Toward Improved Discussions of Methane & Climate

[Peter Ellis]

An article from Skeptical Science that seems to me to be pretty fair and balanced.

http://www.skepticalscience.com/news.php?n=2130

The clincher for me is the palaeoclimate argument: given that orbital forcings meant the Arctic was warmer (and quite possibly seasonally ice-free) several thousand years ago, with no runaway methane release, means the same likely applies to current warming.

[Peter Ellis]

(note the extensive references to the primary literature)

[SteveMDFP]

An article from Skeptical Science that seems to me to be pretty fair and balanced.

http://www.skepticalscience.com/news.php?n=2130

The clincher for me is the palaeoclimate argument: given that orbital forcings meant the Arctic was warmer (and quite possibly seasonally ice-free) several thousand years ago, with no runaway methane release, means the same likely applies to current warming.

No, the same doesn't likely apply to current warming.  Methane released from seabed deposits slowly get oxidized in the water column, but bubble up to the air when release is rapid.  Methane released to the air slowly gets oxidized by atmospherice hydroxyl radicals.  But those hydroxyl radicals can be depleted by large releases, allowing methane to persist in the atmosphere.

In other words, RATE of release is likely to be critical.  Past warm periods got warm slowly.  Our current warming is happening fast.  It's certainly plausible (and in my mind very likely) that rate of methane release from shallow seabeds and permafrost is likely to be determined as much by rate of warming as absolute temperature.

A gigaton of methane released over centuries is going to have much less global impact than the same gigaton released over a decade.

In terms of methane, since we're in unprecedented rate of global warming, we're in unprecedented territory about methane releases.  We have no past road map of relevance for comparison.

[jonthed]

I agree with Steve, and while i recognize my opinion and insight doesn't count for much, I have been disappointed with the scientists, and now skeptical science, who seem to keep saying that the historic record doesn't show such a spike, so it's 'unlikely' there will be one.

Firstly, despite what they have said about previous analogs, I don't see them as being the same as current warming, as the rate of warming, as Steve has pointed out, makes a huge difference to the effect of any methane thawing.

I'm not seeing any previous warming like we're seeing now, including where sea levels are over the shelf, what the arctic sea ice is doing, the injection of ghg we have seen, and the rate of warming we're seeing/going to see.

Regardless of the facts about the mechanism by which the ESAS methane is supposed to thaw according to Wadhams' new disputed paper, you'll probably see this in the news today: "Climate change on pace to occur 10 times faster than any change recorded in past 65 million years, Stanford scientists say"

see here:
http://news.stanford.edu/news/2013/august/climate-change-speed-080113.html

and climate central's piece on it:
http://www.climatecentral.org/news/ecosystems-face-unprecedented-changes-in-the-next-century-16301

If you read the articles, you'll note a quote from Diffenbaugh:
“The key difference is the rate of change,” said co-author Noah Diffenbaugh, a climate scientist and Senior Fellow at the Woods Institute for the Environment at Stanford University, in an interview. “The combination of rate and magnitude over the next century is unprecedented. In the context of the geological record of the last 65 million years, this (change in the 21st century) is likely to be an order of magnitude, or two or three orders, more rapid.”

As if one order of magnitude wasn't enough already.
enough to be concerned.
enough to see there's no historic analog.

And yet people are still insisting the paleo-record means there's nothing to worry about: a large methane release is "unlikely".

I don't follow their logic at all.

The mechanism Wadhams is suggesting seems to be supported by observed data, including observed sea temperatures, perhaps it might need more years to be more certain, but it certainly shouldn't be dismissed based on not having seen anything like what he's suggesting in the paleo-record.

-

As for the mechanism:

How many years has sea ice been retreating so far and for so long over the ESAS? probably less than 20. (http://climate.nasa.gov/key_indicators#seaIce)
How many years have summer sea surface temperatures over the ESAS been above zero in summer? well it used to be mostly ice so again, probably less than 20 (http://www.esrl.noaa.gov/psd/map/images/sst/sst.month.anom.hov.io.gif)

Any previous retreat of sea ice would have been more gradual, and any thawing too.
Any previous warming of summer temps would also have been more gradual, and any thawing too.

Wadhams' mechanism does indeed appear to be a new one, only possible because of the retreating sea ice. coupled with the rate of change and rate of warming, and how critical to the impact of methane release the rate of thawing is, I can't see how the mechanism is unsound or comparable to previous warmings.

That leaves me convinced that there is definitely reason to be concerned.

