Nature Bombshell: ‘Past Extreme Warming Events Linked To Massive Carbon Release From Thawing Permafrost’

Between about 55.5 and 52 million years ago, Earth experienced a series of sudden and extreme global warming events (hyperthermals) superimposed on a long-term warming trend. The first and largest of these events, the Palaeocene–Eocene Thermal Maximum (PETM), is characterized by a massive input of carbon, ocean acidification and an increase in global temperature of about 5 °C [9°F] within a few thousand years.

Thawing permafrost

So begins an article in the journal Nature that offers an unsettling explanation for one of the great climate mysteries: What caused the PETM?

The article’s title gives away the answer: “Past extreme warming events linked to massive carbon release from thawing permafrost” (subs. req’d).

The lead author, climate scientist Rob DeConto, explains in a news release:

“The standard hypothesis has been that the source of carbon was in the ocean, in the form of frozen methane gas in ocean-floor sediments,” DeConto says. “We are instead ascribing the carbon source to the continents, in polar latitudes where permafrost can store massive amounts of carbon that can be released as CO2 when the permafrost thaws.”

The new view is supported by calculations estimating interactions of variables such as greenhouse gas levels, changes in the Earth’s tilt and orbit, ancient distributions of vegetation, and carbon stored in rocks and in frozen soil.

While the amounts of carbon involved in the ancient soil-thaw scenarios was likely much greater than today, implications of the study appear dire for the long-term future as polar permafrost carbon deposits have begun to thaw due to burning fossil-fuels, DeConto adds. “Similar dynamics are at play today. Global warming is degrading permafrost in the north polar regions, thawing frozen organic matter, which will decay to release CO2 and methane into the atmosphere. This will only exacerbate future warming in a positive feedback loop.”

Indeed, the recent scientific literature suggests that the permafrost is poised to be a major amplifying feedback if we are self-destructive enough to ignore yet another dire warning and stay anywhere near our current path of unrestricted carbon pollution:

A 2010 study found our oceans are acidifying 10 times faster today than 55 million years ago when a mass extinction of marine species occurred.

In short, whatever we do, we don’t want to duplicate the conditions of the PETM.  But, tragically, we are. Indeed, a 2011 study that found humans are releasing carbon to the atmosphere 10 times faster now than during the PETM.  “Rather than the 20,000 years of the PETM which is long enough for ecological systems to adapt, carbon is now being released into the atmosphere at a rate 10 times faster,” one of the authors of that study explained. “It is possible that this is faster than ecosystems can adapt.”

Here’s more on this important new study:

[DeConto] and colleagues at Yale, the University of Colorado, Penn State, the University of Urbino, Italy, and the University of Sheffield, U.K., designed an accurate model―elusive up to now―to satisfactorily account for the source, magnitude and timing of carbon release at the PETM and subsequent very warm periods, which now appear to have been triggered by changes in the Earth’s orbit.

Earth’s atmospheric temperature is a result of energy input from the sun minus what escapes back to space. Carbon dioxide in the atmosphere absorbs and traps heat that would otherwise return to space. The PETM was accompanied by a massive carbon input to the atmosphere, with ocean acidification, and was characterized by a global temperature rise of about 5 degrees C in a few thousand years, the researchers point out. Until now, it has been difficult to account for the massive amounts of carbon required to cause such dramatic global warming events.

To build the new model, DeConto’s team used a new, high-precision geologic record from rocks in central Italy to show that the PETM and other hyperthermals occurred during periods when Earth’s orbit around the sun was both highly eccentric (non-circular) and oblique (tilted). Orbit affects the amount, location and seasonality of solar radiation received on Earth, which in turn affects the seasons, particularly in polar latitudes, where permafrost and stored carbon can accumulate.

They then simulated climate-ecosystem-soil interactions, accounting for gradually rising greenhouse gases and polar temperatures plus the combined effects of changes in Earth orbit. Their results show that the magnitude and timing of the PETM and subsequent hyperthermals can be explained by the orbitally triggered decomposition of soil organic carbon in the circum-Arctic and Antarctica.

