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Methane game upgrade

Filed under: — david @ 14 June 2012

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

Shuur E. et al (2008) Vulnerability of Permafrost Carbon to Climate Change: Implications for the Global Carbon Cycle. BioScience, 58(8):701-714.

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.

177 Responses to “Methane game upgrade”

  1. 101
    dbostrom says:

    Pondering on paddies: ok, -duh- I get it, I think. Paddies are constantly converting relatively (!) innocuous C02 into more problematic methane.

    That does seem to be something of a problem. Methane normally transient but paddies make it effectively permanent.

    [Response:Well, a persistent ongoing source will lead to a persistent ongoing higher concentration in the atmosphere, but it’s not “permanent” because if you stop the source the concentration quickly responds. Persistent, however, yes. David]

  2. 102
    SecularAnimist says:

    Steve Fish responded to Geoff Beacon: “Regarding the starving poor you say- ‘Pay them more if they give up their cattle’.”

    The “starving poor” don’t own cattle. And indeed the “starving poor” sometimes wind up starving and poor precisely because they’ve been driven from their land to make room for cattle owned by rich people.

    The rapid growth in meat consumption world wide is not about the “starving poor” feeding themselves from subsistence-grazed goats. It’s about US-style industrial factory animal production spreading throughout the developing world to produce lots and lots of cheap meat for the emerging urban affluent populations. And it’s bringing with it the same disastrous environmental and public health consequences that it has brought to the US.

  3. 103

    “…a crash course in Idiotese.”

    Luckily, such are widely available at no cost online… ;-)

  4. 104
    Jim Eager says:

    DB, good to see that you got it: rice paddies are man-made wet-lands, which are full of anaerobic bacteria that break down rotting organic material to produce methane just as effectively as natural swamps and bogs.

    Ruddiman contends that the invention of wet rice agriculture kick-started human greenhouse gas emissions and is responsible for the slow shallow rise of atmospheric methane when it should have been going down since the Holocene Climate Optimum.

  5. 105
    dbostrom says:

    Jim: Ruddiman contends that the invention of wet rice agriculture kick-started human greenhouse gas emissions…

    Yeah, now that you mention that a dim recollection floats up.


  6. 106
    Ray Ladbury says:

    Geoff Beacon: “Pay them more if they give up their cattle.”

    Hmm. 21 years ago, I had the privelege of traveling with some Samburu tribesmen through the North of Kenya. He told me about how for is initiation, he killed a cheetah that was threatening the village herd, and he had only a spear.

    I am sure that you and he would have a fascinating discussion about your idea. To some cultures, cattle are more than a food source.

  7. 107
    SecularAnimist says:

    Ray Ladbury wrote: “To some cultures, cattle are more than a food source.”

    Indeed. To vegans such as myself, cattle are intelligent and emotional sentient beings worthy of compassion and respect.

    For most “consumers” in the developed west, cattle are not really a food “source” at all. Rather, they are a means for converting nutritious plant foods like corn and soybeans into meat, with a resulting loss of up to 90 percent of the original protein content, at an enormous cost in environmental pollution and public health. They are more accurately described as a food sink than a food source.

    And that’s the model that is being rapidly proliferated all over the developing world.

  8. 108
    dbostrom says:

    Ray: …some Samburu tribesmen…

    Contiguous w/the Maasai. Poor in terms of money, riches measured by cattle count.

    How many “eco tourism” trips need to be cancelled to avoid uprooting these people? How about the folks parading up Mt. Everest?

    I wonder what the methane hit would be if gratuitous visitors had to row to the Galapagos Islands.

  9. 109
    Geoff Beacon says:

    JIm Eager #95

    Geoff, your reply sounds almost exactly like what is coming out from the lukewarmers and even the fake skeptics.

    Ok, I’m a fake skeptic who believes that we need a high carbon price to take from the polluting rich and give to the poor to give them a decent life.

    And that climate change is so much worse than most people realise that we need a high carbon price to drastically curb our flying, driving cars and eating watseful and polluting foods like beef and lamb.

    Given the work of Geoff Lawton and the example of Sepp Holzer, I think we could grow food on most of the world’s land.

    If we ate more healthy, sustainable food and less meat

    … we would go a long way toward permitting a world population of 10 billion to have a potentially sustainable diet comparable to ours. Our food problem may be manageable with minimum pain.