[johnm33]

Oh boy, you're not going to like this. From a catastrophists point of view the east siberian shelf was further from the axis of rotation prior to about 5,200 years bp and even further away before about 11,500 years bp. The axis being before that pretty much where the geomagnetic pole is. This would put the whole area further south [Including that Siberian lake that was 8degC warmer than expected] and allow the possibility that the eye witness accounts/myths/legends, carried down the generations, about the area having a permanent spring climate, contain a grain of truth. Born out to some extent by the 'springtime vegetation' [typical of a black sea meadow] stomach contents of every frozen mammoth I've ever read about. Also check out 'Arctic home in the Vedas' by Tilak. Also IIRC there's an ethnic group in the Lena valley that recall a mass migration to the south [India] in prehistory, and a return after the Mongol conquest of the sub continent, with proven genetic connections to the Punjab. As to the dates of the shifts there are many guesses, my first relates to the time suggested in the Oera Linda, also by timing of the demise of the pygmy mammoths on the new siberian islands, and the massive floods that left 3m [?] mud deposits in mesopotamia, which were pretty much coincident.
 The older date is more speculative, but a comprehensive overview of the facts on the ground can be found in 'When the earth nearly died' Allan/Delair which also has an intimidating bibliography. I have to say I don't altogether share the views of the authors but there is a vast array of facts which should be accommodated by any realistic worldview.
Back to the shelf, the area was above sea level throughout the 'ice age' and also during that whole time we could expect the growth of peat beds, and to quite some depth. I'm too ignorant about the Eemian to speculate beyond that whatever methane event happened was gradual.
 Whatever befell the mammoths froze their stomach contents so quickly that, when defrosted, it was still identifiable and 'fresh', but the same event could be expected to form a serious frozen crust on the aforementioned peat beds.  Whatever process decayed this peat to methane should not have disguised it's provenance, but if/when they take samples I hope they reinstate long deep frozen plugs to reseal the holes, otherwise I'd expect a spreading collapse of the sealing layer.
The most convincing evidence, for me, of polar shift are the ancient agricultural terraces stretching past 18,000ft above lake Titicaca, taken with the ancient seashells, and the current apparently oceanic fauna in it's companion salt lake suggest that either there has been a massive uplifting of the whole area, by 12,600ft, or it previously lay quite close to the equator, and the oceanic bulge meant it was much closer to sea level. Of course if it was near the equator that would put large tracts of amazonia below sea level, and the rest in the arid zone so would explain the sandy nature of its soil. I've never come across any evidence pointing to a more Nilotic period for the Amazon but then who'd be looking. My guess is that the best way of deciding the likelyhood of this is to determine the genetic homeland of the equatorial species of the forest [nearer the Andes and the Mato Grosso?] and to look for candidates for the movement from the likely temperate rainforests to the north.
Actually there's a massive amount more evidence that supports this possible worldview, from all around the world, and it took me 20 odd years of stumbling across it before it undermined my confidence in the regular paradigm [and another 5 before I read what Velikovsky had to say]so I'm not expecting or trying to convince anyone, but as far as a catastrophic methane release goes, if there's any truth in all this, the past is no guide to the future.
 

[johnm33]

As an introduction to catastrophism you could do a lot worse than follow the recommendations of the first reviewer here-  http://www.amazon.com/When-Earth-Nearly-Died-Compelling/product-reviews/1858600081/ref=dp_top_cm_cr_acr_txt?ie=UTF8&showViewpoints=1

[GeoffBeacon]

Peter

It would be good if you could explicitly address the "rate of change" argument.

Is there much "primary literature" on the subject? If there isn't does this mean it can't be an effect?

How do increases in wildfires come in? They produce methane and seem to be showing on the satellite images. (Are satellite maps "primary literature"?)

I saw a graph somewhere that showed that that John Mitchell has the most peer reviewed papers on climate change. He once replied to me saying increases in wildfires were not in climate models.

Perhaps you can find some "primary literature" that says "wildfires are missing from the models and so are ...."

OK, academics might want to be sure of their facts before they publish but I have been dismayed at how difficult it is to get them to answer straightforward questions.  Thanks to John Mitchell, for his candour.

See John Mitchell's comments at the end of Do you believe the European Commission on Climate Change? (http://www.brusselsblog.co.uk/do-you-belive-the-european-commission-on-climate-change/)

I see "primary literature" as a form of regulation and it gives academics their edge in the competitive market of information. It can be used ruthlessly.

Read Tim Worstall's clear and short piece Of course big business loves regulation (http://www.adamsmith.org/blog/regulation-industry/of-course-big-business-loves-regulation)

Big business attitudes shouldn't be in academia but increasingly they are -- but that should be a separate topic.

[GeoffBeacon]

Peter,

And another thing...

What weight would you give to Peter Wadhams' quote in the Guardian

The rapid disappearance of offshore permafrost through water heating is a unique phenomenon, so clearly no 'expert' would have found a mechanism elsewhere to compare with this... I think that most Arctic specialists would agree that this scenario is plausible.

http://www.theguardian.com/environment/earth-insight/2013/jul/31/artic-methane-catastrophe-empirical-evidence]
[url]http://www.theguardian.com/environment/earth-insight/2013/jul/31/artic-methane-catastrophe-empirical-evidence[/url]

Also, is this "primary literature"?

