Climatifact: Seven Points in Support of Shakhova? Or not?


Screen shot 2013-08-27 at 9.15.52 PM

In the Guardian, Nafeez Ahmed raises seven points in defense of the Shakhova hypothesis advanced as “likely” by Whiteman, Hope and Wadhams in a notorious Nature comment, and criticized here and elsewhere.

Specifically, Mr. Ahmed writes in response to Chris Colose’s thorough and meticulous analysis of Shakhova’s excessive claims.

I had an interesting Twitter exchange with Ahmed, which contains the following messages:

me: @NafeezAhmed no the ESAS “methane bomb” event is as close to impossible as anything in earth science can be; actual geophysics refutes it.

NA: .@mtobis lol, really? I guess that’s y major scientific review of the issue in Review of Geophysics says catastrophic methane rls plausible

me: @NafeezAhmed ref pls? I believe you may be conflating issues.

NA: Ref is linked here …

me: @NafeezAhmed If you think “carbon releases from Arctic permafrost …between 50-100 Gt this century” supports Shakhova you need a new beat.

and (perhaps more agressively than was warranted) me: @NafeezAhmed illustrates my claim that science matters and that very few non-scientist journalists can report on science effectively.

so I softened it with me: I’m sure you are a nice guy and I share your view that I’m a nasty old SOB. But I’m right on this, and you aren’t.

This exchange went on further, quite a bit longer than a Twitter conversation comfortably supports. Twitter is no place to hash these sorts of things out. As everyone was getting frustrated, Nafeez Ahmed ended:

NA: @CColose @Perwis @PeterGleick @IdiotTracker @mtobis so wiil wait 4 critique response showing my 7 facts r factoids

And given that Mr. Ahmed has a prominent platform, he is indeed due this much.


Before I take on his 7 points in detail let me defend my snark.

Ahmed refers in the Twitter exchange to a paper in Rev Geophys, suggesting that Arctic thawing may release in excess of 50 GT of C, a very serious matter, amounting to something like 10% of our remaining margin to a best-guess warming around the best-guess dangerous threshhold of 2 C. This is in keeping with my prior understanding, and make no mistake, it is very bad news – it amounts to more than 50 billion tons MORE of fossil fuel that needs to be left in the ground for a given level of damage.

But Ahmed refers to the paper in support of a very different assertion, that 50 GT of methane would be released. It’s commonly assumed as a rule of thumb that an abrupt methane release is from 20 to 70 times worse per molecule than the same amount of carbon released as CO2. So if true this would be very serious business indeed. 50 billion tons of methane would plausibly be civilization-ending and a massive extinction event. But the paper to which he points triumphantly says nothing of the sort.

So I conclude that he doesn’t really know what he is talking about. Specifically he has already shown that he is confused about the distinction between methane releases and CO2 releases, something that someone on the climate beat ought to be clear about.


The fact that there’s a lot of methane under the sea floor is not in dispute. The question is whether there is a way to destabilize a whole lot of it at once.

In order to justify this, Shakhova points to a possibility that some clathrates remain in the frozen phase even though they are at an unstable depth. This can occur if they are encased in water ice. A few nodules of this configuration have been identified, ironically because they are a threat to oil rigs, but they have NEVER been observed in the East Siberian sea, and it’s a long way from a few ounces to fifty billion tons. If fifty billion tons of the stuff were distributed just below the sea floor, the scenario proposed would not be wholly implausible. But there is no evidence of anything remotely like that, and no mechanism whereby it might exist.

Anything which does not directly defend the existence of a large deposit of clathrates existing for millennia at pressures where they ought to have long since disintegrated is not a serious defense of the clathrate bomb scenario. And none of Ahmed’s points address this.


Most of the seven points betray fundamental confusion about clathrates. The lay reader should not be expected to understand these a priori; it is the reporter’s job to elucidate them. But to do so, the reporter has to gain some understanding of the material. Sadly, Ahmed betrays little understanding, though he does have the wit to troll the literature for items which superficially support his unease about methane.

1. The 50 Gigatonne decadal methane pulse scenario was posited by four Arctic specialists, and is considered plausible by Met Office scientists

Whether we should be acknowledging the “Arctic specialists” as actually expert is, frankly, the question at hand.

