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Author Topic: Methane Release Implications  (Read 6460 times)

fishmahboi

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Methane Release Implications
« on: April 07, 2013, 09:54:21 PM »
This stems from the discussion on the When and How Bad thread in the sense that it comes from a worst case climactic scenario whereas a Methane calamity hits earth in the sense that the earth experiences a methane release similar to that of the Permian whereas a Methane release decimated over 90% of the population of the earth (https://en.wikipedia.org/wiki/Permian) whereas Methane is released abruptly and causes temperatures to rise steeply.

There are two scenarios surrounding this that are notable and are shown by two sites, one which is the Arctic News Blog that talks about implications of releases of Methane with one of them being the earth delving into a Runaway Global Warming (according to an article related to the Blog the earth heating by 10 degrees centigrade by 2039 (http://methane-hydrates.blogspot.ie/)

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9. Destruction and Extinction

In the above projection, runaway global warming will catch up with Arctic warming by 2039, resulting in a global temperature increase of 10 degrees Celsius and rising. The heatwaves that will come with such a temperature rise will in itself be enough to cause crop losses at massive scale. Additionally, heatwaves at high latitudes will cause wildfires, e.g. in Siberia, which has a very high soil carbon content (see image below).

However another site talks about this in more detail and most would know of this site as it was linked in the When and How Bad Thread and what I mean by going into detail is that the site talks about the earlier extinction periods that were caused by methane, the two ways in which methane can be released and the implications for the releases along with the damage that can be done to earth which is rather more permanent in the sense that it would take millions of years for the earth to finally recover.

Site: http://killerinourmidst.com/now.html

The two ways in which methane is released according to the site is that it either releases its load abruptly through the slumping of slopes or though more gradual venting that occurs over a number of decades.

The site states that in order for Methane to actually rise to the point of a catastrophe is for the release to be ongoing over a short period of time (the maximum of amount of time according to the site is one thousand years, although the site notates that the timescale could be considerably less).

So basically this thread is to discuss what people feel about the threats posed by large scale methane releases.

Laurent

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Re: Methane Release Implications
« Reply #1 on: October 17, 2014, 10:00:31 AM »
Quite funny piece of information...don't just seat there...do something !
More on Methane Part I: Taking a leak

viddaloo

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Re: Methane Release Implications
« Reply #2 on: October 20, 2014, 08:49:11 PM »
Using only historic data (except for 2014) and the simple trendline you get from Google Chart, this graph when extended to the right, shows a crash year of 2031.

Now, I'm fully aware that this simple trendline is likely too conservative, meaning the crash could come several years ahead of 2031.

If correct, there will be absolutely no sea ice in the Arctic on any day of the year before most of us writing here are gone. And interestingly, also before the IPCC predicts we'll see the very first September day with no sea ice.

What will life look like in a Zero Ice world? And what sort of temperatures are we looking at?
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oren

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Re: Methane Release Implications
« Reply #3 on: October 21, 2014, 12:57:17 AM »
Based on the physics of arctic winter and heat loss to space, as so clearly explained by Chris Reynolds, I can't see a year-round ice free arctic in the near future. The trend of the yearly average is too simplistic to capture the actual behavior of the system. An ice-free summer will be with us soon, for an ice-free winter there'll be a much longer wait.

viddaloo

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Re: Methane Release Implications
« Reply #4 on: October 21, 2014, 01:27:44 AM »
oren, I believe the task of the Yearly Average trend is to capture the trend of the Yearly Average, and not the actual behavior of the system. In other words, for the Yearly Average trend to NOT point to 2031 as the Crash year, or for it to point to a somewhat later year than 2031, the actual behavior of the system should pretty soon cough up a Yearly Average Extent higher than the projected 10–12 k km³ for the next 5 years.

Otherwise the ice will be gone by 2031. All year round.
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viddaloo

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Re: Methane Release Implications
« Reply #5 on: October 21, 2014, 02:08:25 AM »
Barring, of course, any abrupt releases of methane from the permafrost or the Arctic sea, not part of the above graph, which would secure a much earlier ice–free state than 2031, all year round.

