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fryingpan136

Great post, as usual! Yes, this stuff is too important and potentially catastrophic to lose sight of the forest.

Ocean acidification is another potential time bomb from our carbon emissions. If humans are confronted with the loss of protein from the ocean at the same time droughts, flooding, heat waves, and ground water depletion are creating agricultural losses, it could get very ugly for our growing population.

Some whine about the costs of combating climate change. Few consider the long term consequences of global warming.

Steve Bloom

Neven, IMO you should add a highlight on this new paper. I posted it a while back (and I think I may have done the same with the Ballantyne paper when the pre-pub became available a couple months back) but it sank instantly into the slush of the horse race excitement.

That last was perhaps a hint to ease up a bit on the competitive guessing stuff. There are lots of other relevant papers that have passed by with no attention here (or much of anywhere).

Or maybe screw all that and just focus on debating whether to name the cyclones George, Alexander or Louis? :/

Doug Bostrom

With due caution, Neven describes the $60T scenario as an extreme worst-case and speculates that deniers will do their best to ridicule such a proposition.

It's interesting to consider that a scant decade or so ago, anybody daring to hypothesize Arctic sea ice reaching its present parlous condition by the year 2013 would also have been citing an extreme worst-case scenario and would have been mocked by more than the usual suspects.

Without knowing in advance exactly what history of methane will emerge we can confidently posit a continuum of outcomes marked at one end as "undesirable" and at the other "utterly disastrous." The still-unfolding Arctic ice history says we should anticipate being deposited at the wrong end of the continuum.

Alberto Silva

This Nature comment is explicit:

"The release of methane from thawing permafrost beneath the East Siberian Sea, off northern Russia, alone comes with an average global price tag of $60 trillion in the absence of mitigating action — a figure comparable to the size of the world economy in 2012"

The sentence in bold says that the net present value (NPV) of the damage done by just the methane release alone (ignoring all the other climate change and ocean acidification impacts)could be roughly big as the world economy (measured as GPD).

I do not have access to the study on which was based the Nature comment so I cannot make a fully informed opinion, but just the possibility that the costs of climate change could be so big should be a headline in all newspapers of the world.

I just wonder if the discount rate(the rate at which the future revenues or losses are discounted to account for the time value of money, that in turn is a function of economic growth)could go below zero if the world economy slows down and then shrinks due to the cumulative effect of environmental damages.

So far, I do not know a study that includes the "negative growth scenario" as a possibility.


Brian Wind

Honestly, things really do look very bad. I am a long-time amateur naturalist and environmentalist who has become obsessed with global warming. I read everything I can find on this topic, and have become convinced climate change is happening much more rapidly than anyone wants to admit. That includes this blog; instead of sounding alarms is discussing starting a tradition of naming arctic cyclones. Realistically, we have about five years until arctic methane thaws and global warming takes off in earnest. We all know this.
But seriously, none of us, absolutely no-one, can deal with the scale of catastrophe that 4-6 degrees global temperature increase would mean with a global population of 7 bill people. And we cannot deal with the profound social and economic changes necessary to avoid this disaster. I will continue to sound alarms as a private citizen, but no-one can hear me. I become another old man ranting about the end of the world.
So pour a glass of wine, put on some good music, and enjoy the company of family and friends. Time is running out.

George Phillies

" “extra $60 trillion (net present value) of mean climate change impacts” — comparable to total global GDP at present"

The comparison is invalid, because the units are completely different. One is in dollars, the others is in dollars per year.

A rational comparison would be between the cost and the current net worth of the world, or between the cost and the total national product over the years that the damage was inflicted.

Alberto Silva

"A rational comparison would be between the cost and the current net worth of the world"

You are 100% right. I was fooled by the typical use of GDP as the global standard.

Please, could you tell me how may be computed that the "current net worth of the world"?

I have not seen any analysis that make an estimate of that, so I wonder what value is it(and I have asked that many times, and nobody could give me an answer), and as a function of what variables could be computed.

Also, to compare apples with apples will be great to see the estimated costs of climate change damages as a function of time, to compare them with the estimated future GDP.

A-Team

I would echo the concerns of Steve B above.

That South Kara Sea methane full text was an easy and informative read that complemented related studies in the East Siberian and US and Canadian Beaufort Seas.

It provided significant new data and better understanding of events beginning in the last marine transgression at 19 kyr, notably the longer exposures of deeper methane deposits and sediment sources to a radically warmer and thermally more conductive regime.

Meanwhile, the Nature article did not lift a scientific finger towards assessing the methane factual situation.

I didn't add a comment at the time Steve first brought it up. Waste of resources -- I know a great deal on the scientific side of methane and am willing to explain it -- but for the time involved, the background level of participant misunderstandings, the rapidity with which comments get buried, maybe 2-3 others following the commentary, and peak melt season hard upon us -- it couldn't be justified.

Climate science mostly dodders along on its 2100 timeline -- folks still hiding their latest little papers on 1979-2006 ice pack behind paywalled journals, profe$$ional $ociety barriers and minimalist, rarely updated research group web sites -- whereas the mainstream publicaly funded sciences abandoned those practises years ago.

Methane is never going to get a fair shake from scientists deeply -- and mistakenly -- invested in the carbon dioxide modeling culture and the self-imposed holy grail of land temperature sensitivity to its doubling, outdated, irrelevent and mis-placed agendas at this point (400 ppm). Yet that is almost entirely what the public hears about.

What to do? -- we are in a situation here where maybe 1 person here in 20 has full-text access and perhaps 7-8 more have the stomach for them. However under fair use, those with access could quote enough that others would have an unimpeded view (which rarely would add up to a half dozen paragraphs and 1-2 figures).

Sea ice is a done deal -- if not this year, then the next 1-2. So come October slackwater, maybe get serious on developing a methane resource with quality like that of the sea ice.

Hans Gunnstaddar

Steve Bloom, what good does it do to play it safe attempting to build credibility with the same conservatives that projected an ice free Artic in 2100?

I tip my hat to Neven for opening the discussion to what will probably be the next tipping point after an ice free Arctic. If we get conservative and dish it off for someone else some other time, then who and when? I for one am tired of these overly conservative projections that become the accepted platitude by the MSM.

As fast as the Ice volume, area and extent are declining, we should all become mathematicians knowing a probability of disaster is worth every effort to try and avert, not placate for the benefit of greater resource extraction.

Mdoliner43

As a mathematician I look at it from a slightly different slant. From what I understand clathrate release as methane is a function of pressure and temperature. The question is, is this a continuous function. Put another way: are the clathrate deposits physically continuous so that an increase in surrounding temperature will produce an increase in methane release. If so, since methane is already being released, and the temperature rise we are already committed to is perhaps 1 degree more than we have now, that further temperature increase will release more methane which will launch runaway greenhouse climate warming since every temperature increase will release more methane. Only if the temperature can rise at some point without further methane release is there even the remotest chance of some humanly endurable temperature plateau. I have no idea what this function is.