This massive carbon reservoir at the poles “had the potential to repeatedly release thousands of petagrams of carbon to the atmosphere-ocean system once a long-term warming threshold was reached just prior to the PETM,” DeConto and colleagues say. Until now, Antarctica, which today is covered by kilometers of ice, has not been appreciated as an important player in such global carbon dynamics.

In the past, “Antarctica and high elevations of the circum-Arctic were suitable locations for massive carbon storage,” they add. “During long-term warming, these environments eventually reached a climatic threshold,” with permafrost thaw and the sudden release of stored soil carbon triggered during the Earth’s highly eccentric orbits coupled with high tilt….

Overall, they conclude, “an orbital-permafrost soil carbon mechanism provides a unifying model accounting for the salient features of the hyperthermals that other previously proposed mechanisms fail to explain.” Further, if the analysis is correct and past extreme warm events can be attributed to permafrost loss, it implies that thawing of permafrost in similar environments observed today “will provide a substantial positive feedback to future warming.”

The time to slash emissions was a long time ago but now is still much, much better than later, which may, as this study suggests, simply become too late.

69 Responses to Nature Bombshell: ‘Past Extreme Warming Events Linked To Massive Carbon Release From Thawing Permafrost’

  1. SecularAnimist says:

    Joe wrote: “now is still much, much better than later, which may, as this study suggests, simply become too late”

    Given that the permafrost is already thawing, and given that there is more warming on the way from the CO2 that we have already emitted, it is hard for me to see how it is not already too late.

  2. MapleLeaf says:

    We have knowingly set in motion a sequence of events that are going to haunt future generations.

  3. Dan Ives says:

    Agreed, especially considering the other amplifying feedbacks we’ve set in motion, such as the loss of arctic sea ice.

  4. But knowing that it’s “already too late” isn’t very helpful. As Joe points out, doing something now is better than doing something later. Saying it’s “too late” is demoralizing. It’s important to frame these issues in ways that lead to action, not discouragement.

  5. Dan Ives says:

    Joe, I’m afraid I echo SecularAnimist’s thoughts here.

    It seems we are about to reach a point (if we haven’t already) that even an impossible instantaneous zeroing of anthropogenic emissions won’t be enough to stop C02 concentrations from rising solely due to these amplifying feedbacks.

    It seems an event of nearly impossible odds is now required to avert catastrophe. Something like an asteroid impact causing a nuclear winter, unprecedented and sustained volcanic eruptions lasting for years, or humans not only instantly zeroing their emissions but implementing carbon-negative technology on a massive scale.

    Joe, am I over-reacting? I know you’ve posted before about it not being too late, but how does this new information change your position, it at all?

  6. Paul Magnus says:

    I think it probably is too late. Permafrost have started degassing. We really should start thinking about a plan C to preserve some form of continuum to our current ‘civil’ achievements.

  7. wili says:

    We have to face the fact that it is too late to avoid extremely catastrophic global warming and a major mass extinction.

    Too me, this means that we must be even more dedicated to not adding any more extreme damage on top of the the obliteration we have already wreaked on the living planet.

    My analogy is to an abusive son who has beaten is aging mother and now notices that she has entered her death rattle.

    Even though refraining from kicking his dying mother in the face with his steel toed boots will not save her, it is still the decent thing to do.

  8. Joe Romm says:

    I need to do a post on this. There is never a time when mitigation isn’t the best strategy, since it can always get much, much worse.

  9. Joan Savage says:

    The current Holocene Extinction is largely human driven. It has included land animals, a population that is thought to have been largely unaffected in the PETM extinction. If permafrost melt is the driver of a near-future PETM-like extinction, that is on top of the mass extinction that is already in process.

  10. wili says:

    Good point, Joan.

    I try to point this out to people who want to say that “the earth will be fine.” We have no idea how well the earth will recover from this double (at least) extinction event.

