UPDATE: a reader sends a link to a more recent (june 2014) Shakhova interview. The sound quality not as good, which makes it difficult to follow, nevertheless,I am posting this in the interest of furthering the discussion. This is a “part 1” of 3, the others being available at the you tube link.
In the past week, I’ve been posting a number of excerpted interviews relating to the topic of undersea methane releases in the arctic.
This has not actually been something I planned out just this way. The idea was, I wanted to interview as many folks behind the scenes and find out as much as I could, then synthesize everything into a nice tidy video, and release that. But events have kind of overtaken that.
In September, the Royal Society held an event in the UK which drew a number of experts on arctic ice and the rapid changes observed there. Among those was Dr. Gavin Schmidt, of NASA, one of the most highly respected experts on the planet in areas of global climate. Dr. Schmidt gave a well attended lecture on the issue of arctic methane, specifically to push back against what has become somewhat of a Youtube cottage industry, methane disaster porn. It’s not hard to find material proclaiming the imminent extinction of humanity due to the massive release of methane from arctic ocean shelves – and I agree with Dr. Schmidt that this kind of material is irresponsible and divorced from reality.
The scientific source often cited (and then, I think, exaggerated) for such dire pronouncements is the work of Dr. Natalia Shakhova, the University of Alaska in Fairbanks, and her associate Dr. Igor Semilitov. Short story, Shakhova et al were not at the UK shindig, leading to charges of conspiracy to exclude them from the discussion. Since I started this series, I’ve even been getting emails darkly hinting that perhaps I was a tool of that conspiracy, as well. I don’t think a preference to step carefully is indicative of a conspiracy, but never mind.
Among Dr. Schmidt’s strongest arguments are datasets that he says indicate little or no methane breakout in the relatively near paleo-record, from 2 previous eras.
First, the Holocene warm period, – at about the time the planet was coming out of the last ice age, the arctic was warm, possibly warmer than today, for a period substantially longer than the current warmup. The other period, known as the Eemian, was an interglacial, a temperate spell, like ours, just before the plunge in to the most recent ice age, about 120,000 or so years ago. We know it was pretty warm for quite a while – thousands of years – because sea level was high – maybe 15, or 20 feet higher, and a substantial portion of the Greenland ice sheet seems to have melted.
Yet, Schmidt says, we saw no methane breakout.
This paleo argument is compelling to me, as I have always considered the fossil record a powerful indicator of how the current climate will behave.
Could we have more of a buffer for big methane belches than we know? Here are two slides from Schmidt’s lecture – which is not available to my knowledge online, although may be soon, at least in audio.
There’s a lot more material on this, much of which I have not digested myself, but I wanted to get as much of this under-seen and under-discussed material online where people can read it, and spark a tiny bit more informed discussion on the issue, something I am sure Dr. Schmidt, Dr. Shakhova, and all concerned, would like to see happen. There are a lot more perspectives on this than what most people have heard, so now is as good a time as any to hear them.
Clearly this is an important discussion, and more information is needed. Happy to hear from anyone who has additional useful resources on this issue, and ideas about how to broaden the discussion.
RealClimate blog posted a review of the issue, I’m assuming by David Archer, about a year ago:
Methane from the Siberian continental shelf
The Siberian continental shelf is huge, comprising about 20% of the global area of continental shelf. Sea level dropped during the last glacial maximum, but there was no ice sheet in Siberia, so the surface was exposed to the really cold atmosphere, and the ground froze to a depth of ~1.5 km. When sea level rose, the permafrost layer came under attack by the relatively warm ocean water. The submerged permafrost has been melting for millennia, but warming of the waters on the continental shelf could accelerate the melting. In equilibrium there should be no permafrost underneath the ocean, because the ocean is unfrozen, and the sediment gets warmer with depth below that (the geothermal temperature gradient).
Ingredients of Shakhova et al (2013)
- There are lots of bubbles containing mostly methane coming up from the shallow sea floor in the East Siberian Arctic shelf. Bubbles like this have been seen elsewhere, off Spitzbergen for example (Shakhova et al (2013)). Most of the seep sites in the Siberian margin are relatively low flow but a few of them are much larger.
