Author Topic: Melting Arctic an "economic time bomb"  (Read 6681 times)

Anne

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Melting Arctic an "economic time bomb"
« on: July 24, 2013, 11:01:02 PM »
The melting Arctic is an "economic time bomb" likely to cost the world at least $60trillion, according to a study published today in Nature.

Gail Whiteman (professor of sustainability, management and climate change at Erasmus University Rotterdam), Chris Hope (reader in policy modelling at Judge Business School, University of Cambridge) and Peter Wadhams (professor of ocean physics at the University of Cambridge) argue that methane released by melting permafrost will have global impacts that must be better modelled.
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We ran the PAGE09 model 10,000 times to calculate confidence intervals and to assess the range of risks arising from climate change until the year 2200, taking into account sea-level changes, economic and non-economic sectors and discontinuities such as the melting of the Greenland and West Antarctic ice sheets (see Supplementary Information). We superposed a decade-long pulse of 50 Gt of methane, released into the atmosphere between 2015 and 2025, on two standard emissions scenarios. First was 'business as usual': increasing emissions of CO2 and other greenhouse gases with no mitigation action (the scenario used by the Intergovernmental Panel on Climate Change Special Report on Emissions Scenarios A1B). Second was a 'low-emissions' case, in which there is a 50% chance of keeping the rise in global mean temperatures below 2°C (the 2016r5low scenario from the UK Met Office). We also explored the impacts of later, longer-lasting or smaller pulses of methane.

In all of these cases there is a steep global price tag attached to physical changes in the Arctic, notwithstanding the short-term economic gains for Arctic nations and some industries.
(...)
The economic consequences will be distributed around the globe, but the modelling shows that about 80% of them will occur in the poorer economies of Africa, Asia and South America. The extra methane magnifies flooding of low-lying areas, extreme heat stress, droughts and storms.

They call for better models to
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incorporate feedbacks that are not included in PAGE09, such as linking the extent of Arctic ice to increases in Arctic mean temperature, global sea-level rise and ocean acidification, as well as including estimates of the economic costs and benefits of shipping. Oil-and-gas development in the Arctic should also, for example, take into account the impacts of black carbon, which absorbs solar radiation and speeds up ice melt, from shipping and gas flaring.

Splitting global economic impact figures into countries and industry sectors would raise awareness of specific risks, including the flooding of small-island states or coastal cities such as New York by rising seas. Mid-latitude economies such as those in Europe and the United States could be threatened, for example, by a suggested link between sea-ice retreat and the strength and position of the jet stream, bringing extreme winter and spring weather. Unusual positioning of the jet stream over the Atlantic is thought to have caused this year's protracted cold spell in Europe.

More details of the PAGE09 model here (pdf at link).

Anne

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Re: Melting Arctic an "economic time bomb"
« Reply #1 on: July 24, 2013, 11:05:59 PM »
And an interview with Prof. Wadhams in the Guardian.
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<snip>Some people say that a catastrophic methane release over 10 years - your worst-case scenario - is a very low probability event and we don't really need to worry about it. What's your response to that?

Those who understand Arctic seabed geology and the oceanography of water column warming from ice retreat do not say that this is a low probability event. I think one should trust those who know about a subject rather than those who don't. As far as I'm concerned, the experts in this area are the people who have been actively working on the seabed conditions in the East Siberian Sea in summer during the past few summers where the ice cover has disappeared and the water has warmed. The rapid disappearance of offshore permafrost through water heating is a unique phenomenon, so clearly no "expert" would have found a mechanism elsewhere to compare with this.

dorlomin

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Re: Melting Arctic an "economic time bomb"
« Reply #2 on: July 25, 2013, 12:22:48 AM »
There is not one single shred of new physical evidence here. Just a random figure for methane typed into an economic model.

However we now have more headlines about methane doom. Something more that can be used to beat our heads just like the Himalayas 2035 story.

ccgwebmaster

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Re: Melting Arctic an "economic time bomb"
« Reply #3 on: July 25, 2013, 12:58:14 AM »
And an interview with Prof. Wadhams in the Guardian.
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<snip>Some people say that a catastrophic methane release over 10 years - your worst-case scenario - is a very low probability event and we don't really need to worry about it. What's your response to that?

Those who understand Arctic seabed geology and the oceanography of water column warming from ice retreat do not say that this is a low probability event. I think one should trust those who know about a subject rather than those who don't. As far as I'm concerned, the experts in this area are the people who have been actively working on the seabed conditions in the East Siberian Sea in summer during the past few summers where the ice cover has disappeared and the water has warmed. The rapid disappearance of offshore permafrost through water heating is a unique phenomenon, so clearly no "expert" would have found a mechanism elsewhere to compare with this.



Shakhova said several years ago that this was a concern in media before a very abrupt 180 followed by total media silence. I would agree with Wadhams, and on the basis that no further information has been forthcoming (directly at least) from the experts in question - I would assume the original statements stand, and there genuinely is a risk of a multi-gigatonne release of methane on decadal timescales.

I haven't read anything in the papers they've published since to make me think differently (to the original series of statements about it being concerning). The published papers tell an interesting story themselves, reading between the lines a little.

dorlomin

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Re: Melting Arctic an "economic time bomb"
« Reply #4 on: July 25, 2013, 01:05:14 AM »
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Gavin Schmidt ‏@ClimateOfGavin 11h
@cwhope Wow. "Highly possible at any time" Shakhova. I could not disagree more. Paleo provides *no* evidence for this level of sensitivity
From Gavin Schmidt's twitter. Seems I have someone else who agrees with me.


dorlomin

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Re: Melting Arctic an "economic time bomb"
« Reply #5 on: July 25, 2013, 01:07:50 AM »
and there genuinely is a risk of a multi-gigatonne release of methane on decadal timescales.
There isn't. Not even close.

But these attention seeking clowns will see us all crucified by the other side of the mirror for raising false alarms.

Thanks folks, just what we need. Himalayas 2035 redux.

Neven

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Re: Melting Arctic an "economic time bomb"
« Reply #6 on: July 25, 2013, 01:08:17 AM »
There is not one single shred of new physical evidence here. Just a random figure for methane typed into an economic model.

However we now have more headlines about methane doom. Something more that can be used to beat our heads just like the Himalayas 2035 story.

The Himalayas-hype was a typo.

Why can't we discuss worst case scenarios? Do you also get ridiculed when your house still hasn't burnt down, after having paid insurance for 50 years?