  11. prokaryotes says:

    Snow, Water, Ice, Permafrost in the Arctic (SWIPA)

  12. Mike Roddy says:

    It’s a matter of probabilities. Too late or not is not a binary problem. Whatever we do in the short term will be helpful.

    If aggressive emissions reduction has a 20% chance to save humanity- vs. a 1% chance if we do nothing- the choice should be clear.

  13. wili says:

    Good point.

    There is also the point I make below that it is always the good and decent thing to do, in any case.

    And we should remain humble about our ability to know all possible futures–there may be some unknown unknown negative (damping) feedback that can sweep in out of somewhere and keep the worst from happening, in spite of our pathetic behavior, IF we don’t continue pushing every system beyond its capacity to cope.

  14. prokaryotes says:

    Is there somewhere a slideshow/presentation/talk about current climate science, for distribution?

  15. Joseph R says:

    I see no mention of the fact that there are now SEVEN BILLION people (soon to be ten billion) on this rock. Many of these people used to ride bicycles, now they drive cars, build more roads for those cars, have electricity in their homes, are building coal fired power plants as fast as they can.
    Now you say we should act like the person at the beginning of a road construction project and turn our sign around and say STOP.
    Your going to get run over.

  16. Raul M. says:

    Good cartoon of the politicians in the know.
    Starts with a scene of the underground storm shelter banquet hall where the president turns to the first lady and says “do you hear something?”. The scene turns to above the shelter and the last remounts of the white house are caught up in a storm.
    Moral of the cartoon is that at some point it will be about the weather.

  17. Lou Grinzo says:

    Since I am not a scientist, and therefore not hindered by things like Doing Real Science, I’m free to speculate wildly (like most people here). So let me drag out my pet theory about all this.

    OF COURSE it’s the permafrost. Why do I say this? Geography.

    Look at a map of the northern hemisphere. What do you see? A big open ocean surrounded by land. More specifically, an ocean (as opposed to the land at the South Pole) that makes a rapid melting once warming starts very easy — ice dynamics aren’t holding back the process, but accelerating it, and we have everyone’s favorite feedback, albedo flip, accelerating things even more.

    And all that land? It’s perfect for storing and then quickly releasing 1.7 trillion tons of carbon in permafrost (which is what’s up there now) because it’s just the right distance to let plants grow during warm times and then freeze over during colder times.

    In other words, the entire geographic layout is primed for very rapid carbon releases and warming once anything (e.g. orbital perturbations, hairless apes burning fossil fuels) knocks the system even a smidge in that direction.

    Call it the climate version of Jared Diamond’s “Guns, Germs, Steel” explanation about geography and the spread of technology and civilization at constant latitudes.

  18. Y. says:

    Speaking of bad news I have just read the Brookings’ Institute’s report on USA-China relations[1]. Here’s the Chinese section on climate change:

    “While these Chinese suspicions continue today, the Obama administration’s designated projects to develop clean energy are seen as similarly self-interested. To a great number of Chinese economists and opinion leaders, the whole discourse of climate change is a Western conspiracy, which is designed first of all to prevent China and other developing countries from catching up. They believe that by creating the impression that climate change is caused by human activities and that reducing carbon emission provides the solution, the Westerners seek to be able
    to make profits by selling their low-carbon technologies and constraining the rise of economies like China’s that still must
    vastly expand production and infrastructure development to meet the needs of a society that is still transitioning out of poverty and towards a predominantly middle class society.

    Chinese leaders, many of whom have technical and scientific backgrounds, may be more impressed with the mainstream scientific findings about climate change and may not believe in such conspiracy theories. China is truly interested in strengthening cooperation with America and Europe in developing clean energy. However, there is a political risk to echoing Western calls for a green economy with too much enthusiasm, as China’s high speed economic growth has to depend on fossil fuels for many decades to come.”