- The bubbles mostly dissolve in the water column, but when the methane flux gets really high the bubbles rise faster and reach the atmosphere better. When methane dissolves in the water column, some of it escapes to the atmosphere by evaporation before it gets oxidized to CO2. Storms seem to pull methane out of the water column, enhancing what oceanographers call “gas exchange” by making waves with whitecaps. Melting sea ice will also increase methane escape to the atmosphere by gas exchange. However, the concentration of methane in the water column is low enough that even with storms the gas exchange flux seems like it must be negligible compared with the bubble flux. In their calculation of the methane flux to the atmosphere, Shakhova et al focused on bubbles.
- Sediments that got flooded by rising sea level thousands of years ago are warmer than sediments still exposed to the colder atmosphere, down to a depth of ~50 meters. This information is not directly applied to the question of incremental melting by warming waters in the short-term future.
- The study derives an estimate of a total methane emission rate from the East Siberian Arctic shelf area based on the statistics of a very large number of observed bubble seeps.
Is the methane flux from the Arctic accelerating?
Shakhova et al (2013) argue that bottom water temperatures are increasing more than had been recognized, in particular in near-coastal (shallow) waters. Sea ice cover has certainly been decreasing. These factors will no doubt lead to an increase in methane flux to the atmosphere, but the question is how strong this increase will be and how fast. I’m not aware of any direct observation of methane emission increase itself. The intensity of this response is pretty much the issue of the dispute about the Arctic methane bomb (below).
What about the extremely high methane concentrations measured in Arctic airmasses?
Shakhova et al (2013) show shipboard measurements of methane concentrations in the air above the ESAS that are almost twice as high as the global average (which is already twice as high as preindustrial). Aircraft measurements published last year also showed plumes of high methane concentration over the Arctic ocean (Kort et al 2012), especially in the surface boundary layer. It’s not easy to interpret boundary-layer methane concentrations quantitatively, however, because the concentration in that layer depends on the thickness of the boundary layer and how isolated it is from the air above it. Certainly high methane concentrations indicate emission fluxes, but it’s not straightforward to know how significant that flux is in the global budget.
–
What about methane hydrates?
There are three possible sources of the methane in the bubbles rising out of the Siberian margin continental shelf:
- Decomposition (fermentation) of thawing organic carbon deposited with loess (windblown glacial flour) when the sediment was exposed to the atmosphere by low sea level during the last glacial time. Organic carbon deposits (called Yedoma) are the best-documented carbon reservoir in play in the Arctic.
- Methane gas that has been trapped by ice, now escaping. Shakhova et al (2013) figure that flaws in the permafrost called taliks, resulting from geologic faults or long-running rivers, might allow gas to escape through what would otherwise be impermeable ice. If there were a gas pocket of 50 Gt, it could conceivably escape quickly as a seal breached, but given that global gas reserves come to ~250 Gt, a 50 Gt gas bubble near the surface would be very large and obvious. There could be 50 Gt of small, disseminated bubbles distributed throughout the sediment column of the ESAS, but in that case I’m not sure where the short time scale for getting the gas to move comes from. I would think the gas would dribble out over the millennia as the permafrost melts.
- Decomposition (melting) of methane hydrates, a peculiar form of water ice cages that form in the presence of, and trap, methane.
Methane hydrate seems menacing as a source of gas that can spring aggressively from the solid phase like pop rocks (carbonated candies). But hydrate doesn’t just explode as soon as it crosses a temperature boundary. It takes heat to convert hydrate into fluid + gas, what is called latent heat, just like regular water ice. There could be a lot of hydrate in Arctic sediments (it’s not real well known how much there is), but there is also lot of carbon as organic matter frozen in the permafrost. Their time scales for mobilization are not really all that different, so I personally don’t see hydrates as scarier than frozen organic matter. I think it just seems scarier.
The other thing about hydrate is that at any given temperature, a minimum pressure is required for hydrate to be stable. If there is pure gas phase present, the dissolved methane concentration in the pore water, from Henry’s law, scales with pressure. At 0 degrees C, you need a pressure equivalent to ~250 meters of water depth to get enough dissolved methane for hydrate to form.
The scariest parts of the Siberian margin are the shallow parts, because this is where methane bubbles from the sea floor might reach the surface, and this is where the warming trend is observed most strongly. But methane hydrate can only form hundreds of meters below the sea floor in that setting, so thermodynamically, hydrate is not expected to be found at or near the sea floor. (Methane hydrate can be found close to the sediment surface in deeper water depth settings, as for example in the Gulf of Mexico or the Nankai trough). The implication is that it will take centuries or longer before heat diffusion through that sediment column can reach and destabilize methane hydrates.
