Cassandra has moved. Ugo Bardi publishes now on a new site called "The Seneca Effect."

Tuesday, February 7, 2012

Methane hydrates: the next communication bomb in the climate change debate

Methane released from ice is a spectacular and dangerous phenomenon. It is not so just because methane can catch fire, but because, on a large scale, the release it could generate a rapid and devastating global warming. We cannot say much about the time scale of such an event and not even if it could take place at all, but the perception of the possible danger ahead could be a true communication bomb in the climate debate. (the video shows Katey Walter from University of Alaska at Fairbanks experimenting with this methane trapped in ice)

As greenhouse gas, methane is more powerful than carbon dioxide, but there is a much more important difference between these two gases. Carbon dioxide emissions are something that we create and that we can control, at least in principle. If we stop burning fossil fuels, then we stop generating CO2. But, with methane, it is another matter. We have no direct control on the huge amounts of methane buried in ice in the permafrost and at the bottom of oceans in the form of "hydrates" or "clathrates."

Methane hydrates are a true climate bomb that could go off by itself as the result of a relatively small trigger in the form of a global warming. Sufficient warming would cause the decomposition of some hydrates to release methane to the atmosphere. This methane would create more warming and that would generate more decomposition of the hydrates. The process would go on by itself at increasing rates until the reservoirs run out of methane. That means pumping in the atmosphere truly a lot of methane. There are different estimates of the amount stored in hydrates, but it is surely large - most likely larger than the total amount of carbon present today in the atmosphere as CO2. The effects of the rapid release of so much methane would be devastating: an abrupt climate change that could bring a true planetary catastrophe. It is a scenario aptly called the "clathrate gun" and the target is us.

Now, there are plenty of uncertainties about this scenario, and we cannot say much about its timescale or even whether it would happen at all. But uncertainty is something that may make the scenario even more worrisome. People are scared of things they don't completely understand and that they know they can't control. That's surely the case of methane hydrates. We don't know how likely the worst scenarios are, we only know that methane is being released from hydrates right now and that the concentration of methane in the atmosphere is going up. We can't say if that's the start of the clathrate gun going off, but it is enough to be scared. I don't know about you, but I can tell you that I am scared.

The timescale of the clathrate gun may be long enough that we don't have to be worried in the short term. But another explosion seems to be going off much faster, this one in the media. The trend has started with scientific papers. Before 1999, there was not a single paper on the subject in the "sciencedirect" database. In 2011, 49 papers were published and the trend may be exponential. On the Web, Google Trends still doesn't generate a significant increase in the number of searches for terms such as "hydrate" or "clathrate". But we find about 40,000 pages dealing with the combination "climate change", "methane release" and hydrates. Even the mainstream press is starting to report about the subject. So far, the problem of methane hydrates has been largely absent from the debate on climate change. But that may be rapidly changing.

The methane release scenario has all the characteristics needed to catch the public's attention. It is spectacular, gigantic, biblical, and also rapid. It even has an evil sounding name: the "clathrate gun." It is nothing like the tame scenarios of the IPCC that plod on, slowly, up to the end of the 21st century. The IPCC scenario are not meant to be scary: nobody cares about slowly boiling frogs. But do you remember the 2004 movie "The day after tomorrow"? What scares us, mostly, are sudden catastrophic events. Now, think of a blockbuster movie from Hollywood about the clathrate gun. We would see giant hurricanes, biblical droughts, deadly heat waves, devastating floods..... No matter how the story is told, it is a true communication bomb.

Before continuing, let me hasten with a disclaimer. Let me state that I am NOT saying that we (scientists, activists, journalists or whoever) should exaggerate the dangers ahead in order to scare people with the methane story. Absolutely NOT - on the contrary, my point is that a scared public is NOT a good thing for reasons that I will explain in a moment. Let me also state that this post is NOT meant to claim that the clathrate gun is going off, it is meant to discuss how the public would react to the perception that it may be going off. This said, let me go on.

So, let's assume that the clathrate story becomes widely known, how's the public going to react? According to James Schlesinger, "People have only two modes of operation: complacency and panic". The clathrate communication bomb may well lead to a paradigm shift about climate and push the public opinion all of a sudden to the other side of the Goldilock dilemma: from complacency to panic.