    I don’t see carbon-reductions from them with this attitude…


  19. James Cole says:

    I agree with the number of posters above who express the idea that it most likely is too late to avert runaway global warming. The feedback loops are firmly in place already.
    Just note the recent findings of the Russian academy of Sciences that vast methane plumes have started venting from the floor of the shallow arctic seas off of eastern Siberia’s coast. What a few years ago were small plumes, just leakage really, have turned into raging plumes of methane gas. This is just one of the many feed backs in the arctic.
    The most depressing thing as of late is the news of the rate of increase of co2 emitted into the atmosphere is accelerating beyond all the worst case scenarios. Simply put, we have put the accelerator pedal to the floor and are holding it down as we rush towards the cliff. Under any rational judgement, we are acting suicidal. Yet the forces trying to prevent action have gained strength and influence in government and the media.
    This is hopeless. The forces of science and reason are mocked daily in government and the media. My thoughts are almost “Let these idiots roast alive in the runaway global heatwave headed our way”. Humanity refuses to act in the face of all the evidence. In fact they mock the evidence. It is very sick and sad.

  20. Andy C says:

    How has that worked for us so far?

    Analogous to hurricane warnings perhaps? Most people stay put if they think there is a “hope” that the hurricane will miss them. When if becomes apparent there is no hope they flee at the last. . .

  21. Andy C says:

    Hope is not a plan.

  22. EDpeak says:

    This is exactly what I tell people when they ask “but isn’t it too late?” since in some sense it’s the wrong question – they really mean, “isn’t it too late to stop X?” and even if the answer turns out to be “it’s too late to prevent X from happening” there is always a Y worse than X which one can eventually bring about, and it’s not too late to prevent Y (or at least not too late to prevent Z) there is always a “worser” scenario..

    Looking forward to the post on “mitigation is still always a good idea” which I’m sure will help me further refine this point which I already regularly make to younger people, or burned out activists, who often ask me this question..

  23. Mike Roddy says:

    You describe China’s embedded fossil fuel use as if it derives from economics, and quote whining about historical US emissions like it’s a big reason.

    Guess what? China has exactly the same problem that we do. Their coal and utility companies are printing money with coal plants. That means they get to buy politicians and media companies as if they were tipping hotel bell captains. The government slips its spoon into that gravy, too.

  24. prokaryotes says:

    To quantify earth environmental capabilities – the boundaries, we can assess the planetary boundaries

    Look at this graph


    To avoid catastrophic environmental change humanity must stay within defined ‘planetary boundaries’ for a range of essential Earth-system processes, argue Johan Rockström and his co-authors in a Nature Feature. If one boundary is transgressed, then safe levels for other processes could also be under serious risk, they caution. Seven expert commentaries respond to this proposal in Nature Reports Climate Change. Join the debate and listen to the podcast.

    Question is how much “life supporting system” fail with sudden large quantities of methane and other potent greenhouse gases from permafrost melt like Nitrous Oxide..

    Thawing nitrous oxide overlooked: study

    A new study has revealed thawing permafrost can release nitrous oxide, also known as laughing gas, a contributor to climate change that has been largely overlooked in the Arctic.

    The report in the journal Nature Geoscience indicated that emissions of the gas surged under certain conditions from melting permafrost that underlies about 25% of land in the Northern Hemisphere.

  25. prokaryotes says:

    Planetary boundaries is a way of thinking that will not replace politics, economics, or ethics, explained environmental historian Sverker Sörlin of the Stockholm Resilience Centre and the Royal Institute of Technology, Stockholm. “But it will help tell all of us where the dangerous limits are and therefore when it is ethically unfair to allow more emissions of dangerous substances, further reduction of biodiversity, or to continue the erosion of the resource base. It provides the ultimate guardrails that can help societies to take action politically, economically. Planetary boundaries should be seen both as signals of the need for caution and as an encouragement to innovation and new thinking of how to operate safely within these boundaries while at same time securing human well being for all.”

  26. prokaryotes says:

    Lead author Johan Rockström, director of the Stockholm Resilience Centre at Stockholm University, said: “The human pressure on the Earth System has reached a scale where abrupt global environmental change can no longer be excluded. To continue to live and operate safely, humanity has to stay away from critical ‘hard-wired’ thresholds in Earth’s environment, and respect the nature of the planet’s climatic, geophysical, atmospheric and ecological processes. Transgressing planetary boundaries may be devastating for humanity, but if we respect them we have a bright future for centuries ahead.”