Yes this chimes with other publications I’ve seen relatively recently. There’s been too much scare-mongering on undersea methane, which is damaging to the quest for clear information about the effects of climate change.
So thanks for clarifying this issue. It seems some want to go from flat denial to resignation without actually doing anything to reduce emissions anywhere.
Shakhova has stated that the subsea permafrost has been able to warm up a lot faster over the millenia due to its exposure to constant higher temperatures. She and Semiletov think it is approaching equilibrium. They found subsea permafrost in their sediment cores to be at the thaw temperature. Certainly, now that that part of the Arctic Ocean is no longer covered with ice for several months a year, the waters are warming significantly and even at depth.
The response to sea water temperature in prior epochs occurred slowly over thousands of years.
We don’t even know what the ocean circulation was like or where or when or even if the subsea permafrost on the ESAS was exposed to hotter temperatures than it is now.
People conveniently leave out this part of the story.
And Shakhova has also stated that it doesn’t matter if the methane is biogenic or thermogenic — the result is the same for global warming. Further, she has stated that the methane hydrates occur spread out in the subsea permafrost, increasing in concentration until the bottom of the layer of subsea permafrost. It is not like the subsea permafrost is homogeneous.
This region of subsea permafrost and methane hydrates is a lot more complicated than either Gavin Schmidt or Jim Archer make out.
And even Archer writes with plenty of caveats.
It is like people read only what they want to read.
You have to look at both the reassurances and the caveats.
Also, for the purposes of a discussion of the so-called methane bomb, it would be better to include the much more recent interview of Shakhova. It contains a lot more information.
please point me to one. I hope to interview her myself when I have the opportunity.
http://youtu.be/dQDVr1eMLK8
http://youtu.be/dQDVr1eMLK8
June of this year
https://www.youtube.com/watch?v=PVi1lotRLRU
I really don’t think people are exaggerating Shakova’s concerns. It would be pretty hard to to that!
I think when you see videos titled “Human extinction by 2030”, you are dealing with a significant exaggeration.
Does the video say SHE predicts that?
Extinction extremely unlikely, but decimation, perhaps, though for all kinds of other reasons too.
I’m not losing sleep over methane releases either (yet), though it is interesting and should be monitored.
The only plausible thing I can see that is different to previous interglacials is that the rate of change of temperature is so much greater now.
It could act as some kind of thermal shock to release methane at a greater rate than could be metabolised in the past, and it would have to happen over the span of a few years in order to accumulate to problem levels.
However, with higher sea levels the increase in pressure on the sea bed also raises the “bar” for clathrates to be able to decompose.
I keep an open mind, but getting hysterical when there is little evidence is not helpful.
Who is hysterical? Shakova? Or people who take her research to mean the clathrate gun has been fired? Because regardless of how her group’s work is interpreted by others, the issue is whether it was relevant to the conference, and whether they should have been invited to present it. She made a very clear statement in her letter to the organizers.
Schmidt’s talk/slides are available: https://twitter.com/ClimateOfGavin/status/519492681312264193
Glad to see you posting on this. I’ve gotten inundated with it since writing a critique of human extinction grand poobah Guy McPherson.
Your “critique” of McPherson is not very impressive, in that it has many of the same types of “holes” that you accuse him of. At a quick glance, one that stood out was your dismissal of his discussion of declining O2 levels because he cited a “survivalist blog”. Are you not familiar with the past history of O2 levels on the planet and the fact that they are in decline, especially over polluted cities? That there is serious concern on NON “survivalist blogs” about the dying out of phytoplanckton and what that means for O2 levels?
Another thing that struck me was YOUR comment in the comments section in answer to someone seeking a source.