    Beef and land

    And growing rice : A nice video of harvesting in the paddy fields of Texas

  10. 110
    Geoff Beacon says:

    Ray Ladbury 106#

    I wonder what the tribsman would have done with his spear if he knew the many tonnes of carbon dioxide you air flights have created and their consequences for the climate.

    BBC News – Kenya drought: Starvation claims 14 lives in Turkana

  11. 111
    Jim Eager says:

    IIRC, Hank spent time in Africa doing on-the-ground get-your-hands-dirty development work.

    You were saying, Geoff?

    Must be the heat.

  12. 112
    Jim Eager says:

    “Ok, I’m a fake skeptic who believes that we need a high carbon price…”

    It was the part before that, Geoff.
    Seriously, read what you wrote and tell me it doesn’t.

  13. 113
    dbostrom says:

    I wonder what the tribsman would have done with his spear if he knew the many tonnes of carbon dioxide you air flights have created and their consequences for the climate.

    20 years ago? I don’t think most peoples’ game was up to that level, at the time. Just don’t call blasting around the planet at 400 knots “eco tourism” knowing what we do today, that’s my particular small request.

    Anyway, clever rhetorical tactic, though a bit nasty and it doesn’t address the implications Ray pointed out.

    How about you, Geoff? When did you purchase your last airline fare? More than 20 years ago?

  14. 114
    Jim Eager says:

    Whoops, that should have been Ray, not Hank.

  15. 115
    Geoff Beacon says:

    Jim Eager #111

    Sorry. Especially to Hank. I had been to a reception in UK Parliament. Too much wine and frustration – still not quite sober and calm. Flying to Africa on charitable work is a good thing to do. We, in the Pollution Tax Association, made a donation to people do just that – the flying did worry us though.

    The general point stands. Our pollution does kill and it will get worse.

    dbostrom #113.

    Yes I was nasty. Again, sorry Hank.

    I haven’t flown since the summer of Hurricane Katrina. Subsequently, I was joint founder of the No Miles High Club. We never got very far.

    The NMHC motto was “We promise not to fly until we break our promise.” OK, except for a few here, no-one much takes any of this very seriously – and I still eat too much climate destroying cheese. But I suppose we are still in what Colin Challen MP called climate’s “phoney war”. (The phoney war refers to the time at the beginning of WW2 when nothing much seemed to be happening. It didn’t seem like war at all.)

    Anyway, after a frustrating time in Parliament with fuel poverty do-gooders and what seemed like similar on the train home from a professional “Friend of the Earth”, I am still despairing.

    The fuel poverty people and the FOE are pushing energy efficiency but downplay the rebound effect to the point of denial. It is good to help the poor so they don’t have to “eat or heat” but they should not kid themselves it does much towards a low carbon economy without a decent carbon price. We are sinking in greenwash.

    And in the Sahel (to name one crisis) they must decide which of the family should starve – that trumps “eat or heat” for me.

    And I still eat too much planet destroying cheese.

  16. 116
    dbostrom says:

    The NMHC motto was “We promise not to fly until we break our promise.”

    Fair enough; don’t promise what can’t be delivered or you’ll just feel wretched. Flying is a bit too woven into our culture right now to easily swear off.

    Hats off to Geoff.

  17. 117
    Geoff Beacon says:

    Jim Eager #114

    Sorry Ray!!!

  18. 118
    Pete Best says:

    Now that all of the personal posts have started can I ask a more general question regarding fracking and natural gas and leaks of methane. The idea is to attempt to replace much of coal with natural gas and indeed ship some of it abroad in LNG form. So huge slugs of methane from permafrost release aside is leaking methane from pipes and the LNG conversion process an issue or are the amounts too small to matter as LNG/Fracking results in around a 25% reduction in C02 emissions?

    Methane is not that big a deal as its only occupies a small area in the absorption band relative to C02 and its impact is more minimal as its only hangs around for a few years whilst CO2 is the real problem >

  19. 119
    Ray Ladbury says:

    Not all of us have the luxury of staying in place. For some of us, our work takes us far afield. In my case, I was training science teachers.

    I do not think that it is realistic to expect people to change drastically deeply held cultural beliefs and traditions. Nor do I relish the idea of a world where the capability to deploy weapons of mass destruction exists without the unifying potential of travel.

    Mark Twain said “Travel is fatal to prejudice, bigotry, and narrow-mindedness.”

    Perhaps you should try it.