I get that this is low probability risk. What I'm interested in is why it can't be discussed. Why mustn't it be a headline in the media?
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Re: Melting Arctic an "economic time bomb"
« Reply #7 on: July 25, 2013, 03:04:57 AM »
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Gavin Schmidt ‏@ClimateOfGavin 11h
@cwhope Wow. "Highly possible at any time" Shakhova. I could not disagree more. Paleo provides *no* evidence for this level of sensitivity

There is no evidence in Paleo of humans melting Arctic in decades too.

Vergent

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Re: Melting Arctic an "economic time bomb"
« Reply #8 on: July 25, 2013, 03:20:59 AM »


dorlomin,

I'll keep it simple. What was the probability that someone living in the 18th century would die in a car crash?

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CraigsIsland

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Re: Melting Arctic an "economic time bomb"
« Reply #9 on: July 25, 2013, 03:24:24 AM »
There is not one single shred of new physical evidence here. Just a random figure for methane typed into an economic model.

However we now have more headlines about methane doom. Something more that can be used to beat our heads just like the Himalayas 2035 story.

The Himalayas-hype was a typo.

Why can't we discuss worst case scenarios? Do you also get ridiculed when your house still hasn't burnt down, after having paid insurance for 50 years?

I get that this is low probability risk. What I'm interested in is why it can't be discussed. Why mustn't it be a headline in the media?

It should be discussed. And if Sandy was a rare event why isn't one area that has lots of methane stored up not be discussed or modeled? Of course, the 60 trillion number is head-turning but that's exactly why it should be discussed. People care about money, their livelihoods. They don't want to see their wealth to decline when societies could've adapted/mitigate better. I don't want to be the verge on reitieng and the.ln looking at my accounts going, "we'll that's not enough, maybe next year we'll see more carbon being captured or something"

ccgwebmaster

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Re: Melting Arctic an "economic time bomb"
« Reply #10 on: July 25, 2013, 03:31:05 AM »
It should be discussed. And if Sandy was a rare event why isn't one area that has lots of methane stored up not be discussed or modeled? Of course, the 60 trillion number is head-turning but that's exactly why it should be discussed. People care about money, their livelihoods. They don't want to see their wealth to decline when societies could've adapted/mitigate better. I don't want to be the verge on reitieng and the.ln looking at my accounts going, "we'll that's not enough, maybe next year we'll see more carbon being captured or something"

Absolutely. That's exactly the point - regardless of the precise findings - or whatever really is going on up there - good information is not forthcoming. That hardly inspires confidence in the media or governments.

Even setting aside Shakhova's comments (and she is an expert in the field - literally in the field as it involves expeditions and experimental measurements, direct observations in other words) - is it really not interesting to find that there are 1km wide plumes of methane in the Arctic? Even if it were some natural process that was ongoing for centuries is it not newsworthy and interesting discussion material? Why therefore has it been buried?

One can't help but feel that if it were good news - as with the clathrates found to be letting methane go off Svalbard (in deeper water) - it would've made the news somewhere, even in just a tiny corner (and I've been keeping an eye on methane stuff for several years now). In the case of the deeper methane being released off Svalbard they managed to identify by looking at carbonate deposits and hydrogen sulphide concentrations that the activity was not brand new and had been ongoing at some level at least for centuries.

Would it be impossible to do such a thing in the ESAS? Given what is at stake, shouldn't this be a burning question? A large methane release has such serious ramifications that it should be a high priority to try to improve understanding and monitoring of it. If we can whittle the probability down low enough not to care about - fine - that's one possible answer.

Assuming Shakhova is wrong seems altogether less safe, since practically nobody has the credentials to claim greater expertise in this precise matter.

CraigsIsland

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Re: Melting Arctic an "economic time bomb"
« Reply #11 on: July 25, 2013, 04:00:41 AM »
Interesting tidbits from article http://scienceblogs.com/stoat/2013/07/24/arctic-methane-time-bomb-could-have-huge-economic-costs/

- it appears that causes of methane release like a sudden 50gt wouldn't necessarily be because of AGW, it would be more from natural processes (which is a bit sketchy if keep modeling with the same numbers after 20 years and so on) like tectonic plate action, etc. but still, it does not mean that the issue is irrelevant. If the 50gt release happens suddenly, that's an additional 1.3c (i think its celsuis) the planet has to deal with.

ccgwebmaster

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Re: Melting Arctic an "economic time bomb"
« Reply #12 on: July 25, 2013, 04:36:55 AM »
- it appears that causes of methane release like a sudden 50gt wouldn't necessarily be because of AGW, it would be more from natural processes (which is a bit sketchy if keep modeling with the same numbers after 20 years and so on) like tectonic plate action, etc. but still, it does not mean that the issue is irrelevant. If the 50gt release happens suddenly, that's an additional 1.3c (i think its celsuis) the planet has to deal with.

I think it would be impossible to separate out climate change from having played a role, for several reasons:

1. The region is warmer than before, more heat available to melt permafrost (land and seabed)

2. Melting the seabed permafrost arguably makes it easier for free gas under pressure to escape

3. Deglaciation is increasing isostatic rebound, with accompanying (albeit arguably still subtle) increase in earthquakes (the weight of the ice tends to suppress plate movement as I understand it)

4. We have no basis that I know of in recent history to suppose that such a large amount of methane has been released through purely natural processes (back to at least the last glacial termination - it seems reasonable to suppose some measure of methane is usually released as ice ages end in order to account for the closeness of fit between methane and temperature - a link less well appreciated by the public than the one between carbon dioxide and temperature)

It ought to also be noted that any warming from methane is seriously heavily front-loaded, the Drew Shindell (2009) figure is 105x the GWP of carbon dioxide, for a 20 year horizon (if memory serves). The figure quoted of 23x is over a century timescale but the short half life of methane in the atmosphere means it degrades to carbon dioxide well before a century is up.

I doubt that either of those figures takes into account a truly abrupt large release which could overwhelm the mechanism in the atmosphere responsible for breaking down the methane. If the mechanism were overwhelmed, then the warming effects of the methane would be correspondingly even larger as it would take longer to convert to the far milder carbon dioxide (and water).

Overall, I do not think we are on the brink of a true methane catastrophe - but we may well be looking at the normal feedback of methane that occurs as ice/snow cover retreats during periods of warming. That's the relatively optimistic view - and I think fairly well supported by the science.

It would seem to be a more open question if the rate of change is sufficiently fast to allow methane to come out at a rate capable of causing problems on a much larger scale - or if there is enough natural feedback in the system to push us to a point where we would experience something like the end Permian extinction. My impression (without certainty) is that that would require the (long term) destabilisation of deep water clathrates over a larger area than just the ESAS and therefore take a long time for the oceans to warm up to a sufficient temperature.

All that said I don't think we need to take an end Permian methane catastrophe outcome seriously to be concerned - this is like with sea level - who cares if it ends up 25m higher a century or two from now, when just a 1-2m in our lifetimes will be a very bad outcome for our species? Methane is a wildcard on the end of an already very bad hand we've dealt ourselves.

