Arctic Methane Release

[Sciguy]

Here's a link to a 2016 study that provides a good overview of methane in permafrost, both on land and below the sea:

https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2016RG000534

The interaction of climate change and methane hydrates

Carolyn D. Ruppel, John D. Kessler

Note that the paper is critical of the IPCC estimates of Arctic methane emissions:

The annual flux of CH4 to the atmosphere from all sources is estimated at ~555 Tg yr−1. As updated by Kirschke et al. [2013] and summarized in the report of the fifth IPCC [2013], the total top‐down global methane emissions estimate is ~130 Tg yr−1 smaller than the bottom‐up estimate. At present, the top‐down estimation methods do not have the capacity to attribute CH4 to individual geologic sources like gas hydrates. Kirschke et al. [2013] note that both the flux of methane to the atmosphere and the global sink for methane are likely overestimated in the bottom‐up assessment. The commonly adopted assumption for bottom‐up assessment is that ~5 Tg yr−1 CH4 is emitted to the atmosphere from gas hydrate dissociation (e.g., IPCC [2001] and subsequent IPCC panels). The only CH4 source that routinely appears in bottom‐up studies and that has a smaller contribution than gas hydrate dissociation is wildfires [e.g., Kirschke et al., 2013].

The values quoted by the various IPCC reports have never been based on observational evidence for CH4 emissions derived from gas hydrate dissociation since no such measurements exist. A few examples underscore this point: The clearly identified assumption of Cicerone and Oremland [1988] that 5 Tg yr−1 CH4 reached the atmosphere from gas hydrate dissociation has set the stage for the subsequent quarter century. The third IPCC [2001] cites the Fung et al. [1991] forward modeling study, which merely assigned a value for the contribution to atmospheric CH4 emissions from gas hydrate dissociation. This was also the case with Lelieveld et al. [1998], which assumed 10 Tg yr−1 CH4 emissions from gas hydrate for one scenario, a number that was then adopted by the third IPCC [2001]. The Wuebbles and Hayhoe [2002] study cited by the fourth IPCC [2007] is sometimes considered the observationally based source for the now oft‐used 5 Tg yr−1 CH4 estimate for atmospheric CH4 flux from gas hydrates. That study in turn cites Judd [2000], which is a geologic methane seepage study that does not provide an independent estimate for emissions derived from gas hydrate dissociation. Cranston [1994], on which Judd [2000] relies for his hydrate‐related flux discussion, estimates the sum of global diffusive and ebullitive fluxes from marine sediments to the atmosphere to be ~1.3 Tg yr−1 to 13 Tg yr−1 CH4 considering all sources, including shallow‐water seeps and deepwater gas hydrates. The Denman et al. [2007] study cited in the fifth IPCC [2013] is the climate coupling chapter from the fourth IPCC [2007] and not an independent source of information. The fifth IPCC [2013] also refers to Dickens [2003b], which is a book review of Kennett et al. [2003] that did not provide an estimate for CH4 flux to the atmosphere from dissociating gas hydrates, as Dickens [2003a] also did not. Shakhova et al. [2010a], also given as a source for the hydrate‐derived atmospheric CH4 flux in the fifth IPCC [2013], did not attribute the 7.98 Tg yr−1 CH4 flux that they calculated for the East Siberian Arctic shelf to gas hydrate degradation, rather considering a range of potential sources.

It's also critical of the S&S estimate of methane emissions from the ESAS:

Like other PAGH, those that ended up within submerged shelves are unlikely to be widely distributed or sequester large amounts of CH4 [Ruppel, 2015]. Some researchers do infer large amounts of PAGH beneath arctic continental shelves (e.g., 35 Gt C in hydrate beneath the Laptev Sea shelf) [Shakhova et al., 2010a], but several assumptions used in making this estimate may not fully account for the complexity of PAGH systems. Shakhova et al. [2010a] also invoked anomalous shallow gas hydrates beneath the East Siberian Arctic shelf as a potential CH4 source and to explain elevated estimates of CH4 sequestered in gas hydrates. This area was not glaciated at the LGM, as is usually required for shallow gas hydrates to occur, and the origin and existence of possible anomalous gas hydrate deposits remain controversial and require further examination.