  20. 120
    JCH says:

    I once suggested bartering off cultural traditions. Say India gives up their cattle if we agree to eat horse meat instead of beef. Pointless, but one wonders if such an agreement could be made. ~650 million ruminants eliminated and I’ll have Trigger rare.

  21. 121
    wili says:

    There are ways to “travel” without climbing on an enormous chunk of steel that ff thrusts into the sky like a large middle finger shoved into the very face of the deity. Reading, skiping, blogging…all of these can be done at much lower impacts to the planet, especially if powered with renewable energy.

    I stopped flying after (barely) surviving the ’03 killer heatwave in Paris.

    Is it inconvenient sometimes? Yes.

    Should we expect to be able to stop the greatest disruption of life on the planet possibly since life began with out some inconvenience?…

    We could scale back 99% of flights tomorrow with very few extremely negative consequences to anyone (i.e. death, grave illness…). If we can’t conceive of making such rather minor sacrifices, how can we begin to fathom much more trying sacrifices that living within our environmental means will like call for?

    I have found no way other than not flying and not eating meat to get anywhere close to ‘one earth’ on the scale. (Yes, Geoff, it’s flawed, but at this point better than most other such measures out there, imho.)

    If we even on this site, who are more aware of the dangers of GW than nearly anyone else on the planet, aren’t willing to make relatively minor (in the big scheme of things) adjustments in our lifestyles, what is the likelihood that anyone else will? Keep in mind that just a century ago the idea of whizzing around the world on a metal bird in a few hours was beyond the imagination of even the wealthiest and most powerful. Somehow we have gone from this to seeing it not even as a luxury but an absolute necessity.

    Geoff, thanks for starting the NMHC. Is it really completely defunct? There seems to be more awareness of the issue in Europe than in the States (quelle suprise!). I liked that you included humility and humor in your motto.


    Pete at 118–I don’t see anyone here saying that methane ‘isn’t that big a deal.’ After CO2, it is the major GHG. Any additions, from leaks in mining, delivery and use, to melting permafrost and clathrates, is a concern.

  22. 122
    wili says:

    On the other hand, maybe they will be coming out with passenger versions of these soon, making slower but carbon-neutral world travel available to those who can afford it:

    “Work starts on fossil fuel free cargo ship set to transform shipping industry”

  23. 123
    dbostrom says:

    Tailspinning ever further off-topic it’s an absolute fact that making one journey by air will neatly obliterate a year’s conscientious behavior.

    Mindfulness might help; Geoff points out the difficulty of eschewing air travel but just stopping to ask “is this flight necessary” is a step in the right direction. For somebody who flies a handful of times a year a single skipped takeoff is a significant savings in impact.

    For Europeans this decision is a little easier; a dense rail network means there’s actually an alternative to intubation. Here in the US it’s overwhelmingly true that one effectively has three choices: don’t travel, travel by air, or drive. If you’ve got a child several states away who is graduating, getting married etc. you’re going to want to be there, meaning that on average you’re looking at a drive of roughly 1,250 miles if you don’t choose to fly. Sticking to scruples in the face of that is very difficult.

    We used to have a reasonably workable rail network here but we were seduced first by automobiles which eliminated local intercity lines and then by air travel which killed long haul passenger rail. We’ve stepped backward in terms of freight logistics, too. Why did it work out differently in Europe?

  24. 124
    wili says:

    “Global warming is changing Arctic seas from where CO2 is absorbed to where it is produced, new study warns”

  25. 125
    Geoff Beacon says:

    wili #121

    The NMHC still has a website and one of the members started a facebook page – I just discovered it. John Cossham may have told me he set it up but these days … now what was I saying…

    Facebook page is at

    I keep the paying for the NMHC website just in case. Contact me via info__AT__greenrationbook_DOT_org_DOT_uk if you want to do anything with it or the Green Ration Book.

    One thing that worries me about stopping all avation too soon is the issues raised in Unger et. al. Attribution of climate forcing to economic sectors.
    I’m a bit suspicious of some of the conclusions – and it’s now two years old – but it’s a good read. It seems to say that an average airline flight cools the Earth for 30 years before the warming effect kicks in. See fig 2.

    Now the next 30 years could be crucial in triggering some of these feedbacks (methane and otherwise) we have been discussing. Anyway, Borken-Kleefeld et al, Specific Climate Impact of Passenger and Freight Transport tells a different story.