Hans Gunnstaddar

Mdoliner, you wrote; "Only if the temperature can rise at some point without further methane release is there even the remotest chance of some humanly endurable temperature plateau."

Yes, another good math viewpoint. If the ice melt trend in the Arctic is any indication, there will be no intermediary methane plateau.

What's the rate of acceleration in methane releases?, will an interesting one to try and plot on a graph as data builds y2y.

Dan Ellis-Jones

Klon - a very interesting piece of research regarding the Greenland Ice Sheet.

If the inland ice in 2007-2008 was moving at 1.5 times the rate it was in 2000-2001, then with the increased melting in the last 5 or so years, including the virtually total surface melt of last year, the volumes of warmer melt water now under the entire GIS would be massively increased. It would be intriguing to know if the flow rate has increased as well.

Living in Perth, Australia, sea level rise is important to us. We have some of the largest annual increases in SL in the world (or so I've been told) at 9mm per year. To me, it's starting to be visible. We sit at or even a little under seal level, and winter tides are increasingly high, with storm surges innundating the freeway along the river.

I've worked in Climate Change policy for close to 10 years, and about 90% of all the science I've read over that time has said 'things are worse than expected'. IOCI - a scientific research group in Western Australia looked at our climate and impacts, and found that observations have been about 50% worse (more impact, quicker) than their very well developed models.

...and then I went and read about peak oil! whoops!

Jon Torrance

@Brian Wind

If you're going to rant, would you mind not deploying the phrase "But seriously...." in the middle of it? It makes it difficult for those of us who mght be unwilling to let you speak for everyone here about what we all 'know' to respond to everything you wrote up until then, either partially or fully in jest.

fryingpan136

@ Brian Wood

Righteous rant.

I know how you feel about these impending catastrophes not getting the serious attention they deserve. Bad things look likely to happen, but the media and society in general seem unimpressed. Some are certain technology, which is how we got in this mess, will rescue us. Others await the second coming,, so why should they care? Minimizing the huge future impacts, even as the current minor impacts cause death and chaos, is another approach. Plain old denial is also popular.

Looking at the numbers and projecting to an ice free arctic, along with its
feedbacks, leaves me very pessimistic and in need of a good glass of wine.

Cy Halothrin

I don't see how one can really put a total price tag on what global warming will cost us, because the price continually rises as time moves on. So maybe global warming causes crop losses of US$1 billion this year, but 10 years from now it's US$10 billion a year, plus more to repair damaged infrastructure from storm surges. But 20 years from now, it's $1 trillion per year as people are forced to abandon coastal cities and flee to higher ground. Eventually cost goes down, as the economy is in tatters and tent city climate refugees simply die. Cost eventually goes to zero as humanity perishes.

Still, I suppose it's somewhat useful to throw a number out there, to wake people up to the fact that doing nothing costs more than doing something.

Susan Anderson

Cy Halothrin, your current numbers are too low. A brief search provides these:
http://www.insurancejournal.com/news/international/2013/07/25/299600.htm
"1st Half 2013 Natural Disasters Cost $85 Billion – Aon Benfield"

Granted, you only mentioned US crop disasters.

I am grateful to you all, and at the fora, for talking through this with plenty of evidence and thoughtful consideration, neither dismissive nor overly assertive.

George Phillies

Clathrate release is a phase transition. Depending on T,P clathrates either are or are not stable.

George Phillies

Net worth of the world: Full cost of replacing everything. It's a considerable multiple of the GDP of the world, but I do not know which multiple. For example, the city in which I live has a considerable number of structures going back a century, and some going back two centuries; that's a lot of investment, which would need to be replaced using current costs.

I do not know where this number has been computed, though.

Susan Anderson

Back at the ranch, this water vapor animation for context - note Siberia

http://synoptic.envsci.rutgers.edu/site/sat/sat.php?sat=nhem&url=../imgs/wv_nhem_anim.gif

Chris Reynolds

Slightly off topic:

I recently posted a link to my calculations of PIOMAS thickness, it didn't work for some people so here it is again.
https://drive.google.com/folderview?id=0B3pB-kdzoLU3T2RSSGIxYkJVMlU&usp=sharing
I'm posting here because I can't remember where I posted originally. :(

Susan Anderson

Wunderground (Burt's blog) seems like a meteorologists night out together - drunken stats in a whirlwind of information:

http://www.wunderground.com/blog/weatherhistorian/comment.html?entrynum=177

Dan Ellis-Jones

George,

The cost of replacing everything - in a similar manner to insurance - is impossible. We don't have enough resources to incrementally increase the amount of 'things' needed for the growing population as it is - which (assuming climate change/Arctic ice melt doesn't get us first) will stop civilisation before the end of the century (or at least as we know it).

However, there are a couple of silver bullet technologies that might aid us, and prolong our way of life. I'm not sure what I think of these, and if they're realistic. But don't under-estimate the desire of the political and economic 'elites' to keep everything from going pop. I believe the ingenuity of human beings coupled with insanely rich vested interests can work to keep everything going, until they can't!

But currently we are in not only a carbon-constrained world, but an oil-constrained world. There's just not enough cheap oil in the ground, and running through the pipes, to allow global growth like we saw for most of the last decade. This is a permanent fixture (thankfully for the climate!).

We've eaten all the low hanging fruit, the middle hanging fruit is just about gone, and all we have left is the mouldy, shrivelled, difficult-to-get fruit that's being decimated by the prevailing climate. Once that's gone... ?

LRC

Then we run into what happens to Greenland icesheets (same goes for Antarctic). Found this study. http://cires.colorado.edu/news/press/2013/greenland-inland-ice.html
Did find this article http://www.sciencemediacentre.co.nz/2013/07/15/polar-ice-loss-speed-up-may-not-last-experts-respond/
This part struck me as deja vu all over again.
"Now a new study examining the satellite record concludes that natural variability can’t yet be ruled out, and that recent trends could be down to short-term variations, a form of ‘ice sheet weather’. The research was published in Nature Geoscience this week."
Makes you wonder what decade those experts are living in.
There are 3 very influential groups though that are taking GW very seriously. Municipalities, Insurance companies and lawyers. In North America at least the courts are deciding that even 'once in a century' storms are no excuse for lack of infrastructure to handle severe storms as they are deciding the evidence is already in that GW is real and the experts they are choosing to believe
have been warning of severe weather becoming the norm as a result long enough for cities to have made the necessary changes.
The extra costs not only improving infrastructure, but in losing costly law suits will then start making them press more and more on federal level governments to get very serious about GW. Question will be will it be fast enough.
Losing GIS at a faster rate could then cause big problems on the US east coast. Dikes can not be built fast enough to save Florida even if sea level rises a couple of feet, http://www.umces.edu/sea-level (then you must include storm surge from hurricanes) But you also have NYC, Atlanta, Washington ..... Costs to US alone on saving and/or losing densely populated low lying areas of the east coast would be extremely high.
One must also remember that the higher SL rises the faster the ice sheets will disappear. Not only that the Arctic lands around the Arctic Ocean will start getting more and more flooded impacting perma frost and methane deposits.
I was always one who believed the worst case scenario projected was going to be worse then any one saw in print, meaning our kids and grand kids were going to curse us for our stupidity. But I am now thinking I could see things in my life time that 15 years ago the most pessimistic was calling for in 2100+++.