[Dromicosuchus]

There were some rapid warming incidents in the past that might be vaguely analogous to the present warming.  I don't know of any that occurred mid-interglacial, but as I understand it the Dansgaard-Oeschger events in the midst of the glacials were extremely abrupt, and involved temperature spikes around Greenland, at least, that were greater than the temperature changes that have occurred thus far.  On the other hand, that was starting from a far colder baseline, and as they occurred during low-water points for the global ocean, I would suppose that the submerged permafrost available would have been minimal compared to the present day.

Hm.  Another thought occurs to me; how long has the subsea permafrost on the ESAS and elsewhere been frozen?  Did it survive Eemian temperatures, or does it date only from the last glacial, and no further?  I can't find any information on the age of permafrost there (which is, quite possibly, just a result of insufficient diligence in searching), but I did find this, indicating that more southerly, marginal permafrost (never submerged, however, which is an important difference) has managed to last a good 740,000 years--which puts it comfortably pre-Eemian in age.  Again, though, it's the subsea permafrost which is particularly concerning, here, and it's that that we need information on.  I've read a few of Shakhova and Semilitov's papers, but I don't recall a specific age for the permafrost being mentioned.  Anyone else know of a source for that?

[GeoffBeacon]

Dromicosuchus

"Shakhova and Semilitov's papers"

What are the best ones?

Any recent news of Shakhova and Semilitov?

[Apocalypse4Real]

Geoff,

This paper gives the case for potential release:

Doklady Earth Sciences
September 2012, Volume 446, Issue 1, pp 1132-1137
The degradation of submarine permafrost and the destruction of hydrates on the shelf of east arctic seas as a potential cause of the “Methane Catastrophe”: some results of integrated studies in 2011

ABSTRACT:
On the basis of the analysis of published data and in the course of the authors’ long-term geochemical and acoustic surveys performed in 1995–2011 on the East Siberian shelf (ESS) and aimed to research the role of the Arctic shelf in the processes of massive methane outbursts into the Earth’s atmosphere, some crucially new results were obtained. A number of hypotheses were proposed concerning the qualitative and quantitative characterization of the scale of this phenomenon. The ESS is a powerful supplier of methane to the atmosphere owing to the continued degradation of the submarine permafrost, which causes the destruction of gas hydrates. The emission of methane in several areas of the ESS is massive to the extent that growth in the methane concentrations in the atmosphere to values capable of causing a considerable and even catastrophic warning on the Earth is possible. The seismic data were compared to those of the drilling from ice performed first by the authors in 2011 in the southeastern part of the Laptev Sea to a depth of 65 m from the ice surface. This made it possible to reveal some new factors explaining the observed massive methane bursts out of the bottom sediments.

Original Russian Text © V.I. Sergienko, L.I. Lobkovskii, I.P. Semiletov, O.V. Dudarev, N.N. Dmitrievskii, N.E. Shakhova, N.N. Romanovskii, D.A. Kosmach, D.N. Nikol’skii, S.L. Nikiforov, A.S. Salomatin, R.A. Anan’ev, A.G. Roslyakov, A.N. Salyuk, V.V. Karnaukh, D.B. Chernykh, V.E. Tumskoi, V.I. Yusupov, A.V. Kurilenko, E.M. Chuvilin, B.A. Bukhanov, 2012, published in Doklady Akademii Nauk, 2012, Vol. 446, No. 3, pp. 330–335.
http://link.springer.com/article/10.1134%2FS1028334X12080144

[wili]

Nafeez Ahmed at the Guardian directly addresses many of the points made by Chris Colose in the Skeptical Science piece:

http://www.theguardian.com/environment/earth-insight/2013/aug/05/7-facts-need-to-know-arctic-methane-time-bomb


[size=150]Seven facts you need to know about the Arctic methane timebomb[/size]

Dismissals of catastrophic methane danger ignore robust science in favour of outdated mythology of climate safety



Here's the short version of the seven points. Go to the article for the explanation of each:

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

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

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

4. Current Arctic methane levels are unprecedented

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

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

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

[opensheart]

I had not seen the following article posted elsewhere, and thought it might fit best here.

http://climatechangepsychology.blogspot.com/2014/06/dr-natalia-shakhova-interviewed-by-nick-breeze-destabilized-subsea-permafrost-methane-emissions.html

[johnm33]

Spotted this at nakedcapitalism http://www.nakedcapitalism.com/2014/07/gaius-publius-arctic-seafloor-methane-release-double-earlier-estimates.html

[Lynn Shwadchuck]

Open, good to post that link to the Shakhova interview in this thread. We've been discussing it on the 'This is not good' thread, too. http://forum.arctic-sea-ice.net/index.php/topic,484.msg30626.html#new

I'm cross-posting my synopsis of the 45 minute interview here:

Thanks, Sleepy and Terry for posting the Shakhova interview and the expedition links. Kudos to Tenney Naumer and Nick Breeze for getting Shakhova on Skype for such a long interview! It's current, because it's after their winter expedition, while the paper presented in the fall was after last summer's.