CraigsIsland

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Re: Melting Arctic an "economic time bomb"
« Reply #13 on: July 25, 2013, 07:32:42 AM »
Ccgwebmaster- my impression is very much like yours- thanks for writing that out.  8)

It's a bummer we (at least most of modern civilization) can't fathom to live without cars or other really common carbon sources. It doesn't help that Politicians and bankers are about the the short term and not really about the long-term. Welp, lets hope the methane "bomb" doesn't go off.

AartBluestoke

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Re: Melting Arctic an "economic time bomb"
« Reply #14 on: July 25, 2013, 07:42:54 AM »
" Methane is a wildcard on the end of an already very bad hand we've dealt ourselves."

It should be noted that we were also peeking at the deck quite heavily towards the end of the deal.

wili

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Re: Melting Arctic an "economic time bomb"
« Reply #15 on: July 25, 2013, 01:55:07 PM »
The methane "bomb"--on land and under sea--is going off already. It is just a question of how fast it is happening, but it is a global tragedy whatever the rate.

I don't see anything that could possibly stop it from continuing to 'go off' at this point.

If it comes out fast, civilization and most life probably only has a few years left.

If it goes off slow, it will ensure that the effects of our global warming last hundreds to thousands of years longer than they would have otherwise.

The other huge tragedy is that relatively few scientists are actively engaged in researching this area that holds such dire consequences (this according to Hans Joachim Schellnhuber, so if you disagree, take it up with him).

ritter

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Re: Melting Arctic an "economic time bomb"
« Reply #16 on: July 25, 2013, 06:13:22 PM »
There is not one single shred of new physical evidence here. Just a random figure for methane typed into an economic model.

However we now have more headlines about methane doom. Something more that can be used to beat our heads just like the Himalayas 2035 story.


The Himalayas-hype was a typo.

Why can't we discuss worst case scenarios? Do you also get ridiculed when your house still hasn't burnt down, after having paid insurance for 50 years?

I get that this is low probability risk. What I'm interested in is why it can't be discussed. Why mustn't it be a headline in the media?


Thank you, Neven.

Actually, physical evidence of methane plumes has been reported by experts in the field. http://www.sciencemag.org/content/327/5970/1246.abstract
http://link.springer.com/article/10.1134%2FS1028334X12080144?LI=true#page-1

What is at question in my mind, and hopefully being studied, is whether these are background emissions or whether they are recent occurrences. Based on this, I think it is a good thing someone has the foresight to take a look at the potential monetary costs of sudden emissions.  After all, potential pocketbook impacts will be the one single potential motivating factor to do something about it. All that said, it is odd we haven't heard more about it.

Whether subsea methane releases are new or part of the baseline, permafrost is releasing methane as it thaws due to a warming environment. See this thread: https://forum.arctic-sea-ice.net/index.php/topic,370.0.html

dorlomin

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Re: Melting Arctic an "economic time bomb"
« Reply #17 on: July 25, 2013, 07:33:51 PM »
More kickback against these wild speculations masquerading as science.

This time from William Connelly.
http://scienceblogs.com/stoat/2013/07/24/arctic-methane-time-bomb-could-have-huge-economic-costs/

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, and more importantly this is but a “Comment” not (as far as I can tell) a proper peer-reviewed article.

You’d certainly hope it wasn’t peer reviewed, because some of it is dodgy, most obviously the opening paragraph:


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The first Key Point is: is 50 Gt believable? Wiki tells me that annual methane emissions from natural+anthro is about 600 Tg, which is 0.6 Gt by my calculation; so WHW’s 50 Gt is close to 100 years emissions. So its a large number.


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But read that again carefully, noting fault zones, tectonically and seismically active areas. They aren’t (as I read it) saying that the 50 Gt will or might be released due to human activity; they’re saying that geologic events, and leaks through existing holes in the permafrost, might lead to this release. At least I think that’s what they’re saying. In which case its an odd calculation, because they appear to be assuming that all the faults will become active at once. Aren’t they? And my reading of it completely decouples it from GW. So I don’t understand.



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[Update: Someone was kind enough to send me a copy of "Predicted Methane Emission on the East Siberian Shelf", by N. E. Shakhovaa, b, V. A. Alekseevb, and I. P. Semiletova". Its a trifle vague in places, but I think clear enough to be able to tell that the methane emission growth is assumed not modelled or predicted in any sense. Furthermore (and in my opinion extremely suspiciously) they end up with a 50 Gt amount, which is exactly the same number as they got in the 2008 preprint - except now its going to come from GW, whereas previously it was going to come from geological activity. WTF?]


Not one single other voice round here has been prepared to look critically at this report?


dorlomin

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Re: Melting Arctic an "economic time bomb"
« Reply #18 on: July 25, 2013, 07:38:18 PM »
Why mustn't it be a headline in the media?
Because to convince people to change their society we need to keep a credible message.

One that is sober and based on the best science, not some wild speculation fed into an economic model to generate headlines for the authors.

The names lining up against this report are the names of well established credible voices for climate science.

Wild speculation fed into a glorified version of Sim City is not the most sober or defensible bit of science to be in the headlines.

Csnavywx

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Re: Melting Arctic an "economic time bomb"
« Reply #19 on: July 25, 2013, 08:17:02 PM »
I'm going to have to agree with dolormin here. There's no credible evidence that a 50 Gt release of methane is "imminent". Slow leaking via taliks? Sure. But we're talking apples and oranges with the amounts. I believe several credible arguments (both on RealClimate and here from Chris Reynolds) have been made that this is much more likely to be a chronic problem over the next 100 years rather than an abrupt one. Another persistent 500-2000ppbv of methane and high CO2 is likely to be bad enough.

anonymous

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Re: Melting Arctic an "economic time bomb"
« Reply #20 on: July 25, 2013, 09:19:57 PM »
Not one single other voice round here has been prepared to look critically at this report?

Dolormin, it seems you have missed some discussions. The methane bomb is in the news for years and it is not having the communication effect you suppose. Everybody takes it with a grain of salt. I support your notion of a credible message, but in a few cases you need to reply to questions like 'What will happen if we do not follow the path you propose?" or shorter "What is the risk?" One part of the answer is nobody knows for sure what the real consequences of business as usual are, but who can *exclude* major methane releases?

So in some way you are right the methane scenario might not be worth the time needed to discuss. But take it as a metaphor of looming catastrophes, nastily coming up when on no ones screen. Like the current bee problem, which might dwarf methane economically if heavy interruptions of the food chain take place.