“Finally, the release of permafrost carbon will continue for
many years even if atmospheric warming stops. Permafrost has
huge thermal inertia, resulting in a lag between when warming
starts and thaw begins. The start of permafrost thaw typically
occurred 25 or more years after warming started and 20% of
the total thawing occurred after warming stopped in 2100. The
models driven by the A1B scenario, none of which included the
PCF, all stabilize at a new, warmer climate after 2100 when CO2
concentrations level out at 700 ppm. However, our simulations
indicate that the global carbon cycle will not stabilize until at
least 2200. Nearly all thawing of permafrost carbon occurred
before 2100, but 46% of permafrost carbon flux occurred after
2100. Once thawed, the permafrost carbon can take 70 years
or more to decay due to cold soil temperatures and periodic
refreezing. This slow response means that once the PCF starts,
it will continue for a long time.”
Do you fail to see the implications of that? You, McPherson, and I will probably all be long gone since this is not likely to happen by 2030, but 100 or 200 years down the road is just an eye-blink, and talk of “stabilize at a new, warmer climate after 2100 when CO2 concentrations level out at 700 ppm” is mind-boggling. A NEW climate that STABILIZES at 700PPM??
“I’ve even been getting emails darkly hinting that perhaps I was a tool of that conspiracy…..” “I don’t think a preference to step carefully is indicative of a conspiracy….”.
But some of what you said here might make one wonder a bit. “….push back against what has become somewhat of a Youtube cottage industry, methane disaster porn”?. And “….this kind of material is irresponsible and divorced from reality….”? All that actually sounds like the kind of stuff you find being used on on WUWT to describe “warmists”
Dr. Schmidt gave a lecture on the issue of arctic methane, specifically to “push back against methane disaster porn”, and you agree with Dr. Schmidt? And you think the significance of of Dr. Shaknova’s work is “exaggerated”? And is there any credibility to the charge that they were excluded? Why were they not invited?
You also talk about “paleo arguments being compelling” because “the fossil record is a powerful indicator of how the current climate will behave”. I wish it was that clear to me, and Dr. Schmidt’s modeling is not yet convincing.
And is Gary Evans a part of the conspiracy?
“Yes this chimes with other publications I’ve seen relatively recently”. What “chimes”—-the “methane disaster porn”? Or the uncertainty? It must be the former, because “….too much scare-mongering on undersea methane, which is damaging to the quest for clear information….” sounds like psy-war BS talk to me.
“Clearly this is an important discussion, and more information is needed. Happy to hear from anyone who has ideas about how to broaden the discussion”. My two cents—let’s stop sounding like WUWT with the “methane disaster porn” and return to the high quality posts that make Crock so special. Let’s get Dr. S to talk about her latest findings as TenneyN suggests.
“The implication is that it will take centuries or longer before heat diffusion through that sediment column can reach and destabilize methane hydrates”. I love “implications”——Yep, just like we didn’t think the Arctic would be ice-free in summer for many decades, and never even thought about Dark Snow 30 years ago, and never thought the West Antarctic Ice Sheet would go into uncontrollable collapse, and…..
I’ve been reading up on the methane bomb, and I haven’t seen any “porn” yet. Just a whole lot of unsertainty and justifiable worry in the face of that uncertainty. (Maybe I don’t go to the right sites? Can someone direct me to some “methane porn”?)
Excellent post, dumbboldguy — you pointed out all of the things that I wanted to say, that disturbed me about Peter’s post.
Re: ” Can someone direct me to some “methane porn”?”
The Arctic Methane Emergency Group is quite strident and emotive in its appeal that humanity pay more attention to the possibility of a clathrate gun event:
http://ameg.me/
***
And in today’s daily science trawl I spotted an item about albedo at NASAS’s Earth Observatory.
http://earthobservatory.nasa.gov/IOTD/view.php?id=84499&eocn=home&eoci=iotd_readmore
What is surprising to me about this report is that the NASA scientists are finding no particular trend globally as regards albedo. Of course the loss of albedo in the Arctic and the dark snow in Greenland are noted, but planet-wide, there seems to be fluctuation of albedo but no discernible trend.
So much for albedo porn. 🙂
Dang, “albedo porn” sounded interesting.
“No discernable planet-wide trend” means little in the context of what is going on in the arctic, the region of the earth that has warmed the most, where the ice is melting, where the albedo is decreasing, where the wildfires are happening and contributing to the Dark Snow, and where all that melting permafrost and sub-arctic ocean clathrates have got people worried.
PS I would leave off the “quite” when talking about how “strident and emotive” AMEG is. And they are advocating some geo-engineering also. They may be a bit out on the fringe with some of their stuff, but I don;’t see any “porn” on their site.