Very interesting that she argues clearly against geoengineering, going so far as to joke about it. She said, what are we to do, flip the poles so we get the climate of Antarctica in the Arctic? I suspect she's succeeded in talking AMEG out of pushing this idea. I see all the links to their 'strategic plan' are dead now.

It all sounds seriously 'not good'.

Surprises to me (and I've been following her and Semiletov since 2010):

    The part of the East Siberian Arctic Sea closest to shore has only been under water a geologically short time. On this winter's expedition they were surprised to find the permafrost there at the thawing point rather that at the expected minus 7. It should be more stable than the deeper areas.

    Shakhova and Semiletov were doing research on the ESAS in 1998 when they found a single highly concentrated plume of methane. This is what started their dogged search for the answers about the methane that's supposed to be sealed under permafrost.

    She seems to be frustrated that other scientists don't understand that methane hydrates in southern oceans release themselves through oxidation slowly and through a deep water column, where in the case of the ESAS the pure methane gas is released straight to the atmosphere thorough physical pathways (openings in the thawing permafrost) and a shallow water column over the shelf.

    There is a fault/rift that makes catastrophic release a possibility, which would immediately raise the global average temperature 3 degrees.

    They've been very conservative in their estimates of just how many gigatonnes of methane there may be trapped under the permafrost, basing it on the equivalent area on the land-based permafrost. It could go a few kilometers deep or MANY.

    The expedition this summer is making a single line across the arctic. She wishes the international scientific community would share in a project to continuously monitor the vast expanse with observation stations.


The gist of the interview is that things have been changing very fast.

[ghoti]

Meanwhile this week on the Oden people are measuring methane releases in the now ice-free Laptev. Today's blog reports they are seeing methane at levels 10 times higher than normal background in seawater. They are finding hundreds of methane seeps. See:

http://swerus-c3.geo.su.se/index.php/oerjans-blog-leg-1/170-observing-and-investigating

[SteveMDFP]

Meanwhile this week on the Oden people are measuring methane releases in the now ice-free Laptev. Today's blog reports they are seeing methane at levels 10 times higher than normal background in seawater. They are finding hundreds of methane seeps. See:

http://swerus-c3.geo.su.se/index.php/oerjans-blog-leg-1/170-observing-and-investigating

People quite rightly worry about methane reaching the atmosphere, as a potentially powerful (or catastrophic) feedback to global warming.

I'm not sure methane in sea water is any less worrisome, but nobody seems to talk about that much.  Methane at depth depletes oxygen at depth by bacterial action (bacteria "eat" dissolved methane and "breathe" dissolved oxygen, producing relatively harmless CO2).  Methane is poorly soluble in water at surface pressures, but is much more soluble at higher pressures present at depth. (Oxygen is also more soluble at depth, but since oxygen is not produced down there, it never exceeds oxygen levels present in solution at the surface -- very low).

High methane concentrations in sea water, then, promote oxygen depletion.  When sea-floor oxygen levels approach zero (anoxic conditions), different anearobic bacteria "breath" dissolved sulfate, "eat" the same methane, and produce CO2 and toxic hydrogen sulfide.  Hydrogen sulfide, H2S, may have been the chief toxic culprit of the "great dying" of the End-Permian Extinction Event of 250 million years ago.

I brought this up before, and someone pointed out that current trends give us at least 200 years before widespread H2S toxicity become prevalent in the oceans (the technical term is "euxinic").

I'm highly skeptical that we have even that much time before the oceans are all essentially dead and we re-enter the extinction event ecology.

An interesting article here:
http://pangea.stanford.edu/sites/default/files/Payne and Clapham 2012 Ann Rev.pdf

(the spaces in that URL might make the link here choke.  Copy and paste into browser may be needed).

[Apocalypse4Real]

See my summary of SWERUS-C3 resources for following their progress and more:

http://a4rglobalmethanetracking.blogspot.com/2014/07/major-arctic-methane-research-underway.html

[Laurent]

Already posted but may be a little bit of information or link available for you ?
Scientists discover vast methane plumes escaping from Arctic seafloor
http://earthsky.org/earth/scientists-discover-vast-methane-plumes-escaping-from-arctic-seafloor

[Gray-Wolf]

Is it me or did Oden fall silent about their science results after their first press release? They are now approaching the end of their survey and we have had but one science press release about methane plumes and then nothing? The blogs hint at the work going well and the data amassing but no hint at what the general trend in the findings is?

I kinda thought that once we got into the ESS they would be eager to share their results but it appears we will have to wait until the studies are all finished , written up and published before we get any idea of what they have been encountering at the sampling stations?

Maybe I'm just looking in the wrong places? If so could someone give me a 'heads up'?

[morganism]

lotta fear, and no one brought up hydryoxl removal, or even noctilucent clouds

http://www.reddit.com/r/science/comments/2egga9/bbc_news_widespread_methane_leakage_from_ocean/

[ghoti]

I stumbled onto a brief report about this year's methane related field work done by N.  Shakhova. It just reports on what field work they did and where. It will be interesting to see the results published.

http://www.ice-arc.eu/wp-content/uploads/sites/22/2014/07/ICE-Tiksi-2014-submitted.pdf

[Laurent]

Found that pdf very interesting :
http://www.globalcarbonproject.org/methanebudget/13/files/Global_Methane_Budget_2013_GCP.pdf

They say that the methane stays 10+/-2 years in the atmosphere...that's quite precise...so I have to forget about 20 years or even 50... Knowing that it disapear so easily and that it does continue to increase at a tremendous pace, that is quite stunning !

[viddaloo]

They say that the methane stays 10+/-2 years in the atmosphere..

If that's so, Laurent, then why does the IPCC use 100–year values for CH4 forcing? Pure BS?

[wili]

Like everything, it's a distribution curve. A majority is gone after 12 years or so*, but a declining residue remains, though I forget exactly what the curve looks like and how fat a 'tail' it has. The main thing is, though, that the 100 year effect is the average effect over that whole hundred years, including the 100 or so times CO2 GW potential of the first decade or so. So average that in, and consider that there is residue, and that the result methane oxidation is CO2, and you see that its GWP could never go below 1 ever after 1000 years.

(*This is of course given that it has the right conditions, especially access to HO, the hydroxyl radical.)

At least, that is my rather foggy understanding of the thing.

[viddaloo]

OK. So in a truly catastrophic CH4 release, there won't be enough HO around to remove it, and the extreme forcing will continue past the 10 years?

[AbruptSLR]

In order to learn what happens to methane's chemical reactions during a large release event see the linked Isaksen et al (2011) reference (with an open access pdf):

Isaksen, I. S. A., Gauss M., Myhre, G., Walter Anthony, K. M.  and Ruppel, C.,  (2011), "Strong atmospheric chemistry feedback to climate warming from Arctic methane emissions", Global Biogeochem. Cycles, 25, GB2002, doi:10.1029/2010GB003845.

http://onlinelibrary.wiley.com/doi/10.1029/2010GB003845/abstract

Abstract: "The magnitude and feedbacks of future methane release from the Arctic region are unknown. Despite limited documentation of potential future releases associated with thawing permafrost and degassing methane hydrates, the large potential for future methane releases calls for improved understanding of the interaction of a changing climate with processes in the Arctic and chemical feedbacks in the atmosphere. Here we apply a “state of the art” atmospheric chemistry transport model to show that large emissions of CH4 would likely have an unexpectedly large impact on the chemical composition of the atmosphere and on radiative forcing (RF). The indirect contribution to RF of additional methane emission is particularly important. It is shown that if global methane emissions were to increase by factors of 2.5 and 5.2 above current emissions, the indirect contributions to RF would be about 250% and 400%, respectively, of the RF that can be attributed to directly emitted methane alone. Assuming several hypothetical scenarios of CH4 release associated with permafrost thaw, shallow marine hydrate degassing, and submarine landslides, we find a strong positive feedback on RF through atmospheric chemistry. In particular, the impact of CH4 is enhanced through increase of its lifetime, and of atmospheric abundances of ozone, stratospheric water vapor, and CO2 as a result of atmospheric chemical processes. Despite uncertainties in emission scenarios, our results provide a better understanding of the feedbacks in the atmospheric chemistry that would amplify climate warming."

[Laurent]

They say that the methane stays 10+/-2 years in the atmosphere..

If that's so, Laurent, then why does the IPCC use 100–year values for CH4 forcing? Pure BS?

I think it  is because of the big priests of the IPCC (the old one, I know you like them ). They were (some are still) preaching that the CO2 will remain in the atmosphere 100 years or so (and we don't have to worry).
That is because they had some graph that were showing a 100 year decaying, a bit like the joined graph, except that this one show more than 10.000 years up to 100.000 I think.
From : http://www.roperld.com/science/globalwarmingprediction.htm

[viddaloo]

As expected, but extremely scary nevertheless. I'm beginning to see why it's a taboo subject now.

[wili]

Thanks, ASLR. I keep forgetting that crucial study. In case anyone missed it, here's the takeaway:

if global methane emissions were to increase by factors of 2.5 and 5.2 above current emissions, the indirect contributions to [radiative forcing] would be about 250% and 400%, respectively, of the RF that can be attributed to directly emitted methane alone.

So instead of a global warming potential of 105 times that of CO2 over decadal time scales, methane released at these rates would have GWPs of about 250 to over 400 times that of CO2 (unless I'm reading that incorrectly).

At the higher end of that scale, at something like current ratios, I believe methane would become the main forcing in GW, rather than CO2 (but someone with more time and brains than I should check the numbers).

[AbruptSLR]

Don't forget that Isaksen et al 2011, was published before Shindell determined that the 100-GWP for methane is about 34. 

Edit: The above statement is in error, as Shindell published the 34 GWP for methane in his 2009 paper, which of course was before the 2011 Isaksen et al paper.

Also, for those who do not want to download the free access pdf of the Isaksen et al 2011 paper, I provide the attached key table with the following caption:

Caption: "Resultant Radiative Forcing for Assumed Cases of CH4 Emissions from Isaken et al 2011"

[Pmt111500]

OK. So in a truly catastrophic CH4 release, there won't be enough HO around to remove it, and the extreme forcing will continue past the 10 years?

I wouldn't use 'truly catastrophic' in a scientific context here, but essentially, yes, I think this is why AMEG and others are concerned of this. Beginning of such a release would likely mean this is out of our collective hands.

Hence it also could be the methane spikes seen in the paleorecord (f.e. D-O events such as B/A period) are only of the times when methane emmissions exceed the capability of HO-removal pathway, how much of the CO2 in the paleorecord was methane to begin with?

[bligh8]

In the linked article is a interesting read about
METHANE, METHANE HYDRATES, AND GLOBAL CLIMATE

The Dickens Achievement

"Dickens and his fellow scientists provided a realistic scenario as to how hydrate methane could account for the significant negative carbon isotopic change found at the time of the Paleocene-Eocene boundary. Their calculations also showed that there was no other credible scenario that could produce that change. Subsequently, evidence from ODP drilling showed that underwater slumping was involved in at least one hydrate release event, and that that event involved deep-sea extinctions and a slow process of recovery."

http://www.killerinourmidst.com/MH%20and%20global%20climate.html#anchor361517

[Laurent]

(Already posted but a tiny bit of information more ?)
Trapped Methane Escapes as Pacific Depths Warm Up
http://www.truthdig.com/report/item/trapped_methane_escapes_as_pacific_depths_warm_up_20150111

[Laurent]

What if the methane release is not only driven by temps but also by life activity...(that's my thought...)

Five Things The Gulf Oil Spill Has Taught Us About the Ocean
Energy and Life Surround Deep-Sea Seeps
http://www.smithsonianmag.com/science-nature/five-things-gulf-oil-spill-has-taught-us-about-ocean-180955036/?no-ist

Ocean currents impact methane consumption
http://www.eurekalert.org/pub_releases/2015-04/hcfo-oci042015.php

[salbers]

Oh boy, you're not going to like this. From a catastrophists point of view the east siberian shelf was further from the axis of rotation prior to about 5,200 years bp and even further away before about 11,500 years bp. The axis being before that pretty much where the geomagnetic pole is.

The Earth's axis doesn't change that fast from as far as I know.

[anotheramethyst]

Oh boy, you're not going to like this. From a catastrophists point of view the east siberian shelf was further from the axis of rotation prior to about 5,200 years bp and even further away before about 11,500 years bp. The axis being before that pretty much where the geomagnetic pole is.

The Earth's axis doesn't change that fast from as far as I know.

i'm not great at math so can't calculate these things, but i know today's north star wasn't the north star when the egyptians built the pyramids.  so the earth's axis changes in historical human timescales. 

http://earthsky.org/brightest-stars/thuban-past-north-star

[jai mitchell]

13,000 years to go from one extreme to the other, with a 26,000 year rotational period.

http://csep10.phys.utk.edu/astr161/lect/time/precession.html

[salbers]

There may be some confusion in the context of the Earth Axis discussion. I think the original implication was that the geographic latitude of Siberia or other places changes significantly in just a few millenia. This is not the case. Precession is a wobbling motion that does cause the Earth's axis to move relative to the "fixed" stars. However the distance of any particular landform from the rotational pole isn't changing significantly.

[anotheramethyst]

The issue is not whether landmasses move from the rotational adis, they don't (except by tectonic movements which is totally different).  the rotational axis itself shifts, tilting or wobbling its position relative to the sun.  this is a historical cycle that normally does affect the cycle of glacial and interglacial periods.  however, climate change is progressing far more rapidly than any recent period, so i don't think any major earth changes that happen over a thousand years from now are particularly relevant today.  i DO think it's important to understand this in the context of paleoclimate data.

[AbruptSLR]

The linked reference (with an open access pdf) provides a somewhat conservative assessment of methane emission cycles, permafrost & hydrology of the Siberian continental margin:

Archer, D.: A model of the methane cycle, permafrost, and hydrology of the Siberian continental margin, Biogeosciences, 12, 2953-2974, doi:10.5194/bg-12-2953-2015, 2015.

http://www.biogeosciences.net/12/2953/2015/bg-12-2953-2015.html

Abstract: "A two-dimensional model of a sediment column, with Darcy fluid flow, biological and thermal methane production, and permafrost and methane hydrate formation, is subjected to glacial–interglacial cycles in sea level, alternately exposing the continental shelf to the cold atmosphere during glacial times and immersing it in the ocean in interglacial times. The glacial cycles are followed by a "long-tail" 100 kyr warming due to fossil fuel combustion.

The salinity of the sediment column in the interior of the shelf can be decreased by hydrological forcing to depths well below sea level when the sediment is exposed to the atmosphere. There is no analogous advective seawater-injecting mechanism upon resubmergence, only slower diffusive mechanisms. This hydrological ratchet is consistent with the existence of freshwater beneath the sea floor on continental shelves around the world, left over from the last glacial period.

The salt content of the sediment column affects the relative proportions of the solid and fluid H2O-containing phases, but in the permafrost zone the salinity in the pore fluid brine is a function of temperature only, controlled by equilibrium with ice. Ice can tolerate a higher salinity in the pore fluid than methane hydrate can at low pressure and temperature, excluding methane hydrate from thermodynamic stability in the permafrost zone. The implication is that any methane hydrate existing today will be insulated from anthropogenic climate change by hundreds of meters of sediment, resulting in a response time of thousands of years.

The strongest impact of the glacial–interglacial cycles on the atmospheric methane flux is due to bubbles dissolving in the ocean when sea level is high. When sea level is low and the sediment surface is exposed to the atmosphere, the atmospheric flux is sensitive to whether permafrost inhibits bubble migration in the model. If it does, the atmospheric flux is highest during the glaciating, sea level regression (soil-freezing) part of the cycle rather than during deglacial transgression (warming and thawing).

The atmospheric flux response to a warming climate is small, relative to the rest of the methane sources to the atmosphere in the global budget, because of the ongoing flooding of the continental shelf. The increased methane flux due to ocean warming could be completely counteracted by a sea level rise of tens of meters on millennial timescales due to the loss of ice sheets, decreasing the efficiency of bubble transit through the water column. The model results give no indication of a mechanism by which methane emissions from the Siberian continental shelf could have a significant impact on the near-term evolution of Earth's climate, but on millennial timescales the release of carbon from hydrate and permafrost could contribute significantly to the fossil fuel carbon burden in the atmosphere–ocean–terrestrial carbon cycle."

[sidd]

Nice paper in PNAS point to decline in OH- ions rather than increase in CH4 emission as the cause for recent rising methane concentrations. I suspected as much, but this is the first hard evidence i have seen.

doi: 10.1073/pnas.1616426114

sidd

[longwalks1]

From DeSmog Canada via David Suzuki foundation and St. Francis Xavier University

Scientists Find Methane Pollution from B.C.’s Oil and Gas Sector 2.5 Times What B.C. Government Reports
https://www.desmog.ca/2017/04/26/scientists-find-methane-pollution-b-c-s-oil-and-gas-sector-2-5-times-what-b-c-government-reports

Using infrared cameras and gas detection instruments at over a thousand oil and gas sites during a three-year period, scientists from the David Suzuki Foundation in partnership with St. Francis Xavier University recorded fugitive methane emissions being released from facilities directly into the atmosphere on a perpetual basis.

The study estimates methane pollution from industry in B.C. is at least 2.5 times higher than the B.C. government reports. Methane is a potent greenhouse gas with the warming potential 84 times that of carbon dioxide over a 20 year period

Original paper in process
http://www.atmos-chem-phys-discuss.net/acp-2017-109/
Mobile measurement of methane emissions from natural gas developments in Northeastern British Columbia, Canada

doi:10.5194/acp-2017-109                   Open source   Primarily focused on the Peace Area of British Columbia, Canada.

[TerryM]

From DeSmog Canada via David Suzuki foundation and St. Francis Xavier University

Scientists Find Methane Pollution from B.C.’s Oil and Gas Sector 2.5 Times What B.C. Government Reports
https://www.desmog.ca/2017/04/26/scientists-find-methane-pollution-b-c-s-oil-and-gas-sector-2-5-times-what-b-c-government-reports

Using infrared cameras and gas detection instruments at over a thousand oil and gas sites during a three-year period, scientists from the David Suzuki Foundation in partnership with St. Francis Xavier University recorded fugitive methane emissions being released from facilities directly into the atmosphere on a perpetual basis.

The study estimates methane pollution from industry in B.C. is at least 2.5 times higher than the B.C. government reports. Methane is a potent greenhouse gas with the warming potential 84 times that of carbon dioxide over a 20 year period

Original paper in process
http://www.atmos-chem-phys-discuss.net/acp-2017-109/
Mobile measurement of methane emissions from natural gas developments in Northeastern British Columbia, Canada

doi:10.5194/acp-2017-109                   Open source   Primarily focused on the Peace Area of British Columbia, Canada.