Fufufunknknk

DOug noted that "a scant decade or so ago, anybody daring to hypothesize Arctic sea ice reaching its present parlous condition by the year 2013 would also have been citing an extreme worst-case scenario and would have been mocked by more than the usual suspects"

Maybe it is time that the critics and all of their predictions from back then where held to the flame. Their predictions are on record, no?

Andy Lee Robinson

With stakes this high, optimism is an indulgence nobody can afford.

Such high costs are difficult to comprehend, perhaps meaningless. New work and markets will open up based around survival technologies.
Facing extinction ought to be a great motivator and should be quite profitable for someone!

jdallen_wa

Total world wealth in 2012 was probably in excess of $120 Trillion, including infrastructure. A $60 Trillion price tag for the cost of global warming over coming decades is entirely reasonable, especially when you consider the multiple billions of people who will be displaced, and the lost coastal infrastructure resulting from the inevitable eventual sea rise. It is an easy number to defend.

I don't agree with "doom" scenarios which hypothesize the end of civilization and possibly the species. Certainly however, I also think that the deaths of billions of people could be a likely outcome as well, from a combination of weather related havoc, famine, plague and war.

The resulting "warmed" world I think will certainly still be habitable. It's the transition that will hurt... a lot.

Steve Bloom

LRC, I think you misunderstand the point that paper makes. It's that the record of mass loss observations is too short to establish a statistically valid trend based solely on those observations. It's neither here nor there relative to the other ice sheet papers that have come out recently.

Steve Bloom

Interesting new paper (title/abstract):

Increasing amount of Arctic Ocean deep waters in the Greenland Sea

In the last three decades, deep convection has come to a halt in the Greenland Sea. Hydrographic data reveal that during this period temperature and salinity in the deep Greenland Sea have increased at mean rates without precedent in the last 100 years, and these trends are among the highest in the global deep ocean. The origin of these changes is identified as the advection of Arctic Ocean deep waters and the necessary transports to explain them are calculated (0.440.09  Sv). Despite the fact that the deep Greenland Sea hardly covers 0.05% of the global surface, the resulting trends constitutes 0.3% of the World Ocean heat content increase per unit area of earth's surface and 0.1% of the global sea level rise. These results suggest that changes of the deep Arctic Mediterranean and their contribution to the global budgets need to be addressed.

Sounds to me like a fundamental change. And if Arctic Ocean deep waters are advecting out, something else is advecting in.

Kate

@jdallen_wa

"It's the transition that will hurt... a lot"

As a biologist I see this as an evolutionary necessity if we are to evolve any further. Not physically evolve, more social, economic, and scientific evolution.

If anyone needs to be reminded of the steps needed to evolution.

http://biologyreasoning.wikispaces.com/file/view/boxes.gif/227537558/boxes.gif

I'd also like this to be an opportunity where everyone can agree that religions have no place in deciding anything but a few personal and private things.

This is what I hope to live long enough to witness.

dorlomin

The Arctic has been warmer than today during the holocene. Whats more it was warmer for longer.

This mean there were thousands of years for the heat to 'bake' into the deeper ocean. This extra energy came from the Arctic being something like 3 million kilometres closer to the sun during summer than today. At the 60N, the sun was about 40 watts per square meter more energetic than today during, June\ July.

Water takes a long time to warm up.

Kate

I just hope that in some regions there are benefits to a wetter, warmer world...and there should be. It wont be the end, just a big big change.

I've been watching the sea ice concentration animations - so easy to see the ice being cracked apart by the recent storm and continuing system.

http://www7320.nrlssc.navy.mil/hycomARC/navo/arcticicen_nowcast_anim30d.gif

Neven

Kate, please discuss the current state of the ice pack in the ASI update thread, or the Second storm thread. :-)

Ghoshmm

David Archer had a post on the methane issue in Real Climate some 18 months ago.

http://www.realclimate.org/index.php/archives/2012/01/an-arctic-methane-worst-case-scenario/

The worst-case methane scenario stands comparable to what CO2 can do. What CO2 will do, under business-as-usual, not in a wild blow-the-doors-off unpleasant surprise, but just in the absence of any pleasant surprises (like emission controls). At worst comparable to CO2 except that CO2 lasts essentially forever.

Ned Ward

Mdoliner43 writes: [...] that further temperature increase will release more methane which will launch runaway greenhouse climate warming since every temperature increase will release more methane. Only if the temperature can rise at some point without further methane release is there even the remotest chance of some humanly endurable temperature plateau.

I don't think that's correct, though it's a common misconception. A runaway warming would only occur if the methane released by X degrees of warming was enough to directly produce X (or more) degrees of additional warming. If that isn't the case, then the methane feedback (or any positive feedback) will result in warming that approaches some limit, rather than "runaway" warming.

For example, if 1C of warming released enough methane to warm the planet a further 0.2C, that additional warming would result in and additional 0.04C warming, and so on, cumulatively approaching a limit of 0.25C above the initial (non-methane) 1C warming pulse.

There are in fact many positive feedbacks in the climate system that don't lead to runaway warming.

NeilT

As I recall, the sum of the methane clathrates under the sea was something like 3* the total of CO2 currently released to date.

Of course we would not release all of that as much of it is too deep to be affected in the next 1,000 years or so.

However the clathrates aren't the only part of the picture. Land based methane is also an issue.

I've read the articles which say that any "Methane Bomb" would be short lived and would shift us to another level, but would not create a runaway effect. Then again, that higher level would put us so much closer to extinction in one short step.

I'm always wary when a scientist says that things will "just change state and stay there".

Because when it comes to state changes like that, the species survival chances reduce significantly.

I find scientific research too vertical. Not enough joined up thinking to quantify the dangers of climate change.

I always liken it to the study on the impact of texting on the physiology of humans. The study which concluded that after 5,000 years, humans would have grown longer thumbs due to texting. In fact, in 5,000 years time (assuming we survive), any device which requires more than some thought to drive it will be a curiosity in a museum of the "dark ages"....

Ned Ward

dorlomin writes: The Arctic has been warmer than today during the holocene. Whats more it was warmer for longer.

Yes. And my understanding (others here probably know more about this) is that there was probably significantly less sea ice during the Holocene Climate Optimum (~7000 years BP), and during at least some previous interglacials (e.g., MIS 5e).

For me, this tends to argue against the idea that near-future (21st century) anthropogenic warming would lead to any large and abrupt release of methane from the Arctic.