Everybody should know about the worst case scenarios, that's good risk management, it is not like they do not happen if they remain un-discussed. And actually that's the reason we are discussing climate at all, because of the lack of risk management in favor of a credible message saying cheap energy will make you prosper.

And yes, I absolutely support the area wide and year round scientific observation of permafrost. That should have started long time ago. If the outcome of these reports is getting that started soon I can not agree more.

Neven

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Re: Melting Arctic an "economic time bomb"
« Reply #21 on: July 25, 2013, 09:43:54 PM »
Why mustn't it be a headline in the media?
Because to convince people to change their society we need to keep a credible message.


I understand where you're coming from, but it's good to keep in mind that there is no 'we'. Even if this worst case scenario is complete bollocks (I don't agree there, but okay), the least it could do, is serve as a counterweight to the WUWT/FOX craziness.

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The names lining up against this report are the names of well established credible voices for climate science.


Yes, exactly. They now get to position themselves in the middle, instead of being portrayed as extremists by the free market fundies.

But still, I believe that we should discuss worst case scenarios, even if there isn't a solid scientific basis due to lack of observations (like arcticio says). There's what, 1400-1500 GT of methane clathrates out there? And the changes in the Arctic are going much, much faster than anyone has predicted, mainstream science least of all. If that isn't a 1+1 for worst case scenarios, I don't know what is.

Like I wrote last year in Why Arctic Sea Ice Shouldn't Leave Anyone Cold:

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Another way Arctic warming could have worldwide consequences is through its influence on permafrost. Permanently frozen soils worldwide contain 1400-1700 Gigatons of carbon, about four times more than all the carbon emitted by human activity in modern times. A 2008 study found that a period of abrupt sea-ice loss could lead to rapid soil thaw, as far as 900 miles inland. Apart from widespread damage to infrastructure in northern territories (such as roads, houses and pipelines), the resulting annual carbon emissions could eventually amount to 15-35 percent of today’s yearly emissions from human activities.  This would make the reduction of atmospheric greenhouse gases a much more difficult task.

An even more worrying potential source of greenhouse gases is the methane in the seabed of the Arctic Ocean, notably off the coast of Siberia. These so-called clathrates contain an estimated 1400 Gigatons of methane, a more potent though shorter-lived greenhouse gas than carbon dioxide. Methane clathrate, a form of water ice that contains a large amount of methane within its crystal structure, remains stable under a combination of high pressure and low temperature.

At a depth of 50 meters or less, the East Siberian Arctic Shelf may contain the shallowest methane clathrate deposits, and thus those most vulnerable to rising water temperatures. High amounts of methane have been recently been measured over ice-free portions of the Arctic Ocean, and the waters of the East Siberian Sea have been shown to be “super-saturated” with methane; large plumes of methane bubbles have been observed there as well. The origins and significance of these emissions are not yet clear, but Arctic methane emissions in general appear to be rising: methane concentrations in the Arctic now average about 1.90 parts per million, the highest in 400,000 years.
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CraigsIsland

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Re: Melting Arctic an "economic time bomb"
« Reply #22 on: July 25, 2013, 09:58:05 PM »
Why mustn't it be a headline in the media?
Because to convince people to change their society we need to keep a credible message.

One that is sober and based on the best science, not some wild speculation fed into an economic model to generate headlines for the authors.

The names lining up against this report are the names of well established credible voices for climate science.

Wild speculation fed into a glorified version of Sim City is not the most sober or defensible bit of science to be in the headlines.

For some people, putting a dollar amount is the clearest way to demonstrate the cost of a warmer planet. 60 trillion is sobering and a loose analogy for a temperature rise. There's still contextual information from this that can be gained, even discussing it. Sometimes it's good to have a frame shift so people don't focus so narrowly on what has been in the media recently.

I was critical of the headlines, sure. I think most people would know it can be sensationalized and they should think critically for themselves, just like what I did earlier in this thread. This "news" is not all bad. I'd rather hear people talk about it instead of ignoring it.

Anne

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Re: Melting Arctic an "economic time bomb"
« Reply #23 on: July 25, 2013, 10:22:28 PM »
Wild speculation fed into a glorified version of Sim City is not the most sober or defensible bit of science to be in the headlines.

Because it has had a lot of publicity I thought it deserved airing on the forum.

When you describe the model PAGE09 as "a glorified version of Sim City" are you suggesting that economic models have no place? PAGE09 seems to be widely used. (My link here is to the Judge Institute's own description of the modelling tool.) How else are we to get a sense of what the impact might be? I appreciate that the model's value is also dependent on the quality of the information fed in. There are a lot of variables (not enough, some would say – but the more there are, the less stable it will be).  The value of each variable is going to be up for argument. Of course we should treat the model sceptically. Errors in one parameter will get compounded with others. The model is just that, it’s not a crystal ball. The article itself suggests modifications that could improve it.

As for the "wild speculation" - I'm not in a position to gainsay Prof Wadhams's judgment on methane release as I have no experience in ocean physics.  Perhaps it's reasonable to assume Cambridge University, Erasmus University and the Judge Business School would inadvertently appoint "attention seeking clowns". I have a gut feeling that all this talk of clathrate guns is too crazy to be true, so I'd rather not believe it. But that's the sort of gut feeling that deniers have about the effects of CO2, so I discount it. What have you got?

I've seen what William Connelly says. I can't call out this Nature comment piece on internal inconsistency like he does, because I haven't seen the papers on which the 50 Gt release is predicated. I have read articles like this, though.

I understand your alarm at people crying wolf, and how that encourages everyone else to ignore it again and just carry on with BAU. The article doesn't deal in certainties, and we'd all love for these potential consequences never to happen. But it’s not wholly irresponsible, is it, to factor them in? And even if a 50 Gt methane release is one of those unlikely events with huge consequences, it shouldn't be off-limits for discussion. Isn’t some contingency planning at least prudent?
(Though Prof Wadhams, whose area of expertise this is, seems to think it likely.)

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Re: Melting Arctic an "economic time bomb"
« Reply #24 on: July 25, 2013, 10:47:14 PM »
@Anne with regards the planning for a 50 Gigatonne Methane release; is there anything that can be done in preparation for this disaster because I am aware that there are plenty of things an individual can do in an attempt to prepare for something like this, but society in itself seems to be incapable of preparing for this event.