Some people could see that as a welcome event: we would finally see an effort to do something to avoid climate change. But it is not obvious at all that this outcome would be positive. Things done in haste are not necessarily done well. Likely, we would see a frantic effort to "do something," no matter what, no matter how. If the past experience with the energy crisis is a guide, the chances to pick up the best solutions are small (see, for instance, the hype on biofuels). It is probable that we would seek for miracle solutions in large scale geoengineering. Carbon sequestration, sulphate particles in the upper atmosphere, mirrors in space, painting roofs white, what you have.

Would those actions work? Perhaps yes, but we would be moving into a totally uncharted territory. We don't know which could be the best solutions and we can't be sure of the side effects of most of them. Then, wouldn't the energy needed for geoengineering lead to more fossil fuels being consumed and, consequently, more greenhouse gases produced? And, then, suppose that geoengineering works in cooling the planet, wouldn't people revert to complacency and declare that the clathrate gun was a hoax from the beginning? As we move into the future, the problems we have created seem to become bigger just as it becomes evident that we, as a species, are just not equipped with the tools needed to solve them.

Things would have been much simpler if we had been able to find an agreement to tackle the climate problem at its roots, reducing greenhouse emissions. That would have provided a clear target to achieve and little room for wild swings in public perception. But it may well be too late for a strategy based on gradual changes. Things keep changing, and the only sure thing is that we can't stay idle in front of changes. So, get ready for the next big change: the clathrate communication bomb going off!


Some recent articles and posts about methane release from hydrates. This list is not meant to be complete or representative, it is here just to give some idea of how the debate is heating up (a very appropriate metaphor, in this case)


  1. An important fact about methane should be included in publications about methane release.
    The halflife of methane in the atmosphere is 7 - 10 years. It is a transient threat compared to CO2 with a halflife of 60 - 100 years.

  2. That's why it is called "clathrate gun:" it goes off very fast, overwhelming the capability of the system to absorb it.

    1. no, the "clathrate gun"TM metaphor deals with the geologic (not actual) rapidity with which this particular feedback might release stored carbon. The capacitor analogy. It has nothing to do with the short residence time of methane in the atmosphere.

      Also, it does not overwhelm the capacity of the system. It is part of the system. However, the response of the system may be unconfortably low for those operating of human, not geologic, timescales.

  3. Cassandra club,

    once you release fossil carbon, it is practically forever, and then, CH4 reduces to CO2...


    1. Alex,

      Warning: pedant alert :-)

      Chemically, CH4 is oxidised (to CO2) and the oxygen reduced. Your main point stands, just tidying up the science bit.


    2. Correct! As a chemist, I should have noted that immediately. But Alex didn't mean to state the chemistry of the reaction, just to say that CH4 gradually disappears, oxidized (indeed!) to CO2

  4. Dear Sir, I thought I would point out a few things...

    1. the pictures from Ms Walter-Anthony are not Gas Hydrate-derived methane. Just normal pond rot gas that is trapped under the ice during the winter.

    2. there are many sources of methane in the arctic. I am afraid you may be conflating them all under "clathrate gun". Probably the biggest source is organic matter trapped in permafrost. As the permafrost melts, and the organic matter rots. Like unplugging a fridge stuffed with vegetables. Its going to get gassy.

    3. Permafrost melt is not primarily anthropogenically-climate change driven. The arctic is undergoing a very prolonged period of environmental change post ice-age, with very large areas (such as the east siberian shelf) being inundated with sea-water. Those areas of relict permafrost perhaps originally 1000 ft thick, are now thawing, their average annual temperature bumped up by 20F or more. This change, applied at the seafloor for 1000s of years, absolutely swamps the several degrees of change applied at the sea-air surface due to anthropogenic causes.

    4. you may be confusing geologically rapid with rapid in human time scales?


  5. Gentle sir, thanks for your comments. As a matter of clarification, let me elaborate the matter a little:

    1. The movie at the beginning of the post is there only for illustrative purpose and never it is claimed in the post that the exploding methane comes from clathrates. (even though it might)

    2. Of course there are many sources of methane in the whole planet - in addition to the ones you mention I may also cite rice paddies in Asia and other farming activities. The "clathrate gun"; however, refers to a very large source of methane which, as mentioned in the article, is variously estimated but it is likely to be by far the largest one on Earth. That fact is what makes clathrates especially worrisome, but, as you correctly say, not the only source of worry.

    3. I am glad to see that you are so sure that anthropogenic causes are minor in causing the thawing of hydrates. It is perfectly possible; but it changes little to the problem. If you are right, then the problem is even bigger and it is surely unwise to add further pressure to the ongoing thawing phenomenon.

