Arctic Methane Release: The End Of The World As We Know It?

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"Arctic Methane Release: The End Of The World As We Know It?"

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.

Buzz Hoffman, via Flickr

David Archer makes clear in this RealClimate repost that while Arctic methane probably will not be the beginning of the climate catastrophe, it may well be the end — if we don’t control CO2 emissions soon.

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 melting permafrost, which allow 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 200 Gton C although the land surface has taken up enough carbon to achieve net wash. So maybe we’re 1/3 of the way there, say 700 Gton C left to go. The 1200 Gton C of Arctic methane hydrates and the permafrost carbon stack up pretty menacingly against our 700 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.

This piece was originally published at RealClimate and was reprinted with permission.

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36 Responses to Arctic Methane Release: The End Of The World As We Know It?

  1. Sorry to say that it appears Katey Anthony is being a bit too conservative. This is easy to do when taking a snap-shot of current Arctic states and assuming that trend will continue year-on-year. The problem is that Arctic warming is an non-linear event and, as such, we can expect increasing Arctic methane release over the coming years and decades.

    NSIDC noted as recently as last year a potential for the Arctic to contribute as much as a 30% addition to human greenhouse gas emissions. Further, ocean venting of methane is already enough to make an atmospheric contribution. To assume that the ocean will uptake all of the methane vented from hydrates denies current events.

    I suppose the debate has been colored by a range of issues. The first being that some are concerned about ‘doomsday now’ due to Arctic Methane release, while others (excluding climate change deniers) are on the side of stating that Arctic Methane release probably won’t be so powerful a feedback.

    The issue is the level of feedback and its growth over time. We need reasonable measurements for this. Not just opinions. And I think, given evidence of methane contributing to rapid warming in the past, there should be substantial concern for Arctic methane release providing a substantial amplifier to human-caused warming in the decades to come.

  2. Jack Burton says:

    I am so clad to see a major article here on Arctic Methane, this is what has me up nights.
    And a major YES, it is perhaps conservative.
    I for one am tired of linear thinking, events in the arctic are now anything but linear. What happened yesterday do not transpose to today. Look how out the model for arctic melting were!
    Look at how fast the methane plumes the Russians discovered went from being meters across to topping a kilometer across. What a year or two??
    I know science must be conservative and I accept that. But, get off the linear models they are not going to predict what is coming.

  3. A good tonic to anxiety is to examine the change in global atmospheric methane concentrations rather than to point to increases in regional sources. And global atmospheric methane concentrations haven’t changed much. And won’t change much even with large increases in Arctic methane: temperate zone sources already are much larger.

    Methane’s contribution will be, as the article points out, to prolong the long tail of global warming. It’s actually very hard to extract free methane from hydrates: energy companies are, after all, pursuing fracking technologies which extract methane from rock formations rather than attempting to extract methane from near-continental hydrate deposits.

  4. Models are important. I would just like to see a few take into account the non-linear responses that are apparent the the paleo-climate research. At that point we could compare goal posts and then get a decent idea of their relative accuracy.

    And I agree with you entirely about the linear thinking being off. Responses to forcings, both negative and positive, tend to be nonlinear in nature. We’re still stuck in a Holocene way of thinking — when homeostasis was the reality. But the Holocene is over and we are in a period of transition to the next state of Earth’s energy balance. What the geological past indicates is that this period of change will be anything but linear. Further, with the forcing, i.e. greenhouse gasses, still accumulating, any baseline measure is almost impossible to establish. In essence, we have a set of apparently amplifying feedbacks on top of an already amplifying forcing. Given this entirely unnatural state, we should assume that the geological past would indicate the least of what we should expect from human-forced climate change.

    Hansen notes that we are at the stage of amplifying feedbacks, not runaway warming. Not yet at least. And given Hansen’s record on this, being one of the most accurate among the scientists, and given that even Hansen has been outpaced by events, now is certainly not the time to lean too heavily on the false comforts of linear expectations.

    One last point and I’m done. This survey focused on the Alaska environment. That said, there is quite a bit more of the Arctic to take into consideration. And looking at Alaska and the region surrounding it, it is one of the least volatile, thus far, when it comes to methane release. Much of the real action, so far, has been in Siberia and just off the coast of East Siberia. As the Arctic continues to warm, it is possible that other regions will show the volatility that Siberia is currently experiencing. We shall see.

    In the infantry, we had a saying when dealing with a potential crisis situation. And I think it applies here:

    “Stay alert. Stay alive.”

    Best regards and best of luck!

