Can SRM save our Bacon?
Andrew Lockley
Hi
I wonder if anyone can shed light on the potential of geoengineering in a high GHG atmosphere ?
If we have massive methane excursions from the arctic, will we be able to create a safe climate? The paleoclimatic record shows dramatic cooling through volcanism, but that wasn't in a high GHG world .
If there's a whole load of methane around, there will be a massive polar amplification. This reduces the ocean over turning circulation , and potentially lead to an anoxic event, and possibly further methanogenesis.
I am not sure that, even with a maximal SRM effort, we can avoid the climate transitioning into a state in which society is unsustainable due to an anoxic event.
If this is the case, we potentially have a very brief window in which to geoengineer, perhaps only five or ten years
I'd value comments on this.
Thanks
A
Eugene I. Gordon
Andrew:
There are many unknowns due to the infantile state of the climate science. Whether it is 5-10 years or 25 before warming begins to introduce additional dangers, some not yet anticipated, there is no doubt it will. No doubt you heard of Reilly’s addendum to Murphy’s Law. Reilly was a graduate student of Prof. Murphy. His robust hypothesis was that Murphy was an optimist.
I would bet on upper atmosphere SO2 additions for cooling, since for sure it works and is relatively easy to implement, and pray there are no unmanageable consequences.
-gene
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Ken Caldeira
I think your use of the word "infantile" to refer to the state of climate science skirts close to the ad hominem.
Would you also refer to the "infantile state of the science of turbulence"?
Is this vocabulary being used because use think that climate science has tremendous potential for growth and development, or is this word being used with a denigrating tone? If you are intending the former, I suggest you use a word like "nascent", which is less open to mis-interpretation.
If you are suggesting that climate scientists lack the maturity and sophistication that characterize scientists working in other fields, I think your characterization is without foundation.
I would appreciate it if you would choose your words carefully.
Best,
Ken
___________________________________________________
Ken Caldeira
Carnegie Institution Dept of Global Ecology
260 Panama Street, Stanford, CA 94305 USA
+1 650 704 7212 kcal...@carnegie.stanford.edu
http://dge.stanford.edu/labs/caldeiralab @kencaldeira
Eugene I. Gordon
Ken:
It was not meant to be denigrating just meant to indicate that it is early times. Indeed in science there is a scientific method that in mature stages ends with a Theory. The Theory is a follow-on to a robust hypothesis that has withstood all challenges in the sense that the hypothesis is consistent with and explains all related observation and the Theory allows accurate prediction. I know you know this so I am a bit surprised at your question. Climate science in fact has a long way to go, it is not robust and it cannot predict future change accurately. That is not to say much good work has not been done; but much remains to be done. Maybe immature would have been a better choice. I doubt if I would give ground on ‘immature’. It is why I keep insisting that geoengineering must be viewed as a critical contingency and why it must be allowed to build the pieces even if not put in place until clearly needed.
-gene
vogle...@gmail.com
Sense you posted the question, I have reviewed a few Paleoclimatology studies and books and they all paint a gruesome picture of what we may be looking at. Here are just a few that came up.
http://geology.geoscienceworld.org/cgi/content/abstract/31/1/87
http://www.pnas.org/content/108/14/5542.abstract I found this paper interesting due to the discussion on methane hydrates being released. But, O2 poor atmosphere makes this off somewhat.
http://adsabs.harvard.edu/abs/2010AGUFM.B41D0327S Limited connection to the question but good background.
http://books.google.com/books?id=jd01mugCR7EC&pg=PA235&lpg=PA235&dq=methane+weathering&source=bl&ots=wB5Hv-nYFw&sig=zWtpHS182Ra7cqDbRrShCVpaXvY&hl=en&ei=oEuiTbuVKOLiiAK_gvmOAw&sa=X&oi=book_result&ct=result&resnum=2&sqi=2&ved=0CB0Q6AEwAQ#v=onepage&q=methane%20weathering&f=false I have not had time to read the book but Pg 235 has an interesting description of the effects of large methane release to the climate and further on starts to ask the main question in this thread.
http://books.google.com/books?id=yRMgYc-8mTIC&pg=PA967&lpg=PA967&dq=methane+weathering&source=bl&ots=ODF86It7MF&sig=EuwNAHUuHZ5gvPrqdX-18o_RAXk&hl=en&ei=oEuiTbuVKOLiiAK_gvmOAw&sa=X&oi=book_result&ct=result&resnum=4&sqi=2&ved=0CCMQ6AEwAw#v=onepage&q=methane%20weathering&f=false Pg 967 has reference to the past historic out come of large methane releases.