Suzuki is a Canadian icon. His popularity here as "The Voice of Science" is unmatched.
A National Treasure
Terry

[Cid_Yama]

Nice paper in PNAS point to decline in OH- ions rather than increase in CH4 emission as the cause for recent rising methane concentrations. I suspected as much, but this is the first hard evidence i have seen.

doi: 10.1073/pnas.1616426114

sidd

What do you think caused the decline in hydroxyls?  It is a predicted response to rising methane emissions.

They can't measure Hydroxyls directly so they used reaction time of 1,1,1-trichloroethane to infer Hydroxyl loss. 

Yes, there is both a rise in methane concentrations AND hydroxyl loss, as a result of increasing methane emissions.  Better stated, Hydroxyl production can't keep up with rising methane emissions.

It's not rather than, it's because of.

And that should scare your socks off.  A few years ago they found a 'Hydroxyl Hole' over the Western Tropical Pacific allowing unchecked rise of methane to the stratosphere.

  http://www.climatecentral.org/news/huge-hole-in-earths-detergent-layer-found-over-pacific-17302

         

[Bruce Steele]

Sidd and Cid-Yama, I looked at the location of the OH hole and consequent ozone hole and immediately had some questions about how UV might contribute to the coral bleaching events that we all know are
co-located. I don't have much to contribute except questions but apparently yes increased UV can be a contributing factor in Coral bleaching events. Why is it we haven't heard more about these combinations of what I agree should " scare your socks off" events. More stratospheric methane , less OH, less ozone, more UV at surface, and massive coral bleaching?

https://www.researchgate.net/publication/232770403_Ultraviolet_radiation_and_coral_bleaching

I draw the co-location from the 2014 climate gate piece linked by Cid-Yama

[Bruce Steele]

Sidd, I looked up the PNAS article you cited "Role of atmospheric oxidation in recent methane growth"

Abstract
The growth in global methane (CH4) concentration, which had been ongoing since the industrial revolution, stalled around the year 2000 before resuming globally in 2007. We evaluate the role of the hydroxyl radical (OH), the major CH4 sink, in the recent CH4 growth. We also examine the influence of systematic uncertainties in OH concentrations on CH4 emissions inferred from atmospheric observations. We use observations of 1,1,1-trichloroethane (CH3CCl3), which is lost primarily through reaction with OH, to estimate OH levels as well as CH3CC3 emissions, which have uncertainty that previously limited the accuracy of OH estimates. We find a 64–70% probability that a decline in OH has contributed to the post-2007 methane rise. Our median solution suggests that CH4 emissions increased relatively steadily during the late 1990s and early 2000s, after which growth was more modest. This solution obviates the need for a sudden statistically significant change in total CH4 emissions around the year 2007 to explain the atmospheric observations and can explain some of the decline in the atmospheric 13CH4/12CH4 ratio and the recent growth in C2H6. Our approach indicates that significant OH-related uncertainties in the CH4 budget remain, and we find that it is not possible to implicate, with a high degree of confidence, rapid global CH4 emissions changes as the primary driver of recent trends when our inferred OH trends and these uncertainties are considered.

[SCYetti]

I am curious about the CO₂ equivalency of methane. I find it stated as the 100 year equivalent of anywhere between 20 and 34. The 20 year equivalent of between 75 and 86. IIRC the one year equivalent was once given as about 170.

Since I started following the subject 5 years ago the presence of methane has increased only slightly but seems to have been consistently above 1700 parts per billion. If we were to use the 1 year CO₂ equivalent of 170 at 1.7 parts per million total CO₂ we would get equivalence of over 700 parts per million CO₂. Is that possible? What would climate models look like using similar numbers?

[longwalks1]

I have been going with the 5 year as 86 (20 year 70?) for my cursory look.  So for a ball park figure of 1700ppm methane using 20 year models,, that would be 1.7 ppt methane time 70 yields 120  added to the CO2e.  I do go with the view that a large part of todays values is still highly influenced by rice farming and ruminants (cattle).  I saw some graphs of the last 10,000 years and the advent of rice farming and domestication of ruminants did cause a rise. 

I really can't speak for the models.  My hunch is that anything over a 20 year model for CO2e is not well grounded. 

[salbers]

It may help to consider the baseline values of CO2 and CH4 being compared against. In addition the forcing from CO2 is logarithmic, and from CH4 is approximately a square root dependence (and also dependent on N2O).

https://www.esrl.noaa.gov/gmd/aggi/aggi.html (see Table 1)

If we use the year 1750 as a reference for methane it would be 700ppb. Good question about the earlier farming impact. Prior to that the average over the past million years is about 500ppb, with variations up to about 700ppb.

https://en.wikipedia.org/wiki/Atmospheric_methane#/media/File:Atmospheric_Concentrations_of_Methane_Over_Time.png

The total CO2e from the non-CO2 gases is about 90ppm. CH4 has about 25% the radiative forcing of CO2 at present, compared with the year 1750 reference amounts of each. However a new study has this fraction closer to one third, when shortwave IR absorption features are accounted for.

http://onlinelibrary.wiley.com/doi/10.1002/2016GL071930/full