Circum‐Arctic Ocean continental shelves have long been presumed as a source of atmospheric CH4 emissions [e.g., Kvenvolden et al., 1993], and attention in recent years has focused on the Siberian shelves, where [Shakhova et al., 2014] estimate annual atmospheric CH4 emissions of up to 17 Tg CH4 when ebullitive and diffusive fluxes are combined. Thornton et al. [2016] described a continuous shipboard survey of CH4 concentrations in the atmosphere and near‐surface waters in much of this same area. They conclude that ebullition does not substantially contribute to the sea‐air CH4 flux, which they calculate to be less than 2.9 Tg yr−1 CH4. They also note that some of the previously reported atmospheric CH4 concentrations on the East Siberian Arctic shelf may be unrealistic. Like Kvenvolden et al. [1993] and Kort et al. [2012], Thornton et al. [2016] underscored the critical role of sea ice in trapping CH4 until leads or ice‐out conditions render possible the diffusive release across the sea‐air interface. Continuous sea‐air CH4 flux surveys like that of Thornton et al. [2016] have also been conducted on the U.S. and Canadian Beaufort shelf [Pohlman et al., 2012]. Measurements there reveal high nearshore CH4 concentrations inferred to be produced in organic‐rich sediments, but regional annual flux is several orders of magnitude lower than the Thornton et al. [2016] estimate for the Siberian shelves and comparable to that recorded for the North Sea [Bange et al., 1994].

This paper also includes a good overview of estimates of potential methane sources in the Arctic, an overview of carbon sinks on land and in the ocean, and a summary of methane releases assumed from paleo-climate studies, like the PETM event and the Quaternary Warming Event (also know as the Clathrate Gun).

The paper concludes:

On the contemporary Earth, gas hydrate is dissociating in specific terrains in response to post‐LGM climate change and probably also due to warming since the onset of the Industrial Age. Nevertheless, there is no conclusive proof that the released methane is entering the atmosphere at a level that is detectable against the background of ~555 Tg yr−1 CH4 emissions. The IPCC estimates are not based on direct measurements of methane fluxes from dissociating gas hydrates, and many numerical models adopt simplifications that do not fully account for sinks, the actual distribution of gas hydrates, or other factors, resulting in probable overestimation of emissions to the ocean‐atmosphere system. The new generation of models based on ocean circulation dynamics holds the greatest promise for robustly predicting the fate of gas hydrates under climate change scenarios [Kretschmer et al., 2015] and could be improved further with better incorporation of sinks.

At high latitudes, the key factors contributing to overestimation of the contribution of gas hydrate dissociation to atmospheric CH4 concentrations are the assumption that permafrost‐associated gas hydrates are more abundant and widely distributed than is probably the case [Ruppel, 2015] and the extrapolation to the entire Arctic Ocean of CH4 emissions measured in one area. Appealing to gas hydrates as the source for CH4 emissions on high‐latitude continental shelves lends a certain exoticism to the results but also feeds catastrophic scenarios. Since there is no proof that gas hydrate dissociation plays a role in shelfal CH4 emissions and several widespread and shallower sources of CH4 could drive most releases, greater caution is necessary.

[Viggy]

7,000 Pingo Like Features on land erupting in the same year would be 2.9 million tons of methane, or about one-half of one percent of global emissions.

Maybe this is a silly question but wouldn't that be a very significant amount? Given Methane's 10-12 yr atmospheric life, if emissions stayed constant, it would stand to reason that methane in the atmosphere would stay constant. A 0.5% increase alone, would contribute 9.3 ppb/yr to atmospheric methane concentrations.

For context, CH4 rose by 7.13 ppb last year in aggregate

[bbr2314]

If methane traps have released repeatedly before, WHAT was the mechanism that stopped release?

Could it be that as sea ice dwindles and snowcover increases, meltwater flux also rises constantly, but the see-saw of ice loss -> snowcover gain ultimately yields a year when warming can dominate even more thoroughly than 2011-12?

This scenario would look like 2011-12 but with more extant snowcover to start and end the summer. This would be accompanied by less icecover than that year, with the ESS going ice free for the entire year (in whole or partially).

