduce the CO2 back to 300 ppm and to adapt to the conditions.
Susan Anderson wrote: “we fail to imagine people who simply believe what they are told if they approve of the source, and automatically disbelieve anything that contradicts that”
I think we often fail to appreciate the vast amount of money that has been poured into creating exactly that state of mind in millions of people over the last 30 years or so.
Can any of us smart and skeptical folks here be quite so sure of what we would believe or not believe if we had been relentlessly hammered 24×7, year after year, decade after decade, with sophisticated propaganda developed by the most insidious minds of Madison Avenue to push our carefully-researched psychological buttons, and disseminated by the most powerful mass communications technologies ever conceived, as have the particular demographic groups targeted by the so-called “right wing” media?
Steve Fish @164
I’ve not met before the metaphor “…the big elephant in everybody’s room” (presumably something important but ubiquitously unmentioned) and am further mystified by the idea that solving AGW through reducing world population could be described as “conceptually simple but expensive.” It did however raise some intriguing thoughts.
Generally, while a simple reduction in the human head count appears to provide a solution to AGW (if there were ten times less of us, there would be a tenth the emissions sounds logical enough), folk usually have in mind the burgeoning population of third world countries when they talk of such overpopulation. Of course, these are the very nations who are not really the cause of the AGW problem but who are in the front line when it comes to its impacts. Further, it’s not just the wealthy nations but wealthy communities, indeed wealthy households that really lie at the root of the AGW problem. Or perhaps a more equitable way of reducing emissions would be to be mindful of the impact a person’s age has even on their annual emissions.
As I say, intriguing thoughts.
Re- Comment by dbostrom — 2 Jul 2012 @ 1:26 PM:
The post I responded to specifically referred to albedo in a manner suggestive of how global warming is affected. However, frequently misunderstood is the fact that when retrofitting a house is that it is much more cost effective to put an inexpensive reflective barrier below the roof, in the attic, than to reroof with white roofing. When building a new house the combination of a white roof and the reflective insulation is best, but the gains are pretty small. With understanding, a builder can construct a chimney effect that uses heat gains inside a house plus attic solar heat to help keep a house cool.
Solving the heat island effect, which is not of much importance in the larger scheme of things with white roofs, sounds like the sheep albedo effect to me.
Steve
Re- Comment by MARodger — 2 Jul 2012 @ 2:58 PM:
Because you are confused- The elephant in the developing world’s room has to do with the near certainty, if nothing is done, of we all, or our offspring, being able to witness the death of billions from starvation and war over resources (food), live, via satellite. The conceptually simple solution required to stop continuing overproduction of humans is to 1) Empower women, in the poor areas where multiple male offspring or large families are thought to be necessary (often by men), to be able to make the reproductive choices for themselves and their own family; 2) Families (e.g. male heads of family in the parts of the world of importance) need to be provided with a minimal source of income in a manner such that they are able to count on some level of economic stability; And, 3) Methods of contraception should be provided to parents. As I said, such a program would be expensive and would depend upon stable energy supplies for the developed world.
You are correct that it is the developed world that is the source of the CO2 problem, but you need to recognize that it is the developed world that is the only agency that can help the rest of humanity to get through the peak fossil energy/climate heating/ocean acidification/fresh water shortage/desertification/overpopulation crisis. We have to solve our fat cat problems quickly in order to be able to help the rest of the family. Steve
Steve, the UN Pop. Fund, UK, and Gates Fund seem to be putting renewed emphasis on your third priority.
http://www.prweb.com/releases/2012/7/prweb9663298.htm
MARodger wrote: “… a simple reduction in the human head count appears to provide a solution to AGW …”
Sure it does — if any reduction in GHG emissions resulting from that “simple reduction in the human head count” will occur within the next five to ten years.
The most aggressive, but still humane, imaginable measures to slow the growth of the human population — such as those you enumerate — certainly won’t achieve that result.
Whereas simple, readily available, cost-effective (and even profitable) measures to reduce fossil fuel consumption by the small minority of “human heads” who populate the industrialized nations could easily do so.
Re- Comment by SecularAnimist — 3 Jul 2012 @ 9:50 AM:
You say- “…industrialized nations could easily do so.”
To which I heartily agree. Especially my good old U.S. of A. Steve
Guys, basically we got a whole herd of fricking elephants jostling for position in the room.
1)There’s the end of fossil fuels, increasing scarcity of other critical resources (e.g. rare earths, helium, Pt group metals, etc.)
2)There is certainly overpopulation.
3)There is overconsumption.
4)There is environmental degradation as we try to cope with 1-3.
5)There is climate change.
6)There is the need to develop and deploy a new energy infrastructure.
7)There is the need to develop sustainable manufacturing.
8)There is the need to develop a sustainable economic model that doesn’t rely on growing consumption or growing population for its sustainability–and which will even work with a shrinking population.
9)There is a need to develop a democratic form of government that works despite the fact that most of the population is too stupid to even understand their own self interest, let alone science or policy.
10)There is the fact that the current global economy is a giant shell game trying to keep us from seeing that the money we thought we had really isn’t there.
Any one of these could sink us. Some could destroy civilization. They will all make each other worse. And that is just off the top of my head
Re- Comment by Ray Ladbury — 3 Jul 2012 @ 7:34 PM:
I agree, but as Brother Al used to say, with 50K watts of AM power from Tijuana in 1966, I am a pestamist.
Steve
Re Comment 146,
Thank you Professor Archer.
D Coyne