I guess I'm not really sure what is meant by an "Arctic Time Bomb". If it's an event that would be unprecedented during the Pleistocene, then why didn't previous warm-Arctic episodes (during other interglacials) set off this "Time Bomb"?

On the other hand, if by "Time Bomb" we just mean a series of feedbacks that contribute to a somewhat milder and periodically or perennially ice-free Arctic Ocean -- i.e., a return to conditions that may have occurred several times over the past million years -- then it becomes more understandable. The analogy of a "bomb" doesn't seem particularly helpful, though.

michael sweet

Dorlomin,

According to Marcott et al summarized here, it is currently hotter than at any other time in the Holocene. The current forcing is greater than the forcing at any time in the Holocene, only the oceans heat capacity is keeping the temperature anywhere near what it was earlier in the Holocene.

Please provide a cite to support your wild claim that it was warmer in the past during the Holocene. That is a denier meme that is not in fact true.

michael sweet

Dolomin and Ned,
According to Marcott et al summarized here, it is currently warmer than at any time in the Holocene. It is a denier meme that it was warmer earlier in the Holocene. Please produce a cite to support your wild claim that it was warmer earlier in the Holocene. Only the great heat capacity of the ocean is keeping the temperature near what it was earlier in the Holocene.

Since it is now warmer than at any other time in the Holocene, we certainly need to be worried that natural gas that has been trapped for thousands of years might be released.

dorlomin

it is currently warmer than at any time in the Holocene. It is a denier meme that it was warmer earlier in the Holocene.

Not in the Arctic.
dorlomin

http://www.sciencedirect.com/science/article/pii/S0277379103002956

The spatio-temporal pattern of peak Holocene warmth (Holocene thermal maximum, HTM) is traced over 140 sites across the Western Hemisphere of the Arctic (0–180°W; north of ∼60°N). Paleoclimate inferences based on a wide variety of proxy indicators provide clear evidence for warmer-than-present conditions at 120 of these sites. At the 16 terrestrial sites where quantitative estimates have been obtained, local HTM temperatures (primarily summer estimates) were on average 1.6±0.8°C higher than present (approximate average of the 20th century), but the warming was time-transgressive across the western Arctic. As the precession-driven summer insolation anomaly peaked 12–10 ka (thousands of calendar years ago), warming was concentrated in northwest North America, while cool conditions lingered in the northeast. Alaska and northwest Canada experienced the HTM between ca 11 and 9 ka, about 4000 yr prior to the HTM in northeast Canada.

A-Team

Ned writes "significantly less sea ice during the Holocene ... argue against the idea that near-future would lead to any large and abrupt release of methane "

Prior to its gradual inundation by sea water (which continues to this day), land permafrost was frozen to very considerable depth during the last, long ice age. That cap, now under continental shelf water and still frozen, is completely impermeable to upward methane diffusion (except at faults and talik lake chimneys which are only now melting).

Because inundating water was very cold and heat diffusion intrinsically very slow, warmer mid-Holocene episodes never entirely melted the cap and so methane accumulating under the cap (primarily from oil shale thermal decomposition in the case of ESAS) was never purged but instead continued to accummulate. Methane clathrate does not exist at depth because of the earth's geothermal gradient.

The South Kara Sea methane article Steve B brought up has a good discussion for that region. Only the offshore cap past the 20 m contour has become permeable to date.

R. Gates

Doug B. said:

"It's interesting to consider that a scant decade or so ago, anybody daring to hypothesize Arctic sea ice reaching its present parlous condition by the year 2013 would also have been citing an extreme worst-case scenario and would have been mocked by more than the usual suspects."

_____
This is an excellent point, and one that leads to a larger point-- the current decline in sea ice and rapid changes going on in the Arctic is not predictable from even the recent past i.e. 10 years ago. We are seeing a rapid regime change that no model could predict because it represents a dragon-king, nonlinear disconnect brought about by a combination of positive feedbacks. Unfortunately, our human brains are not wired to recognize such nonlinear jumps for what they are. Our brains are wired to use current smooth linear changes to predict future behavior.

The potential rapid release of methane-- rapid from a geological perspective, just as the the release of CO2 has been, is only one of several potential nonlinearities based on the substational kick that the human carbon volcano is giving to the climate. When you kick a chaotic system like the climate this hard, the response will be nonlinear (must be nonlinear in fact.) So while a large methane release is a concern, what might be of even more concern is that the odds are very high that there are other nonlinear repsonse "dragon-king" events that we simply can't know about lurking just over the horizon.

Kevin McKinney

Apologies if I missed it in this excellent but voluminous comment thread--however, if you read the "Methane Costs" paper, the $60 trillion mean cost is *cumulative.* The rate is about $1 trillion yearly.

The paper is available here:

http://www.nature.com/nature/journal/v499/n7459/pdf/499401a.pdf

On another topic in the thread:

dorlomin, your assertion seems well-supported at first blush--don't have time to look further at it right now, though I want to come back to it--but I think it's unfair and incorrect to say that the idea of warmer temperatures further back in the Holocene is a 'denier meme.'

There's a lot of literature out there about the "Holocene Optimum," which had temps peaking 8-10K back. (Though I'm willing to believe that this work is older, and hence doesn't hold for post-2000 temperature values.)

BTW, it's another denier meme that we're 'just recovering from the Ice Age (by which is generally meant 'the last glaciation'), so of course it's warming.' The 2000-year cooling trend found in papers like Kaufman et al, 2009, is a strong antidote to that argument. Of course, it would only be strengthened by clear evidence that current temps do in fact represent the new Holocene 'peak.'

Ned Ward

Re comment by Michael Sweet:

During the mid-Holocene, insolation at 65 N during June and July was more than 30 W/m2 higher than it is today. You can't look at a global paleo temperature record and compare that to Arctic temperatures. Orbital forcings in the Arctic are much greater than for the globe as a whole, particularly if you look at a single season (e.g., summer).

Sam

My oh my- so many problems.

The PAGE09 model has more than a few flaws and defects. All of these seem to dramatically underestimate impacts and consequences.

But let's start with the real kicker. They limited the impacts at 100% of GDP, which they show occurring between 5-6 degrees C. Read that again. They limited the financial impacts at the consumption of the entire GDP! Can you say end of civilization? I thought you could. So, the buried lead in their study is that civilization is over by the time we get anywhere near a 5 degree C rise. And we are fully on course for that.

Some added problems.

The model is entirely anthropocentric. These are the financial costs. They are costs for infrastructure, changes in agriculture, health impacts, etc... These are then discounted in standard ways (presumably at 3.3% or greater). These two choices have huge impacts on the results.

The first excludes the entire cost of the loss of more than half of all species on earth, not to mention the end of agriculture as we know it, mass population dislocation and death and other 'little' things like that.

The second essentially devalues anything beyond 50 or so years (or less). So the largest of the impacts count as zero in the result.

This continues the long term fallacy of using accounting methods for present value on a debt stream. PV works if you have a large chunk of cash up front and you are deciding how to invest. It works not at all on accumulated future debt. To the contrary, it drives decisions that result in larger future impacts and lesser near term costs. So, by all means, defer all actions to the future. That'll fix it.