  26. 126
    Geoff Beacon says:

    Ray #119

    That deserves an answer but at the moment I’m whacked.

  27. 127
    Jim Larsen says:

    78 Ray L said, “Killian, I know of no mechanism for clathrate decomposition that is sensitive to human population….And even if we were to find the bomb about to go off, what, pray, would we do about it ”

    The Russians have already demonstrated methods to harvest permafrost-covered methane and the Japanese are working on clathrate harvesting (as are others). So yes, clathrate decomposition can be done by humans, and we could switch from traditional CH4 harvesting to permafrost and clathrate CH4 harvesting.

    90 Wili said, “the main post shows that we don’t have to wait hundreds of thousands of years for methane to leak out–methane is seeping out now, and it is on the increase. The only question is how fast this increase is going to take place…And again, the pools of free methane gas we’re talking about don’t have to wait for all of the overlying permafrost to thaw. Just a crack, perhaps from the deep roots of one of the new trees now growing in the tundra, to provide a route for its escape into the environment is sufficient.”

    I disagree with the first bit. Since permafrost thaw slows down exponentially (or so) as depth increases, the question is whether the current increase will peak and then fall dramatically or not.

    The second bit, well:
    “It is uncommon for roots to penetrate to a depth greater than 2 m”$file/fcin078.pdf

    – though it’s said that the deepest roots are from a type of fig that can reach 400 ft.

    The average natural gas well is ~5,500 ft deep

    So, unless the “BIG” stores of natural gas are far shallower than everywhere else in the world, you’re just not going to release them via permafrost thaw in the short term. According to Wiki (permafrost article), it takes 3,500 years to build permafrost down to 719 ft and 775,000 years to build permafrost down to 2,256 ft. So, once you get below 500 ft or so, (assuming thaw rates are similar to build rates) permafrost really is PERMAfrost. Yes, there are chimneys and CH4 from below 500ft will get released, but you’d have to provide some sort of citation/data/logic to convince me that the amount will be catastrophic.

    More serious is what happens at the surface. Lots of tundra is becoming wetlands. That means chronic CH4 release. Lots of the taiga will burn. That means a bunch of pretty quick CO2. So, the most likely future is a massive spike of CH4 and CO2 as the shallow permafrost thaws and the forests burn, followed by chronic release of CH4 from the new wetlands in the ex-tundra. Add in a CH4 burp and/or sustained release from the ESAS and you’ve got a mess, not a catastrophe – though adding a mess to our current situation could result in a catastrophe!

  28. 128
    Jim Eager says:

    Re swearing off air travel, we did so in ’98, but then had to fly a few years back when our vacation plans were stopped cold by a rail strike and I had to scramble to book a last minute flight or forfeit all our lodging deposits. Otherwise, all travel on that trip would have been by train, ferry, bus or foot (a stretch of coastal hiking trail).

    I know of two people who began to rethink air travel when I told them we’d quit. Unfortunately, I know many more who think we’re nuts.

  29. 129
    melty says:

    Hate to be a pedant but:

    “… data that is so much more voluminous than before that it becomes different in kind.”


    “… data that are so much more voluminous than before that they become different in kind.”

    [Response:My grandmother would approve… David]

  30. 130
    melty says:

    This thread got a bit off-topic didn’t it? Air travel? I thought this was about Arctic carbon (CH2 and CO2)?

    re: “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.”

    What happens to that methane?

    re: “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.”

    Define “all at once”: a year, a decade, half a century? what counts as “all at once”?

  31. 131
    melty says:

    CH4, obviously.

  32. 132
    SecularAnimist says:

    Re: air travel.

    Solar powered dirigibles. Think about it.

    [Response:Might be a good reason to stop pissing our He (which we get from gas reservoirs) into the skies (where it evaporates to space in a decade, forever) in our cooking gas and stupid parade floats. Personal peeve of mine. David]

  33. 133
    Geoff Beacon says:


    Continuing your off topic #129. Do read Data on Wikipedia.

    … and can you give me an example of an analog datum in analog data?

    How can analog data be the plural of something that doesn’t exist?

  34. 134
    Jim Larsen says:

    122 wili mentioned B9 sailfreighters.

    I visited their home page and watched the video. It was frustrating because the FIRST thing I (and probably most anybody else) want to know is how many knots they go. If it were me, I’d say “Current cargo ships average X knots. Our ships average Y knots fully loaded.” Since they declined to tell us, my assumption is they are VERY slow. (They did talk about “equivalent performance” in one sentence, but what does that mean? BE EXPLICIT!)