We have already seen what has unfolded with a .1% volume loss from Greenland since 2002. A summer with severe sea ice loss / very low #s, and methane release, is likely (IMO) the only way to get a major Greenland melt event well in excess of what we saw before and during 2012.

Such a melt event (aggravated by release of methane) would be capable of releasing enough cold freshwater to resuscitate the halocline and seal the traps. Which explains why releases have never been to severe. And also why glaciation has historically re-commenced so rapidly after peak warming.

Both methane release and snow / meltwater feedbacks are self-reinforcing at this point and possibly the two dominant drivers behind inter-annual variation re: heat and cold, respectively, in the NHEM. Why wouldn't a massive methane release plausibly cause a correspondingly horrific Greenland melt event that effectively re-seals the Arctic Ocean, and what other mechanism explains why they have always been re-sealed previously / why would this time be any different?

[Viggy]

Why wouldn't a massive methane release plausibly cause a correspondingly horrific Greenland melt event that effectively re-seals the Arctic Ocean, and what other mechanism explains why they have always been re-sealed previously / why would this time be any different?

The Arctic methane release will cause the next Ice Age and Santa is going to move to Hudson Bay. Do you have any other hits you can play?

[kassy]

If methane traps have released repeatedly before, WHAT was the mechanism that stopped release?

Or how much did they release if they did?


One limit is the amount of energy they receive.

This has two components:
Length of the time of the interglacials. The length of time the permafrost was exposed and then the time needed to melt deep enough to gather those pockets.
 
Amount of energy. All previous interglacials were due to the Milankovich cycles. This changes the amount of sunlight warming the north but the warming pattern is not like now.

Whatever CO2 we emit and remains in the atmosphere is warming the whole planet 24 hours a day everywhere and all that heat is going somewhere. What we are doing is unprecedented so i am not sure which historical comparisons would work.

For another perspective see the link in post 550 of this thread.
 

[johnm33]

There are cold adapted bacteria [psychrophiles] that produce methane, so even if a 'field' exhausted itself it could recharge. Then again until we know for sure we should assume that the sediment [below the permafrost] could have warmed from below and entered a different methane producing regime. https://www.livescience.com/34657-coldest-temperature-bacteria-found-in-permafrost.html

[Serrara Fluttershy]

https://paulbeckwith.net/2018/12/13/methane-levels-from-copernicus-rise-literally-off-the-charts/

Paul Beckwith just posted this...is anyone here that could verify if these findings can be taken at face value?

[Cid_Yama]

Apparently, instead of adding another color to the color ledger, which is usually what happens when levels exceed the top of the scale for whatever, they chose instead to adjust the color scale upward by 100 ppb for methane.

Seems deceptive.  Since if you compare color maps from prior to 12/11/18 and after, they may look the same, but represent higher levels of methane.

     

   

[Serrara Fluttershy]

Apparently, instead of adding another color to the color ledger, which is usually what happens when levels exceed the top of the scale for whatever, they chose instead to adjust the color scale upward by 100 ppb for methane.

Seems deceptive.  Since if you compare color maps from prior to 12/11/18 and after, they may look the same, but represent higher levels of methane.

     

 

Deception on who's part?

[wdmn]

Changing the scale without mentioning it [would be] deceptive.

Beckwith's title is also deceptive.

[kassy]

Moving the bottom colour would be ugly so i guess this is the best solution to fix the current maps.

Plus they probably mentioned it somewhere.

People use different baselines for pre-industrial warming and i am sure that the colour codes for old years sea ice have also changed on some products etc.

I would not call it deceptive but it´s more one of those annoying things.



 

[Sciguy]

Here's a chart of in-situ methane monitoring at the NOAA lab in Barrow, AK:



And here is Mauna Loa, HI:



The charts don't show an abrupt increase in methane levels recently.

Here's a link to the globally averaged annual growth rates:

https://www.esrl.noaa.gov/gmd/ccgg/trends_ch4/

The most recent monthly update is from September as they take a few months to do quality control on their flask measurements.  September 2018 methane concentration was 1860.2 ppb, an increase from September 2017 level of 7.5 ppb.  That's about the same level of annual increase in previous years (2016 saw an increase of 7.08 ppb and 2017 7.13 ppb).