More over, the model uses a triangular distribution for parameters. The world operates mostly as log normals with long right hand tails, and occasionally as normal distributions also with long right handed tails.

And perhaps worst of all, it completely excludes everything we do not know but now see evidence for, such as the methane clathrate collapse issues that lead to highly non-linear step changes in the system;whereas the model assumes monotonic simple linear responses.

Perhaps the only good thing about the study is that the result despite these overwhelming failings is so catastrophically large as to get the attention of the financial types who run everything.

We are at a time now where averting the most extreme catastrophe imaginably is only barely possible if we do absolutely everything imaginable to stop using fossil fuels immediately. The body real politic on the other hand only sees the very near term and views the shale oil and gas as the panacea to world problems, and more growth fueling more wars to steal resources as the answers.

We are headed headlong into the abyss with our foot cramming the pedal to floor, and afterburners on full. Woo hoo!

Sigh.
Sam

NeilT

Reading Doug B and R Gates' comments reminded me of something I read a while back on RealClimate.

It was posted in January 2007. I'm sure it was prompted by the 2005 sudden retreat of the ice and it was very "forward" thinking at the time. 2040 for <2m sqkm SIE was almost "unthinkable" at the time. Forget a decade ago, even 6 short years ago, what has happened since was unthinkable. Certainly anyone who proposed it would be ridiculed.

http://www.realclimate.org/index.php/archives/2007/01/arctic-sea-ice-decline-in-the-21st-century/

In fact if you read the comments, people are questioning the fact that the most aggressive scenario had been used and what was the "more likely" path to be if we used the less aggressive options in the AR4 scenarios.

Of course we all know what happened. The summer of 2007 happened and everyone then knew that "tipping points" were not just a theory but were real and happening right now.

Mark Serreze was fully vindicated in his statements and we shifted to a new reality.

Let's go back and LOOK at those "Tipping Point" diagrams....

They really did look plausible until October 2010. Since then we've had impact after impact and the models have varied little.

R Gates says our minds don't see the nonlinear jumps. Actually I'd say they do. It is the models, statistics and heuristics which can't see nonlinear jumps. Whether our minds see it or not, it is not possible to present that position, from the observed data.

But that is what nonlinear is all about. A departure from the observed trend and the setting of a new trend with new data.

However when academic strictures demand that there is an observed trend before we can prove what we are suggesting. The problem being that the change is now happening so quickly that there is no time to create the new observed trend.

Fortunately for the Scientists and unfortunately for all the other creatures on the planet, within the next 5 years this paradox will be resolved. Because there won't be any ice left to observe in September.

Then we can model what did happen for the next 40 years safe in the knowledge that we "know" what happened. If not how or why....

Wal

Total amateur here.
I watched a Horizon documentary about the Permian Triassic extinction. It said it took about 10000 years (in roughly two phases - a big release of CO2 that warmed the planet about 5C, then this triggered a big release of methane that warmed the planet another 5C).
I'm as concerned about global warming as anyone, but can someone explain in short words if/how the equivalent problem would happen faster this time?

George Phillies

"George,

The cost of replacing everything - in a similar manner to insurance - is impossible. "

We built it; we can replace it. A trillion a year -- the actual cost, is entirely affordable for the current planet. In fact, it is entirely affordable though expensive for the United States.

With respect to population, in most of the world population increase is cranking to a stop due to increasing standards of living.

Sam

Wal,

One can only hope we don't approach the Permian Triassic extinction conditions. But we do seem to be in a headlong race to be number one, even in terms of extinction.

One thing to remember is that looking back 250 million years in time, our ability to resolve anything less than ten thousand years is virtually non-existent. Said differently, we cannot tell the difference between 10,000 years and a blink with the available tools.

Sam

Mtobis

The methane story is greatly exaggerated. I'm not saying this is good news, but it is not as bad as many are trying to make out.

http://www.igbp.net/news/features/features/methanenotadampsquibnotyetatimebomb.5.19b40be31390c033ede80001011.html

http://www.washingtonpost.com/blogs/capital-weather-gang/wp/2013/07/25/methane-mischief-misleading-commentary-published-in-nature/

http://www.realclimate.org/index.php/archives/2012/01/much-ado-about-methane/

I do not understand the reason that with so much to worry about people look for even more to worry about than the evidence warrants.

Shared Humanity

Wal.....It said it took about 10000 years (in roughly two phases - a big release of CO2 that warmed the planet about 5C, then this triggered a big release of methane that warmed the planet another 5C). I'm as concerned about global warming as anyone, but can someone explain in short words if/how the equivalent problem would happen faster this time?

I would be very surprised if it would happen any faster. Maybe some one else could weigh in on the question.

Having said this the Permian extinction wiped out 98% of marine life and 83% (I think) of all terrestrial life. Please tell me that a near total extinction of life on earth is not the trigger you have for deciding we have a problem?

LRC

@ Steve Bloom | July 26, 2013 at 10:20
I did understand what they were trying to say. I guess I did not get my point that we have heard this exact same story in regards to Arctic ice a few years back.
If I were making this study and was seeing what is happening with Arctic ice and glacier fields in general my inclination would be to say there is enough evidence. But is not that part of the problem we are having right now, science tends to couch there work in terms that give them a way out if they are wrong and the general public and media sees that as a high degree of uncertainty. My belief is that GW is to such a stage that being careful and scientific is no longer a very helpful tool to use scientifically, because in 10 yrs your paper becomes useless.

Ned Ward

Mtobis writes: I do not understand the reason that with so much to worry about people look for even more to worry about than the evidence warrants.

Yes. Since the mid-1990s atmospheric methane has generally increased by 0.1% to 0.3% per year. This rate is much lower than in the mid-20th century. As noted, radiative forcing from methane increases approximately linearly around the current value (it's not really a linear response, but close enough over a short range) so even at 0.3% per year it would take more than 200 years to double the radiative forcing from methane.

I think it's reasonable to be keeping a close eye on the biogeochemistry of methane sources and sinks. But there doesn't seem to be much cause for serious concern at this time.

wayne

Steve, bring the papers out whenever a faux pas is done, I think its more interesting in focusing on melt and freeze up mechanics. From the papers I've read, there is a huge gap of studying, for instance, boundary layers, they are nebulous, they are fuzzy, misunderstood, "something that is above" in the summer, the papers are largely touching the tip of the iceberg, so this site is really cutting edge, because the papers are rare and incomplete. As far as calling cyclones names, I agree that it seems silly,
but we can call them AC2013-1...2....3 etc. Its a temporal identification, a place in time, the Cyclones only exacerbate sea ice conditions, especially morphology, it would be rather interesting to know the ice better. We really don't have access to the good stuff in remote sensing, I would rather Neven collects money for real good High Resolution radarsat images. I am ready to pitch in to get better images on special occasions. Right now would be good to study North of Beaufort and by the Pole wide open areas.