    I found this which says one particular 491ft cargo ship has 13,614HP. The biggest wind turbine in the world produce 6710 HP, and that’s from a 122 meter diameter blade. Ships are moving somewhat in the direction of the wind, so that slows down the effective wind speed, and since the wind isn’t directly from the rear, the effectiveness is reduced, so they can’t harness as much power as a turbine. This reinforces my fear that B9’s ships are SLOW.

    They also said that 40% of the time they run on engines just like every other ship. Since the sails always exist, B9’s freighters will be less efficient than current designs when the wind isn’t blowing from behind. Since ships can double their efficiency with a small decrease in speed, I’m not sure that the technology is better than just putting a speed limit on cargo ships. That they want to source their fuel via renewables is irrelevant. ANY ship can do the same.

    It’s interesting, but without more info it seems they are asking customers of shippers to increase their costs via delays.

  35. 135
    Ray Ladbury says:

    Jim Larsen,
    OK, so we are going to “harvest” 50 Gtons of methane and release 137.5 Gtons of CO2, and this will be a great victory? Somehow, I don’t think so.

  36. 136
    wili says:

    Jim Larsen–Thanks for the great stat on fig roots!

    “So, unless the “BIG” stores of natural gas are far shallower [under permafrost]”

    It is my impression that this is exactly the case, but I don’t have time right now to track down the sources. (Anyone else is free to. (Where’s Hank when you need him?)

    Geoff, thanks for the links. I’ll be in touch. If anyone else has insights or links about the short and long term effects of flights on climate, I would be interested. But the same type of argument could be made about dirty coal plants.

  37. 137
    dbostrom says:

    David: Might be a good reason to stop pissing our He (which we get from gas reservoirs) into the skies (where it evaporates to space in a decade, forever) in our cooking gas and stupid parade floats.

    Free market fantasists insisted (by law) it be sold at low, low prices; legislated lunacy. Resultant shortage is now threatening a myriad of applications.

    In 1996, a cost-cutting Republican Congress passed legislation requiring the government to get rid of most of its massive helium stockpile, which is located underground near Amarillo, Texas, the self-proclaimed helium capital of the world. NASA, Congress proclaimed, would have to get its helium from private operators instead.


  38. 138
    Jim Larsen says:

    135 Ray L said, “OK, so we are going to “harvest” 50 Gtons of methane and release 137.5 Gtons of CO2, and this will be a great victory?”

    For Exxon et al it will be. Like Animal Farm (and per SCOTUS), corporations’ interests are more important than ours.

    However, one technique for extracting CH4 is to pump CO2 into the reservoir. The CO2 makes an even better clathrate than CH4. So it could be a closed loop. Extract CH4, burn, capture resulting CO2, pump back in, extract more CH4.

    Hmm, double the wells, double the pipelines, add a step for capture… that sounds less profitable. Nope, NOT a good idea….whew, I almost put people over profit. Sorry. I won’t let that happen again.

  39. 139
    Jim Larsen says:

    On the B9 freighters… sailing ships have to tack, which can turn a 1000 km trip into a 10,000 km trip. Even at the same speed, B9’s ships will be far slower than current ships.

    Doesn’t mean the idea isn’t grand. Perhaps we need to slow down a bit.

  40. 140
    dbostrom says:

    Jim: On the B9 freighters… sailing ships have to tack…

    Maintaining a steady heading in the direction of methane is like close reaching to something 20 points windward. :-)

    Classifying freight is a possibility. Braeburn apples from New Zealand can wander around the Pacific longer than mangoes from Hawaii.

    Preening, strutting America’s Cup owners are justifying themselves at least a little bit with their recent uptake of built foils as opposed to traditional sails. Operation, maintenance and efficiency advantages of these could well see them playing a key role in commercial logistics, down the road. Cup boat owners are financing a lot of good research.

  41. 141
    MARodger says:

    melty @130

    Methane is sucked out of the air by Wikipedia, I think. Or is it explained by Wikipedia? I can never remember which.
    Methane is created near the Earth’s surface, primarily by microorganisms by the process of methanogenesis. It is carried into the stratosphere by rising air in the tropics. Uncontrolled build-up of methane in the atmosphere is naturally checked — although human influence can upset this natural regulation — by methane’s reaction with hydroxyl radicals formed from singlet oxygen atoms and with water vapor. It has a net lifetime of about 10 years, and is primarily removed by conversion to carbon dioxide and water.
    “Methane also affects the degradation of the ozone layer.