And speaking of methane: Eagerly awaiting the first 2014 post on the subject on the ASI Blog. Is it possible at this stage to say something about the relation between major ice loss and methane releases? Are they purely one–directional, or do they work both ways? Ie can a major methane release secure an even greater ice melt in the short term?
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viddaloo

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Re: Methane Release Implications
« Reply #6 on: October 21, 2014, 09:04:33 AM »
Just found this. Chris writes in April:

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If all of this seems ridiculous to you, then consider the alternative to an inflection in the trend of April volume in the Central region, continuing the trend regardless gives an ice free Arctic in April by 2037, surely nobody expects that!
Yup, you may be on to something there. I expect that, based on data in the PIOMAS series (see graph above). Although that graph pointing to a 2031 crash is probably too conservative, as abrupt future melting is not considered.
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Michael Hauber

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Re: Methane Release Implications
« Reply #7 on: October 27, 2014, 11:15:03 AM »
Skeptical science have an interesting article on permafrost thawing.  They estimate that the thawing of perma-frost could lead to a warming of as much as 1.6 degrees by 2300 under the lowest emissions scenario (RCP2.6).  The suprprising thing is that under the most pessimistic scenario of RCP8.5 the warming due to perma-frost thaw goes down and is at worst only 0.8 degrees.

How could this be?  Surely if we have a faster warming rate then more permafrost will thaw, which will provide more warming due to perma-frost?  Well more perm-frost will thaw, but under a high emissions scenario the much greater Co2 saturation of the atmosphere will result in less warming for every tonne of perma-frost thawed.  A very important negative feedback, which at least according to the macDouggal paper Skeptical Science references, wins out.  Another obvious negative feedback is that as the surface perma-frost thaws the remaining perma-frost will be protected by an increasingly deep layer of soil, which is a good insulator.

But wait, the permafrost warming in the worst case scenario of 0.8 degrees is not the full story.  There are significant issues that the MacDougall paper does not address.  In particular it does not even consider methane, but Co2 only.  If we refer to the Shur paper on permafrost emissions we see that many experts believe that enough methane may be emitted to double the warming impact of the Co2 alone.  So that would be 1.6 degrees by 2100.  Perhaps the number could be made still higher if we consider that the major negative feedback on Co2 permafrost warming is the saturation factor.  Methane is actually not a stronger greenhouse gas than Co2.  It is only considered much stronger because every tonne we currently add to the atmosphere will contribute a lot more warming.  And that is because methane conentrations are 100s of times lower than Co2 and has not yet reached saturation.

The saturation feedback will still be relevant in a large scale methane release.  Current saturation in peak absorption bands is about 80%.  I would guess that as we first hit saturation the negative feedback may be significantly weaker than it currently is for Co2.  If the methane isn't held back by negative feedback as much as co2 it may more than double the 0.8 degrees and permafrost may contribute more than 1.6 degrees.  However in this game I've found guesses like this can sometimes be misleading....

The other significant result of this paper is that if we stop GHG emissions totally then in this scenario Co2 will not go down at all.  This is because the perma-frost emissions will continue, and be strong enough to replace the Co2 being absorbed by the oceans.  Consider that other slow feedbacks such as albedo/ice sheet and that ocean inertia will both contribute further slow warming. 

I am then reminded of the metaphorical boiling frog.  But not as a metaphor for the current century, which is fast enough that we are actually doing something about the problem (if less action and slower than many including I would prefer).  But a metaphor for future centuries.  Modelling suggests that the warming rate post 2100 if we cease Co2 emissions could be only a few tenths of a degree per century.  However this may continue on for many centuries.  If we double Co2 in the next 50 years and do nothing to remove it then full earth system feedbacks may result in 8 degrees warming, after thousands of years.  That would render large portions of the planet uninhabitable for humans (35 degree wet bulb temperature is guaranteed fatal heat dose).  But in any century, would we have the motivation to act on only a few tenths of a degree warming?  The action required would be a draw down of Co2, which is much harder than not emitting it in the first place, and perhaps it would never get done.  The ultimate slow boiling frog.

But at least we would have a long time to adjust to housing the last remnants of the human race somewhere near the poles.
Climate change:  Prepare for the worst, hope for the best, expect the middle.

wili

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Re: Methane Release Implications
« Reply #8 on: October 27, 2014, 12:23:21 PM »
Yes, that was an interesting rather counter-intuitive finding about the reduced effect of permafrost thaw under McDougal et al's model under RCP 8.5.

But really, if we do go that path, the amount that permafrost is contributing will be the least of our worries.

Similarly, by the time we reach methane levels where the saturation feedback becomes relevant, we will already be pretty much toast.

So while these factors are interesting scientifically, they don't help us much in imagining a viable future under worst case scenarios. (Though they do suggest that it will be difficult for the climate to undergo such extreme runaway warming that it approaches Venus levels, for example--some comfort in that, I suppose).

Also note that, iirc, even the Shur paper only considered methane levels at 3% of the total permafrost carbon emissions. The recent study on Methanoflorens microbes seems to suggest that there are a lot more methanogens in thawing permafrost than previously assumed (though I haven't been able to peruse the entire article yet, so I may be off here).