  5. Mike Roddy says:

    “We have cut 200 Gt C, but the land surface has taken up enough carbon to achieve a net wash”. Not sure if this is true, but even if it is, forests could have taken up much more of our GHG emitted carbon had they not been so ravaged. You don’t offset forest destruction through replanting tree farms:

    A key part of doing something about climate change is to reduce consumption of wood for things like paper towels, packaging, and two by fours. This is especially true in the US, where we produce and consume roughly 25% of the earth’s wood products. Climate scientists rarely address this issue.

  6. Some scientists are noting the potential for an up to 50GT release of methane from the Arctic at any given time.

    So if you look at the boundaries established by scientists, you have one set arguing that methane release contributes to the long tail of global warming and you have another set noting the risk of large pulse releases on the order of 50GT at a time.

    I wouldn’t call this range a tonic. I’d call it a test between two potential realities. One is gradually worse as time increases. The other shows a potential for sudden breakdown, as we’ve seen with Arctic sea ice.

    Unfortunately, the scientists who were counseling for a gradual deterioration of Arctic sea ice conditions were proven wrong. Do we really want to be in the same state when it comes to methane?

  7. Jakob Wranne says:

    The end to the world as we know it comes before the methane has its impact.

  8. John McCormick says:

    Jeffrey, another tonic for anxiety is to compartmentalize the whole damn problem and get on with other important anxiety-prone things.

    Arctic methane release is only a portion of global methane release and increasing concentration in the atmosphere. When One considers all other sources of methane release in this warming and continuously greater warning planet, the collective sum of emissions at any time period will be smaller than the collective total next year, next decade.

    The dam has sprung many leaks and we are not paying attention to their potential to weaken the entire dam. Instead we are focused on one leak at a time..event then not doing anything to stem it and prevent future leaks.

    Oh, you say that comet is on a trajectory to strike earth. Maybe yes, maybe no. Lets keep an eye on it and see who’s model is correction.

  9. There are temperate zone methane hydrate deposits so we already have a model of how these things outgas with warmer temperatures. We should examine Arctic deposits to see if they differ significantly.

    My intent wasn’t to downplay methane as a concern, but to help ratchet back the rhetoric on the issue. CO2 is menace enough and if we can control it, we’ll most likely have controlled Arctic methane as well.

  10. Spike says:

    I see Svalbard in the Arctic has been shown to be warmer than at any time in the past
    1 800 years in a new study, and furthermore

    “Climate models suggest that by 2100 Svalbard will warm more than any other landmass on earth, due to a combination of sea-ice loss and changes in atmospheric and oceanic circulation, according to the International Panel on Climate Change 2007 report. In a study published last year in the journal Advances in Meteorology, Norwegian researchers estimate that average winter temperature in Svalbard could rise by as much as 10 degrees C, or 18 degrees Fahrenheit.”

    So big temperature increases over and above what are currently unusually warm temperatures look likely so I do wonder about the future impact on both permafrost and oceanic methane hydrates. I note Jim Hansen writes seriously about the methane hydrate threat, which given his record makes me rather wary.

  11. Have to agree with you here. I guess for me the concern is what happens if we don’t ratchet back the CO2. Not doomsday now as some seem to be saying, just worried about what the next decades look like under BAU fossil fuel emissions.

    A decent metaphor, perhaps, would be that human CO2 emission acts like a ‘gateway drug’ to the possible crack cocaine of an increasing methane release?

    Best to you, sir.

  12. Paul Magnus says:

    Yes, her appreciation of risk in this article is wanting.

  13. Paul Magnus says:

    Keep calm and carry on….

  14. Paul Magnus says:


    “while Arctic methane probably will not be the beginning of the climate catastrophe”

    Catastrophe has begun. Haven’t you noticed?

  15. Paul Magnus says:

    Climate Chaos shared a link.
    about an hour ago

    Record Arctic Snow Loss May Be Prolonging North American Drought | Wired Science |
    Melting Arctic snow isn’t so dramatic as melting sea ice, but it the snow may be vanishing just as rapidly, with potentially profound consequences for weather in the United States. The upshot: The ongoing North American drought, the worst since the Dust Bowl of the 1930s, may have been fueled in par…

  16. Paul Magnus says:

    Seismic activity is also increasing in the Arctic due to gw. This will have consequences in terms of methane release from the land and the seabed. There will also be more landslideS as a result, which will also trigger major release…

  17. Richard Miller says:

    Archer says,
    “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.”

    This needs clarification.

    It is my understanding that methane typically oxidizes into CO2 (so with you get the uberpotent short term warming of methane coupled with the centuries to thousands of years warming of CO2) and water vapor, which is also a greenhouse gas. My guess is that Archer assumes this when he talks about the long tail of warming, but it would be helpful if this was more explicit.