    As for your second question, in very rough terms “all at once,” all emitted next year would provide a forcing something like 50x the current net man-made forcing but lasting only 10 years (although such quantities may require more time to disappear), it would be gone before its full impact is felt. So, back-of-fag-packet peak global temp increases of 20 deg C (?) which would likely kick off some interesting feedbacks of greater longevity.
    Emitted over a century, the full but smaller impact would be felt of about 10 deg C (?), with longer periods pro rata. So that lead us to the question of how much extra global warming constitutes a “nightmare“?

  42. 142
    KR says:

    Solar powered dirigibles. Think about it.

    That’s actually quite interesting for this thread – methane is a viable lifting gas ( Perhaps we can make use of the extra methane produced by climate change in this fashion?

    Of course, it’s a bit flammable, so there’s still the “explody” problem… :)

  43. 143
    Ray Ladbury says:

    KR, you will note that the Hindenberg did not explode–rather it burned. Here’s an experiment. Start with 2 balloons. Fill one with hydrogen or CH4 only–taking care to keep air out. Fill the other halfway with air, then fill it the rest of the way with hydrogen. Pass a spark into balloon 1 (H2 or CH4). It will burn but will not explode. Try same with balloon 2–but you might want to wear earplugs.

  44. 144
    dbostrom says:

    Ray Ladbury says: …will note that the Hindenberg did not explode–rather it burned..

    As well, in plain point of fact even hydrogen-filled airships are not that likely to ignite. Outside of combat losses of airships were and still are (even for helium) down to inability to deal w/vigorous weather.

    How to reliably ignite an airship employing hydrogen for lift is covered here:

    The Scourge of the Zeppelins

    Meanwhile we blithely and routinely scurry around w/over a gigajoule of energy in our gasoline tanks, which regularly escapes.

  45. 145
    KR says:

    Clearly I need to employ /sarc or /joke more often (…

    More seriously, I would absolutely _love_ it if airships came back into fashion.

  46. 146
    D Coyne says:


    In response to comment 49, you said “Ok I stand corrected.” I would suggest you edit the original article to reflect this correction because most people don’t read all the comments. We don’t have 700 Gt of Carbon left to emit, as of the end of 2011 we have emitted about 550 Gt of carbon (the Allen paper uses data through 2006 and I have added emissions from 2007 to 2011) so we have 450 Gt NOT 700 Gt left to emit to reach 1000 Gt of Carbon emissions.

    D Coyne

    [Response:OK. Really corrected this time. David]

  47. 147
    Jim Larsen says:

    I wrote B9 with my concerns, and they wrote back:
    “We are currently testing the hull in a towing tank and the rig in a wind tunnel and so will be able to predict with a much higher degree of certainty our operational speeds.

    Our concept design is for commercially viable ships – stated on the first line on the home page of the website. This means that they must travel at speeds cat least comparable with fossil fuel powered conventional ships.
    Within a week or so we’ll have harder data verified by the Wolfson Unit at Southampton University and that will be posted on the website, so do please check back soon.”

    So the issue is that they aren’t ready yet. It seems they are going for true parity. Let’s hope they make it!

  48. 148
    Hank Roberts says:

    > IIRC, Hank spent time in Africa

    Not me. Someone else who’s commented here has.

  49. 149
    Killian says:

    Looks like more to add to the sensitivity issue, particularly highlighting linkages/connections > complexity of the system. I think this fits well with the finding by Hansen, et al., that 400 ppm might be enough to melt Greenland, though the article in question doesn’t specify any level.

  50. 150

    Jim 139: Cutty Sark:
    Her greatest recorded distance in 24 hours was 363 nautical miles (NM) (averaging 15 knots), although she recorded 2163 miles in six days, which given the weather over the whole period implied she had achieved over 370 NM some days.[13] By comparison, Thermopylae’s best recorded 24 hour distance was 358 NM. Cutty Sark was considered to have the edge in a heavier wind, and Thermopylae in a lighter one.[14]

    The daily total would be a fair indication of her performance as that distance would be measured between two positions 24 hours apart on track. That beats super-slow steaming by a long way.

    The Benigns stand a chance; besides they may be all we have.