R. Gates

NeilT said;

"R Gates says our minds don't see the nonlinear jumps."

-------
Not exactly what I said. We certainly can see dragon-kings after they've happened-- sometimes well after. What I said was that our brains are wired to predict the future by a linear extrapolation of the past, and thus both dragon-king regime changing events are not something our brains are able to process while they are happening and certainly not predict. A sudden methane release, unthinkable 10 years ago, now is in the realm of possible because the Arctic has changed so much and so a big methane release becomes a remote (a black swan) but possible event by linear extrapolation of the past.

Steve Bloom

George Phillies above: "With respect to population, in most of the world population increase is cranking to a stop due to increasing standards of living."

Sadly no. That certainly was the thinking a few years ago, and it probably is true for some regions, but check current news for the reassessment based on recent data.

Steve Bloom

Overall the Eemian is probably a far better period for comparison than the mid-Holocene. In both cases the warming was driven by Milankovitch forcing, and people should be careful to consider the differences between that and anthropogenic forcing. E.g. the latter features winter warming, differences in circulation changes between the two may be considerable since Milankovitch forcing is so uneven in terms of geography and season, and present warming is much faster.

Re the P-T extinction, the trigger was a magmatic province. These emit CO2 at a far slower pace that we are. In any case the climate so far back was different in some fundamental ways, so even without the rate difference it probably makes for a poor analog. A much better one is the PETM, although it was still slow by comparison. current thinking seems to be that while methane hydrates were involved, the trigger was Antarctic permafrost induced by Milankovitch changes (no ice cap then, so lots of permafrost in Antarctica, and maybe lots of methane hydrate on the continental shelf).

More later.

Steve Bloom

R Gates, as we get older we also tend to acquire more of an ideological commitment to the status quo, which makes us resistant to seeing and admitting contrary changes.

Wal

Shared Humanity | July 26, 2013 at 20:25 said:

Please tell me that a near total extinction of life on earth is not the trigger you have for deciding we have a problem?

I first heard about global warming 30 years ago and was surprised it didn't kick in faster. I guess I didn't realize the heat would go into melting ice and warming the ocean, and not just heating the atmosphere.
But this only delays when it kicks in.
I think Wadhams and others think this delay means humans will not act until too late. I wanted to know when too late is and how fast it ramps up after that.
I have read some about this and asked some senior academics about it and some are hopeful it is not too late and some think it is not at all clear that it is not too late to hold off something drastic.

dorlomin

Re the P-T extinction, the trigger was a magmatic province. These emit CO2 at a far slower pace that we are.

It started with a prolonged cooling on a planet that was all one continent so huge areas of land were desert.

There is also likely to have been some pretty serious sea level fluctuations.

The PT is very likely a rather poor analogy at best, especially as there have been other big methane events including relatively recently in the Paleocene Eocene.

LRC

R Gates, as we get older we also tend to acquire more of an ideological commitment to the status quo, which makes us resistant to seeing and admitting contrary changes.

Posted by: Steve Bloom | July 26, 2013 at 21:50
That all depends on what your background training is. My dad loved history and gave me some of that also. If you observe history there are 3 constants. 1) It is always changing from a short time span thinking. 2)Current generation is always newest and most correct. 3)Look back in time long enough certain themes keep on repeating.
Man's propensity to wreck ones environment resulting in destroying ones current civilization is a theme you will have seen repeated over and over. We are just doing it on a far larger and grander scale.

Neven

I do not understand the reason that with so much to worry about people look for even more to worry about than the evidence warrants.

This isn't about worrying per se (to me), but about worst case consequences of current changes in the Arctic. Why can't we discuss worst case scenarios that aren't warranted by the evidence because there is far too little evidence? This could be 2004 and us talking about Arctic sea ice loss.

No one (or almost no one) is saying that this is a done deal, that BAU will lead to it 100%, the authors of the Nature article definitely aren't. They're just saying what would happen if it did. And the rapid rate of change in the Arctic is the very reason why I think they should be allowed to do that and bring it on the table.

Read Wadhams' response to Jason Samenow's poorly written hit piece.

If there is anything this controversy should lead to, it's more research, and not knee-jerk dismissal. And that goes for every potential consequence of Arctic sea ice (and spring/summer snow cover) loss, not just the effing shipping and fossil fuel exploration.

There's a price tag to this event! I don't care if it's 6, 60 or 600 trillion. The point is, it's not zero, even if we can't quantify it.

jonthed

Am I to understand that people are down playing the threat of a sudden methane release because there were warmer times in the deep past that had no such sudden release?

Surely that's completely disregarding the difference in rate of change between current warming and previous natural warmings?

If previous warm periods came about slowly due to natural changes in the forcings (milankovitch cycles etc.) and methane is a short lived ghg, then there would of course not be a sudden methane pulse.

However, current rate of warming is so much faster and if the same amount of methane is to be released but over a much shorter time scale then surely the feedback will be much stronger and the threat of sudden methane release much more probable.

What am I missing?

Also, there are so many potential disaster scenarios with climate change, that just because we don't know with accuracy what will happen, the fact that there are multiple threats and that if even just one of them is worse than the optimistic scenarios then the world is going to be in for a very rough time, surely should warrant serious action.

It seems like we're playing russian roulette with a gun that we don't know how many bullets are in, but we're hoping it's actually empty, so we play on.

Sam

It seems like we're playing russian roulette with a gun that we don't know how many bullets are in, but we're hoping it's actually empty, so we play on.

We seem to be playing Russian Roulette with a howitzer. By the time we understand our error we will be long past being able to tell.

NeilT

R. Gates said

"Not exactly what I said. We certainly can see dragon-kings after they've happened"

Actually I've noticed that the forums and this blog has a lot of people who see dragon-kings up front.

What I've also noticed is that the requirement for a large body of evidence tends to make those who calculate every last thing out, in order to try and give a reasoned argument, see only what has gone before as overshadowing what will happen in the future.

But, as you rightly say, there is no reasoned argument for a dragon-king style step change.

I see Science lagging because it tries to explain the inexplicable with previous observation.

That can only take you so far. It's like sitting on a horse backwards and trying to determine what countryside the horse is walking through.

Yes you will know it's a valley or a plain or that it's undulating or flat.

What you will not see is the great big chasm ready to swallow you up. Because there isn't one behind you so you don't expect one up front.

For something we understand so poorly, the calculations are most exacting and the predictions are ever more precise. And equally wrong for it.

dorlomin

Surely that's completely disregarding the difference in rate of change between current warming and previous natural warmings?

It takes time to warm a lot of water. Especially when that water spends all winter facing the darkness of the empty universe with little more than some CO2 and the occasional cloud to insulate it. Those long, hard, cold winter nights will see huge amounts of energy radiating into space until the ice forms.

Previously there was time, thousands of years of time for energy to build in the Arctic Ocean.