  27. prokaryotes says:

    Maybe the fundamental reason for this “orbital-permafrost soil carbon mechanism” is so to position a planet in an optimal orbit around the sun. Because large quantities of greenhouse gases in the atmosphere is a strong driver for geomorphological activities – which have been shown to alter the tilt of earth axies. So it has been shown that within these climate changes and deglaciation times – sudden sea level rise had occurred, together with 300% more earthquake activity and other phenomena – which in turn alters profoundly the earth gravitational field.

  28. prokaryotes says:

    I think you tried responding to me in post #7. Well, i looked for the slides of An Inconvenient Truth, but it seems they are not public. I look for something for free of charge re-distribution – educational purposes.

  29. Sasparilla says:

    Thank you for the article Joe, more confirmation of what we’ve all been thinking (and hearing about previously).

    As Hansen has said, its been long enough that we’ve reloaded the methane clathrate gun as well – I don’t think its reasonable to think that won’t start to go off as we warm the ocean further.

    As many others have pointed out – we’re on the way to an ice free arctic in the summer (around the permafrost and over the clathrates) etc. from a strictly reducing our emissions standpoint its hard to see how we’d stop everything.

    But, as Joe said and as we all have seen (with the news of how fast climate change is advancing faster than expected etc. over and over) – it can always get worse especially with climate change.

    The other point is that we don’t just have emissions reductions to use. They are the main thing we have to do first or nothing else will matter.

    But we can paint every roof on every house and factories white over a period of 5 years and you’ve just changed the albedo of a significant area of the planet to ice – do the roads and parking lots and its even more significant, then move beyond that – that would affect how things play out.

    Go for large scale bio-char CO2 reductions from the atmosphere on a planetary level – that would affect things as well.

    And there will be a ton of other tricks we’ll think up to use once we start acting (we’re smart when we decide to do something especially if its important).

    As we have seen with the media waking up to climate changes impact on the weather recently – that will continue and increasingly be in the news in the future just from the weather and at some point it will become a must do now for the US general population overcoming the forces of xxxx in Washington currently resisting climate action. It’ll happen and if history is any guide we won’t see it coming even though we’re looking for it.

    Don’t despair, it looks bad but the game’s not over yet, not by a long shot. JMHO…

  30. Tom King says:

    Its a bit like being a ghost in a twilight zone episode where we gradually uncover the methodology of our own destruction. It all feels like deja vu as we check off each box in our list. Increasing CO2 – check, Deforestation – check, Dieing Oceans – check, Tundra off-gassing – check.

    About this point in the script we discover the ruins of a previous civilization that looks strangely familiar.

  31. John Mason says:

    Just read the paper. Bottom line is that at favourable points in orbital cycles, 900ppm carbon dioxide is all that it takes to tip things over the edge.

    Given what is already occurring up in the Arctic (and we desperately need as much data as possible on this, a situation which I know will improve a lot over the next few years), this paper is describing the parameters that are required to essentially reboot the planet’s operating system. It might be like a Windows 7 machine crashing and then rebooting to Windows 3.1 i.e. the basics will all be there but the details will be completely different.

  32. Y. says:

    A) Are you responding on auto-pilot? There’s no ‘whining about US emissions’ in the quote. More like ‘crazy conspiracy theories and putting (unsustainable) growth first’.

    B) Given their not exactly democratic political system, I don’t know if “buying politicians and media companies” is the reason. The leaders don’t need to be reelected, and they can just take all the local coal companies’ money as it is, so an economic explanations seems more likely. We do need to change this attitude. Any good Climate Change site in Chinese?

  33. Peter says:

    The PETM and other hyperthermals so long ago are now likely the result of mostly orbital variations and axial tilt of the home planet, causing the melting of permafrost. The former theory of melting methane hydrates now less important.