    4. Perhaps you have slightly misinterpreted my post. As clearly stated in the disclaimer, I am NOT saying that the clathrate gun is going off now, nor that it will go off in a timescale of years or decades. The point of my post lies in the uncertainty of the timescale and on the possible reaction of the public to the threat.

    Thanks to you!

    1. Dear Mr. Bardi

      re 1: yes it is illustrative,but I think illustrative of a process entirely different from what the post is about, that's all.

      re 2: rice paddies is of course a red herring in the context of the clathrate gun. But degrading submerged permafrost is not -- it is in fact a key to much of what one reads on-line about methane catastrophes and what not.

      re 3: hard to answer that. It is only unwise if the further pressure is not negligle and alternatives to that pressure apparent. But I don't think that is the case. As to how negligable or not it is, it would be good to have you consider the USGS analysis that I linked to...

      re 4: But you ARE saying that the "Clathrate Gun"TM exists, which is assuming facts not in evidence. Just giving a process a name does not mean it is real or if real, relevant.

      I will note that all of us have known for a while that asteroids and supervolcanoes do exist and that either can have real devasting impacts. but folks seem to be able to handle it. Like those that live in SF. Those thinks have real, non-zero probabilities. For this, though, its all so speculative, I think. And in fact, the emerging science as reported in the link I provided and a RealClimate, etc., just is not very compelling at the moment.

      All the best

    2. In Tuscany, we have a say that goes "better to be afraid than to get it" (Meglio aver paura che buscarne")

    3. Ugo
      Your post has caused me to go through my stock of old hard copy reprints from late 80s early 90s. (I am getting to be an old guy.)
      There was a lot of work being done on atmospheric methane back then, if not so much on clathrates, because 300 years of measured modern levels showed a modest interglacial level of something like 0.7p.p.m., rising to around 1.7p.p.m., and still rising. (There were fluctuations in the rate of accumulation. For example, there had been a 1% yearly increase over 15 years to 1994 but there was an anomalous 'pause' reported in 1992.)
      Clathrates are certainly part of the big picture over geological time scales (see my reference to the early Eocene below). Methane from clathrates is assumed to be 'old' methane, but how old are the recently observed releases from the different sources? Do we have recent resolution of that question in the new studies?
      The rise and fall of atmospheric methane has been a feature of 'natural' glacials and inter-glacials over, what, a million years? In particular, factors like the raised interglacial temperatures, rising sea level and isostatic rebound', and even high-latitude wet-peat formation, do not appear to have triggered a significant 'runaway' positive-feedback pulse of CH4 during our last 15Ky. Part of the reason might lie in the fact that many soils, including tundra soils, 'eat' CH4 as well as having potential to emit the gas. Soil CH4 emission is mostly associated with saturated soil moisture.
      However if we go back to the geological ages, there was very little ice on earth for most of earth's history, including no ice-cover at the poles. The release or sequestration of carbon, including CH4 played major roles. (One hypothesis around 1990 saw as significant a CH4 'umbrella' over the poles during the un-reactive polar winters, but other studies seemed to show that long term CH4 at the poles must have been continually renewed from large excess elsewhere.)
      Whether the example of the early ice-free Eocene (involving clathrates) can provide a credible comparison when we consider a putative modern CH4 pulse 'trigger' event, still seems doubtful to me, but if our future world temperature goes a long way beyond known previous inter-glacial maxima, who can tell what the result will be? I for one would like to see anthropogenic CH4 release curtailed wherever possible in any case. Release from natural gas spillage and coal mining were flagged up in 1993. Climate change is bad enough as it is, and our scientific knowledge has come on a great deal since my collecting papers from Nature et al. 20 years ago. Ugo, keep us posted (and keep me up-to-date)! Panic never was a useful survival mode.
      [If it would help, I can post several references from the earlier period.]
      Thanks again

    4. Phil, I don't know, the only thing that is clear is that there is a burst of interest on the clathrate question. Some people are scared to say that they are scared, others are simply scared. In general, I think we should watch carefully as the scientific debate; something should come out of it, although it is always difficult to predict the evolution of "threshold" systems. If you have a structured comment that you would like to publish, I would be happy to post it on this blog.



Ugo Bardi is a member of the Club of Rome, faculty member of the University of Florence, and the author of "Extracted" (Chelsea Green 2014), "The Seneca Effect" (Springer 2017), and Before the Collapse (Springer 2019)