Thursday, December 29, 2011

Revkin vs Revkin: the final battle

Andrew Revkin has completed his methane trilogy. The final installment, "More Views on Climate Risk and Arctic Methane," like part two "Leaders of Arctic Methane Project Clarify Climate Concerns" could be taken as a debunking of his original post on the subject ("Methane Time Bomb in Arctic Seas – Apocalypse Not"). But I prefer to think of it as journalism (very good journalism, when all is said and done) in real time.

 Revkin begins his journey with the piece in the Independent, which he (correctly) recognizes as overhyped. He thinks he already knows this is rubbish, based upon his reporting in 2010:

This all builds on what I was told in 2010, when I last visited the question of methane releases from Arctic seas. . . .  I urge you to read, and pass around, the 2010 post — “The Heat Over Bubbling Arctic Methane.”
He talks to a couple of scientists, and gets a couple of quotes bolstering his view that nothing can have changed:

To review, the authors confirm “drastic bottom layer heating over the coastal zone” that they attribute to warming of the Arctic atmosphere, but conclude that “recent climate change cannot produce an immediate response in sub-sea permafrost.” That’s the understatement of the year considering their conclusion that even under sustained heating, the brunt of the sub-sea methane won’t be affected in this millennium.
We of course do not need the brunt of it, but only, say 2% of it, to radically transform the world(1). No matter. Onward to the "publish" button!

Yet, he cannot have been without the nagging feeling that he forgot something. Something kind of important. Something like talking to the scientists being debunked. But they were on vacation! (2)

So, to his credit, he does a follow-up to that post when Natalia Shakhova and Igor Semiletov check in. And Revkin is no Michael Bay; his sequels are all better than the original. In part two, we find that these researchers were not panicky about methane plumes, as the Independent made them sound, be had real and legitimate concerns about the accuracy of the models Revkin spent his first post praising:

Yes, modeling is important. However, we know that modeling results cannot prove or disprove real observations because modeling always assumes significant simplification and should be validated with observational data, not vice versa. Much of our work includes this field validation. Last spring, we extracted a 53-meter long core sample from the East Siberian Arctic Shelf, to validate our conclusions about the current state of subsea permafrost. We found that the temperatures of the sediments were from 1.2 to 0.6 degrees below zero, Celsius, yet they were completely thawed. The model in the Dmitrenko paper [link] assumed a thaw point of zero degrees. Our observations show that the cornerstone assumption taken in their modeling was wrong.
The obvious thing to do after this bombshell was to talk to even more scientists, which Revkin has now done. While none of them look like retreating to a compound in the Rockies just yet, no one appears quite as sanguine as the December 14 Revkin of "Apocalypse Not":

Raymond T. Pierrehumbert: But the clathrate release problem is in a rather different category from the runaway greenhouse issue. It has to be seen as just one of the many fast or slow carbon catastrophes possibly awaiting us, in a system we are just groping to understand. The models of destabilization are largely based on variants of diffusive heat transport, but the state of understanding of slope avalanches and other more exotic release mechanisms is rather poor — and even if it turns out that rapid methane degassing isn’t in the cards, you still do have to worry about those several trillion metric tons of near-surface carbon and how secure they are. It’s like worrying about the state of security of Soviet nuclear warheads, but where you have no idea what kind of terrorists there might be out there and what their capabilities are — and on what time scales they operate.

Edward Brook: One problem with this discussion is that there is no definition of “time bomb” so people get confused. It seems quite likely that continued global warming will increase the emissions of methane from permafrost deposits and marine hydrates. Some of that will get in to the atmosphere, though … some will also be consumed in the water column and in soils. This “chronic” source may increase over time, and affect climate, but for the reasons you discussed it is likely to be slow, and not a catastrophic risk. [So we can't say there's nothing to worry about for a millennium?] Of course it is still important
He goes on to quote a few other scientists to the effect that yes, methyl hydrates may contribute to climate change as a feedback, but no, massive near-instantaneous releases don't seem very likely. Which is comforting, of course, but only up to a point. Besides the fact that they could be wrong (and we know that climate science is not at its best when predicting when stuff is gonna melt) even if they are spot on, how gradual are we talking? Suppose a linear release over a thousands years -- 0.1% per year. That's 1.7 Gt of methane -- roughly half the amount of methane in the atmosphere today. Even if half of it were oxidized in the water column, you would still double the amount of methane in the atmosphere in four years and increase it by a factor of ten in fairly short order. Sweet dreams.