For comparison, in the 1980's, methane levels increased by more than 10 ppb each year from 1984 to 1989.  The increase was less in 1990, at 8.74 ppb, and then it soared to 13.99 ppb in 1991.

So the increases in the past three years are actually lower than the increases we saw in the 1980s and early 1990s.

[wdmn]

The more I watch Paul Beckwith, the more I think he is (unconsciously or consciously) doing more harm than good.

[Nemesis]

@wdmn

Beckwith is no climate scientist. He is in fear for his children and grandchildren. He is spreading the word. What's better, being hit by some video or being hit by some Paradise wildfire?

[Nemesis]

There have been lots of prophets in history shouting "The world goes to hell!" But don't be afraid, most people don't care much, they are busy with other things, that's it, the caravan always moves on and on until it doesn't, no matter how many prophets.

[wdmn]

Beckwith is pretty much a scientist though, and often references the U of Ottawa climate lab in his videos.

"He is in a Ph.D. program, with a focus on Abrupt Climate System Change (atmosphere, oceans, Arctic, methane…)."

Some of his material is helpful, but the problem with whipping people into a frenzy is that it's unsustainable. Too much leads to either defeatism, or even a strange kind of climate change denial.

[Nemesis]

Beckwith didn't reference to the U of Ottawa anymore for quite a while now. He got no climatology Ph.D., he was into optics if I remember right. He can't be a defeatist as he votes for climate engineering and books about hardwiring happiness into the brain (see his recent videos)

[Wherestheice]

Beckwith is pretty much a scientist though, and often references the U of Ottawa climate lab in his videos.

"He is in a Ph.D. program, with a focus on Abrupt Climate System Change (atmosphere, oceans, Arctic, methane…)."

Some of his material is helpful, but the problem with whipping people into a frenzy is that it's unsustainable. Too much leads to either defeatism, or even a strange kind of climate change denial.

If everyone treats the the problem as something for the grandchildren to worry about, then we’re all dead.

[Nemesis]

Well, it's not just about some grandchildren, but it's (not only) about the children of this world, who will have to pay for the crimes of the fossil fuel industry. You heard about James Hansen fighting for his grandchildren, right? You also heard about Greta Thunberg, right?

[wdmn]

Satellite spies methane bubbling up from Arctic permafrost
Radar instrument aboard a Japanese probe can spot signs of gas seeping from lakes that form as the ground thaws.
https://www.nature.com/articles/d41586-018-07751-w

In a 2,000-square-kilometre area around the Barrow Peninsula in northern Alaska, for instance, the team calculated that lakes release an average of 0.6 grams of methane per square metre of water surface each year — which equates to around 141 kilograms of methane per square kilometre. That is about 84% lower than some previous estimates based on measurements at individual lakes, Engram says, but lines up well with estimates based on atmospheric measurements.

[TerryM]

If everyone treats the the problem as something for the grandchildren to worry about, then we’re all dead.

Bear in mind that my eldest grandchild is in his thirties.
Terry

[Wherestheice]

“We had no idea subsea permafrost was thawing so fast”

https://phys.org/news/2018-12-arctic-permafrost-giant-world-carbon.html?fbclid=IwAR1Xc_BLBB6JIAWtuslOhEhFvrF6LZBMw8cqe0Ow6WURzhbW6J5cshhuydU#jCp

[kassy]

The researchers have been comparing the temperatures of permafrost on land and underwater. About 10,000 years ago, the temperature of both permafrost types was about -18˚C. They found that permafrost on the ground has now warmed up to about -10˚C but under the sea it has reached 0˚C. "That was surprising," Prof. Gustafsson said. "I had no idea that subsea permafrost was thawing so quickly.

That 0C is one interesting number...

[vox_mundi]

Methane Gas Triggered Tsunami Fires After 1993 Japan Earthquake, Scientist Says   
https://weather.com/news/news/2018-12-20-methane-gas-tsunami-fires-japan-earthquake

Fires that consumed a Japanese port in the wake of a 1993 earthquake-triggered tsunami were likely caused by methane gas released from the seabed during the tremor, a Japanese scientist said.