Anne

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Re: Melting Arctic an "economic time bomb"
« Reply #25 on: July 25, 2013, 11:04:59 PM »
@Anne with regards the planning for a 50 Gigatonne Methane release; is there anything that can be done in preparation for this disaster because I am aware that there are plenty of things an individual can do in an attempt to prepare for something like this, but society in itself seems to be incapable of preparing for this event.
I really don't know. Emergency planning is quite a specialist topic but I'd guess you'd be looking at things like zoning development, costing sea defences, planning how you'd organise local sustainability in energy and food supplies. It all sounds rather inadequate but I am no expert. Perhaps there is nothing that can prepare for the most extreme outcome, but that doesn't excuse looking at more likely scenarios. At least people who are expert - and here in the UK we have them at national and local government level - should be tasked with thinking about it.

wili

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Re: Melting Arctic an "economic time bomb"
« Reply #26 on: July 26, 2013, 12:01:35 AM »
The other point is that the entire clathrate threat, bad as it may be, is but one of many, many feedbacks looming or starting to kick in, each feeding back on each other.

--Albedo changes in sea ice and terrestrial snow already seem to be well underway, as is the albedo shift as trees make their way into what used to be the (mostly) treeless tundra.

--warming ice encourages dark cryophilic bacteria which alters albedo

--As sea ice disappears, that also represents a phase shift--all the heat that went into melting all that ice is now 'free' to heat other areas.

--On the carbon cycle front, terrestrial permafrost melt has been in the news lately, and that is another huge potential source of carbon. The boreal forests are another huge potential source.

--Soils, peat and forests elsewhere around the world are drying up, burning up, and in the process releasing more carbon.

--The melting GIS and Antarctic ice sheets are also going to expose long-buried carbon to be released into the atmosphere. http://thinkprogress.org/climate/2012/07/15/513685/forest-feedback-rising-co2-in-atmosphere-also-speeds-carbon-loss-from-forest-soils-research-finds/

--The increasingly ice-free Arctic Ocean is also producing larger waves than it has experienced in at least thousands of years, and these, along with warm air and rain, are eroding islands and coastlines releasing carbon in those soils.

--Trees in some areas are starting to exude CO2 rather than taking it in http://channel.nationalgeographic.com/channel/videos/six-degrees-could-change-the-world/

--back to clathrates--as the methane dissolves in the water, it reacts with oxygen, creating increasingly anaerobic and acidic conditions that could kill most life in the water, life that itself will release more carbon as it dies. (With total anoxia, their decomposition will create massive quantities of deadly H2S gas.)

I could go on and on.

Some of these will have larger effects than others, and some may never happen (we can hope) while others are already well underway.

But each of them feedback not only on itself but also on all the others.

This makes it extremely difficult to model accurately. But recent failure of all models for Arctic ice melt suggest that we are largely underestimating the speed at which these feedbacks will feed off each other and accelerate.

Again, the main point of all of this is that we must rapidly bring to a halt our habit of un-sequestering massive quantities of safely sequestered carbon into the atmosphere.

We are poking at--actually really walloping--hornet nests the scope of whose reaction we cannot know for certain (despite assurances from some corners to the contrary).




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Re: Melting Arctic an "economic time bomb"
« Reply #27 on: July 26, 2013, 03:43:43 AM »
@Anne with regards the planning for a 50 Gigatonne Methane release; is there anything that can be done in preparation for this disaster because I am aware that there are plenty of things an individual can do in an attempt to prepare for something like this, but society in itself seems to be incapable of preparing for this event.

I feel a need to point out that while a 50GT methane release over decadal timescales as indicated by Shakhova (and reiterated here by Wadhams) isn't necessarily quite as catastrophic as some people seem to think (while still being rather catastrophic compared to the normal mainstream views).

My understanding is that if there is an abrupt release of a significant quantity of methane of the type postulated that the main effect we will see is a period of above trend warming - potentially significantly above trend, but of limited duration as methane breaks down (unless the feedback triggers more release - but the bottom line is that there is still a floor under the process).

So we dump in 50GT over 10 years - a reasonable worst case - and so what? We get a substantial amount of above trend warming and climate change accelerates for bit. Nothing has fundamentally changed except in terms of timescale. All we have really done is fast forward climate change a bit - some decades, a century - whatever.

Yes - the rate of change will be even higher than present (for a while) and therefore relatively more damaging - but we already have very serious changes underway within the earth system and very serious future projections that totally disregard this additional contribution.

Accordingly, I object to classifying it as an instantly apocalyptic scenario - and would appreciate a more detailed explanation from anyone who wishes to do so to explain precisely why and how it is any worse than simply fast forwarding x decades of what climate change will do anyway...?

[EDIT] I'd like to also note that the present atmospheric concentration of methane is sustained in fair part by ongoing human activity, and with the demise of civilisation and radical changes causing major human population losses - that source may well diminish...
« Last Edit: July 26, 2013, 03:48:59 AM by ccgwebmaster »

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Re: Melting Arctic an "economic time bomb"
« Reply #28 on: July 26, 2013, 03:46:36 AM »
@Anne with regards the planning for a 50 Gigatonne Methane release; is there anything that can be done in preparation for this disaster because I am aware that there are plenty of things an individual can do in an attempt to prepare for something like this, but society in itself seems to be incapable of preparing for this event.
I really don't know. Emergency planning is quite a specialist topic but I'd guess you'd be looking at things like zoning development, costing sea defences, planning how you'd organise local sustainability in energy and food supplies. It all sounds rather inadequate but I am no expert. Perhaps there is nothing that can prepare for the most extreme outcome, but that doesn't excuse looking at more likely scenarios. At least people who are expert - and here in the UK we have them at national and local government level - should be tasked with thinking about it.

I think it's irrelevant in this context - I don't see any evidence of any government planning that seriously caters to even what is expected to happen this century under IPCC terms. No sign of even moderate emission cuts any time soon, no sign of serious endeavours to harden infrastructure or manage a retreat from coastal cities, etc...

So while there isn't any plan that can handle (at the macroscopic level) an abrupt release of methane, there is also no plan to adequately handle the far tamer mainstream view of climate change...

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Re: Melting Arctic an "economic time bomb"
« Reply #29 on: July 26, 2013, 03:57:30 AM »
A few more notes I want to tack onto this thread:

http://link.springer.com/article/10.1134%2FS1028334X12080144

Quoted from the above link:
Quote
The emission of methane in several areas of the ESS is massive to the extent that growth in the methane concentrations in the atmosphere to values capable of causing a considerable and even catastrophic warning on the Earth is possible.


Not language one sees very often in abstracts for papers from reputable and highly experienced scientists in their field.

