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 summit’s 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 Kramer’s 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 system’s 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 don’t 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 “geoengineering” 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? Kramer’s 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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