On July 12, 1993, a magnitude 7.8 earthquake struck in the Sea of Japan, triggering a tsunami that crashed into Hokkaido and Okushiri islands in northern Japan, according to the U.S. Geographical Survey. As the monster wave hit the smaller outlying Okushiri, at least five boats moored in the island's Aonae Harbor simultaneously burst into flames. The tsunami waves and high winds drove the flames inland, where numerous buildings in the port were consumed by the fires. 

 Enomoto noted that with the amount of methane gas buried beneath the seafloor off the coast of Japan, further analysis is needed to heed off potentially disastrous consequences from methane gas-triggered fires should disaster strike again.

[vox_mundi]

Melting Ice Sheets Release Tons of Methane Into the Atmosphere
https://m.phys.org/news/2019-01-ice-sheets-tons-methane-atmosphere.html

The Greenland Ice Sheet emits tons of methane according to a new study, showing that subglacial biological activity impacts the atmosphere far more than previously thought.

... Professor Jemma Wadham, Director of Bristol's Cabot Institute for the Environment, who led the investigation, said: "A key finding is that much of the methane produced beneath the ice likely escapes the Greenland Ice Sheet in large, fast flowing rivers before it can be oxidized to CO2, a typical fate for methane gas which normally reduces its greenhouse warming potency."
...  With Antarctica holding the largest ice mass on the planet, researchers say their findings make a case for turning the spotlight to the south. Mr Lamarche-Gagnon added: "Several orders of magnitude more methane has been hypothesized to be capped beneath the Antarctic Ice Sheet than beneath Arctic ice-masses. Like we did in Greenland, it's time to put more robust numbers on the theory."

 Guillaume Lamarche-Gagnon et al. Greenland melt drives continuous export of methane from the ice-sheet bed, Nature (2018).

[Theta]

Near Future Global Extinction To Be Caused by Methane

http://arctic-news.blogspot.com/2019/01/global-extinction-within-18-34-months.html?m=1

Recent data from the Arctic confirm an exponential rise in the temperature anomaly of the Arctic stratospheric methane which is now 65 degrees C above the normal, while it was only 20 degrees C above the normal, 6 to 8 years ago...

The Major Arctic Permian Style, Methane Blowout - Firestorm Event which will cause the release of some 50 Gt of methane from the Arctic shelf and slope (Shakhova, 2010), a 10 Degree Centigrade Rise in Mean Global Atmospheric Temperatures causing a Catastrophic Permian Style Global Extinction Event, is timed to begin on 4th September, 2021 using an Atmospheric Methane Global Warming Potential of 100. This is an end Summer event for the Northern Hemisphere.

Any idea of what the implications of this are with regards forecasting future emissions of methane and whether or not this prediction could actually be true or may even play out in the extreme near term?

[sidd]

Re: whether or not this prediction could actually be true

No.

sidd

[Human Habitat Index]

Re: whether or not this prediction could actually be true

No.

sidd

Can you expand on your reasoning ?

[oren]

Because that source is a pile of BS.

[Theta]

What about the information itself. Is there any possibility of it actually being sound and if so, will there be any warning signs, because, quite frankly, I find the idea of suddenly boiling alive one day to be frightening.

[oren]

What about the information itself. Is there any possibility of it actually being sound and if so, will there be any warning signs, because, quite frankly, I find the idea of suddenly boiling alive one day to be frightening.

I am sorry but that source is not based on science. It only seems like science because of some similar terms. There is no information I can discern. "Temperature anomaly of arctic stratospheric methane is now 65 degrees C above normal" - What? Where? How? It's completely bogus.
I recommend not to read such "blogs" and remove them from you favorites list. Sam Carana, Guy McPherson, etc. - keep away. I understand this is frightening, but so is watching horror movies. You must realize this is fiction. It's like those madmen standing on barrels at Hyde Park Corner screaming about the end of the world. Don't listen if you value your sanity.

[Theta]

What about the information itself. Is there any possibility of it actually being sound and if so, will there be any warning signs, because, quite frankly, I find the idea of suddenly boiling alive one day to be frightening.