I'd also like to toss this into the mix - I can't cite anything especially scientific for it as it's just something I made a mental note about several years ago:

http://www.upi.com/Science_News/2013/04/02/Giant-pockmarks-found-on-Pacific-seafloor/UPI-57781364947020/
Quote
Gas release from the larger pockmarks may have been sudden and possibly even violent, with a massive volume being expelled into the ocean and atmosphere within hours or days, the scientists said.


http://www.sci-news.com/othersciences/geophysics/article00985.html
Quote
Scientists believe they are the ancient remnants of vigorous degassing from under the seafloor into the ocean. The structures (the largest being 6.8 miles by 3.7 miles in diameter and 328 feet deep) are at water depths of about 0.6 miles and there is currently no sign of gas being emitted from them.


http://www.nzherald.co.nz/nz/news/article.cfm?c_id=1&objectid=10874910
Quote
The three structures are part of a field of many thousands of smaller pockmarks that extends east from Banks Peninsula for several hundred kilometres.


http://www.radionz.co.nz/news/national/131837/enormous-craters-found-off-nz-coast
Quote
The largest one found on the Chatham Rise is 11 kilometres across at its widest - enough to enclose Wellington city - and 100 metres deep.


To me the above sounds like a pretty strong candidate for abrupt outgassing of methane from substantial clathrate reservoirs. Can anyone provide a detailed and plausible alternative explanation for this multitude of seabed craters, including some very large ones?

Alternatively if anyone has more information on the science behind it I'd love to hear about it - I'm running off a little mental note I made several years ago on this one (if I had to guess, I'd wonder if they dated from the end Permian...).

Steve Bloom

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Re: Melting Arctic an "economic time bomb"
« Reply #30 on: July 26, 2013, 03:59:15 AM »
Quote
Gavin Schmidt ‏@ClimateOfGavin 11h
@cwhope Wow. "Highly possible at any time" Shakhova. I could not disagree more. Paleo provides *no* evidence for this level of sensitivity
From Gavin Schmidt's twitter. Seems I have someone else who agrees with me.

Paleo also provides no analog for this situation.

Csnavywx

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Re: Melting Arctic an "economic time bomb"
« Reply #31 on: July 26, 2013, 04:08:23 AM »
Steve, exactly.

What paleoclimate evidence we do have suggests that sea level rise from a potential collapse WAIS is a considerably bigger (relative) medium-term threat than a catastrophic methane release in this century.

More time should be devoted to this than an extreme tail-risk scenario like catastrophic methane release.

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Re: Melting Arctic an "economic time bomb"
« Reply #32 on: July 26, 2013, 04:51:01 AM »
More time should be devoted to this than an extreme tail-risk scenario like catastrophic methane release.

I think that judgement really lies with each person participating (or not) in the thread. Sometimes other people only speak up to voice an opinion that a discussion isn't worth having, which seems to me not to add to the discussion.

You refer to paleo evidence in support of your assertion that WAIS collapse is a more credible scenario than significant methane clathrate outgassing - could you please possibly include a reference to this evidence to help people assess the assertion? (I would argue both are possible outcomes that ought to be taken seriously, they are not mutually exclusive either)

In an earlier comment you mentioned methane release from taliks - I thought that term was generally used to refer to land based permafrost features, the situation on the ocean shelf is somewhat different to on land.

From what I've seen of the responses to the Wadhams article at both the ignorant and the well informed levels, an awful lot of people don't seem to really grasp the differences between what's happening on land versus what's happening in the sea. They too often say things that relate to land based permafrost to refute statements made in relation to submarine permafrost. My understanding is that all this relates very specifically to the very large methane clathrate deposits found on the East Siberian Shelf (ESS, sometimes ESAS if you toss in an "Arctic").

[EDIT] On a similar note about nuances, many commentators don't seem to grasp that the ESAS is a shallow water area, and the usual ways the methane would be prevented from escaping to the atmosphere do not meaningfully apply here. Furthermore the clathrates here are temperature stabilised, not pressure stabilised and - as we should all know - the Arctic is warming rapidly and significantly, with strong elements of positive feedback (snow and ice albedo).

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Re: Melting Arctic an "economic time bomb"
« Reply #33 on: July 26, 2013, 08:05:06 AM »
In 2002, I used Deming's methods on CT data to calculate  that there would be a major loss of Arctic Sea ice within a decade.  Gavin Schmidt called me an "Alarmist" for that, even after 2007.

In 2010 and again this year, it rained on the high snow fields, above the glaciers in the Himalaya.   That rain should have all been snow.  At this point, I fear the 2035 date is one of the best forecasts ever published by the IPCC.  It was claimed that that data was not "peer reviewed".  In fact, it came from a bunch of ice climbers that know as much about those glaciers as anyone in the world. I think the 2010 floods on the Indus and the 2013 floods on the Ganges point to coming problems in those watersheds caused by rain on the snow fields.  Those guys got it exactly correct.

There is enough methane in various forms under Arctic region that successive burps of that size are possible, with each making the next more likely.  And, each would carry its own price tag. 

The less CO2 that people put into the atmosphere, the fewer burps of  methane that are likely to be charged to our account.  Each burp will be a huge expense.  When all feed backs are included, reducing human CO2 emissions really is cost effective at any discount rate and on any time frame. Any kind of end of pipe treatment such as carbon capture is always more expensive than avoiding generation of the waste.  The reason people advocate for things like carbon capture is that they think they can make a profit on the process.






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Re: Melting Arctic an "economic time bomb"
« Reply #34 on: July 26, 2013, 08:39:58 AM »
The less CO2 that people put into the atmosphere, the fewer burps of  methane that are likely to be charged to our account.  Each burp will be a huge expense.  When all feed backs are included, reducing human CO2 emissions really is cost effective at any discount rate and on any time frame.

Unless committed natural feedbacks are sufficient to render further human contributions of carbon dioxide insignificant from where we stand, in which case cutting carbon dioxide emissions no longer has any meaningful bearing on climate change (it's still worth doing to wean people off fossil fuels to improve the resilience of modern civilisation). The ESAS clathrate deposits alone contain enough carbon to multiply the existing human contribution to atmospheric carbon dioxide several times over (and there are multiple other elements of the earth system capable in principle of adding comparable or greater amounts of carbon dioxide than all historic human activities to date).

It's worth noting that a significant amount of current atmospheric methane concentration is due to human activity. Given the short half life in the atmosphere, this represents a relatively easy (and more importantly - quick) way for us to reduce the forcing from greenhouse gases (although it is by no means clear that this would be sufficient to alter the outcome at this stage).

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Gavin Schmidt detailed response on "economic time bomb"
« Reply #35 on: July 26, 2013, 11:20:57 AM »
Reprint of a "post" sliced on tweeter by Gavin :
https://twitter.com/ClimateOfGavin
__________________________________


Some more context on Arctic methane release story

1) Methane is an important part of the anthropogenic radiative forcing over 20thC. Human caused increase from 0.7ppm to 1.8ppm

2) Methane emissions have a direct GHG effect, and they effect atmospheric chemistry and strat water vapour which have additional impacts

3) Direct forcing from anthropogenic methane ~0.5 W/m2, indirect effects add ~0.4 W/m2. (For ref: CO2 forcing is ~1.8W/m2)

4) natural feedbacks involving methane likely to be important in future - via wetland response to T/rain chng, atmos chem &, yes, arctic src

5) monitoring and analysis of atmos conc of CH4 is very important. However, despite dramatic Arctic warming and summer sea ice loss  in recent decades, little change has been seen in atmos concentrations at high latitudes.