I can't judge Andrew Revkin harshly in this. It's impossible for me to dislike the man (how could I -- he left a comment on my blog!) The worst thing you can say about him is, he's a blogger. He's quick off the draw. Sometimes he'll print first and collect more facts afterwards. He has hobbyhorses and is the more likely to launch into debate to defend positions he's staked out before. But he will keep eleborating, keep talking to people, and correct his original views where they were excessive or misinformed (though you still need to change the date of publication (Oct 19, not Dec 6) in your original post, Andy!) What can I say to that, without being a hypocrite? Let he who has never done a quick edit after reading comments, cast the first stone.


1) 2% of 1700Gt = 34Gt, increasing the existing methane burden in the atmosphere by a factor of tem, with a change in forcing of about +4W/m^2. Given that such a release over a short time period would overwhelm the supply of reactive species to break it down, despite methane's normally short life in the atmosphere, you'd probably be looking at a good 30 years of that before it even began to wane.

2) If I had ever made that excuse to an editor of mine, they would have fried me in extra virgin olive oil and served me with a light white sauce. Especially if I included nothing in the piece to the effect that "I tried to contact these people, but I couldn't reach them."


  1. I wish it were only a trilogy. You've stumbled on the reality that Dot Earth is journalism, revealed. As with science, journalism is a journey. The old 20th century notion of the page-one story or nightly news report definitively distilling the world into sound bites is history. My blog provides an over-the-shoulder view of my inquiry on tough issues. As it happens, Igor Dmitrenko has strongly disputed the S&S interpretation of his paper. There's an update on that post (and probably yet another piece coming).

    Check the following link for Dmitrenko's initial response. There's more from him after the new year.

  2. Ho boy, Dmitrenko. Dr. Revkin (Dr. is honorary, pace Pace U) has found somebody respectable to support his view that we don't need to be as worried as we are. The platform he provides to the fan club of deniers, who come in a variety of flavors, distracting and delaying at best, is not good. He seems to have bought the phony skeptic PR meme that those who find real-time developments exceed the worst predictions are part of the problem.

    We should all be shouting from the rooftops: pay attention, it's time to act. I don't think being quiet and polite is helpful, that's what the fossil fuel and anti-regulatory cohorts, "they're all socialists", "science is a religion", "the hockey stick is evil, hide your eyes", etc. etc. clubs want, for us all to shut up. Unfortunately, they have found a way to persuade "reasonable people" to join the circular firing squad. As noted, it is hard to dislike him, but I think among those who are not being helpful are those who promote the idea that the middle is way to the right of center. That's how the environment has disappeared completely from all sides of the debate over our future.

    The "middle" is really the planet, not any of us and its vote is becoming quite clear. Time to stop exploiting and find a way to share (of course: that makes me a communist, hah!)
    (Susan Anderson)

  3. Silly Susan. You never have figured out the the most obvious impetus to oppose you people is your desire to censor. Gets our dander up, you know. Then we have to read thousands of emails from your "Team" describing efforts to hide data, prevent papers from being published, and avoid FOIA requests. Your credibility is gone and your likability never existed.

  4. The platform he provides to the fan club of deniers, who come in a variety of flavors, distracting and delaying at best, is not good.

    Deniers are never going to lack for platforms. Nor is Dmitrenko a denier or anything like that. Revkin is not quite as worried as you and I are, but that doesn't make him an enemy of the planet. We should look for commonalities rather than differences.

    Look at the recent Pew Poll ( -- the deniers are losing the argument with their own Republican base. We need to win that middle. The more worried you are, the more you should be thinking about how we build a consensus for action.

  5. So is it still 'Apocalypse Not'?

  6. RC has a pretty good post on the methane issue: