Arctic Methane Release

[Bruce Steele]

Bryman, I don't worry about inflammable language  so much and having spent much time in public process and meetings doesn't give me much hope for a meaningful treaty. I have a feeling that
800 ppm will be a little later arriving than BAU projections predict but I also think foot dragging ,ignorance and greed will allow enough CO2 emissions to kick in some nasty positive feedbacks. It doesn't really matter when we hit 800 ppm but if it is positive feedback that gets us there the long term consequences may be even more dire than our ff contributions alone feeding our planetary disaster.
 I was pushing acidification in the public arena as far back as 2006. People thought I was quite mad.
There have been plenty of examples of dire news being tamed for a public audience . Madmen have shown some fairly accurate prescience to date so I try to listen even if I don't like the message or the delivery. So when I say the current rate of emissions is greater than the one that caused the largest extinction event in the fossil record I may be correct , saying it however gets me unpleasantly labeled.
On balance I will accept the label.  Calm, calm now . Put them behind you .

Elsie B

Should a man
be the last one 
up before dawn
and down the docks
alone,
waiting for his turn too

The last turn of the rudder
No prize this

The chatter of gulls
An annoyed heron
hearing his passing
The ring of the rigging
and the first snap of the diesel

His company: 
Voiceless footsteps
Ten thousand dawns 
headed out
Red dull red glows 
an unlit cabin
The slow roll of open water

Calm, calm now
Put them behind you
Push the throttle up
and move into that which held
titans before you

What remains is the
patina of immortality 
granted an old fisherman
and a very tough old man

----------------------------
This is for a local legend, Ralph Hazard.
His boat was the Elsie B
I was asleep on my boat in the harbor. Ralph woke me as he headed down the dock at his typical 3:00 a.m. exit. 

[viddaloo]

Has anyone seen the mixing ratio for methane, layer 74, 469 mb for April 9th yet? The Obama administration has stopped the service on April 8th, and this follows the shut–down of Mauna Loa methane measurements earlier this winter, on February 7th.

[bryman]

Bryman, I don't worry about inflammable language  so much and having spent much time in public process and meetings doesn't give me much hope for a meaningful treaty. I have a feeling that
800 ppm will be a little later arriving than BAU projections predict but I also think foot dragging ,ignorance and greed will allow enough CO2 emissions to kick in some nasty positive feedbacks. It doesn't really matter when we hit 800 ppm but if it is positive feedback that gets us there the long term consequences may be even more dire than our ff contributions alone feeding our planetary disaster.
 I was pushing acidification in the public arena as far back as 2006. People thought I was quite mad.
There have been plenty of examples of dire news being tamed for a public audience . Madmen have shown some fairly accurate prescience to date so I try to listen even if I don't like the message or the delivery. So when I say the current rate of emissions is greater than the one that caused the largest extinction event in the fossil record I may be correct , saying it however gets me unpleasantly labeled.
On balance I will accept the label.  Calm, calm now . Put them behind you .

Elsie B

Should a man
be the last one
up before dawn
and down the docks
alone,
waiting for his turn too

The last turn of the rudder
No prize this

The chatter of gulls
An annoyed heron
hearing his passing
The ring of the rigging
and the first snap of the diesel

His company:
Voiceless footsteps
Ten thousand dawns
headed out
Red dull red glows
an unlit cabin
The slow roll of open water

Calm, calm now
Put them behind you
Push the throttle up
and move into that which held
titans before you

What remains is the
patina of immortality
granted an old fisherman
and a very tough old man

----------------------------
This is for a local legend, Ralph Hazard.
His boat was the Elsie B
I was asleep on my boat in the harbor. Ralph woke me as he headed down the dock at his typical 3:00 a.m. exit.

While you are certainly entitled to your opinion, I highly doubt scientists are being terribly low with their estimates. I will take the word of Gavin Schmidt, who I have talked to personally, over the words of some on this forum who seems to like their doomsday fix. I believe that a treat will be signed, as does AbruptSLR.

[jai mitchell]

Has anyone seen the mixing ratio for methane, layer 74, 469 mb for April 9th yet? The Obama administration has stopped the service on April 8th, and this follows the shut–down of Mauna Loa methane measurements earlier this winter, on February 7th.

If you wait until 12:00 noon pacific time you can give them a call and say "aloha".


    Contact Name: John Barnes
    Address: NOAA - Mauna Loa Observatory
    1437 Kilauea Ave. #102
    Hilo, Hawaii, 96720, United States
    Phone: (808)933-6965
    Fax: (808)933-6967

[viddaloo]

You think they're waiting for me, The User, as in The Only User, to telephone them and say their service hasn't been up for 2 full months?

Maybe you're right. How much is a 5–second phone call to Hawaii these days?

[jai mitchell]

you may want to contact Ed Dlugokencky over at the ESRL.  He is quite kind and will respond to an email.  Last I checked he was responsible for compiling the continuous monitor data.  I wouldn't be too concerned, there is often a time lag between collection and publishing of results, they are not done in real time as far as I can tell.

[bryman]

You know Jai, I find it curious you haven't responded to me yet.

[viddaloo]

you may want to contact Ed Dlugokencky over at the ESRL.  He is quite kind and will respond to an email.  Last I checked he was responsible for compiling the continuous monitor data.  I wouldn't be too concerned, there is often a time lag between collection and publishing of results, they are not done in real time as far as I can tell.

Thanks for that advice, Jai. I'm mostly concerned that with the downfall of the MetOp2, we now have no updated reports for methane. Not sure I made that crystal–clear in my comment above. The service that stopped April 8th was the MetOp CH4 reporting. If it takes more than 3 days to get back up again, data will be lost forever, as per US Department of Commerce information policies.

[Ned W]

(Originally posted elsewhere on ASIF, moved here by the author.)

There is a new review paper in Nature on the greenhouse gas flux from permafrost.  ASLR mentioned it in passing on the previous page, but it deserves a bit more notice here.

Climate change and the permafrost carbon feedback

Abstract:

• Large quantities of organic carbon are stored in frozen soils (permafrost) within Arctic and sub-Arctic regions. A warming climate can induce environmental changes that accelerate the microbial breakdown of organic carbon and the release of the greenhouse gases carbon dioxide and methane. This feedback can accelerate climate change, but the magnitude and timing of greenhouse gas emission from these regions and their impact on climate change remain uncertain. Here we find that current evidence suggests a gradual and prolonged release of greenhouse gas emissions in a warming climate and present a research strategy with which to target poorly understood aspects of permafrost carbon dynamics.

Press release from University of Alaska-Fairbanks here:

Scientists predict slower permafrost greenhouse gas emissions

My take -- permafrost is melting and degrading rapidly, and will continue to provide CO2 and CH4 to the atmosphere ... but at a modest rate, not in the form of a sudden "methane bomb".  This should not be a surprise to most people here, as I think the evidence against a "bomb" scenario has been clear for some time (see Gavin Schmidt's comments last year).

[viddaloo]

My take -- permafrost is melting and degrading rapidly, and will continue to provide CO2 and CH4 to the atmosphere ... but at a modest rate, not in the form of a sudden "methane bomb".  This should not be a surprise to most people here, as I think the evidence against a "bomb" scenario has been clear for some time (see Gavin Schmidt's comments last year).

Logically, at least, it's very hard to provide 'evidence' for or against abrupt/sudden/surprising/unexpected CH4 releases of the scale associated with the 'bomb' scenario. 'Most people' have never heard of methane at all, much less that it could be catastrophic sometime in the near future. Rather than participating in a he said–she said about CH4, because what people say frankly isn't that interesting, because we don't know their reasons for saying it, I look at the condition of the barrier (thawing seafloor) between the CH4 hydrates and the warming Arctic ocean, and I apply some logic, like the ocean is just going to keep on warming, thawing more barrier seafloor.

Studied this way, the catastrophe scenario is just as relevant now as last year, as the ocean has not started cooling, and the only (scientific) reason one could have for dismissing it would be new revelations that abrupt releases did not happen in the geological past. We have not seen such reports from scientists, therefore a CH4 surprise cannot be ruled out, IMO.

PS: I'm still getting the 'you may only read the first page of this paper' treatment from Nature and ReadCube. Rest of the pages are intentionally blurred. What am I doing wrong?

[jai mitchell]

You know Jai, I find it curious you haven't responded to me yet.

sorry Bry I did not see your attack.

Gavin is completely off base in asserting that a methane pulse release is unsubstantiated in the paleo record.  this is because there has not been an a palaeo analog to our current global system conditions.  specifically we have not, in the entire EPICA dome C record, experienced a period where the arctic temperatures have been at interglacial values for > 10,000s years. 

Consequently, the ESAS has currently been inundated for over 8,000 years longer than at any time in the last 800,000 years.  This warm ocean disassociation has allowed a significantly greater warming precursor to achieve greater depths under the ESAS than ever before in the paleo record. 

as an aside note:

the reason that the ESAS has been allowed to warm at this length of time is explained by ruddiman.  Where early agriculture land-use and rice cultivation led to a 5,000 B.C.E. forcing value that prevented a re-emergence into North American ice age nucleation. 

Now that the ESAS has been allowed to experience a warming profile greater than that experienced in the previous 800,000 years we will now force it to experience a hothouse climate that will first be experience sometime around 2055 when the first June 21 ice free arctic condition will set in.  This will produce an 8-20C regional warming pulse and an extremely rapid subsea warming event.  This type of environment has not been experienced prior to 55 million years ago and the Eocene maximum. 

There is no paleoclimate analog that can rule out the potential for a massive methane release under these conditions.
_____________

more specifically, with regard to the recent publication of heat balance analysis of increased microbial activity in a rapidly thawing permafrost environment.  You must realize that the temperature profile curves show that the >1 Meter depth response is hindered by their climate model. 

Their sub 1 meter depth disassociation activity doesn't occur prior to 2085 due to their limited, gradually warming climate model, that only looks at relative forcing and does not include the bifurcation event that will occur under a total loss of summer sea ice.   In the real world environment, once that microbial activity does engage below 1 meter, and is fed on an annual basis by summer temperature spikes, the resident microbial heating will produce a self-sustaining reaction that drives a sub 3 meter disassociation response over the next 15 years.  This is blatantly obvious from the temperature profile charts.

The reason that this is devastating is that is shows when this warming is set below 2 meters, subsequent to the 10C warming that will take place in a mid summer sea ice loss environment, that the deeper permafrost will remain UNFROZEN even in the depths of winter, due to microbial heating.

[Gray-Wolf]

So , as a complete novice in all of this are you suggesting that the model is so 'basic' it just has a column of permafrost which is looked at over time as temps increase? The strata does not have 'features' like capped free methane reserves or ice lenses? Does the model allow for tectonic features like faulting?

When I look at the submerged permafrost I worry about the sea water percolating into the strata once features (chimneys) evolve and so gaining access to deeper layers ( to melt) well before the gradual 'top down' warming arrives?

Let gunpowder off unconstrained and you get a 'phoof' and some smoke. Constrain it inside something and you get a different result. Are we to expect similar from either pockets of free methane once the cap that constrains them becomes degraded enough to allow fracture?

And then what of that 'perfect', layered, modeled permafrost? Can it relate meaningfully to a strata riddled with imperfections (and the behaviours these 'imperfections' allow?)?

When we look at a Yamal crater we can see just how much more 'surface at depth' is exposed to warming. Expand this ( like we saw off shore with the growth of the 'chimneys' over a single year) and you begin to see disruption throughout the surface layers over single seasons........ not a steady top down event.

Each summer we see more 'lakes/pools' drain across the permafrost as they melt out the ice that holds them in place. Where does this 'free water' drain? What impact does this have on the strata it flows through?

So I'm asking just how 'realistic' are the promises we gain from folk enamored by such data?

[bryman]

Jai, I wasn't talking about permafrost. I was talking about your ridiculous claim that climate scientists think that IPCC projections are too low by up to 300-400%. Not only is there no evidence for that anywhere, Gavin haas also said it's way off. As far as the ESAS, an abrupt release cannot be ruled out, but it is far from certain, as Shakhova, Wadhams, Yurganov, and others have said.

[Ned W]

Gavin is completely off base in asserting that a methane pulse release is unsubstantiated in the paleo record.  this is because there has not been an a palaeo analog to our current global system conditions.  specifically we have not, in the entire EPICA dome C record, experienced a period where the arctic temperatures have been at interglacial values for > 10,000s years. 

Huh?  Where'd you get that from?  There have been longer interglacials.  MIS-11 lasted twice as long as the current interglacial has (so far), long enough for Greenland to lost virtually all its ice:



The Eemian interglacial wasn't as long as MIS-11, but enough warmth accumulated to melt a large fraction of the ice in Greenland.

Greenland hasn't lost nearly that much ice in this interglacial.  So why assume that the ESAS has been subjected to so much more accumulated warming?  This whole claim about a bomb lurking under the ESAS that somehow survived previous interglacials -- when Greenland lost all or most of its ice -- is just untenable.

[viddaloo]

Thanks for that advice, Jai. I'm mostly concerned that with the downfall of the MetOp2, we now have no updated reports for methane. Not sure I made that crystal–clear in my comment above. The service that stopped April 8th was the MetOp CH4 reporting. If it takes more than 3 days to get back up again, data will be lost forever, as per US Department of Commerce information policies.

[bryman]

So , as a complete novice in all of this are you suggesting that the model is so 'basic' it just has a column of permafrost which is looked at over time as temps increase? The strata does not have 'features' like capped free methane reserves or ice lenses? Does the model allow for tectonic features like faulting?

When I look at the submerged permafrost I worry about the sea water percolating into the strata once features (chimneys) evolve and so gaining access to deeper layers ( to melt) well before the gradual 'top down' warming arrives?

Let gunpowder off unconstrained and you get a 'phoof' and some smoke. Constrain it inside something and you get a different result. Are we to expect similar from either pockets of free methane once the cap that constrains them becomes degraded enough to allow fracture?

And then what of that 'perfect', layered, modeled permafrost? Can it relate meaningfully to a strata riddled with imperfections (and the behaviours these 'imperfections' allow?)?

When we look at a Yamal crater we can see just how much more 'surface at depth' is exposed to warming. Expand this ( like we saw off shore with the growth of the 'chimneys' over a single year) and you begin to see disruption throughout the surface layers over single seasons........ not a steady top down event.

Each summer we see more 'lakes/pools' drain across the permafrost as they melt out the ice that holds them in place. Where does this 'free water' drain? What impact does this have on the strata it flows through?

So I'm asking just how 'realistic' are the promises we gain from folk enamored by such data?

It looks likely that the Yamal craters may have had to do more with free methane deposits and pingos than hydrates. The pingos, according to satellite maps, are located right where the craters are.

[AbruptSLR]

Jai, I wasn't talking about permafrost. I was talking about your ridiculous claim that climate scientists think that IPCC projections are too low by up to 300-400%. Not only is there no evidence for that anywhere, Gavin haas also said it's way off. As far as the ESAS, an abrupt release cannot be ruled out, but it is far from certain, as Shakhova, Wadhams, Yurganov, and others have said.

bryman,

If you do not wish to limit this exchange to "Arctic Methane Releases", then I recommend that you move this discussion to one of the following threads (you pick); as a rapid natural Arctic methane emissions is only one of many positive feedback mechanisms (e.g. deep atmospheric convection in the tropics that effect cloud cover, Arctic Amplification, rapid reductions of anthropogenic aerosols thus reducing the masking effects of such aerosols, etc.) that may accelerate global mean temperature increase beyond the AR5 projections (i.e. meaning that the effective climate sensitivity in the next century or so (including temporary methane emissions from hydrates, permafrost degradation, hydro-fracking, and other sources) may be two, three or four times greater than the approximately 3C ECS assumed by AR5).  Otherwise, it seems that we should limit our discussion here to methane releases (preferably in the Arctic).

http://forum.arctic-sea-ice.net/index.php/topic,1020.0.html

http://forum.arctic-sea-ice.net/index.php/topic,1053.700.html

http://forum.arctic-sea-ice.net/index.php/topic,1091.0.html

Best,
ASLR

[bryman]

Did you not see the post where I mentioned Yamal? Also, I highly doubt a 12 degree Celsius change is likely. Eight is possible but also not likely. And methane release is by far the biggest of the potential feedbacks. All others pale in comparison, and I'm calling out Jai on his extreme projections that are completely unsupported by any evidence.

[jai mitchell]

Ned,

Thanks for that fix.  You are right of course, I was specifically talking about Gavin's analog of the Eemian as a way to preclude future methane release from the ESAS later this century.  The warming of the ESAS occurs subsequent to inundation by rising sea levels.  The sea level highstand record for the Eemian indeed does provide a close analog to Holocene sea level records and inundation.  So in this my understanding was indeed incorrect.

Therefore, Gavin's analog is much better than I had thought and my skepticism of his assertions are significantly reduced. 

However, the Eemian was solar-driven and had much cooler arctic Winters and warmer Summers than present time.  In this environment then, it seems to me very unlikely that the Eemian summer arctic ice-free states happened prior to the summer solstice.  Therefore, the amount of arctic sea warming may have been less than what will be experienced when our arctic sea ice reaches <1,000 km^2 on June 1 later on this century.

another potential problem with the analog is that the sea level at end-Eemian was 9 meters +/- 1 meter higher than today which would have nearly doubled the surface pressure at the ESAS and helped to prevent clathrate disassociation under a warming scenario.



Finally,  the Eemian was 2-3 C warmer than pre-industrial temperatures on a globally averaged scale.  We will be hard pressed to prevent reaching this temperature by 2050 and we may reach it as soon as 2030 (see graphic:  http://www.scientificamerican.com/sciam/assets/Image/articles/earth-will-cross-the-climate-danger-threshold-by-2036_large.jpg ) , with the potential for significant overshoot and a release that could produce 6c of warming by 2080.

couple this with the complete loss of June 1st summer sea ice, significantly warmer arctic winters and only 2 meters of additional sea level rise by 2080 and the possibility of clathrate release under this scenario is still a moderate possibility.

However, if we do get to that level of warming by 2080 then there won't be very many lifeforms on planet earth to care if the clathrates do go.   

[jai mitchell]

Did you not see the post where I mentioned Yamal? Also, I highly doubt a 12 degree Celsius change is likely. Eight is possible but also not likely. And methane release is by far the biggest of the potential feedbacks. All others pale in comparison, and I'm calling out Jai on his extreme projections that are completely unsupported by any evidence.

Bry

In reading your response above, your own assertion of possible 8 and remotely likely 12C of warming is very much in line with my understanding of the matter.  Perhaps you can post a link to where I said what you think I said and we can discuss it there?

[bryman]

With pleasure: http://forum.arctic-sea-ice.net/index.php?topic=1053.msg40351#msg40351
I don't know where you came up with that whopper, but Gavin thinks it's a load of crap, and so do I. Your numbers are completely unsupported at all by any climate scientists. No one has even hinted at an increase of 8 plus degrees, and if they have, they are completely in the minority.

[wili]

bryman, may I kindly suggest to you as a 'newbie' here that you lower the level of bile in your posts, please.

Your claim "No one has even hinted at an increase of 8 plus degrees" is not accurate (though I will refrain from calling it a 'load of crap') and there is a whole thread devoted to the topic here that you might want to peruse before opining about it further.

I don't know what Gavin has or hasn't said about the level of understatement by IPCC. He did co-author a paper with Schindell and others a few years ago that gives a GWP of methane that is about 30% higher than that given in the current IPCC. Yes, that's not 300%, but we are talking about matters of degree rather than sign, and there is no particular need to use profanity and bile to engage in such discussions. Just a friendly suggestion.

[jai mitchell]

With pleasure: http://forum.arctic-sea-ice.net/index.php?topic=1053.msg40351#msg40351
I don't know where you came up with that whopper, but Gavin thinks it's a load of crap, and so do I. Your numbers are completely unsupported at all by any climate scientists. No one has even hinted at an increase of 8 plus degrees, and if they have, they are completely in the minority.

see you there.

[AbruptSLR]

(Originally posted elsewhere on ASIF, moved here by the author.)

There is a new review paper in Nature on the greenhouse gas flux from permafrost.  ASLR mentioned it in passing on the previous page, but it deserves a bit more notice here.

Climate change and the permafrost carbon feedback

Abstract:

• Large quantities of organic carbon are stored in frozen soils (permafrost) within Arctic and sub-Arctic regions. A warming climate can induce environmental changes that accelerate the microbial breakdown of organic carbon and the release of the greenhouse gases carbon dioxide and methane. This feedback can accelerate climate change, but the magnitude and timing of greenhouse gas emission from these regions and their impact on climate change remain uncertain. Here we find that current evidence suggests a gradual and prolonged release of greenhouse gas emissions in a warming climate and present a research strategy with which to target poorly understood aspects of permafrost carbon dynamics.

Press release from University of Alaska-Fairbanks here:

Scientists predict slower permafrost greenhouse gas emissions

My take -- permafrost is melting and degrading rapidly, and will continue to provide CO2 and CH4 to the atmosphere ... but at a modest rate, not in the form of a sudden "methane bomb".  This should not be a surprise to most people here, as I think the evidence against a "bomb" scenario has been clear for some time (see Gavin Schmidt's comments last year).

Part of the problem of addressing the climate change issue is that its complexity does not readily lend itself to being addressed by the conventional reductionist scientific method that decision makers (& the public) have common to rely upon.  Earth systems have multiple fat-tailed feedback mechanisms (which are currently dominated by positive rather than negative feedbacks); and while it is correct that science must use a reductionist approach to sub-divide these various mechanisms (which have different degrees of non-linearity, on different time-scales; with different initial & boundary conditions; and at different forcing rates & forcing magnitudes) in order to study them; unfortunately, to date the various climate change computer models have not been capable of adequately re-integrating all the synergistic (frequently non-linear) mechanisms.  The US DOE has taken the lead in trying to re-integrate all of the reductionist inputs using Earth Systems Modeling, and which their state-of-the-art projections in CESM –High Resolution projections showed high climate sensitivity (see the third to last link at the end of this post), these preliminary findings (which did not rely on excessively high methane emissions) have been discounted as potentially being biased (due to uncertainties about non-linear responses) on the high-side (i.e. discounted for potentially erring on the side of greater drama). 

Thus we are left with individual scientists and reporters discussing their reductionist finding (like a blind man describing an elephant to be snake like while he feels its trunk); and no one presenting a coherent reliable, timely, integrated overview (& I include the AR5 projections and Gavin Schmidt modeling efforts).  A good example of this is the linked article by The Guardian focused on the recent Schuur et. al. (2015) paper (see second to last link at end of post), in which the researchers scale-back the rate of earlier (e.g. Schurr & Abbot, 2011) GHG emissions from permafrost degradation.  While the reporter (Karl Mathiesen) entitles this article "Permafrost 'carbon bomb' may be more of a slow burn, say scientists"; he does have the grace to point at the end of his article to the even more recent Danish report by Hultman et al (2015) paper (see last link at end of this post) implies that the Schuur et al (2015) findings may be erring on the side of least drama (see extract below). However, even this caveat at the end of The Guardian article, Karl Mathiesen ignores multiple other factors that could work synergistically to accelerate GHG emissions from permafrost degradation, including: (1) Arctic Amplification, (2) the discontinuous nature of the permafrost (see: http://innovations.coe.berkeley.edu/vol7-issue8-feb2014/studying-the-arctic-tundra.html), (3) invasion insect pests & invasion ground squirrel borrowing (see: https://agu.confex.com/agu/fm14/meetingapp.cgi#Paper/20090), (4) degradation of boreal forest in the taiga (see: http://news.mongabay.com/2014/0604-sutherland-taiga.html), (5) wildfires & reduced albedo associated with the shrub growth on the tundra (see: http://onlinelibrary.wiley.com/doi/10.1111/gcb.12852/abstract), (6) penetration of warm surface water into the groundwater, (7) synergy between different soil microbes that have evolved to work together (see: http://www.nature.com/ncomms/2014/140214/ncomms4212/full/ncomms4212.html), ( a reduction in the masking effect of Asian anthropogenic aerosols that could quickly double the current Arctic Amplification of two times the global mean surface temperature increase, (9) reductions in atmospheric hydroxyl ions resulting in longer residence times for methane, (10) probable future Arctic oil & gas development, (11) increasing sea level rise will flood more permafrost leading to more degradation (see: http://onlinelibrary.wiley.com/doi/10.1002/2013JF002987/abstract), (12) the balance between CO₂ & CH4 emissions (see: http://link.springer.com/article/10.1007%2Fs10533-014-0012-0#page-1), (13) photochemical oxidation (see: http://www.sciencemag.org/content/345/6199/925) and (14) the influence of soil chemistry (see: http://www.pnas.org/content/early/2014/04/02/1314641111).

http://www.theguardian.com/environment/2015/apr/09/arctic-carbon-bomb-may-never-happen-say-scientists

Extract: "The Danish study looked at several sites in Greenland and measured the amount of warming in the soil generated by microbial metabolism – the process that causes compost to generate its own heat. The amount of heat produced at sites with a lot of organic material in the soil, such as peat bogs, was 10 to 130 times higher than sites with more mineral soils.
“Results show that the impact of climate changes on natural organic soils can be accelerated by microbial heat production with crucial implications for the amounts of carbon being decomposed,” said the study. “Permafrost thawing in organic Arctic soils accelerated by ground heat production represent a potentially critical global-scale feedback on climate change.”
Gurney said this effect would be limited to regions further from the poles where the permafrost was warmer - allowing microbes to survive. He said it was in these areas that the extra warming from microbes could cause something approaching the carbon bomb effect. But the carbon contained in these regions was only a part of the total carbon stored in the permafrost.
“We are talking about a fraction, but not a tiny fraction. It is a considerable amount of carbon,” he said. “In Canada and the Yukon it might be around 20%.”"

R. Justin Small, Julio Bacmeister, David Bailey, Allison Baker, Stuart Bishop, Frank Bryan, Julie Caron, John Dennis, Peter Gent, Hsiao-ming Hsu, Markus Jochum, David Lawrence, Ernesto Muñoz, Pedro diNezio, Tim Scheitlin, Robert Tomas, Joseph Tribbia, Yu-heng Tseng, & Mariana Vertenstein, (December 2014), "A new synoptic scale resolving global climate simulation using the Community Earth System Model", JAMES, Volume 6, Issue 4, Pages 1065–1094, DOI: 10.1002/2014MS000363

http://onlinelibrary.wiley.com/enhanced/doi/10.1002/2014MS000363/

E. A. G. Schuur, A. D. McGuire, C. Schädel, G. Grosse, J. W. Harden, D. J. Hayes, G. Hugelius, C. D. Koven, P. Kuhry, D. M. Lawrence, S. M. Natali, D. Olefeldt, V. E. Romanovsky, K. Schaefer, M. R. Turetsky, C. C. Treat & J. E. Vonk (09 April 2015), "Climate change and the permafrost carbon feedback", Nature, Volume: 520, Pages: 171–179, doi:10.1038/nature14338


http://www.nature.com/nature/journal/v480/n7375/full/480032a.html

J Hultman J, MP Waldrop, R Mackelprang, MM David, J McFarland, S Blazewicz, J Harden, MR Turetsky, AD McGuire, MB Shah, NC VerBerkmoes, L Lee, K Mavrommatis, and JK Jansson (2015), “Multi-Omics of Permafrost, Active Layer, and Thermokarst Bog Soil Microbiomes,” Nature, doi:10.1038/nature14238


http://www.nature.com/nature/journal/vaop/ncurrent/abs/nature14238.html

[AbruptSLR]

Ned,

Thanks for that fix.  You are right of course, I was specifically talking about Gavin's analog of the Eemian as a way to preclude future methane release from the ESAS later this century.  The warming of the ESAS occurs subsequent to inundation by rising sea levels.  The sea level highstand record for the Eemian indeed does provide a close analog to Holocene sea level records and inundation.  So in this my understanding was indeed incorrect.

In the way of color commentary, the linked reference suggests that permafrost thawing from the submergence of the ESAS about 14,600 years ago is a possible source of the both the abrupt carbon release and the associated abrupt increase in mean global temperature at the onset of the Bolling/Allerod, and that a similar occurrence could happen with continued global warming, as further sea level rise will flood substantial areas of currently un-submerged Arctic permafrost:

Peter Köhler, Gregor Knorr and Edouard Bard, (2014), "Permafrost thawing as a possible source of abrupt carbon release at the onset of the Bølling/Allerød", Nature Communications 5:5520; DOI: 10.1038/ncomms6520

http://www.nature.com/ncomms/2014/141120/ncomms6520/full/ncomms6520.html

Abstract: "One of the most abrupt and yet unexplained past rises in atmospheric CO2 (>10 p.p.m.v. in two centuries) occurred in quasi-synchrony with abrupt northern hemispheric warming into the Bølling/Allerød, ~14,600 years ago. Here we use a U/Th-dated record of atmospheric Δ14C from Tahiti corals to provide an independent and precise age control for this CO2 rise. We also use model simulations to show that the release of old (nearly 14C-free) carbon can explain these changes in CO2 and Δ14C. The Δ14C record provides an independent constraint on the amount of carbon released (~125 Pg C). We suggest, in line with observations of atmospheric CH4 and terrigenous biomarkers, that thawing permafrost in high northern latitudes could have been the source of carbon, possibly with contribution from flooding of the Siberian continental shelf during meltwater pulse 1A. Our findings highlight the potential of the permafrost carbon reservoir to modulate abrupt climate changes via greenhouse-gas feedbacks."

See also:
http://www.reportingclimatescience.com/news-stories/article/did-permafrost-melt-cause-abrupt-ice-age-co2-rise.html

[bryman]

bryman, may I kindly suggest to you as a 'newbie' here that you lower the level of bile in your posts, please.

Your claim "No one has even hinted at an increase of 8 plus degrees" is not accurate (though I will refrain from calling it a 'load of crap') and there is a whole thread devoted to the topic here that you might want to peruse before opining about it further.

I don't know what Gavin has or hasn't said about the level of understatement by IPCC. He did co-author a paper with Schindell and others a few years ago that gives a GWP of methane that is about 30% higher than that given in the current IPCC. Yes, that's not 300%, but we are talking about matters of degree rather than sign, and there is no particular need to use profanity and bile to engage in such discussions. Just a friendly suggestion.

Crap is not profane. Using an f-bomb is profane, and there are others on this site, such as viddaloo, who use the same level of rhetoric as I do, yet they are not reprimanded. That being said, AbruptSLR, what you fail to mention is that the most substantial feedback is methane release from permafrost, terrestrial and marine. Those are the ones worth paying the most attention to.

[jai mitchell]

bryman
see response here:  http://forum.arctic-sea-ice.net/index.php/topic,1053.msg49903.html#msg49903

[wili]

"viddaloo, who use the same level of rhetoric as I do, yet they are not reprimanded"

LOL

http://forum.arctic-sea-ice.net/index.php/topic,1227.msg49891.html#msg49891

[DungeonMaster]

"viddaloo, who use the same level of rhetoric as I do, yet they are not reprimanded"

Bryman, by their definition, you can't read private messages on those topics.

Everybody, please focus on topics, stay polite, and remember that we might not know everything yet... so cautious words are always welcome.

[Shared Humanity]

bryman, may I kindly suggest to you as a 'newbie' here that you lower the level of bile in your posts, please.

Your claim "No one has even hinted at an increase of 8 plus degrees" is not accurate (though I will refrain from calling it a 'load of crap') and there is a whole thread devoted to the topic here that you might want to peruse before opining about it further.

I don't know what Gavin has or hasn't said about the level of understatement by IPCC. He did co-author a paper with Schindell and others a few years ago that gives a GWP of methane that is about 30% higher than that given in the current IPCC. Yes, that's not 300%, but we are talking about matters of degree rather than sign, and there is no particular need to use profanity and bile to engage in such discussions. Just a friendly suggestion.

Crap is not profane. Using an f-bomb is profane, and there are others on this site, such as viddaloo, who use the same level of rhetoric as I do, yet they are not reprimanded. That being said, AbruptSLR, what you fail to mention is that the most substantial feedback is methane release from permafrost, terrestrial and marine. Those are the ones worth paying the most attention to.

I suppose you can hold whatever opinion you want about your word usage and I doubt your contributions, such as they are, will get you banned as Neven is not prone to doing this and I  would argue against banning anyone but I do believe you risk being placed on my ignore list. I must be getting more intolerant as it took viddaloo hundreds of comments to get this reaction from me. I come here to learn and the kinds of posts I enjoy provide me with these opportunities.  The most recent posts by AbruptSLR and Jai Mitchell are examples of the kinds of posts that I learn from.

Yours.......not so much.

[bryman]

bryman, may I kindly suggest to you as a 'newbie' here that you lower the level of bile in your posts, please.

Your claim "No one has even hinted at an increase of 8 plus degrees" is not accurate (though I will refrain from calling it a 'load of crap') and there is a whole thread devoted to the topic here that you might want to peruse before opining about it further.

I don't know what Gavin has or hasn't said about the level of understatement by IPCC. He did co-author a paper with Schindell and others a few years ago that gives a GWP of methane that is about 30% higher than that given in the current IPCC. Yes, that's not 300%, but we are talking about matters of degree rather than sign, and there is no particular need to use profanity and bile to engage in such discussions. Just a friendly suggestion.

Crap is not profane. Using an f-bomb is profane, and there are others on this site, such as viddaloo, who use the same level of rhetoric as I do, yet they are not reprimanded. That being said, AbruptSLR, what you fail to mention is that the most substantial feedback is methane release from permafrost, terrestrial and marine. Those are the ones worth paying the most attention to.

I suppose you can hold whatever opinion you want about your word usage and I doubt your contributions, such as they are, will get you banned as Neven is not prone to doing this and I  would argue against banning anyone but I do believe you risk being placed on my ignore list. I must be getting more intolerant as it took viddaloo hundreds of comments to get this reaction from me. I come here to learn and the kinds of posts I enjoy provide me with these opportunities.  The most recent posts by AbruptSLR and Jai Mitchell are examples of the kinds of posts that I learn from.

Yours.......not so much.

And I don't learn much from your posts either. AbruptSLR at least provides evidence to support his claims and doesn't presume certainty when making his points, which is more than I can say for Jai. And yet Viddaloo has the same type of rhetoric. Hypocrisy ring a bell to you? I'm not going to waste my time arguing with you. Put me on you ignore list, for I will do the same to you.

[wili]

I suppose you can hold whatever opinion you want about your word usage and I doubt your contributions, such as they are, will get you banned as Neven is not prone to doing this and I  would argue against banning anyone but I do believe you risk being placed on my ignore list. I must be getting more intolerant as it took viddaloo hundreds of comments to get this reaction from me. I come here to learn and the kinds of posts I enjoy provide me with these opportunities.  The most recent posts by AbruptSLR and Jai Mitchell are examples of the kinds of posts that I learn from.

Yours.......not so much.

+1

[Lennart van der Linde]

Everybody, please focus on topics, stay polite, and remember that we might not know everything yet... so cautious words are always welcome.

+1

[GeoffBeacon]

The awe with which some here regard Gavin Schmidt's views, I find a bit overdone.

All respect to Dr Schmidt for his knowledge and energy but has anyone here read Shakhova's letter to Sir Paul Nurse, when she and her team were not invited to present their empirical results to the Royal Society meeting last year ...

Our colleagues and we have been studying the East Siberian Arctic Shelf (ESAS) for more than 20 years and have detailed observational knowledge of changes occurring in this region, as documented by publications in leading journals such as Science, Nature, and Nature Geosciences...

To date, we are the only scientists to have long-term observational data on methane in the ESAS...

To our dismay, we were not invited to present our data at the Royal Society meeting. Furthermore, this week we discovered, via a twitter Storify summary (circulated by Dr. Brandon), that Dr. G. Schmidt was instead invited to discuss the methane issue and explicitly attacked our work using the model of another scholar, whose modelling effort is based on theoretical, untested assumptions having nothing to do with observations in the ESAS. While Dr. Schmidt has expertise in climate modelling, he is an expert neither on methane, nor on this region of the Arctic. 

https://robertscribbler.wordpress.com/2014/10/15/ignoring-the-arctic-methane-monster-royal-society-goes-dark-on-arctic-observational-science/

P.S. I hope Chris Reynolds will return to the subject. as in Arctic Methane: A Cause for Concern.
http://dosbat.blogspot.co.uk/2012/02/arctic-methane-paleo-perspective.html

[viddaloo]

The awe with which some here regard Gavin Schmidt's views, I find a bit overdone.

All respect to Dr Schmidt for his knowledge and energy but has anyone here read Shakhova's letter to Sir Paul Nurse, when she and her team were not invited to present their empirical results to the Royal Society meeting last year ...

Our colleagues and we have been studying the East Siberian Arctic Shelf (ESAS) for more than 20 years and have detailed observational knowledge of changes occurring in this region, as documented by publications in leading journals such as Science, Nature, and Nature Geosciences...

To date, we are the only scientists to have long-term observational data on methane in the ESAS...

To our dismay, we were not invited to present our data at the Royal Society meeting. Furthermore, this week we discovered, via a twitter Storify summary (circulated by Dr. Brandon), that Dr. G. Schmidt was instead invited to discuss the methane issue and explicitly attacked our work using the model of another scholar, whose modelling effort is based on theoretical, untested assumptions having nothing to do with observations in the ESAS. While Dr. Schmidt has expertise in climate modelling, he is an expert neither on methane, nor on this region of the Arctic. 

https://robertscribbler.wordpress.com/2014/10/15/ignoring-the-arctic-methane-monster-royal-society-goes-dark-on-arctic-observational-science/

P.S. I hope Chris Reynolds will return to the subject. as in Arctic Methane: A Cause for Concern.
http://dosbat.blogspot.co.uk/2012/02/arctic-methane-paleo-perspective.html

Truly a disgrace, GeoffBeacon.

I get the feeling this story is being "don't panic"ed, meaning it's considered too scary for people to know about, so kept partly in the dark, *really* scaring those of us who can use the internet and a search engine.

I guess science in the Free West isn't what it used to be.

[crandles]

Stoat's take on that was rather different:

[Update: this post was mainly about PW, so I missed:

“Consequently, we formally request the equal opportunity to present our data before you and other participants of this Royal Society meeting on the Arctic and that you as organizers refrain from producing any official proceedings before we are allowed to speak.”

from S (thanks m). If you’re not familiar with science, or the way meetings work, you may not realise how utterly risible this demand is. Its hard to know what S+S are thinking, in saying this: are they really the pompous asses that demand makes them out to be?]

http://scienceblogs.com/stoat/2014/10/07/wadhams-and-the-mighty-shtwit-storm/

[GeoffBeacon]

Well I'm glad I started this.

The point I was making is that we shouldn't make what some philosopher or other called "the argument from authority" too seriously.

It's not exactly a fallacy as the philosopher maintained: I do accept that some may know more than others and I'm not the most knowledgeable around or someone with the best judgment.

But I have seen the Last Hours video that features real scientists. It suggests we might be heading for another great dying caused by methane clathrate dissociation. (How does this connect with the latest in Science Magazine about a great dying from ocean acidification?). So if a great dying is on the cards we better be watching.

A few years ago I had a bit of a battle at Real Climate on the missing feedbacks in climate models. I got no answers and that made me think the modelers had a bit of "scientific reticence". It wasn't that their models were wrong (We all know models are wrong to some extent.) but  I felt a reluctance to admit their shortcomings.

Perhaps I shouldn't conflate the "science community" with "government departments" but I've decades of spin from them downplaying the climate issue. It's made me a low grade conspiracy theorist. Probably a bit more than Joe Romm.

What I want to hear/see is a calm discussion from people I recognise as open minded as well as knowledgeable. Sometime Gavin's a bit too forthright for my liking. It's one thing not to suffer fools gladly. It's another to think that nearly everyone else is a fool.

However, I rather liked Stoat's support of Gavin in "Wadhams and the mighty [sh|tw]it storm".
http://scienceblogs.com/stoat/2014/10/07/wadhams-and-the-mighty-shtwit-storm/

Good entertainment.  I hope Peter can see the funny side.

P.S. I did ask for judgments from people on this forum on Last Hours. I don't think there was much of a response.

P.P.S. Who is this Nick Breeze who was been interviewing Shakhova? And why is my local Wifi hotspot saying about his website

Sorry, you can’t access this page at XXXXXX
Access might be restricted to some websites where the content is considered unsuitable to view in a public family environment.

[crandles]

P.P.S. Who is this Nick Breeze who was been interviewing Shakhova? And why is my local Wifi hotspot saying about his website

Sorry, you can’t access this page at XXXXXX
Access might be restricted to some websites where the content is considered unsuitable to view in a public family environment.

http://envisionation.co.uk/index.php/blogs/99-russian-scientists-excluded-from-presenting-important-research-as-nasa-goddard-director-tries-to-discredit-observational-scientific-research

works for me at the moment.

[viddaloo]

P.S. I did ask for judgments from people on this forum on Last Hours. I don't think there was much of a response.

Where did you ask for that? URL?

[crandles]

www.lasthours.org

Very doomish. No uncertainty, virtually no timescales just 'it is happening'.
Only timescale I remember is 'Arctic summer sea ice will be gone this decade'.

I doubt that though I admit I did think it did look likely a couple of years ago.

If you express such certainty and then are shown to be wrong it seems likely to have an effect like crying wolf, you just don't get believed. Is the term 'doomer porn' being used for this or is that just for people who like to scare themselves?

[GeoffBeacon]

Crandles

I don't remember any timescales either. Just that if the Earth heats 6°C then 12°C will follow due to clathrate dissociation. But I'm interested in your judgment..

What odds do you put on the Earth reaching 6°C given BAU?

What odds do you put on the 12°C if the 6°C is reached?

I believe the LastHours scenario a bit so

6°C with BAU is a 60% chance.

If 6°C then 12°C from clathrate dissociation. That's a 60% chance too.

Timescale for a "clathrate great dying", say,  150 years, provided that the ocean acification great dying doesn't happen first.

P.S.I can get Nick Breeze's website in my office but not at XXXXX's wifi hotspot. But I can't get the campaigning site SumOfUs.org there either.

[crandles]

>What odds do you put on the Earth reaching 6°C given BAU?

Very much depends on how 'BAU' plays out. If renewables become cheaper than fossil fuels then fossil fuels will be phased out over next 30 years or so. 30 years of 2.5ppm/yr at present tapering down to zero from energy would keep us to 440ppm CO2 which is under two thirds of a doubling. It would take climate sensitivity of over 9C to get us to a 6C rise from that. Nobody is considering that. While there is still concrete, land use change, methane and so on still increasing it is a lot slower without fossil fuel energy and a lot can happen in that time.

If renewables cost decreases suddenly stop so that fossil fuels stay cheaper then 6C could be reached eventually but I doubt it will happen until well after we reach 560ppm CO2 which is around 60 years away at 2.5ppm/yr. While action may seem slow, a lot can happen in less than 60 years.

>What odds do you put on the 12°C if the 6°C is reached?

I have no idea how much vunerable clathrates there are.

[GeoffBeacon]

Crandles

Thanks. That helps (me at least)

[AbruptSLR]

>What odds do you put on the Earth reaching 6°C given BAU?

Very much depends on how 'BAU' plays out. If renewables become cheaper than fossil fuels then fossil fuels will be phased out over next 30 years or so. 30 years of 2.5ppm/yr at present tapering down to zero from energy would keep us to 440ppm CO2 which is under two thirds of a doubling. It would take climate sensitivity of over 9C to get us to a 6C rise from that. Nobody is considering that. While there is still concrete, land use change, methane and so on still increasing it is a lot slower without fossil fuel energy and a lot can happen in that time.

If renewables cost decreases suddenly stop so that fossil fuels stay cheaper then 6C could be reached eventually but I doubt it will happen until well after we reach 560ppm CO2 which is around 60 years away at 2.5ppm/yr. While action may seem slow, a lot can happen in less than 60 years.

>What odds do you put on the 12°C if the 6°C is reached?

I have no idea how much vunerable clathrates there are.

cradles,

While I very much appreciate your hopeful scenarios, the highest resolution CESM published to date (linked below) suggests that the Earth already has a relatively high climate sensitivity, which could increase nonlinearly as other positive feedbacks gain strength:

R. Justin Small, Julio Bacmeister, David Bailey, Allison Baker, Stuart Bishop, Frank Bryan, Julie Caron, John Dennis, Peter Gent, Hsiao-ming Hsu, Markus Jochum, David Lawrence, Ernesto Muñoz, Pedro diNezio, Tim Scheitlin, Robert Tomas, Joseph Tribbia, Yu-heng Tseng, & Mariana Vertenstein, (December 2014), "A new synoptic scale resolving global climate simulation using the Community Earth System Model", JAMES, Volume 6, Issue 4, Pages 1065–1094, DOI: 10.1002/2014MS000363

http://onlinelibrary.wiley.com/enhanced/doi/10.1002/2014MS000363/

Abstract: "High-resolution global climate modeling holds the promise of capturing planetary-scale climate modes and small-scale (regional and sometimes extreme) features simultaneously, including their mutual interaction. This paper discusses a new state-of-the-art high-resolution Community Earth System Model (CESM) simulation that was performed with these goals in mind. The atmospheric component was at 0.25° grid spacing, and ocean component at 0.1°. One hundred years of “present-day” simulation were completed. Major results were that annual mean sea surface temperature (SST) in the equatorial Pacific and El-Niño Southern Oscillation variability were well simulated compared to standard resolution models. Tropical and southern Atlantic SST also had much reduced bias compared to previous versions of the model. In addition, the high resolution of the model enabled small-scale features of the climate system to be represented, such as air-sea interaction over ocean frontal zones, mesoscale systems generated by the Rockies, and Tropical Cyclones. Associated single component runs and standard resolution coupled runs are used to help attribute the strengths and weaknesses of the fully coupled run. The high-resolution run employed 23,404 cores, costing 250 thousand processor-hours per simulated year and made about two simulated years per day on the NCAR-Wyoming supercomputer “Yellowstone.”"


Extracts: "The high-resolution CESM was run under “present-day” (year 2000) greenhouse gas conditions (fixed CO2 concentration of 367 ppm). This was chosen so that direct comparisons could be made with recent-era observations of fine-scale and large-scale phenomena. The prognostic carbon-nitrogen cycle was not used in this simulation.

[BengalBangles]

cradles,

While I very much appreciate your hopeful scenarios, the highest resolution CESM published to date (linked below) suggests that the Earth already has a relatively high climate sensitivity, which could increase nonlinearly as other positive feedbacks gain strength:

R. Justin Small, Julio Bacmeister, David Bailey, Allison Baker, Stuart Bishop, Frank Bryan, Julie Caron, John Dennis, Peter Gent, Hsiao-ming Hsu, Markus Jochum, David Lawrence, Ernesto Muñoz, Pedro diNezio, Tim Scheitlin, Robert Tomas, Joseph Tribbia, Yu-heng Tseng, & Mariana Vertenstein, (December 2014), "A new synoptic scale resolving global climate simulation using the Community Earth System Model", JAMES, Volume 6, Issue 4, Pages 1065–1094, DOI: 10.1002/2014MS000363

http://onlinelibrary.wiley.com/enhanced/doi/10.1002/2014MS000363/

Abstract: "High-resolution global climate modeling holds the promise of capturing planetary-scale climate modes and small-scale (regional and sometimes extreme) features simultaneously, including their mutual interaction. This paper discusses a new state-of-the-art high-resolution Community Earth System Model (CESM) simulation that was performed with these goals in mind. The atmospheric component was at 0.25° grid spacing, and ocean component at 0.1°. One hundred years of “present-day” simulation were completed. Major results were that annual mean sea surface temperature (SST) in the equatorial Pacific and El-Niño Southern Oscillation variability were well simulated compared to standard resolution models. Tropical and southern Atlantic SST also had much reduced bias compared to previous versions of the model. In addition, the high resolution of the model enabled small-scale features of the climate system to be represented, such as air-sea interaction over ocean frontal zones, mesoscale systems generated by the Rockies, and Tropical Cyclones. Associated single component runs and standard resolution coupled runs are used to help attribute the strengths and weaknesses of the fully coupled run. The high-resolution run employed 23,404 cores, costing 250 thousand processor-hours per simulated year and made about two simulated years per day on the NCAR-Wyoming supercomputer “Yellowstone.”"


Extracts: "The high-resolution CESM was run under “present-day” (year 2000) greenhouse gas conditions (fixed CO2 concentration of 367 ppm). This was chosen so that direct comparisons could be made with recent-era observations of fine-scale and large-scale phenomena. The prognostic carbon-nitrogen cycle was not used in this simulation.

If it isn't too troublesome, could you point towards the sections of the CESM that point towards a high and nonlinear climate sensitivity? The abstract and summary did not seem to point towards that conclusion.

[crandles]

>What odds do you put on the Earth reaching 6°C given BAU?

I rushed a little to finish that answer. While 1.5 or 2C may be dangerous particularly for undeveloped countries, I think ECS of 5C or warming of 5C is undoubtedly catastrophic. Just because I don't see much chance of getting to 6C warmer quickly doesn't mean I don't think 2C is dangerous and 4C will have major adverse effects. There is much more chance of getting to 4C and 2C looks hard to prevent.

[Ned W]

If it isn't too troublesome, could you point towards the sections of the CESM that point towards a high and nonlinear climate sensitivity? The abstract and summary did not seem to point towards that conclusion.

The paper ASLR cited doesn't mention climate sensitivity and is not about climate sensitivity.  It's just a description of a set of experiments using CESM.  I have no idea why ASLR thought that paper was some kind of rebuttal to crandles's post.

[AbruptSLR]

Ned W,

When Earth System Model scientists publish papers they generally assume that the readers know that climate sensitivity parameters such as ECS, TCR, or TCRE are emergent values based on the global mean temperature rise projections as a function of the radiative forcing input.  In the case of the paper that I linked to the radiative forcing input was a fixed CO2 concentration of 367ppm, and per the attached output (i.e. panel b of Figure 1, where the thick line shows the CESM-H run while the thin line shows the standard CESM run) the global mean surface temperature rise in less than 30-years was over 1C temperature rise.

While I never said that this is solid proof that climate sensitivity is unexpectedly high, and I am not saying so now; I am very definitely saying that is not advisable to play brinksmanship to see how close to the carbon budget limit that we can get (if we have not already gone into the inadvisable range), when the ESM selected by the DOE to be the foundation of their state-of-the-art ACME program indicates such a strong response to such restricted forcing (particularly when the CO2-equivilant value is currently over 485ppm).

[crandles]

It looks to me like the thin grey line (standard resolution) indicates the model has not reached equilibrium at the start and levels out at just over 288K. Not quite clear where the thicker line (increased resolution) levels off but it looks like about 288.8 to 289K to me.

Both these increases are due to the model not being fully spun up to reach equilibrium. i.e. the upward drift and difference is due to the model being out of balance not due to change in CO2 level.

While it may be tempting to think that the higher resolution model goes up more therefore its sensitivity will be higher, I am not at all sure that that follows. You obviously have to correct such a difference to get a sensible hindcast.

Anyway the 1C rise in 30 years is clearly an artifact of the model not being fully spun up and it isn't realistic or any sort of projection.

> is not advisable to play brinksmanship
I agree with that.

[AbruptSLR]

I concur that with such a complex, nonlinear run as for the reported CESM - H response that it can be difficult to distinguish between model bias, spin-up and true response.  Nevertheless, I believe that it is fair to say that the high resolution run is more responsive than the standard model run, and we are (society is) gambling that deep tropical atmospheric convection is not contributing more to a higher current value of ECS than AR5 assumes.

For further background on the risks that AR5 may well be erring on the side of least drama see the recent (& older) discussion on this topic in the following thread, beginning with my Reply #752:

http://forum.arctic-sea-ice.net/index.php/topic,1053.750.html