I think Guy massively underestimates the huge gap between when our extinction becomes inevitable and when it will actually happen. On the other hand Gavin seems most determined to downplay the possibility of a rate of change that human civilization simply will not cope with.
Already we have methane and CO2 at levels not experienced in the prior history of man. It is already inevitable that we will get a climate not previously experienced by man. Worse we will get there at a pace not experienced on this planet before.
Previous extinction events have been after massive emissions over tens of thousands of years. We have over the last hundred years, increased CO2 well over an order of magnitude faster. But this has been only been for an geologically very short period. So although massive and fast our gross emissions do not, yet, compare with prior extinction events.
(We criticize those who want and believe in endless growth and an ever better future. Yet this belief is a fundamental necessity for our capitalist, consumerist civilization. When this belief is shattered our modern economy will go down and go down quickly and our industrialized civilization will follow. The deniers understand this in a way we do not, but in this the deniers are right.)
The planet ‘may’ be warming. Three consequences were posited:
1) The ice sheets could start melting. They checked. Yes, they’re melting. How FAST is another question.
2) The permafrost could start venting. They checked. Yes, they’re venting. How FAST is another question.
3) The Siberian Sea methane could start venting. Shakhova checked. Yes, its venting. How FAST is another question.
But if Shakhova did nothing else but confirm our suspicions, its enough. That’s three for three. Is a Tsunami coming? Is runaway AGW coming? Is a methane bomb coming? I understand that for Science, these kinetic determinations are important, now that we’ve done nothing about this issue for 120 years. But, thermodynamically, these phenomena are now confirmed: the 120-year old predicted change is, in fact, happening, everywhere we think to look. We should not disown what Shakhova and others have achieved, just because they can’t calculate the exact advance of Armageddon.
Maybe a Methane bomb will not occur in our lifetimes.
Just consider that sentence, and wonder at what a randomized travesty we’ve hatched for our children. We are actually arguing over whether extinction will come now or later. Later, we conclude, and this is what our new definition of ‘triumph’ is.
I agree with the DOG’s admirable comments – lets leave “disaster porn” to Watts and Omnologos (their language is beginning to rub off – shudder) – just makes the case for replacing those coal burning power stations even more urgent:-
Methane ice is not only an Arctic phenomena, there was a large discovery off New Zealand’s coast earlier this year:
“A joint New Zealand-German research team has discovered a huge network of frozen methane and methane gas in sediments and in the ocean near New Zealand’s east coast.”
Also several studies indicate there are vast pockets buried under the Antarctic ice awaiting liberation, large atmospheric concentrations already detected, I wonder how many years will pass before this too becomes a pressing issue.
An interesting Guardian piece on the Arctic methane from Dr. Nafeez Ahmed (executive director of the Institute for Policy Research)
Seven facts you need to know about the Arctic methane timebomb
“6. Arctic conditions during the Eemian interglacial lasting from 130,000 to 115,000 years ago are a terrible analogy for today’s Arctic”
http://www.theguardian.com/environment/earth-insight/2013/aug/05/7-facts-need-to-know-arctic-methane-time-bomb
https://www.niwa.co.nz/news/joint-new-zealand-german-3d-survey-reveals-massive-seabed-gas-hydrate-and-methane-system
Of course, many see something like that and just see the dollar signs. It’s not economical to extract them now for fuel, but the technology is progressing. The Japanese think it’s a potential game changer for their economy:
http://www.energybiz.com/article/13/03/japan-rocks-energy-world-successfully-mining-unconventional-natural-gas
Also:
http://www.postandcourier.com/article/20140105/PC16/140109725
It’s not enough that we’re increasing global temperatures and setting up possible methane releases on their own, we’ve also got to stir them up a bit to keep our economy strong. That’s some good thinkin’!
From the second article:
“”The bottom line is methane hydrates aren’t ready for prime time,” he said, but the technology and need might be only 10, 12, 15 years away.”
And:
“”If we’re going after it, we’d better be careful,” said Richard Charter, senior fellow at the Ocean Foundation, a nonprofit ocean conservation advocate. ”
I’d have hoped an ocean conservation advocate would say that being careful is not going after it at all.
Good article from Dr. Ahmed. I’ve wondered about point 7.