More importantly, the McDougal study, important as it is for at least trying to include some 'slow' carbon feedbacks, also:
>does not include permafrost deeper that three meters (it can be about a mile deep in places), >doesn't include free methane pools that exist at deeper levels,
>doesn't include deposits under ice sheets that will be more and more exposed,
>doesn't include coastal erosion,
>and doesn't include non-terrestrial, sea bed methane sources.

Add all these in and it is clear that we have further heating and higher GHG levels in store for us in future decades and centuries even if we stop all further GHG emissions today (or really, last year). That's why we really don't have any more time--talk of a 'carbon budget' by some is just daft--we're way overdrawn on that account already.

Good point about the boiling frog problem. We do indeed have to move rapidly from an economy that emits carbon to one that actually draws down atmospheric carbon levels. In some ways, this just involves changing the rules of the game (and perhaps changing the stories in our heads about what gives our lives value). But in actuality, such rule changes (and story changes) are beyond revolutionary.

But then, revolutions do happen on occasion.

ETA: And yes, the only thing that worries me more than sudden, massive methane release is the probably more likely slower but inevitable release of all that carbon over centuries to millennia...that would ensure that our initial warming lasts millennia to millions of years longer than it would have otherwise, damning yet more species to certain extinction and probably delaying the period for any potential recovery of complex life on earth, if that ever even has a chance to happen.
« Last Edit: October 27, 2014, 12:40:05 PM by wili »
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Michael Hauber

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Re: Methane Release Implications
« Reply #9 on: October 28, 2014, 11:37:41 AM »

More importantly, the McDougal study, important as it is for at least trying to include some 'slow' carbon feedbacks, also:
>does not include permafrost deeper that three meters (it can be about a mile deep in places), >doesn't include free methane pools that exist at deeper levels,
>doesn't include deposits under ice sheets that will be more and more exposed,
>doesn't include coastal erosion,
>and doesn't include non-terrestrial, sea bed methane sources.


McDougal also include a negative feedback for release of nutrients from thawing perma-frost causing an increase in plant growth (and I would assume the newly available non frozen ground should increase plant growth as well).

So are any of those important?  Is there any way to put a number to them?  My gut feel is that only the sea methane - which is very important, but a separate issue to what this paper is looking at, and the perma-frost below 3.5 meters may matter.  I find it odd that the study would leave out the methane under 3.5 meters, and the methane factor as covered by Shur unless the author was reasonably confident that these factors do not matter much.  Perhaps if there is a reasonable scientific case that in the best case these factors do not matter much the study could be worth something as an indicator of the best case with more work to be done on the worst case.  Otherwise if these factors are major factors than why do the study in the first place?
Climate change:  Prepare for the worst, hope for the best, expect the middle.

wili

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Re: Methane Release Implications
« Reply #10 on: October 28, 2014, 11:47:50 AM »
"unless the author was reasonably confident that these factors do not matter much"

That's a pretty big assumption. All models are simplifications. IIRC, McDougal et al. themselves point out how their assumptions mean that their conclusions are on the conservative end. And this is exactly where most scientists like to be, for better or worse.

But give them credit--all the other IPCC models up to then just ignored all carbon feedbacks altogether, so this is a big advance, even if, as I'm sure the study authors would agree, much much more work needs to be done.

Limiting to 3 meters means you don't have to make an exact estimate of how much of the permafrost is deeper than that and by how much. It is also the material most likely to thaw in the coming decades, so is most relevant for the near term.

There will surely be some new growth in the Arctic as it warms. But note that in the near term that will add to local warming because of change of albedo. It will also never come close to matching the carbon stored in the permafrost, since that store is larger than all the carbon in all terrestrial life on earth.

"A force de chercher de bonnes raisons, on en trouve; on les dit; et après on y tient, non pas tant parce qu'elles sont bonnes que pour ne pas se démentir." Choderlos de Laclos "You struggle to come up with some valid reasons, then cling to them, not because they're good, but just to not back down."

Laurent

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Re: Methane Release Implications
« Reply #11 on: December 09, 2014, 12:40:47 PM »
A very interesting documentary on methane (available in French/German, sorry)

Energiequelle Methan
http://www.arte.tv/guide/de/043870-000/energiequelle-methan

Méthane, rêve ou cauchemar?
http://www.arte.tv/guide/fr/043870-000/methane-reve-ou-cauchemar?autoplay=1

Laurent

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Re: Methane Release Implications
« Reply #12 on: January 06, 2015, 05:28:38 PM »
Researchers discover scientific surprise studying underwater methane seeps
http://phys.org/news/2015-01-scientific-underwater-methane-seeps.html