Andrew Revkin on methane -- Reassuring, but inaccurate

After the disturbing piece in the Independent, I was looking for somebody to talk me down, and Andrew Revkin seems to have set himself precisely that task in "Methane Time Bomb in Arctic Seas – Apocalypse Not." He is all reassurance:

If you read the Independent of Britain, you’d certainly be thinking the worst. The newspaper has led the charge in fomenting worry over the gas emissions, with portentous, and remarkably similar, stories in 2008 and this week.
If you read geophysical journals and survey scientists tracking past and future methane emissions, you get an entirely different picture:
A paper published in Dec. 6 in the Journal of Geophysical Research appears to confirm pretty convincingly that the gas emissions seen in recent years are from a thawing process that has been under way for 8,000 years — since seas rose sufficiently to cover the near-shore seabed.

I have to say, however, that the more Andy Revkin tries to play the part of the sane middle ground in the climate debate -- not too denialist, not too excited -- the less I am inclined to trust what he says at face value. "I occupy the sane middle ground" is an ideological self-description like any other, and Revkin regularly illustrates the distorting effects that rigidly pursuing that can have. Let's look at the abstract of the paper:

Summer hydrographic data (1920–2009) show a dramatic warming of the bottom water layer over the eastern Siberian shelf coastal zone (<10 m depth), since the mid-1980s, by 2.1°C. We attribute this warming to changes in the Arctic atmosphere. The enhanced summer cyclonicity results in warmer air temperatures and a reduction in ice extent, mainly through thermodynamic melting. This leads to a lengthening of the summer open-water season and to more solar heating of the water column. The permafrost modeling indicates, however, that a significant change in the permafrost depth lags behind the imposed changes in surface temperature, and after 25 years of summer seafloor warming (as observed from 1985 to 2009), the upper boundary of permafrost deepens only by ∼1 m. Thus, the observed increase in temperature does not lead to a destabilization of methane-bearing subsea permafrost or to an increase in methane emission. The CH₄ supersaturation, recently reported from the eastern Siberian shelf, is believed to be the result of the degradation of subsea permafrost that is due to the long-lasting warming initiated by permafrost submergence about 8000 years ago rather than from those triggered by recent Arctic climate changes. A significant degradation of subsea permafrost is expected to be detectable at the beginning of the next millennium. Until that time, the simulated permafrost table shows a deepening down to ∼70 m below the seafloor that is considered to be important for the stability of the subsea permafrost and the permafrost-related gas hydrate stability zone.

Just as important, look at the dates on the paper:

Received 18 April 2011; accepted 28 July 2011; published 19 October 2011.

Sharp readers will note that the dates don't match; the date of publication is Oct 2011, not Dec 2011. We'll get to that in a minute. For the moment let's focus on the paper itself.

Now, I'm not sure this is quite as reassuring vis-a-vis the boiling seas of the East Siberian Arctic Shelf as Revkin seems to think. For although he says "A paper published in Dec. 6 in the Journal of Geophysical Research appears to confirm pretty convincingly that the gas emissions seen in recent years are from a thawing process that has been under way for 8,000 years" this paper was submitted in April, months before scientists were dispatched to the shelf to investigate the expanding methane plumes. So while the study may reassure us about emissions "in recent years" it has nothing to say, specifically, about what the Independent was reporting about -- the very recent trip to examine the area after reports of huge plumes of gas.

Let me be very clear: here at IT, we listen to scientists; we don't dismiss them. Revkin talked to permafrost experts, who feel the recent plumes can be accounted for by their permafrost model. That model also says we don't need to worry about a large amount of methane escaping the East Siberian Arctic Shelf. However, it does not appear that that model was developed with, tested by, or compared to the data from the expedition dispatched in September (remember, the paper was submitted in April!) So unless there is more to the story, the scientists Revkin spoke with may think they can explain the observations, but they haven't explained the observations as yet. Indeed, the observations haven't even been reported yet.

I initially assumed -- I'm sure this wasn't deliberate on Revkin's part -- that when he referred to a paper published Dec 6, which reassures us about the findings of the expedition dispatched in September, that the paper was about the expedition dispatched in September. It is not. It's about a model of permafrost melting. And to be absolutely clear, we do not scorn modelling studies at IT. They are very important. The paper says that the model can adequately explain the small methane plumes observed in prior years as part of a long-term process, not a short-term, rapidly worsening degradation of permafrost. But there is no indication that the model has been tested against the new observations. The timeline doesn't seem to work.

I also thought -- and this time based on what Revkin explicitly stated -- that he had linked to the study published on Dec 6. Here's the quote:

But read this summary of the paper from the American Geophysical Union, which publishes the journal, and see if you feel reassured that the “methane time bomb” there is safe for a long time to come:

[T]he authors found that roughly 1 meter of the subsurface permafrost thawed in the past 25 years, adding to the 25 meters of already thawed soil. Forecasting the expected future permafrost thaw, the authors found that even under the most extreme climatic scenario tested this thawed soil growth will not exceed 10 meters by 2100 or 50 meters by the turn of the next millennium. The authors note that the bulk of the methane stores in the east Siberian shelf are trapped roughly 200 meters below the seafloor… [Read the rest.]

Here’s the link to the paper itself: “Recent changes in shelf hydrography in the Siberian Arctic: Potential for subsea permafrost instability.”

But if you click on the link to the AGU summary, you quickly slowly realize that these are two different papers, one called "Siberian shelf methane emissions not tied to modern warming" by Colin Schultz, and “Recent changes in shelf hydrography in the Siberian Arctic: Potential for subsea permafrost instability,” by Dmitrenko et al. the AGU summary was published Dec 6; the actual paper was published October 19.

So Revkin has conflated two different papers by different authors into one confused the summary's date of publication with the paper itself; he started off talking about the Independent's account of Dr. Semiletov's recent trip to the Arctic and his recent AGU presentation, but he didn't talk to Semiletov or reference that presentation.

So the Independent did publish a sensational story, a story that does look remarkably similar to one they published in 2008 (a good catch by Revkin.) But if you are comparing the two stories, the Independent's has this claim: they actually wrote about the findings of the expedition. They referred to Semiletov's talk at the AGU, which presumably relates to his paper in press "Trace gas emissions from sub-sea permafrost" (no abstract I could find) and not to either of the papers published by different authors about permafrost models developed prior to the recent observations.

So while it is as a general rule wise not to panic, and, especially on the subject of science, to wait for the dust to settle before reaching any conclusions, all the facts cited by Revkin in support of his languor are reported inaccurately and/or oversold.

Andy Revkin now wears the hat of a blogger, but he sometimes seems to have brought with him into his new career the very attributes that brought about the decline of traditional journalism: he is sloppy, he cares more about appearing moderate and fair than reporting the facts accurately, and while tsk-tsking at the sensationalism of the Independent, he neglects to do the basic stuff like talking to the principal people involved and actually getting the facts about the subject of his article.

Update: Revkin's response is below. I reply here.