I am sorry but that source is not based on science. It only seems like science because of some similar terms. There is no information I can discern. "Temperature anomaly of arctic stratospheric methane is now 65 degrees C above normal" - What? Where? How? It's completely bogus.
I recommend not to read such "blogs" and remove them from you favorites list. Sam Carana, Guy McPherson, etc. - keep away. I understand this is frightening, but so is watching horror movies. You must realize this is fiction. It's like those madmen standing on barrels at Hyde Park Corner screaming about the end of the world. Don't listen if you value your sanity.

Point taken, though the statement is notable because nobody else has ever said this before, not even guy McPherson

[Gray-Wolf]

I've been voicing my concerns over the 7,000+  'Pingo like structures' across Yamal and Semileto's
"3 years from development to ruture".....

That would mean we ought to expect Yamal to go 'Pop' over summer this year?

Whether this will lead to a methane burp of a proportion likely to drive near instant temp forcings across the region (prior to global dispersion of the gas) or not I do not know!

I would also suggest that nobody else really 'knows' what we are to , or are not to ,expect either?

Talk of free methane reserves capped by the permafrost leaves open the potential for breaches in the 'cap' and a rapid leaking of that free methane into the atmosphere.

The rupture of the permafrost across Yamal (and on the sea bed off Yamal) may well open up pathways for reserves to migrate along? ( I think the region has a number of major fault lines under the permafrost reserves and out into the the Arctic Basin so plenty of room for 'free methane' to migrate along to any newly opened 'exit points' ?

[gerontocrat]

And no data from NOAA, merci, M'sieur Le Trump.

[Wherestheice]

There are a lot of McPherson and carana haters, but honestly. In my opinion there not far off. Maybe just a few decades

[magnamentis]

And no data from NOAA, merci, M'sieur Le Trump.

there is no reason to not go to work in such an agency where people are:

- very well paid year-in year-out

- have mostly very safe jobs for many years

- will be compensated once the shut-down is over

to me it is a bit disturbing that people who have such jobs and claim to work in the name of science and for the good of the people and the world lay down their work because they have to wait a bit longer than usual for their wages.

i for one at times work many YEARS for friends who have a good idea and can't afford to pay wages and i wish the so-called environmentalists and scientists would be a bit less after the money which BTW i'm not so totally fond of scientist like many others in this forum, they work for money and carrieres and their results are often influence through this facts.

who claims to work for a good case should first re-consider his/her needs and push back money as a main motivator a bit before making such claims.

[Mozi]

In this case they are not allowed to work, even if they wanted to.

[Sciguy]

The Siberian permafrost is very thick, 700m - 1000m onshore, 300m - 600m offshore.  The fastest meltrates of the offshore permafrost, due to warm water in contact with the surface of the ground is 1.4 m per year.  It would take several centuries to melt through all of the permafrost.

The methane is distributed in pockets throughout the permafrost, so a little bit will be released each year.  Most will be consumed by bacteria, dissolved in water or reduced by reaction with OH in the atmosphere.

We've had a lot of discussion about the pingo-like structures in Siberia upthread.  Review the discussions on previous pages.  They contain less methane that is released by fossil fuel extraction operations, especially fracking, each year.  Even if 7,000 went poof in the same year, there wouldn't be a very large spike in atmospheric methane concentrations.

[Wherestheice]

The Siberian permafrost is very thick, 700m - 1000m onshore, 300m - 600m offshore.  The fastest meltrates of the offshore permafrost, due to warm water in contact with the surface of the ground is 1.4 m per year.  It would take several centuries to melt through all of the permafrost.

The methane is distributed in pockets throughout the permafrost, so a little bit will be released each year.  Most will be consumed by bacteria, dissolved in water or reduced by reaction with OH in the atmosphere.

We've had a lot of discussion about the pingo-like structures in Siberia upthread.  Review the discussions on previous pages.  They contain less methane that is released by fossil fuel extraction operations, especially fracking, each year.  Even if 7,000 went poof in the same year, there wouldn't be a very large spike in atmospheric methane concentrations.

Ken,

your not convincing me that this is not a problem

[Wherestheice]

The Siberian permafrost is very thick, 700m - 1000m onshore, 300m - 600m offshore.  The fastest meltrates of the offshore permafrost, due to warm water in contact with the surface of the ground is 1.4 m per year.  It would take several centuries to melt through all of the permafrost.