So what about “is considered plausible by Met Office scientists”? This was exactly the point of contention on Twitter. Ahmed has conflated CO2 and methane.

VERDICT: conflation and confusion

2. Arctic methane hydrates are becoming increasingly unstable in the context of anthropogenic climate change and it’s impact on diminishing sea ice

In support, aside from an article in EOS (more a newsmagazine for scientists than a journal) we see a quote from a peer reviewed journal:

“… causing the liberation of methane from decomposing hydrate… If this process becomes widespread along Arctic continental margins, tens of Teragrams of methane per year could be released into the ocean.”

But tens of teragrams is about two orders of magnitude too low to make a difference.

Further, as evidence that the emissions are  a consequence of recent climate change rather than part of the background climate, Ahmed offers:

“… has led about 10 expeditions in the Laptev Sea but during the 1990s he did not detect any elevated levels of methane. However, since 2003 he reported a rising number of methane ‘hotspots’, which have now been confirmed using more sensitive instruments.”

Identifying the clear fallacy here is left as an exercise for the reader.

VERDICT: obscure references, confusion about quantities, unwarranted extrapolation

3. Multiple scientific reviews, including one by over 20 Arctic specialists, confirm decadal catastrophic Arctic methane release is plausible

A couple of reviews do give some support to this, but are vague about time scales. The DOE report specifically says:

“The time scales for destabilization of marine hydrates are not well understood and are likely to be very long for hydrates found in deep sediments but much shorter for hydrates below shallow waters, such as in the Arctic Ocean… Overall, uncertainties are large, and it is difficult to be conclusive about the time scales and magnitudes of methane feedbacks, but significant increases in methane emissions are likely, and catastrophic emissions cannot be ruled out… The risk of a rapid increase in [methane] emissions is real but remains largely unquantified.”

To emphasize: “The risk of a rapid increase in [methane] emissions is real but remains largely unquantified.”

There is a very wide gap between a rapid increase (which, again, everybody believes possible) and the 50 GT CH4 scenario, because the current release is orders of magnitude less than gigatons per year. That leaves plenty of room for acceleration without hitting the cataclysmic level. Further, this evidence doesn’t support the immediacy of that scenario at all.

VERDICT: While this is the best supported of the seven points, it is far from rising to the occasion on quantities or time scales, and does not in any way support the idea of a large deposit of unstable clathrates near the sea floor.

4. Current Arctic methane levels are unprecedented

Yes, they are at the high end of the instrumental record, but they are not climbing rapidly.

Despite NOAA scientist Dr Dlugokencky‘s reassurances that current Arctic methane emission levels are nothing to be “alarmed” about, his own data shows that Arctic methane levels were 1850 ppb in yr 2000, rising up to 1890 ppb in 2012.

Oh please, this is just silly. A 2 % increase in 12 years, assuming it’s not just measurement noise or random variation,will not get us to a ten thousand per cent increase very quickly.


5. The tipping point for continuous Siberian permafrost thaw could be as low as 1.5C

In support of this:

New research led by Prof Antony Vaks published this year in Science analysing a 500,000 year history of Siberian permafrost found that “global climates only slightly warmer than today are sufficient to thaw significant regions of permafrost.” The study by eight experts found that there is a tipping point for continuous thawing of permafrost at 1.5C which “can potentially lead to substantial release of carbon trapped in the permafrost into the atmosphere.”

Yes, this is definitely on the table. Unfortunately, it has nothing to do with undersea methane.

VERDICT: Confusion and conflation again.

6. Arctic conditions during the Eemian interglacial lasting from 130,000 to 115,000 years ago are a terrible analogy for today’s Arctic

This is plausible as it stands, but as a response to Chris Colose it is terrible, because Colose is not relying on the Eemian but on the early Holocene as the analogous period. So the refutation is strictly a strawman.

This is backed up by a meandering quote from “Prof” Paul Beckwith,  the “Professor Beckwith” who is a grad student at Ottawa U. The one who predicted  in May of this year that all the Arctic sea ice would vanish this year. He is a gloomy Gus indeed, but his track record isn’t all that impressive.