6) There are large stores of carbon in the Arctic, some stored as hydrates, some potentially convertible to CH4 by anaerobic resporation

7) there's evidence in deep time records of large, rapid exogenous inputs of carbon into climate system; leading theory relates this to CH4

8 ) it is therefore not silly or alarmist to think about the possibilities, thresholds and impacts for these kinds of events

9) in more recent past, there have been a number if times when Arctic (not necessarily globe) has been significantly warmer than today.

10) Most recently, Early Holocene, which had significantly less summer sea ice than even 2012. Earlier, Eemian 125kyrs ago was sig warmer

11) At neither of these times is there any evidence for CH4 emissions or concentrations in excess of base pre-industrial conditions.

12) this means that we are not currently near a threshold for dramatic CH4 releases. (Though we may get there)

13) Much of the concern re dramatic changes in Arctic methane come from one off surveys and poorly calibrated remote sensing

14) thus potential for Arctic CH4 to have threshold behaviour is real, but very lg scenario used in Nature comment is not realistic

15) We should be monitoring the Arctic better than we are, and we should be alert for 'surprises' in the greenhouse.

16) But we should not take what-if sensitivity experiments as predictions.

----------------

(old lurker on ASIB, first post. Thanks, Neven and all the contributors for the great job done here)

Anne

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Re: Melting Arctic an "economic time bomb"
« Reply #36 on: July 26, 2013, 12:04:50 PM »
Welcome to the forum, Phil, and thanks for posting Gavin's comments.

Prof Wadhams is talking specifically about the offshore permafrost on the East Siberian Arctic Shelf.
Quote
As far as I'm concerned, the experts in this area are the people who have been actively working on the seabed conditions in the East Siberian Sea in summer during the past few summers where the ice cover has disappeared and the water has warmed. The rapid disappearance of offshore permafrost through water heating is a unique phenomenon, so clearly no "expert" would have found a mechanism elsewhere to compare with this.
Interview in the Guardian 24 July 2013

Quote
The layer of methane there may only be 20 metres thick, and so more susceptible to Arctic warming. He agreed there is a question about how much methane will be released and how quickly, but he told us the process could happen sooner rather than later:

"Summer [Arctic sea] ice retreat now is enough to expose the shallow sea beds containing permafrost, so we are already in danger."

Wadhams, quoted in Carbon Brief 24 July 2013. The whole article is worth reading for its coverage of the arguments.

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Re: Melting Arctic an "economic time bomb"
« Reply #37 on: July 26, 2013, 12:35:35 PM »
Quote
The layer of methane there may only be 20 metres thick, and so more susceptible to Arctic warming. He agreed there is a question about how much methane will be released and how quickly, but he told us the process could happen sooner rather than later:

"Summer [Arctic sea] ice retreat now is enough to expose the shallow sea beds containing permafrost, so we are already in danger."

I think that's a typo - I think the methane clathrate deposits are more like 200m thick? (I've confirmed this with someone who knows)

dorlomin

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Re: Melting Arctic an "economic time bomb"
« Reply #38 on: July 26, 2013, 01:13:18 PM »
During the early Holocene the earth was about 3-5 million km closer to the sun during NH summer that it is today .

Solar energy during June\July would have been (at its peak) in the order of 40 watts per square meter higher.

These conditions would have lasted for thousands of years. It take time for energy to heat up water. Back during the Holocene climate optimum we think the Arctic was warmer than even today (that may not last much longer) but you have energy and time in abundance to warm that water.

I have seen little to nothing to suggest the current methane leaks are new. I have seen nothing to explain why these methane 'bombs' did not go off then or off during the Eemian, the previous interglacial, when it was unambiguously warmer for a good many thousand years during summers.

Lots of 'i's' to dot and 't's' to cross.
« Last Edit: July 26, 2013, 01:22:04 PM by dorlomin »

Anne

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Re: Melting Arctic an "economic time bomb"
« Reply #39 on: July 26, 2013, 01:24:14 PM »
Quote
The layer of methane there may only be 20 metres thick, and so more susceptible to Arctic warming. He agreed there is a question about how much methane will be released and how quickly, but he told us the process could happen sooner rather than later:

"Summer [Arctic sea] ice retreat now is enough to expose the shallow sea beds containing permafrost, so we are already in danger."



I think that's a typo - I think the methane clathrate deposits are more like 200m thick? (I've confirmed this with someone who knows)
My bad. I cut and pasted that bit without thinking. The point is not the thickness of the methane deposits but the depth at which they are found, which is a shallow 20m.  See eg the interview with Dr Shakhova here. Her paper in question is behind a paywall here.

Neven

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Re: Melting Arctic an "economic time bomb"
« Reply #40 on: July 26, 2013, 01:49:00 PM »

I have seen little to nothing to suggest the current methane leaks are new. I have seen nothing to explain why these methane 'bombs' did not go off then or off during the Eemian, the previous interglacial, when it was unambiguously warmer for a good many thousand years during summers.


How about the winters? I've always wondered about the differences between the current warm period and for instance the Holocene Climatic Optimum. I understand that summers warmer than now, but we now have greenhouse gases making the winters warmer. Would that make a difference to methane clathrates?
Il faut cultiver notre jardin

dorlomin

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Re: Melting Arctic an "economic time bomb"
« Reply #41 on: July 26, 2013, 02:23:18 PM »
How about the winters?
Complex.
The earth would be further from the sun for NH winter but you would have a NH summer autumn with less sea ice and less snow pack so less albedo. It would be how long it took to cool down for the land permafrost. For the ocean, once the ice forms I think it slows energy loss quite a bit. Unless I am wrong most of the energy loss would go into ice formation rather than cooling deeper water.

I think it would take a mixture of GCMs and proxies to get a full answer. I have read the tree line may have been a couple of hundred miles north to todays limit.

For the Eemian, the Greenland icesheet itself is likely to have been somewhat smaller. The permafrost lines are likely to have been much further north.

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Re: Melting Arctic an "economic time bomb"
« Reply #42 on: July 26, 2013, 04:34:25 PM »
I have seen little to nothing to suggest the current methane leaks are new. I have seen nothing to explain why these methane 'bombs' did not go off then or off during the Eemian, the previous interglacial, when it was unambiguously warmer for a good many thousand years during summers.