    Here is a scientific statement of this process:

    Tropospheric oxidation
    The predominant mechanism for removal of
    methane from the earth’s atmosphere is
    oxidation within the troposphere by the hydroxylradical (OH). The hydroxyl radical is responsible for the breakdown and removal of a host of trace gases, including methane, and for this reason is known as the ‘cleanser of the atmosphere’. In essence, atmospheric OH effects a low temperature combustion of ‘fuels’, such as methane and other hydrocarbon species, by eventually oxidising methane to carbon dioxide,
    as would happen if methane were burned.

    And this,

    “Some of this methane can get trapped (as a gas, as a solid, dissolved or eaten) and some makes its way to the atmosphere where it is gradually broken down to CO2 and water (H2O) vapor in a series of chemical reactions.”

    See here

  18. Richard Miller says:

    Dear Mike,

    Your comments on forests are quite helpful. This is a really big deal that needs more attention. Are there any more recent studies that you know of making a similar argument?

  19. Mike Arney says:

    I’m confused by issue of our available carbon “budget” to stay below 2C warming. Prof Archer puts the budget at 700 GtC left to go. But on Climate Progress, Brad Johnson’s Carbon Bubble infographic (as well as Bill McKibben’s Rolling Stone article) puts the number at 565 GtCO2, which I believe would be 565/3.7= 154 GtC. This is a huge difference. As someone trying to help with this problem on a personal and civic level, I’d really like to understand this.

  20. Paul Magnus says:

    creepy feeling on seeing this….

    Mars Water: NASA’s Curiosity Rover Finds Signs Of Ancient Stream

  21. rollin says:

    I just a few questions and a short statement. What is the predicted rate of methane release from all arctic surfaces at 2 degree C temp rise(would be much higher in the arctic)? Why is the methane greenhouse effect calculated out to 100 years if it disappears after 10 years? Is the radiation increase effect from lowering atmospheric SOx being taken into account?

    We are already seeing very significant effects at 0.8 C rise in global average temps. With the arctic being even more sensitive to global warming, any results based on current testing will underestimate the effects. I agree that runaway global warming is unlikely but that does not mean natural feedbacks combined with industrial inputs will not release enough to bring us back to a version of the PETM and probably much faster than in the past.

  22. john c. wilson says:

    The answer to your first question is no one has any idea. No one has any idea what the release is right now. It is all guesswork and we don’t even know how much we don’t know.

    To the second question. It’s because after 100 years all the methane has reacted and broken down to CO2. Though even that is dicey because the chain of reactions proceeds differently at different altitudes. The ten years figure came out of a hat. If you pay close attention you’ll find a lot of that.

    To the third question. It varies. Better read any particular text closely. Most of the time simply because you ask that question you are way ahead of the game.

  23. Just a few short years ago the consensus was that the methane hydrates in the sea floor below the Arctic Ocean would remain frozen due to temperature and pressure.

    Boy was that wrong!

    Semiletov and Shakhova have sea bed cores that showed the hydrates to be slushy at temperatures below 0 C.

    Alaska is a long way from the Laptev Sea.

    Also note that the depth of the sea over the continental shelf there is as shallow as 50 meters, and the water there is a lot warmer than it used to be.

    I don’t think we can say anything with confidence about how much methane will be emitted and when.

    All we do know is that things are happening a lot faster than anyone predicted they would 5 years ago.

    The land-fast ice shelves around Ellesmere had been there for more than 60,000 years, according to sediment cores and the types of shelled creatures found in them.

  24. Mulga Mumblebrain says:

    Hasn’t that been the paradigm for so long? The climate science community, by and large, has produced predictions that have been way outdone by reality, yet the denialists genocidaires still screech ‘alarmist’. I for one am amply alarmed.

  25. Spike says:

    This site may be helpful

  26. Mulga Mumblebrain says:

    And mega-tsunamis, too.

  27. Mulga Mumblebrain says:

    The runoff from the great Siberian rivers, the Lena, Ob and Yenisei, is warming quickly. Too many synergies, too many ‘unknown unknowns’. Yet the ‘experts’ keep issuing insouciantly naive calls not to panic. At least panic might impel activity, rather than navel gazing as the house burns down around us.

  28. Spike says:

    “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.”

    Don’t quite follow Prof Archer there. If methane has a life of 10 years then I presume 0.5Gt of the atmospheric reservoir is destroyed each year if the level were stable. If 1% of the hydrates degraded to the air annually that would add 12Gt per year to the atmosphere and would produce a major increase in levels unless degradation increased similarly. Or am I looking at this wrong?