    This makes our situation even more dicey, since permafrost is now beginning to melt rapidly and will accelerate in coming years. With our own C02 from FF soaring, we are on a path toward probable doom. As the arctic warms more quickly then the rest of the planet, this will pump billions of tons of additional C02 into the atmosphere, along with ours. This is insane-

  34. John Mason says:

    “To a great number of Chinese economists and opinion leaders, the whole discourse of climate change is a Western conspiracy….”

    That is a neat example of why economists and opinion leaders are not fit to decide the future of Planet Earth!

    Cheers – John

  35. wili says:

    I don’t think I tried to reply to your comment at #7, but I did view the video and found it quite informative. Any idea when it came out. (I always find the lack of indication when videos were produced to be frustrating.)

  36. George says:

    Just curious, there was a study out a few months ago which stated that the Arctic had 50% less sea ice than today back around 8000 years ago. Why was there an amplifying feedback mechanism then?

  37. George says:

    I’m curious, how much permafrost does this study say existed on earth prior to the PETM? I thought that even before the 5C increase of global temps, the earth was already much warmer than today, and had much higher amounts of Co2 1000ppm perhaps?

  38. Dan Ives says:

    If you can provide a citation for your study, then perhaps we can begin to answer your question. There were likely hundreds of scientific studies “out a few months ago.”

  39. Mike Roddy says:

    A) That sentence may not come directly from your post, but is essentially correct.
    B)Chinese leaders need to stay in power, too, and keep their own fingers in the trough. The details and methodologies might be different from the US, but the process is the same. I’m not sure what your point is here.

    My brother heads the Far Eastern Studies program at USF. Maybe you should talk to him, or someone else who has studied and worked in China.

  40. Andy Hultgren says:

    Mike – well said. Completely agree. It is not a binary problem but a question of probability.

  41. Rabid Doomsayer says:

    “The cancer will be ripped from the host and that cancer is man” Frank Herbert

    I think that it is probably too late already. But I might be wrong.

  42. Peter says:

    George, what is your point? The main premise here is that vast amounts of C02 entered the atmosphere over a very short geological time frame- 55 million years ago- same as today, but even much faster.

    Should we consider see global temperatures rise 5 degrees Cor more before the year 2100?

  43. clays says:

    So massive amounts of carbon, more than today, and it took a few thousand years to heat up 5 degrees?

    But somehow today they say we’re all dead tomorrow if we don’t ditch cars for bikes?

  44. Peter says:

    NO- you misread. The amounts of carbon we are forcing into the atmosphere are 10 times faster then what happened in the PETM.

    At the rate we are going we will induce as much carbon into the atmosphere by 2050, that took the 5-10 thousand years of the PETM.

  45. caerbannog says:

    Perhaps you should consider the *rate* at which the carbon is released. Time-scales matter.

  46. SecularAnimist says:

    Joe wrote: “There is never a time when mitigation isn’t the best strategy, since it can always get much, much worse.”

    I don’t exactly agree.

    I do, of course, agree with urgent and aggressive mitigation efforts — because it remains possible that it is NOT too late to avoid catastrophe if we rapidly phase out fossil fuels, which I believe can be done much faster than most people imagine.

    But that’s not quite the same thing as saying that mitigation can prevent the situation from getting “much, much worse”.

    If you are in a car speeding towards a concrete wall, it may be a matter of life and death to slow down the car as much as you can even if you can’t stop before you hit the wall. The slower the car is going when it hits, the more likely you are to survive — maybe you can walk away from the crash relatively unscathed. Maybe the car won’t be totaled.

    But this does not apply if, instead of a wall, you are headed towards a cliff. If you can’t stop the car before you reach the cliff, you are going over it, and how fast you are going doesn’t matter that much.

    The big question about global warming, then, is whether it is a concrete wall, or a cliff.

    And these sorts of studies suggest that it is a cliff.

    That’s not an argument for doing nothing — it’s an argument that mitigation is even MORE urgent, and that we not only need to end all emissions ASAP, but also need to draw down the already dangerous excess CO2 (which we can do with organic agriculture and reforestation).