VERDICT: straw man

7.Paleoclimate records will not necessarily capture a large, abrupt methane pulse

Now, we swing back to saying that it HAS occurred in the recent geological past, indeed at the time which Colose says is the better analogy. In evidence (evidence which in point 6 were implied to be nonexistent) there is a paper referring specifically to a biotic feedback, and NOT clathrate-related.

VERDICT: self-contradiction, confusion and conflation


I am pleased to report, based on knowledge which by happenstance I had before the current controversy, that the specific mechanism Shakhova threatens us with is implausible in the extreme. I am pleased to report that no plausible different mechanism which could rapidly release this enormous quantity of methane has been proposed either. I base the second claim on the fact that people have been casting about for one, and in the end not come up with any.

There is a serious caveat that 50 GT or more of carbon dioxide (CO2) (as opposed to methane (CH4)) may well be released as a consequence of Arctic thawing. CO2 is, though much more common and much longer-lived in the system, less dangerous by weight than methane. But 50 GT is a very large quantity even of CO2. As such, it is a big enough and uncertain enough term that it is a real threat. But it is not a guaranteed catastrophe like the Shakhova hypothesis, and not relevant to it. That Ahmed repeatedly refers to it interchangeably with the Shakhova scenario is telling.


* Gavin Schmidt has been quoted saying “The scenario they used is so unlikely as to be completely pointless talking about,””

* In the same article, David Archer, a coauthor of the first papers on the global clathrate inventory, is more subdued but argues in the same direction:

“It’s weird for me to be saying, ‘Oh, it could never happen.’ It’s always the wrong side of things when you’re talking about nature,” says David Archer of the Arctic methane catastrophe scenario. “But,” he adds, “nobody’s come up with a defendable way of it happening all at once.”

* Chris Colose:

“I’ve seen the Guardian’s most recent response.  I still think it conflates many different issues, including varying sources of CH4 releases (e.g., in his point #7, the 2009 Science paper he references with respect to the Younger Dryas are talking about wetlands, not hydrate destabilization), and still presents no evidence for a significantly new Arctic methane source to the atmosphere….again, observed methane emissions around the Arctic are not evidence that they are a new source.  The point #4 about highest CH4 levels in 800k is due to direc anthropogenic activity, not hydrate destabilization, and renewed growtth in atmospheric CH4 has been attributed to a few different factors (Dlugokencky has recent literature on this).  If a positive hydrate feedback exists, it is currently very small and not emerging clearly.”

* Andy Skuce:

“None of the references in the Guardian article point to observations of shallow gas hydrates on the ESAS. There are shallow gas hydrates (around 60 metres depth) reported in Yamal, some 2000 km away, but those are (according to the author) relict hydrates thought to have been formed when that area was overlaid by an icesheet (or a marine transgression) and have been preserved in a metastable form after disappearence of the icesheet (or regression of the sea). As far as I know, nobody has proposed those kinds of events in this part of eastern Siberia. On the contrary, the local sea level on the ESAS has risen since the last glacial maximum, submerging the permafrost that formed when the shelf was exposed land.

“All of the references cited show that hydrates form below 200 metres depth in areas of permafrost. The Shakhova et al 2010 paper does not present any geophysical or sampling evidence for hydrates above 200m on the ESAS. Permafrost, yes, gas leaks yes, but not shallow hydrates.”

* in short, Gavin Schmidt again:

“There is still no evidence of actual (thermodynamically unstable) shallow hydrates on ESAS. Sorry, but I’m not buying it.”

* A comment by Nisbet et al is being submitted to Nature

Clearly large individual events can and probably will occur in the near future, such as major pockmark bursts and perhaps massive submarine landslides on hydrate, while local bubbling may be widespread on shelf seas. But even with such events the geological record shows that the total decadal hydrate-sourced methane reaching the  atmosphere is very unlikely to exceed 1 Gt, and may be far less than that. After millennia of cold, Late Glacial hydrates were probably more abundant and more rapidly destabilized by marine transgression and warming than will be the case in the current rapid Arctic warming. A 50 Gt decadal release, at a rate ~100x greater that during glacial/postglacial transitions, is thus improbably large.


For those of us trying to cope with public denial, this offers us a case that we can study without having our usual frustrations color our judgment. There is no better way to understand the creation of zombie pseudo-facts among the opponents of climate policy than to see an instance among its supporters.