After reviewing this short list of documents, and as a layperson, I can see the need for a far more aggressive preparation of SRM injection. Not 1 "fire hose in the sky" but hundreds would seem to be needed if methane release begins in earnest. The rapid domino effect would be seemingly impossible to stop once it started. A major global disruption lasting no fewer than 20 yrs is what even I. as a layperson. can see coming. It would seem better to stop the snow ball from rolling at all than stop it half way down the hill.
Thanks for the question and education.
Stephen Salter
Several computer models show that tropospheric cloud brightening can
offset at least 4 or maybe 6 watts per square metre . The log term
means that it gets progressively harder but not impossible to increase
the offset. We get the choice about where to spray so we have control
of initial conditions and so may be able to exert some control about
getting more or less precipitation or at least avoid the very bad
places. We should know more about this quite soon. If the climate
situation changes, perhaps by another Pinatubo we can stop very quickly
(a few days) or increase quite quickly if there are enough vessels.
I understand that stratospheric aerosols can do a similar amount
offset. I had thought that the effect was linear but there has been a
suggestion that the more you spray the greater the chance of particles
coalescing and falling out more quickly. The effects last about two
years depending on height so you cannot do a sudden turn off. The
obvious solution is to use both with the cloud albedo tweeter doing fine
adjustments to the stratospheric sulphur woofer.
The costs given in the Royal Society report for a cooling of one watt
per square meter were made on the sumption that the entire spray fleet
was scrapped each year. If you follow the reference to the Robock paper
for costs of the aircraft launch system you will see that they assumed
that the capital cost of planes was zero and all they were paying for
was fuel, spares and and crew time. However the costs of both
techniques are so much smaller than Stern predicts for doing nothing
that you can ignore them.
If you are worried about ocean over turning you could look at the file
/Hurricanes carbon and fish in the /Hurricanes folder at the site below
my signature.
Stephen
Emeritus Professor of Engineering Design
Institute for Energy Systems
School of Engineering
Mayfield Road
University of Edinburgh EH9 3JL
Scotland
Tel +44 131 650 5704
Mobile 07795 203 195
www.see.ed.ac.uk/~shs
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Angus Ferraro
Doesn't your claim that climate science is in its infancy (which I
think is the word you intended, rather than 'infantile') rather
conflict with your claim that geoengineering is a viable option? I
don't see how uncertainty in climate prediction leads to failure to
act on greenhouse gas emissions, and how that leads to geoengineering.
We cannot accurately predict the results of geoengineering, after all.
I don't say that we shouldn't research it, but I'm saying the same
modelling uncertainties apply.
Angus Ferraro
On Apr 10, 8:09 pm, "Eugene I. Gordon" <euggor...@comcast.net> wrote:
> Ken:
>
> It was not meant to be denigrating just meant to indicate that it is early
> times. Indeed in science there is a scientific method that in mature stages
> ends with a Theory. The Theory is a follow-on to a robust hypothesis that
> has withstood all challenges in the sense that the hypothesis is consistent
> with and explains all related observation and the Theory allows accurate
> prediction. I know you know this so I am a bit surprised at your question.
> Climate science in fact has a long way to go, it is not robust and it cannot
> predict future change accurately. That is not to say much good work has not
> been done; but much remains to be done. Maybe immature would have been a
> better choice. I doubt if I would give ground on 'immature'. It is why I
> keep insisting that geoengineering must be viewed as a critical contingency
> and why it must be allowed to build the pieces even if not put in place
> until clearly needed.
>
> -gene
>
> Caldeira
> Sent: Sunday, April 10, 2011 1:02 PM
> To: euggor...@comcast.net
> Cc: andrew.lock...@gmail.com; geoengineering
> Subject: Re: [geo] Can SRM save our Bacon?
>
> Eugene,
>
> I think your use of the word "infantile" to refer to the state of climate
> science skirts close to the ad hominem.
>
> Would you also refer to the "infantile state of the science of turbulence"?
>
> Is this vocabulary being used because use think that climate science has
> tremendous potential for growth and development, or is this word being used
> with a denigrating tone? If you are intending the former, I suggest you use
> a word like "nascent", which is less open to mis-interpretation.
>
> If you are suggesting that climate scientists lack the maturity and
> sophistication that characterize scientists working in other fields, I think
> your characterization is without foundation.
>
> I would appreciate it if you would choose your words carefully.
>
> Best,
>
> Ken
>
> ___________________________________________________
> Ken Caldeira
>
> Carnegie Institution Dept of Global Ecology
> 260 Panama Street, Stanford, CA 94305 USA
>
> On Sun, Apr 10, 2011 at 9:28 AM, Eugene I. Gordon <euggor...@comcast.net>
> For more options, visit this group athttp://groups.google.com/group/geoengineering?hl=en.
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> You received this message because you are subscribed to the Google Groups
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