  47. SecularAnimist says:

    caerbannog wrote: “Time-scales matter.”

    The only thing that matters to clays is repeating the Heartland Institute’s talking points.

  48. Joe Romm says:

    Your analogy is actually doubly flawed. I’ll do a post.

  49. prokaryotes says:

    We require carbon negative technologies, to get us into the save zone.

  50. George says:

    “Large variations in Arctic sea ice
    ClimateFor the last 10,000 years, summer sea ice in the Arctic Ocean has been far from constant. For several thousand years, there was much less sea ice in the Arctic Ocean – probably less than half of current amounts. This is indicated by new findings by The Centre for Geogenetics at the University of Copenhagen. The results of the study will be published in the journal Science.”

  51. Mark E says:


    How many of us commentators have eaten meat from the petro-fuel based grain-fed animal industry in the last 48 hours? Meat from hunting or local grazing animals doesn’t count. Just petrofuel & grain fed meat industry.

    Is it reasonable to hope for critical mass on global warming, when our own bellies are full of fossil-fuel meat? If you give up fossil-fuel meats, you’ll have lots of chances to talk about direct action with all your immediate contacts. Without YOUR direct action, there is zero hope for meaningful social change. If you lack inspiration, see the movie “Gandhi”.

  52. Icarus says:

    This quote from the paper in question seems significant to me:

    These results show the potential for high-latitude climate forcing to trigger massive terrestrial carbon release, initiating positive warming feedbacks that can account for the sudden and extreme nature of past hyperthermals. We find that Antarctica and high elevations of the circum-Arctic were suitable locations for massive carbon storage during the late Palaeocene and Early Eocene. During long-term warming, these environments eventually reached a climatic threshold, at which permafrost thaw and sudden release of stored soil carbon27 were triggered during maxima in the long eccentricity and obliquity orbital cycles.

    We have the same potential for a sudden release of stored soil carbon today, and are rushing towards the climate threshold which would trigger permafrost thaw at a rate which is (I estimate) about 50,000 times faster than the long slow warming trend which preceded the PETM and other hyperthermals.

    We know that Arctic amplification is already a factor of 3 or so(global warming is around 0.8C, Arctic warming is over 2C) but my understanding is that as the Arctic sea ice disappears, the amplification will be much greater. We won’t have to wait for the entire planet to warm by 8 or 9C, in order to release all the permafrost carbon – if Arctic sea ice is gone in summer within this decade, as seems very likely, we will surely have triggered enough Arctic warming to set off this ‘permafrost bomb’ by then, I would have thought.

  53. Michelle M says:

    The one thing we could do…could have done…is have fewer children. It’s not too personal when all of humanity is at stake. It makes me angry to see idiots trying to stop women from planning the size of their families because they ascribe to an archaic belief system encoded over two thousand years ago, when large families meant survival. Now they mean death for all of us. We have, through our selfish choices, become a cancer to the planet, and we many not survive its attempts to rid itself of the disease.

  54. Mulga Mumblebrain says:

    The ‘study’ (see below) emanates from Denmark, home of Lomborg, the cosmic ray theory of Svensmark and the failed Copenhagen Conference and the Western conspiracy there to force an unfair climate treaty on the poor world. Forgive my cynicism, but it smells of obfuscation and confusionism, at best.

  55. Mulga Mumblebrain says:

    An even more tragic and ghastly approach was manifested by some of the victims of the firestorm in Victoria in February 2009 that took over 170 lives. The poor blighters ignored warnings of the coming inferno (predicted for days as temperatures soared to 46 degrees Celsius)and sat at home, the shutters down, the air-con cranked to max, watching DVDs. When they finally looked outside and saw the approaching firestorm, some stayed put and died at home, while others, attempting to flee too late, crashed into each other in the impenetrable dark on the backroads and died horribly right there.

  56. Mulga Mumblebrain says:

    The earth will, probably, be just fine-in a few million years, when Homo destructans will be long, long, gone.