Quoting from the above link to the Eemian:

Quote
Changes in the earth's orbital parameters from today (greater obliquity and eccentricity, and perihelion), known as the Milankovitch cycle, probably led to greater seasonal temperature variations in the Northern Hemisphere, although global annual mean temperatures were probably similar to those of the Holocene


So not really a lot warmer, taking a big picture view - and that's before you take into account that we are warming rapidly currently - not approaching and floating along a nice gentle plateau at current temperatures.

It seems carbon dioxide and methane levels during this time were nowhere near current levels (rather important little detail).

I see no basis to use the Eemian as a case study for the modern day conditions, especially as rate of change is particularly important with methane. The Eemian has already been pretty much flogged to death as an unsuitable analog in other threads.

In any event:

http://www.aip.org/history/climate/xMethane.htm

There was a considerably rise in methane concentrations around this time, notwithstanding that the rate of change was likely far slower and therefore there was much more time for the methane being released to break down and keep overall concentrations low. Where do you suppose it came from?

With methane, it would be possible to achieve very different results based on the rate of the warming. Some amount of clathrate contribution to the rise in methane levels during the Eemian seems perfectly plausible, and the massively different situation prevents any conclusions being drawn to support an argument that we are on safe ground right now.

[EDIT] This link looks somewhat at past warm climates and examines their usefulness a little.
http://www.ncas.ac.uk/index.php/en/climate-blog/397-warm-past-climates-is-our-future-in-the-past

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Re: Melting Arctic an "economic time bomb"
« Reply #43 on: July 26, 2013, 06:34:06 PM »
Is there a way to date the hydrates and if so has it been done?


If Arctic hydrates are exclusively younger than Eemian times it indicates that whatever clathrates had formed earlier have outgassed during the Eemian & will do so again as we reach for Eemian temperatures. Since we're heating things up much more rapidly than ever before it seems as though what could have been a measured release in the past might accelerate and cause a feedback allowing the 20 year effects of CH4 to cause ever more rapid outgassing.


I'm personally convinced that Shakhova and Semiletov were told at some point to keep quiet about the results of their 2011 cruise. Hope this doesn't require me to don the tinfoil chapeau.


Terry
« Last Edit: July 26, 2013, 06:44:39 PM by TerryM »

dorlomin

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Re: Melting Arctic an "economic time bomb"
« Reply #44 on: July 26, 2013, 06:49:53 PM »
So not really a lot warmer, taking a big picture view
Yes it was. Especially in the high boreal latitudes.
  - and that's before you take into account that we are warming rapidly
Yes rapidly. I have already made that point. It takes a huge amount of time for to warm seas and oceans. We had that time in the early Holocene and the Eemian. The word 'rapidly' kind of suggests that time is one quantity we have not had in abundance with this warming eh.


Quote
It seems carbon dioxide and methane levels during this time were nowhere near current levels (rather important little detail).
Why is this an important detail? They are only important for the additional energy they radiate back to the surface. Important compared to what, the massive increase in summer insolation we had in either period? I am suspecting you have not read what I have written.

Quote
I see no basis to use the Eemian as a case study for the modern day conditions,
Well bully for you.

Quote
There was a considerably rise in methane concentrations around this time, notwithstanding that the rate of change was likely far slower and therefore there was much more time for the methane being released to break down and keep overall concentrations low. Where do you suppose it came from?
You are asking me that? Seriously? You dont know the main sources of methane?



Quote
With methane, it would be possible to achieve very different results based on the rate of the warming.
Blah blah blah. You have not read what I have written and just gone into your by-the-numbers routine. 

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Re: Melting Arctic an "economic time bomb" -Wadhams responds to criticism
« Reply #45 on: July 26, 2013, 06:52:05 PM »
Prof Wadhams responds to Jason Samenow's NYT criticism.
Quote
<snip>What is 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.

dorlomin

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Re: Melting Arctic an "economic time bomb"
« Reply #46 on: July 26, 2013, 06:55:28 PM »
I'm personally convinced that Shakhova and Semiletov were told at some point to keep quiet about the results of their 2011 cruise.
That is about the most unlikely thing I have heard for a while.

Here is one of their presentions

Quote
Prorating these numbers to the areas of hot spots (210×103 km2) adds 3.5Gt to annual methane release from the. ESAS
They managed to claim the Arctic was realsing about as much CH4 per year as there was in the atmosphere at the moment.

They are not exactly shy about 'maximising' the impact of their results.

dorlomin

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Re: Melting Arctic an "economic time bomb"
« Reply #47 on: July 26, 2013, 06:58:57 PM »
Quote
up to 7C according to satellite data. That warming extends the 50 m or so to the seabed
Let see a link to your peer reviewed research showing this warming at 50m then Professor Wadhams.

And then explain what happens in winter.

Anne

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Re: Melting Arctic an "economic time bomb"
« Reply #48 on: July 26, 2013, 07:04:59 PM »

I'm personally convinced that Shakhova and Semiletov were told at some point to keep quiet about the results of their 2011 cruise. Hope this doesn't require me to don the tinfoil chapeau.
But not before Semelitov had given this exclusive interview to The Independent in December 2011. ;)
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"Earlier we found torch-like structures like this but they were only tens of metres in diameter. This is the first time that we've found continuous, powerful and impressive seeping structures more than 1,000 metres in diameter. It's amazing," Dr Semiletov said.

"I was most impressed by the sheer scale and the high density of the plumes.  Over a relatively small area we found more than 100, but over a wider area there should be thousands of them," he said.

He was en route to presenting his findings to the American Geophysical Union meeting in San Francisco, before their paper was published.
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"I am concerned about this process, I am really concerned. But no-one can tell the timescale of catastrophic releases. There is a probability of future massive releases might occur within the decadal scale, but to be more accurate about how high that probability is, we just don't know," Dr Shakova said.

"Methane released from the Arctic shelf deposits contributes to global increase and the best evidence for that is the higher concentration of atmospheric methane above the Arctic Ocean," she said.

"The concentration of atmospheric methane increased unto three times in the past two centuries from 0.7 parts per million to 1.7ppm, and in the Arctic to 1.9ppm. That's a huge increase, between two and three times, and this has never happened in the history of the planet," she added.


Anne

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Re: Melting Arctic an "economic time bomb"
« Reply #49 on: July 26, 2013, 07:08:35 PM »
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up to 7C according to satellite data. That warming extends the 50 m or so to the seabed
Let see a link to your peer reviewed research showing this warming at 50m then Professor Wadhams.

And then explain what happens in winter.
The article I was quoting from has commenting enabled. It would be great to have a response to your questions there.