The methane is distributed in pockets throughout the permafrost, so a little bit will be released each year.  Most will be consumed by bacteria, dissolved in water or reduced by reaction with OH in the atmosphere.

We've had a lot of discussion about the pingo-like structures in Siberia upthread.  Review the discussions on previous pages.  They contain less methane that is released by fossil fuel extraction operations, especially fracking, each year.  Even if 7,000 went poof in the same year, there wouldn't be a very large spike in atmospheric methane concentrations.

Here's an image showing how pingos can form.
https://wol-prod-cdn.literatumonline.com/cms/attachment/02afa0b0-7772-4b96-8852-e61a835840ca/grl22378-fig-0002.png
It's from a paper dating back to 2007.
https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2006GL027977

Ocean heat can travel down via pingos and reach greater depth where more methane is contained in hydrates. Note what Natalia Shakhova said seven years ago:
https://skepticalscience.com/arctic-methane-outgassing-e-siberian-shelf-part2.html

The sea surface near Svalbard is warming strongly, as much as 17.4°C or 31.4°F warmer recently than in 1981-2011. Stronger storms increase the possibility of large influx of warm salty water from the Atlantic Ocean that can easily destabilize hydrates, given that much of the Arctic Ocean is very shallow and the East Siberian Arctic Shelf is on average only 45 m deep.


Also some of the recent ESAS work from S&S is interesting
https://www.eurekalert.org/pub_releases/2017-08/tpu-rsd081517.php

[Wherestheice]

https://ac.els-cdn.com/S187661021830136X/1-s2.0-S187661021830136X-main.pdf?_tid=eee50895-b956-4247-b680-05b40841615e&acdnat=1547362884_25f9510dab638f26a19dc31ade625ded

[Theta]

https://ac.els-cdn.com/S187661021830136X/1-s2.0-S187661021830136X-main.pdf?_tid=eee50895-b956-4247-b680-05b40841615e&acdnat=1547362884_25f9510dab638f26a19dc31ade625ded

So what are you thinking? Instant venusifocation in a day once a blowout occurs?

[Wherestheice]

https://ac.els-cdn.com/S187661021830136X/1-s2.0-S187661021830136X-main.pdf?_tid=eee50895-b956-4247-b680-05b40841615e&acdnat=1547362884_25f9510dab638f26a19dc31ade625ded

So what are you thinking? Instant venusifocation in a day once a blowout occurs?

No. I don’t think earth will be anything like Venus for hundreds of millions of years. If not billions

[Shared Humanity]

These fanciful speculations about unlikely events do not belong on this thread. Far better for this conversation to take place here.

https://forum.arctic-sea-ice.net/index.php/topic,1428.350.html

[Archimid]

The Siberian permafrost is very thick, 700m - 1000m onshore, 300m - 600m offshore.  The fastest meltrates of the offshore permafrost, due to warm water in contact with the surface of the ground is 1.4 m per year.  It would take several centuries to melt through all of the permafrost.

How do you determine the maximum melt rate? If it gets warmer or wetter does the melt rate accelerates or is it capped?

The methane is distributed in pockets throughout the permafrost, so a little bit will be released each year.

A little bit relative to global methane or local methane? If the little bit is global, how significant is it local? how much regional warming high methane concentrations can create?

Most will be consumed by bacteria

Heat is the byproduct of that reaction. Increased methane cause increased temperatures. Bacterial metabolism cause increased temperatures. Increased temperatures cause methane release.

 

dissolved in water

And what happens then. The cycle surely doesn't end there.

or reduced by reaction with OH in the atmosphere.

Reduces to water vapor and CO2, both increase local surface level warming.

We've had a lot of discussion about the pingo-like structures in Siberia upthread.  Review the discussions on previous pages.  They contain less methane that is released by fossil fuel extraction operations, especially fracking, each year.  Even if 7,000 went poof in the same year, there wouldn't be a very large spike in atmospheric methane concentrations.

I look at from the perspective that we have to close down 7,000 extraction operations just to break even with pingo induced warming. That ignores all non pingo possible methane sources. Once you add pingos and all sources, does it become significant in a global basis?  How about on a hemispheric basis? Or maybe on an Arctic basis?