  57. Mulga Mumblebrain says:

    Individual human beings exist on a distribution, a continuum of intellectual, moral and psychological attributes, from angels to daemons. Needless to say, the denialist rabble do not represent the ideal human type. What is worse, their negative characteristics, rather than being ameliorated by education and social reproach, are, instead, actively fomented and exacerbated by Rightwing politicians, business interests and MSM brainwashers.

  58. George refers to Funder et al 2011:

    Discussed here (the comments make clear why Funder et al is not applicable to conditions of today, and why George’s interpretation of it is incorrect):

    An open-copy may be obtained here:

  59. Nick B says:

    On the subject of whether it is too late the answer is yes; the fix is most certainly in! Add to this article the bigger risk of methane burps from the thawing sub-sea permafrost and “catastrophe” does not quite do the situation justice. The Arctic Methane Emergency Group ( propose immediate research into geoengineering to cool the Arctic and prevent a complete summer thawing of the ice.

    It seems rational that after so many years engineering the current crisis to come our way, we should use our best brains to protect the atmosphere for future generations. We need to take action now on this: cool the Arctic and pull back down the the excess carbon that is in the air until we get to 315(ish) ppm carbon in the air.

  60. Joan Savage says:

    The normal high in solar insolation from the Milankovitch cycle wasn’t enough added energy to kick on the amplifying feedbacks of a PETM-type extinction.

  61. Joan Savage says:

    Note that the abstract of the article in Science refers to “8500 and 6000 years ago” which converts to “6500 and 4000” b.c.e. (b.c.e.:before Christian/common era, the most recent 2000 years).

  62. Joan Savage says:

    That difference wasn’t in the above comment – it showed up elsewhere.

  63. George says:

    But since there was 50% less sea ice for centuries when compared to our lowest extent in modern times (2007) and the temperatures at the high latitude were significantly warmer than today, you would think that more black water would absorb more incoming sun and create a positive feedback, that would in turn melt more permafrost. What gives?

  64. Joan Savage says:

    George, We know the Arctic eventually iced up again, and the researchers indicated that it might have been over three thousand years. That would have been in the absence of today’s high CO2 concentration, and possibly also with a decrease in average insolation. Bear in mind that they reported that the Arctic was not ice free – just at lower extent. That means that the water temperature would have stayed near to the phase transition.

  65. Joan Savage says:

    George, and anyone else interested, the Canadian Cryospheric Information Network has a nice page on permafrost that says there was less permafrost in the mid Holocene.

    In some ways the present compares to the warm mid Holocene, and in some ways it doesn’t. We are way past it for atmospheric CO2 concentration.

  66. wili says:

    IIRC, the most recent study on the matter predicted that additional heating from permafrost melt would bring an additional quarter of a degree C at most by end of century.

    I think this is a very big long-term problem, but the science is not yet there to call it an immediate game changer.

  67. Bill Henderson says:

    Excellent discussion around melting permafrost and our present inaction but Joe you need to write a column on “It is possible that this is faster than ecosystems can adapt.”

    I added a comment under the recent WMO post which said global temp was rising at .166 per decade Leemans and Eickhout say .4 per decade is game over and with time lags and present emissions .4 is too close.

    Tanada at answered:
    Here is some simple math that might reassure you. It is projected that each doubling of CO2 leads to a base temperature increase of 3C. If you take 280 ppm as the pre fossil fuel mass use level 280/3 gives you a 1C rise for each 93.33 ppm increase. From pre fossil fuel to 2000 AD we increased pretty close to 1C and 94 ppm so there is a fair amount of confidence in that projection being confirmed. To get to the level where we would be increasing .3C a decade you would need to be explosively growing the fossil fuel use rate enough to emit 3.7 ppm/y. With all the constraints coming online from Peak Oil where is this extra carbon going to come from?

    Hey Joe, could you go here with pen in hand?

  68. Jose says:

    Peak Oil doesn’t reduce emissions, it leads to dirtier fuels such as tar sands and heavier grades of crude. And there’s also plenty of coal.