Even a blow torch wont bring a pot to the boil in seconds. Energy needs time to warm water.

Kevin O'Neill
"It takes time to warm a lot of water. Especially when that water spends all winter facing the darkness of the empty universe..."

It isn't necessary to warm the entire Arctic Ocean. The only area of interest for methane release is basically the East Siberian Arctic Shelf (ESAS).

This is a very shallow area and the water at the seafloor had already risen 2.1C between 1985 and 2009. As the ice retreats faster and earlier each year we can expect further increases in the water temperatures.

Shakhova and Semiletov take the position that the current ESAS methane releases show that the subsea permafrost 'lid' is already perforated.

A-Team

Wayne writes, "I will pitch in to help Neven purchase High Resolution radarsat images on special occasions... North of Beaufort and by the Pole"

Ok, how about you buy the first 2-3 and we will follow up with as many more as needed. The quality looks great!

 photo radarsat_zps9b9e6c1b.jpg

Devon Island, lower CAA (undated):

 photo devon_zps008964c4.jpg

A-Team

Along the lines of Kevin's comment, it's worth putting Wadham's actual response on the record here.

"In support of your skepticism about methane emissions you quote authors who wrote before the enormous retreat of summer Arctic sea ice and its oceanographic effects became so evident.
The mechanism which is causing the observed mass of rising methane plumes in the East Siberian Sea is itself unprecedented and hence it is not surprising that various climate scientists, none of them Arctic specialists, failed to spot it.
What is actually happening is that the summer sea ice now retreats so far, and for so long each summer, that there is a substantial ice-free season over the Siberian shelf, sufficient for solar irradiance to warm the surface water by a significant amount – up to 7C according to satellite data.
That warming extends the 50 m or so to the seabed because we are dealing with only a polar surface water layer here (over the shelves the Arctic Ocean structure is one-layer rather than three layers) and the surface warming is mixed down by wave-induced mixing because the extensive open water permits large fetches. So long as some ice persisted on the shelf, the water mass was held to about 0C in summer because any further heat content in the water column was used for melting the ice underside.
But once the ice disappears, as it has done, the temperature of the water can rise significantly, and the heat content reaching the seabed can melt the frozen sediments at a rate that was never before possible."

I won't examine the views the 'chief meteorologist' at Capital Weather Gang who has not a clue what a peer-reviewed scientific journal is.

Tenney Naumer got a good comment in to the effect, if all else fails, just saying, hey if your priorities permit, maybe actually glance at the Shakhova papers.

wayne

A-Team, if Neven has a huge following in the thousands, we probably could buy a single shot. The higher resolution pics explain a whole lot more facets than we can interpret with the current array of public domain photos. In particular the nature of the ice near the Pole seem extremely interesting because there is a lot of sea water over quite a large area. Without a closer look, our interpretations of what is happening is much more uncertain. In addition, some people out there already have some photos over the seasons, they are expensive when fresh, if you have some, care to share?

Fairfax Climate Watch

methane clathrates float, by the way. If they are shaken loose from the sediment holding them down, say by the explosively expanding thaw of nearby clathrates, then they will float up into the water column.

Rlkittiwake

I'm rarely shocked, but this is the pole cam today:

http://psc.apl.washington.edu/northpole/NPEO2013/18.jpg

Their array's been wiped out.

Fairfax Climate Watch


Does anyone know of a study that examines what the sea ice going seasonal will do to the water temperature of the East Siberian Shelf? Or, a study of what it will do to the terrestrial permafrost thaw rate and thermokarst methanogenesis rate?

A-Team

Best observational thing going on land permafrost methane seems to be low elevation overflights by Carve.

"The CARVE science team is busy analyzing data from its first full year of science flights. What they're finding, Miller said, is both amazing and potentially troubling.
"Some of the methane and carbon dioxide concentrations we've measured have been large, and we're seeing very different patterns from what models suggest," Miller said.
"We saw large, regional-scale episodic bursts of higher-than-normal carbon dioxide and methane in interior Alaska and across the North Slope during the spring thaw, and they lasted until after the fall refreeze.
In July 2012 we saw methane levels over swamps in the Innoko Wilderness that were 650 parts per billion higher than normal background levels."

 photo carveMethane_zps4aad4425.png

Kevin Hood

Here's a blog post about a recent large methane pulse out of Arctic Russia around July 21-23:

http://robertscribbler.wordpress.com/2013/07/24/large-troubling-methane-pulse-coincides-with-arctic-heatwave/

Dragon-kings are awakening.

Killian

My whole life is about solutions. I became aware of the energetic and economic issues in 2006, then later that same year the climate issues due to the IPCC IV coming out came to the fore and I happened to read a response from a scientist saying it was much worse due to the lack of ice science in the IV.

Katey Walters, et al's research had me convinced in 2007 we'd see a minimum of 1M SLR, probably 2M and 3M or more quite possible by 2100.

Maslowski's research just reaffirmed this and then we had the Big Melt of '07, which now is more like the Kinda Unusual Melt. The Big Melts came later.

So I went off on this save the world agenda because I also became a father in 2007. What I have learned is: The solutions are simple, will come from the bottom (and must), can be done in decades, and mean fundamental changes in how we live.

But they are simple. But it's a choice. We collapse or not because we chose to unless the physical tipping points have gone just too far. But even that was a choice.

If you'd like to talk about the solutions, we can do that. Understand this: We already know how to solve these problems. We need no new research, no new toys, no new tech.

Additional complexity is anathema to a collapsing society. Read J. Tainter, if you haven't already.

Clare

SORRY I'm always OT but just in case you need an escape for a moment you might enjoy seeing what Gareth Renowden does in his 'spare time'.
And Neven is a gardener-in-waiting after all!

http://www.podgardening.co.nz/gareth-renownden.html

Kate

btw, new storm near Laptev, caused by the heat in Russia. Could become very troublesome in the days to come.

Neven

Kate, wrong thread!

And Neven is a gardener-in-waiting after all!

Our house is going to be built next month, we'll start gardening next year (preparing for it this fall, of course). Hopefully in 10 years I'll have a page like Gareth. :-)

Il faut cultiver notre jardin!

GeoffBeacon

Are there local effects of high methane concentrations?

High local concentrations mean a local greenhouse effect but can it be big enough to significantly raise local temperatures and produce a local feedback mechanism?

dorlomin

High local concentrations mean a local greenhouse effect but can it be big enough to significantly raise local temperatures and produce a local feedback mechanism?

No. People are often getting excited about difference of 1 or 2% compared to the background levels.

In terms of the Arctic specifically it is completely dwarfed by orders of magnitude by the changes in the sea ice cover.

Kate

Sorry Neven :(
I love gardening too! good luck

GeoffBeacon

Dorlomin

I'm not getting that excited but you do miss my point.

The 1 or 2% you mention is measurements over a large area. (Actually I make the reports levels of 1950 ppb a bit over a 4% rise).