    There looks to be a market for anyone who could come up with a way of accelerating atmospheric methane degradation in the future.

  29. perceptiventity says:

    And it is even greater percentage wise than dramatic Arctic Sea Ice loss this summer:

    “…For a start, June 2012 snow cover was not just the record of June. Excluding Greenland with its ice cap, the June 2012 anomaly was the record for all months in the entire 45 year record. The anomaly stood at 5.74 million square kilometres, pipping the December 1980 record by 0.13 million square kilometres, although this again is hardly front page news…”
    “…Another way of visualising this early melt is that the average snow limit at the height of the melt season is now a whole 500 miles further North than it was 27 years ago…”

  30. perceptiventity says:

    Don’t forget we are on to getting a “Venus Syndrome” here

  31. Nick B says:

    It does seem that David Archer lacks credibility amongst those who are following the methane situation in the Arctic. Semiletov / Shakhova have reported with 1km wide plumes of methane that have only just appeared. Recent reports are of these venting points increasing in number. Archer’s article implies that this is not happening now but could happen at some point on the horizon. He is dreaming.

    The Arctic situation is the biggest current symptom of climate change that threatens us right now and we should be discussing ways of containing it. We geoengineered ourselves to this point – now it is time to engineer a solution.

  32. Raul M/ says:

    Many point to the chance of runaway warming. Does that expression have any true meaning?
    For example, is walkaway warming a linear warming expression? Warming likened to falling off a cliff also also has a limit to the speed of the warming as the effect of gravity would limit the fall. But what forces would limit the feedback processes and the speed buildup of the warming process. I ask because beyond the obvious answer that the limits to warming must be related to what is comfortable to the majority of life forms. The speed increases of the rate of warming relate to the amount of engineering required to correct for our mistakes of the past and present.

  33. mikkel says:

    I too am disappointed by how cavalier the conclusion is. Not only does it neglect to mention that methane becomes CO2 but there are increasing hypotheses and modelling about how a fast rate of change could create a massive methane release similar to the firing of an action potential in a neuron.

    If true then the tipping point would be unknowable until it was too late.

  34. Mulga Mumblebrain says:

    Going out with a BANG, not a whimper.

  35. perceptiventity says:

    East Siberean Arctic Shelf is shallower compared to temperate methane deposits where pressure rather than temperature stabilises them.

    “…Nonetheless, the hydrates in the sediments of the seafloor do remain frozen: after all, they are icy lattices. In addition, they remain frozen even well above the normal melting point of ice (0°C; 32°F), and at temperatures up to about 15°C (59°F). They manage this feat because of the enormous pressure that exists at these depths. The pressure is due to the weight of the overlying water. This weight accumulates so rapidly that just 10 meters (yards) below sea level, the pressure from the water alone is equivalent to that of the atmosphere. Every additional 10 meters adds another equal amount of weight…”

  36. perceptiventity says:

    “…I believe that the non-gradual (massive, abrupt) emission mode exists for a variety of reasons. First, wherever in the World Ocean such methane outgassing releases from decaying hydrates occur, they appear to be torch-like with emission rates that change by orders of magnitude within just a few minutes. Note that there was no additional seal such as permafrost to restrict emissions for hundreds of thousands of years anywhere in the World Ocean. Imagine what quantity of methane has been stored beneath sub-sea permafrost if even now, when the permeability of permafrost is still limited, the amount of methane annually escaping from the ESAS is equal to that escaping from the entire World Ocean. Another important factor is that conversion of hydrates to free gas leads to a significant increase in the gas pressure. This highly-pressurized gas exerts a geological power that creates its own gas migration pathways (so-called “chimneys” within sediments). It is even more important to understand that the nature of the permafrost transition from frozen to unfrozen is such that this physical process is not always gradual: the phase transition itself appears to be a relatively short, abrupt transformation, like opening a valve. Remember that the gas “pipeline” is highly pressurized. There could be several different triggers for massive releases: a seismic or tectonic event, endogenous seismicity caused by sediments subsiding pursuant to hydrate decay, or sediment sliding on the shelf break; the shelf slope is very steep, and the sedimentation rates are among the highest in the ESAS. As for the amount that could possibly be released, this estimate represents only a small fraction of the total amount of methane believed to be stored in the ESAS (3.5% of 1400 Gt). Because these emissions occur from extremely shallow water, methane could reach the atmosphere with almost no alteration; the time scale of such releases would largely depend on the spatial distribution and capacity of the gas migration pathways…”