Dear Simon-- I wonder if you could expand a bit on your remark that: > These simulations could be of great use - indeed, the objective uncertainties around > geoengineering are so large as a basic fact that I actually believe anyone who > believes it to be automatically good or automatically bad for the climate to > be more or less ideological."
I am wondering whether you are referring to uncertainties about whether they would work or not, or a sense that we have no idea about unintended consequences and outcomes that might make them a poor alternative to continuing with global warming without geoengineering? I ask because it seems to me that the uncertainties related to continuing on with global warming carrying the climate at a very rapid pace into conditions not experienced in at least many millions of years must surely be larger than those associated with using analogs to natural cooling mechanisms to try to keep the climate near to the relatively familiar and understandable situation where we are now (or recently were). Despite the large uncertainties about future global warming, indeed, in part because of the uncertainties, we are confident enough to be encouraging the world to end its at least economically beneficial fossil fuel use. As Paul Crutzen suggested, that efforts to slow, stop, and reverse global warming through mitigation are going so slowly when the risk seems so high of irreversible consequences would seem to me to suggest that at least some tolerance of uncertainties about geoengineering needs to be acknowledged and accepted---that level to be determined by a risk analysis based not on geoengineering alone, but on global warming with and without geoengineering of various types or degrees. Thank you in advance then for a bit more explanation of your position. Regards, Mike MacCracken On 8/6/13 3:31 PM, "Simon Driscoll" <[email protected]> wrote: > Hi Russell, > > I feel like I've been asked a couple questions on behalf of someone else's > article that I simply *posted* - the article gives his email address should > you wish to contact him about it on this forum. > > As such, yes. One can debate over precise wording, but I agree - I hope I > understand you correctly. > > On resolution in general, I think improved resolution could be tremendously > useful - as pointed out by Tim Palmer and others in recent climate studies > (with a mention to geoengineering in the below quote by Tim). These > simulations could be of great use - indeed, the objective uncertainties around > geoengineering are so large as a basic fact that I actually believe anyone who > believes it to be automatically good or automatically bad for the climate to > be more or less ideological. Such studies as below could be a strong factor in > having models reasonable enough to make much stronger statements about > geoengineering impacts. > > "Overall, the experience in Project Athena confirmed the general expectation > of the World Modeling Summit that dedicated computational resources can > substantially accelerate progress in climate simulation and prediction. The > availability of such resources not only enabled some detailed explorations of > issues that were previously considered beyond the scope of computers used for > climate but also was an important incentive for the formation of the > international team. ... An important element of this collaboration was the > presence of experts from national modeling centers, which argues in favor of > another of the summit¹s recommendations, namely the enhancement of national > modeling capabilities in the key centers around the world. ... the impact of > dramatically increased spatial resolution was apparent for numerous important > aspects of climate, including such diverse features as North Atlantic > blocking, tropical cyclone intensity, and patterns of regional climate change. > Considerable more work is needed to carry on the investigation of how best to > take advantage of future improvements in high-end computing for higher > fidelity climate simulation and insights into future climate change." > http://journals.ametsoc.org/doi/pdf/10.1175/BAMS-D-11-00043.1 > > "Just as the nations of the world came together to fund the Large Hadron > Collider, allowing scientists to study the moments after the Big Bang in the > sort of detail needed to reveal the workings of mother nature, so the nations > of the world should come together to fund the sort of supercomputers that > would allow us to simulate the climate of the coming century with much greater > reliability than is currently possible. The impact that this will have for > mitigation, adaptation and geoengineering policies is likely to be enormous." > http://www.rmets.org/weather-and-climate/climate/climate-change-simulation-tim > -palmer > > Best wishes, > > Simon > > ________________________________________________ > > Simon Driscoll > Atmospheric, Oceanic and Planetary Physics > Department of Physics > University of Oxford > > Office: +44 (0) 1865 272930 > Mobile: +44 (0) 7935314940 > > http://www2.physics.ox.ac.uk/contacts/people/driscoll > > ________________________________________ > From: [email protected] [[email protected]] on > behalf of Russell Seitz [[email protected]] > Sent: 05 August 2013 22:29 > To: [email protected] > Subject: [geo] Re: Geoengineering carries unknown consequences > > Simon, would you agree that model grid resolution is a metric for > distinguising between 'local' phenomena manifest within the model grid pixels > , and 'global' phenomena manifest in the dynamics of the extended grid ? > > On Thursday, August 1, 2013 2:06:19 PM UTC-4, Simon Driscoll wrote: > The physicists out there may have already seen this short article: > http://www.physicstoday.org/resource/1/phtoad/v66/i8/p8_s3 (also copied down > below) which may be of interest to group members. > > Best wishes, > > Simon > > +++ > > I read with interest David Kramer¹s piece on geoengineering (Physics Today, > February 2013, page 17<http://dx.doi.org/10.1063/PT.3.1878>). I must say, I am > more alarmed by what the geoengineers in his report are proposing than by the > climate changes that are taking place. I believe geoengineers are removed from > scientific reality. They ignore the fact that the climate system and its > components‹clouds, hurricanes, and so forth‹are highly nonlinear and thus very > sensitive to the initial conditions and to changes in the parameters. > Nevertheless, one could study the system¹s response in a probabilistic way > when certain parameters are changed or when we introduce fluctuations, if the > relationships among all the components are known exactly. > > And here lies the whole problem with geoengineering. The formulation of the > climate system and its components is only approximately known. More than 30 > climate models are floating around in the climate community, and their > predictions about general dynamics simply don¹t agree with each other. In a > recent > publication,1<http://www.physicstoday.org/resource/1/phtoad/v66/i8/p8_s3#c1> > we considered 98 control and forced climate simulations from 23 climate models > and examined their similarity in four different fields (upper-level flow, > sea-level pressure, surface air temperature, and precipitation). We found that > except for the upper-level flow, the agreement between the models is not good. > Moreover, none of the models compares well with actual observations. > > One person in the Physics Today story said that geoengineering may result in > changes in various weather patterns, but nobody knows what the changes are > going to be and how they will affect the climate system. If the warming in the > Arctic is a big event to mitigate, then it will require a significant > ³geoengineering² effort. To me, that means significant changes will occur > elsewhere. Who can say whether those changes will be less serious than those > taking place now? How can geoengineers talk about modifying clouds and albedo > when clouds are represented in the climate models as mostly linear > parameterizations? > > Kramer¹s report did not mention hurricanes, but geoengineers also propose to > dissipate them. Hurricanes are unique in the climate system because they > represent major self-organization. As physicists well know, self-organization > occurs in dissipative systems in which energy is not conserved but instead is > exchanged with the environment. Hurricanes involve huge amounts of energy. > Scientists have little idea how the atmosphere and the ocean will be affected > if that energy is not allowed to be exchanged. > > I would not have a problem with geoengineering if the physics and dynamics of > the climate system were well known. Climate scientists have a good idea of the > large-scale flow of ocean currents, but detailed measurements are not > available. They know the basic physics of cloud formation and its > thermodynamics but do not fully understand detailed cloud microphysics or the > complex connections between climate and ecosystems. And with complex nonlinear > systems, details are important. So we need to make an effort to improve our > understanding of our climate system and its components before we try to > operate on it. We can engineer a car or a plane because we know the underlying > physics of motion, combustion, and flight, and we understand the role of every > component. Can geoengineers say the same about climate? > > ________________________________________________ > > Simon Driscoll > Atmospheric, Oceanic and Planetary Physics > Department of Physics > University of Oxford > > Office: +44 (0) 1865 272930 > Mobile: +44 (0) 7935314940 > > http://www2.physics.ox.ac.uk/contacts/people/driscoll > > -- > You received this message because you are subscribed to the Google Groups > "geoengineering" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To post to this group, send email to [email protected]. > Visit this group at http://groups.google.com/group/geoengineering. > For more options, visit https://groups.google.com/groups/opt_out. > -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. 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