We should not find out if methane is a danger to a civilization or not. This happened before. Many times. It was disastrous then, over centuries, but the methane was also emitted over centuries. We have hands down surpassed in greenhouse gas release rate of the worst extinction events yet we are assuming the Earth's climate system will react at the pace of the old extinction events.

[wili]

There will also likely be an increase in biological activity on and in the ocean floor, both microbial and more complex life forms. These are of course hard to model, but could burrow into methane pockets, releasing the gas more quickly than a merely physical model would suggest is possible.

And then there are slopes. I large release at a crucial point along a slope could cause a kind of un-zippering effect, iirc.

I think we can't be complacent about these possibilities, but at the same time they all just mean that we have to double down on reducing our lion's share of the contribution in hopes that the optimists are right and that these more rapid release mechanisms don't end up coming into play, at least at current levels of warming.

[Sciguy]

Here's a link to a 2017 update of the IPCC AR5 report by the UK Royal Society:

https://royalsociety.org/~/media/policy/Publications/2017/27-11-2017-Climate-change-updates-report-references-document.pdf

Excerpts relevant to methane clathrate release:

Clathrates: Some economic assessments
continue to emphasise the potential damage
from very strong and rapid methane hydrate
release (Hope and Schaefer, 2016), although
AR5 did not consider this likely. Recent
measurements of methane fluxes from
the Siberian Shelf Seas (Thornton et al.,
2016) are much lower than those inferred
previously (Shakhova et al., 2014). A range
of other studies have suggested a much
smaller influence of clathrate release on the
Arctic atmosphere than had been suggested
(Berchet et al., 2016; Myhre et al., 2016). New
modelling work confirms (Kretschmer et al.,
2015) that the Arctic is the region where
methane release from clathrates is likely
to be most important in the next century,
but still estimates methane release to the
water column to be negligible compared to
anthropogenic releases to the atmosphere.
A recent review (Ruppel and Kessler, 2017)
emphasises that there remains little evidence
that clathrate methane is reaching the
atmosphere at present. Although methane that
is oxidised in the water column will not reach
the atmosphere, it will have the effect of further
lowering the pH of the ocean (Boudreau et al.,
2015). A recent modelling study joined earlier
papers in assigning a relatively limited role to
dissociation of methane hydrates as a climate
feedback (Mestdagh et al., 2017).

Excerpt related to permafrost melt:

Permafrost: A review published in 2015
(Schuur et al., 2015) made new estimates of
the amount of carbon stored in permafrost,
both near the surface and at depth. It also
summarised experimental evidence about
how much carbon would be released, and
in what form, when permafrost melts. This
led to a new estimate that about 100 Pg of
cumulative carbon emissions (with a wide
uncertainty) would be released from thawing
permafrost by 2100 under RCP8.5. This leads
to a significant positive feedback, but the
review emphasised that emissions are “likely
to be gradual and sustained rather than
abrupt and massive”. A recent modelling study
estimated that permafrost carbon releases
could contribute up to 12% of the change in
global mean temperature by 2100 (Burke et al.,
2017). Studies since 2013 therefore confirm the
importance of permafrost carbon release as
a positive feedback, and the need to include
it accurately in Earth system models, but
they do not support considering it to exhibit
threshold behaviour.

[Wherestheice]

https://truthout.org/articles/release-of-arctic-methane-may-be-apocalyptic-study-warns/

[Tor Bejnar]

So, it's Armageddon or … not. 

Do we get insurance for the 1% chance?  How about for the 0.001% chance?  I don't know anybody who has asteroid-collision insurance, but lots of people who have more auto liability coverage than what is required by law, but not a $100,000,000 worth (against some rare event, for sure). 

Are we (humans) resigned to suffer and die if the scientific nay-sayers are correct?  Or do we believe they are just wrong and can be ignored?  (Or "I'm old and will be dead by then, surely.")

[Wherestheice]

It’s not even that the methane release is a 1% chance. We know the permafrost is melting, we know global warming is accelerating. We know a BOE is coming. The only question is when. Will it be in our lifetimes, or our grandchildren’s. More research needs to be done I think we can all agree on that