The key question is why Ahmed is clinging to his illusion about what science says quite so steadfastly. A follow-up essay will relate this to the question of “postnormal”, i.e., politically salient science. Science as normally practiced quietly ignores unsupportable arguments. Political commentary picks them up with a vengeance. In practice we end up with one reasonably harmonious scientific community which makes ordinary progress in the ordinary way, and a public which perceives fringe players as key, and two competing communities at war over a contested hypothesis.

We need journalists who have the ability to make actual judgments. Difference splitting is not the only way to get this wrong. Aligning with a political position and judging evidence on its congruence with that politics is another. There is false symmetry about science, but it results from a real symmetry about political reporting which is indifferent to balancing evidence.

I have no opinions about Nafeez Ahmed outside this incident. In this case he has bet on the wrong horse. This is not without precedent, and people make mistakes. But the tenacity and relative incoherence of his defense is harder to forgive.


Nafeez Ahmed responds. Or tries to, anyway.  I respond to his response briefly. I don’t think he’s really changed the balance of evidence on the question.

UPDATE 2: UPDATE: Nafeez has withdrawn his support for the Shakhova scenario. I have verified that it is him via his Twitter account.


  1. I hope you'll take it as a good sign that everything you're writing here reflects my understanding of those questions and the overall situation exactly. Another paradigm like that to my mind has always been James Lovelock's.

  2. Thanks for this, Michael.

    One niggle is that when you say: "It’s commonly assumed as a rule of thumb that an abrupt methane release is from 20 to 70 times worse per molecule than the same amount of carbon released as CO2." You should have said "20 to 70 times worse per unit mass". (A CO2 molecule is 2.75 heavier than a methane molecule and those GWP factors are expressed in terms of mass.)

    It's a pity that so much science discussion goes on in semi-private, at conferences and in informal exchanges, yet that largely goes unreported to the general public, who have to rely on journalists (who are usually under-qualified, overworked and underpaid). I suppose that science blogs help fill that gap somewhat, but I suspect that, even there, scientists are reluctant to write opinions that they would freely disclose over coffee or beer. There really is a need for more scientific discussion at a level somewhere between the formality of journal articles and the informality of gossip.

  3. > The key question is why Ahmed is clinging to his illusion about what science says quite so steadfastly

    Because he has nothing else. He has written his post as though he was an expert, or at least as someone who knew what he was talking about. Confessing that he was completely wrong - which is what you're asking for; that he admit he has based this all on a paper he was unable to evaluate by people whose expertise he was unable to evaluate - would leave his credibility definitively shredded. So his best bet (in terms of his career, of course; he isn't worried or even very interested in truth) is to bluff it out. He's got a pulpit in the Graun, and you haven't. Anyone with a clue on this issue knows NA clueless, but that's a very small set of people. He'll just move on to the next issue. Or perhaps keep bluffing on this one: who knows?

  4. Pingback: Arctic methane ‘time bomb’ could have huge economic costs? – Stoat

  5. It has a sort of one - it's very difficult to think about this problem without a target, and this target is an intuitive/political compromise between economic and environmental risk.

    My guess is that it will shift to 3 C soon enough, because we missed the boat on 2, not because 2 was ever all that safe.

    The point is that whatever the final outcome, extra carbon makes it harder for a given damage level, or more damage for a given effort level.

  6. On communication, see David Roberts (a week ago about pulling up a bar stool, and lots else). I'm not sure he's going to survive his withdrawal, tweeting like mad!

    This is a bit OT, but since I'm here:

    The sad truth is that there’s no guarantee against heartbreak, in this or anything else. ... The decisions we’re making today will reverberate for centuries, and so far we’re blowing it.

    .... How do we maintain our equilibrium, our happiness and fighting spirit, with disappointments so common, victories so rare, and unthinkable loss looming?

    .... we remain terribly inept at the simple task of predicting what will happen more than a few years out.
    We don’t anticipate the lateral moves, the lurches, the phase shifts.
    grasp every opportunity. We don’t know when history might unlock the door, so we have no choice but to keep pushing on it.

    And really, what else are we going to do?
    When we ask for hope, then, I think we’re just asking for fellowship. The weight of climate change, like any weight, is easier to bear with others.