There are several reports of LOCAL methane levels being hundreds of times background level. I don't know how far these reported levels reach up the atmospheric column but if 1% of the column (the bottom 100 metres?) has that sort of concentration it would double the amount of methane in the column compared to background levels.

This would warm the place beneath creating some further methane generation. With stable atmospheric conditions this may last for weeks.

I don't suppose that this would have the same impact as burning tundra (a feedback not accounted for in the CMIP5 climate models) but it does rather irritate me that no-one seems to have done the sums.

Perhaps you could help?

P.S. I think I have read reports of methane levels 1000s of times background.

dorlomin

it would double the amount of methane in the column compared to background levels.

You mean add an extra 1/2 a watt of energy per square meter?

Apocalypse4Real

To help illustrate methane release change and accumulation from 2002 to 2012 in the northern hemisphere, I posted some imagery on the ASIF:

See comments 60-61.

http://forum.arctic-sea-ice.net/index.php/topic,459.60.html

Susan Anderson

Thanks again for the wonderful discussion and links. Andrew Freedman sheds some light on the location of the North Pole camera:

http://www.climatecentral.org/news/melting-at-north-pole-how-bad-is-it-16294

Temps in northern Siberia continue warm, one at 27C (79F) at Khatanga (Arthropolis from daily graphs here).

Twemoran

I agree with A-Team's assessment. The buildup of CH4 beneath the frozen cap wasn't released during the Holocene Thermal Maximum because of the time required for the heat pulse from the inundation of the ESAS to work it's way down through the frozen cap. Shakhova raised this point back as early as 2010 I believe.
The cap is no longer entirely impermeable and with warm bottom water now melting it from above as geo-heating attacks from beneath it will melt out. The gas pressure probably will cause the ever thinning cap to rupture rather than continue leaking.
Watkin's point is that without summer ice keeping water hovering around 0C, this new warmer pulse is working it's way down, melting rapidly as it goes.
The fact that CH4 didn't vent during the Holocene Maximum shouldn't viewed with relief, but rather with horror as we realize that we're faced with a much larger problem than would have been the case had CH4 been venting at low rates over long periods of time.
Terry

dorlomin

The buildup of CH4 beneath the frozen cap wasn't released during the Holocene Thermal Maximum because of the time required for the heat pulse from the inundation of the ESAS to work it's way down through the frozen cap. Shakhova raised this point back as early as 2010 I believe.

So now its not longer current warming that is causing this release?

Or are we expected (with no evidence) to believe that the Arctic has spent the past 4000 years getting itself into a state where it is just exactly ready to react like no other interglacial to less warming that it has experienced in previous interglacials?

There are gaps in these stories you can drive a truck through.

40 watts per square meter of extra warming does not set of this catastrophy but a couple of years of less ice cover and a small human sourced gas forcing of about 2.5 watts a square meter does?

Ned Ward

I suppose it's possible that all through the Holocene warmth has been slowly working its way down through the permafrost to the point where the additional warming from AGW would be enough to set off the "bomb".

But in that case I'd have to assume that the "bomb" would have gone off anyway, sooner or later, since the present interglacial is apparently scheduled to persist for several tens of thousands of years.

I'd also have to assume that this "bomb" was a regular feature of previous interglacials.

Twemoran

Ned & dorlomin
I think that the frozen cap that makes up the ESAS has been melting since it was inundated at the end of the last ice age. The recent warm bottom water, available since summer ice has melted off, is only accelerating a process that has been ongoing since that time.
Left to it's own devices the cap would have vented large amounts of CH4, but probably over long enough time periods to avoid catastrophic releases. With CH4 having 105 times the GHG potential of CO2 over a twenty year period the rate of escape is critical and as I understand it that is what S&S were researching.
The HTM was too soon after the bitter cold of the ice age for this to have occurred & without AGW we'd be slowly cooling at this time in preparation for the next ice age so slow venting would have been expected.
Terry

Fairfax Climate Watch

If you want some idea of what radiative and terrestrial vegetative effects of large increases in atmospheric methane are, there's this 2012 paper:

http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-11-00533.1

Steve Bloom

"I'd also have to assume that this "bomb" was a regular feature of previous interglacials."

But it wasn't, per the ice cores. As Gavin Schmidt points out, anyone thinking it's going to happen now needs to explain why it didn't then.

Jai Mitchell

Steve,

here are my notes on the subject:

Eemian reason for lack of (runaway warming)

1. Milankovich cycles were slower

and

2. biomass of land and (especially) ocean capture of carbon was approximately 10X more abundant than now.

these two factors prevented the catastrophic release of CH4 due to the slower (by several orders of magnitude) rate of thaw and release coupled with the (single order magnitude) increased ability to remove CO2 by biomass activity.

and

3. Solar cycles coupled with variable AMOC freshening provided a short term albedo pulse increase (due to surface snow) on a decadal average cycle that produced significant short period cooling. This was recovered slowly.

So, basically the slow period of a Milankovich driven interglacial allowed the biosphere to adjust to increased CH4 emissions and these emissions happened very slowly compared to a greenhouse-gas driven temperature pulse during an interglacial.

The only real analogy to this is the PETM. which DID have a methane pulse and DID have a runaway warming effect (though not a Venusian one).

Jai Mitchell

It should also be noted that, according to several the current Milankovich cycle, we should be heading down into another Ice Age. If you do a comparison of previous interglacials to now, the rate of return to ice age system should have happened close to 1000 years ago. and Certainly should have happened by now. There are some theories that indicate that pre-industrial land use patterns (read- agriculture based CH4 emissions) have already affected the climate and in a typical interglacial the ESAS would now be frozen over solid throughout the year.

dorlomin

Milankovich cycles were slower
Time, It takes lots and lots of time to heat oceans. Previous interglacial had that time. We don't.
biomass of land and (especially) ocean capture of carbon was approximately 10X more abundant than now.
Where do you get this figure from.
Solar cycles coupled with variable AMOC freshening provided a short term albedo pulse increase
Hand waving.
It should also be noted that, according to several the current Milankovich cycle, we should be heading down into another Ice Age.
And 'several' others disagree.

Sam

Dorlomin,

What you are experiencing has a name. It is called denial. Good luck with cognitive dissonance to come.

Sam

dorlomin

What you are experiencing has a name. It is called denial
Deniall Quinn?

Jai Mitchell

dorlomin,

you asked why, I gave you a few reasons. The fact is that the arctic has never warmed so far so quickly, this is not a normal interglacial cycle.

the increase in arctic sea heat enthalpy content at the 0-50M has been observed to increase as the ice pulls back due to absorbed solar radiation, in a localized area.

This is expected to increase, by several orders of magnitude when the arctic becomes ice free in the early summer (June 1).

Will it lead to a short-term clathrate driven pulse? I doubt it. Will it lead to a massive decadal scale increase in the release of carbon from above and below-sea permafrost? emitted into a scenario of a rapidly warming world that is experiencing strong declines in natural carbon sinks?

Yes, I am very much afraid so.

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