Jim - at the risk of continuing a thread that's perhaps already gone on too long, there's two of your statements that I don't understand. (I respond only because maybe there's potential to reach consensus.)
1) I use the word "implementation" or "full-scale" to mean offsetting some useful fraction of the warming, where we could quibble about whether that means 30% or 50% or 100%. It is clearly possible to conduct a test (albeit spatially global) at an amplitude too small to offset any useful fraction. (Though it might take a long time if its 1%.) You would describe that as implementation, I wouldn't. Some fraction of the population would agree with you, some fraction would agree with my use of the words. 2) Either we believe that there are NO circumstances in which one would EVER deploy geoengineering, or we believe that there are circumstances in which we might. That strikes me as a rather binary belief system. If the former is true, there's no need to do any further research indoors or out, technocratic or social. But if the latter is true, then surely understanding the research path that we "might" or "could" follow is useful? I concede that I don't follow how articulating what it would take to get us from here to there results in a slippery slope argument any more than starting research but not articulating the longer term. (And supporting research if we believe there is no long term seems odd.) doug From: [email protected] [mailto:[email protected]] On Behalf Of James R. Fleming Sent: Wednesday, September 29, 2010 5:42 PM To: [email protected]; geoengineering Subject: Re: [geo] Re: Can solar radiation management be tested? Colleagues, Is global climate engineering untested? -- Yes, with the exception of the historical example I provided, which was US and Soviet nuclear devices detonated in the magnetosphere between 1958 and 1962 as a form of sabre-rattling during the Cold War. These tests led to the Limited Test Ban Treaty. Is global climate engineering untestable? -- Yes, since a global "test" would be an implementation. The key word is global. OIF patch experiments are not global, nor are they justification for SRM tests that "pump it up and spew it out." Do I support research in climate engineering? Yes, but keep it indoors and please, please include the humanists and social scientists and take their work seriously. Remember, climate engineering is not to be left to the technocrats. We need research by ethicists, sociologists, psychologists, historians, etc., Do I support Ken's 3-phase program that escalates from computer modeling and lab tests to "development of a deployable system?" No, this outlines a slippery slope greased with conditional statements. Caldeira and Keith use 31 "coulds" and 9 "mights" in the short Issues in S&T article. Yet, we do not disagree on Phase I, except I would argue for more funds going to atmospheric science in general, not earmaked for geoengineers. Now, I have to leave for a meeting about military efforts to control the Van Allen Belts during the Cold War. Jim On 9/29/10 7:01 PM, "Ken Caldeira" <[email protected]> wrote: Robock et al (Science, 2010): "We argue that geoengineering cannot be tested without full-scale implementation." Fleming (Slate, 2010): "Global climate engineering is untested and untestable..." In summarizing this conversation, it seems universally agreed that flat statements like these are simply untenable, in that everyone acknowledges that there are many tests that can be done (both in the real world and in numerical simulations) that will help improve our ability to predict consequences of deployments of climate intervention systems. (Couldn't someone equally argue that "climate consequences of emissions reductions are untestable" ?) As with all large scale deployments in complex systems (c.f., electricity generation and transmission, highway systems) there is no way prior to full-scale system deployment to be able to predict all consequences of that deployment. Nevertheless, there are a large number of things that can be done to improve our predictive ability. It is clear that we need either good models or lots of time with mid-sized-tests to predict climate consequences of a full-scale deployment with confidence.. This state of affairs makes it clear that we should be working hard to improve and test climate models and to conduct field experiments that can improve process representations in those models. As Stephen Salter points out, there are many things to be tested beside large-scale climate consequences. Alan Robock and co-authors may feel they knows what they meant when they wrote those words, but I think what they meant was not what they wrote. It seems to me that the content of their statement is something like: "If we are unwilling to rely on climate models and are unwilling to spend decades doing mid-sized tests in the environment, then there is no way to test the climate consequences of geoengineering schemes without full-scale implementation." To understand large scale climate consequences of a geoengineering deployment, we will most likely need to rely on climate models, and I think that is what Robock et al meant to say. There are plenty of tests we can do in the field (e.g., testing hardware, tests aimed at improving physical process understanding and improving representations of those processes in the models). We can test climate model performance using a wide variety of observations (e.g., Mt Pinatubo). We can also test various climate intervention proposals in climate models (and our trust in those results of those tests should increase as models improve and are evaluated on a broader range of measures). It is damaging to efforts to conduct these climate engineering tests to have people going around saying things like "geongineering cannot be tested without full-scale implementation" when this statement is clearly wrong as written: there are many valuable tests that can be done, both in the real world and in models. ___________________________________________________ Ken Caldeira Carnegie Institution Dept of Global Ecology 260 Panama Street, Stanford, CA 94305 USA +1 650 704 7212 [email protected] http://dge.stanford.edu/labs/caldeiralab @kencaldeira "Marriage cannot be tested without full-scale implementation." -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en. -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en.