  7. The illustration implies magic thinking, but I think it goes too far to imply ideas about methane have a parallel in followerrs of the Kabbalah (Alastair Crowley like). I have tried to ignore it, but it is typical of the kind of exaggeration that is getting us all into trouble.

  8. yes, we will have to wait on events, possibly a year or more ... I think pants on fire is too extreme but have (mostly) desisted on the subject for the time being. imnhso the infighting is giving people wanting a target to shoot at the wrong bullseye.

    Meanwhile, I found this while looking for something else:

    "MIRTHE / CEE Team Measures Methane Emissions in Northern Alaska"

  9. William: Anyone with a clue on this issue knows NA clueless, but that’s a very small set of people. He’ll just move on to the next issue. Or perhaps keep bluffing on this one: who knows?

    You were right the first time, he moved on. Specifically, in his latest Guardian piece, he claims that the US motivation to attack Syria is because of gas. The gas in question is, naturally, methane, not Sarin.

    There are lots of references, as usual, and I hope that somebody checks them out, because I'm not going`to.

  10. It's not infighting as far as the scientific community is concerned; it's only made to look like infighting by the outsiders. In this way it is similar to denialist pseudoscience.

    The swath of the public and the press it targets is different, but the methodology is similar. That's why it's important.

    That in turn is why science cannot be simply cut out of the public conversation, much as we all, most scientists included, wish it could be. Detecting junk science is, in the end, not a trivial or easily acquired skill.

  11. Pingback: Ramasse-miettes – Ocasapiens - Blog -

  12. Pingback: Another Week of Climate Instability News, September 1, 2013 – A Few Things Ill Considered

  13. He's a journalist; their credibility is regularly shredded, but such is the modern news media, even in the grauniad, that that is irrelevant to their employment. In fact creating more controversy is usually better for them, since more page hits and more angry letters to the editor are a good thing nowadays.

  14. Pingback: Why the jury's still out on the risk of Arctic methane catastrophe | Nafeez Ahmed |

  15. Pingback: Why the jury's still out on the risk of Arctic methane catastrophe | Nafeez Ahmed

  16. Pingback: Why the jury's still out on the risk of Arctic methane catastrophe | Nafeez Ahmed | GreenOrg

  17. Pingback: Klimaatjagers: op zoek naar kantelpunten (‘tipping points’) in het klimaatsysteem | Klimaatverandering

  18. Pingback: Rebuttal to Michael Tobis’ unsubstantiated attacks on the work of Shakhova

  19. OK, this is completely off-topic.

    It's coming up on the one-year anniversary of your receipt of the Woody Guthrie award ... have you passed the award on to someone else yet, or do you have ideas?

    Nick Stokes did a nice job of reconstructing the history of the award. I think this is complete:

    Aerchie (Aerchie's Archive)
    Honji (Honji's Harangues)
    honestpoet (Enough is Enough)
    Mike Kaulbars (Greenfyre)
    Dan Satterfield (Dan's Wild Science Journal)
    John Cook (Skeptical Science)
    Steve Carson (Science of Doom)
    Nick Stokes (Moyhu)
    Bart Verheggen (Our Changing Climate)
    John Nielsen-Gammon (Climate Etc)
    James Annan (James' Empty Blog)
    Michael Tobis (Planet3)

    In recent years it seems to have gotten stuck in something of a climate-change theme -- don't know if this should be considered a bug or a feature. The list also seems to have become somewhat male-dominated.

    Anyway, just curious about this.

  20. Pingback: Why the jury still out on risk of Arctic methane catastrophe | marketspace

  21. Thank you MT.

    The scary-talkers seem to mostly quit mentioning the fundamental assumption (that "shallow" "metastable" "hydrates" exist and in large quantity. Over time, those terms fade out of their blog posts.

    If only they'd understand how the volume numbers become very different when those assumptions change.

    If there's such a clathrate, then a liter of clathrate turns into 150, 160, or more liters of methane.
    If there's no clathrate, then a liter of sediment or permafrost contains less than a liter of methane.

    This seems rather like assuming every pressure cooker is a bomb,
    then urging panic because department store shelves and mail order catalogs are FULL of them.

  22. Pingback: Too alarmist? | Wotts Up With That Blog

  23. Pingback: Too alarmist? | And Then There's Physics

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.