Thanks - It would never have occurred to me to view SRM and CDR as in competition. One is fast, cheap, imperfect, and imposes poorly understood risks. The other is slower but gets at the root problem. I might view them as either just different, or as complementary.
I’m not going to put words in David’s mouth, but I don’t think the phrasing of “only known” was intended to suggest that something like 350 ppm was not technically possible, but simply that even if we were to achieve that, there would still be temperature increase and associated climate risks – though perhaps small enough that no-one would even consider SRM – and in that sense, I get your point that saying “only” might decrease the likelihood of reaching 350. From: [email protected] [mailto:[email protected]] On Behalf Of Ronal W. Larson Sent: Tuesday, April 14, 2015 8:03 PM To: [email protected] Cc: Andrew Lockley; Geoengineering Subject: Re: [geo] Climate engineering, no longer on the fringe | Harvard School of Engineering and Applied Sciences Professor MacMartin et al Thanks for the response. See few inserts below. On Apr 14, 2015, at 12:10 PM, Doug MacMartin <[email protected]> wrote: Hi Ron: j. Yes, I agree completely with David… regarding the “only known” part, I think absolutely everyone on this list agrees that CDR is a great thing to pursue, but I do not think that there are any CDR approaches (including the one you note in point g) that could substantially reduce temperatures in the next 50 years; even going to zero emissions tomorrow won’t actually reduce temperatures, just slow their rate of increase. [RWL1: My point was that there are proponents of CDR technologies that disagree with Prof. Keith’s belief. To say nothing on this list to the charge that CDR can’t accomplish 350 ppm in 50 years seems technically and ethically inappropriate. So “only known way to substantially reduce climate risk” seems fair. Regarding the “weakest argument” part, I think that any rational evaluation of the risks of SRM would say that if there is any other available mitigation/CDR pathway to reach some given temperature without SRM, then that will most likely be less net risk. [RWL2: We are in disagreement for the first sentence and in agreement on the second (because you have used the term “CDR”). That is, I would never promote SRM as a substitute for mitigation (which is what “buying time” could be interpreted to mean). [RWL3: Mitigation is not the issue. Most of my career has been in mitigation - and getting off fossil fuels completely in 20-25 years is possible - with overall cost savings. The stronger arguments for SRM in my view are (a) there is no other pathway (mitigation + CDR) that would get temperatures/climate risks down mid-century, (i.e. SRM as a possible supplement on top of mitigation/CDR) [RWL4: I greatly appreciate that you have here again included “CDR". My interpretation of Prof. Keith’s remarks is that he would not. and (b) I don’t trust decision-makers to be rational (they obviously aren’t), so even though more aggressive mitigation might be a wiser choice per unit of reduced climate risk, I don’t expect us to somehow miraculously be on that pathway, [RWL5: I agree it (say 350 ppm in 50 years) is unlikely, but the likelihood goes way up if we reject that SRM is “the only known way.” and thus in 20-30 years we’ll be faced with the same concern over reducing temperatures/climate risks late century after we have failed to cut emissions as much as we should in the next 20 years. (That argues for researching it, not deploying it.) [RWL6: I need to be more sure of your meaning. To be doing something meaningful with CDR in 20 years, we have to start now (and of course should have started long ago). We need to be both reducing and removing emissions as fast as we can - and certainly not hold off on any viable CDR approach until we achieve a stable CO2eq level. b. More generally, why is it that every time someone talks explicitly about SRM, they’re supposed to also mention CDR? They are different things that both happen to have been labeled geoengineering, but have about as much in common as CDR does with renewable energy, yet I’m sure someone is allowed to mention solar power in a sentence without referring to CDR… [RWL7: I disagree two ways. First, I believe SRM and CDR are in competition, especially when the term “only” is used. They can be used cooperatively as well. Secondly some forms of CDR (specifically biochar and BECCS) are able to supply renewable energy. I agree that sentences can talk of solar/wind without mentioning CDR. But to talk about biochar and BECCS without talking of their carbon neutral “energy storage” character is a big mistake. the question that you extracted doesn’t talk about geoengineering generically, it talks about SRM only. [RWL8: Maybe I’m thin skinned, but I take CDR to be directly (not indirectly) intended when using the term “only” (which you have not done). I’m sure you’re aware that David has worked on CDR (DAC) also, so you hardly need to ask whether he thinks it is a good idea. [RWL9: I suppose DAC still has a chance, but Prof. Socolow has put quite a question mark in that. Prof. Keith would seem to agree when he uses the term “only known way” for SRM. (And on a minor note, I don’t know why you would expect an answer by one professor to speak for an entire academic department; like all of us, David speaks for himself, not for SEAS.) [RWL10: I intentionally coupled them to point out the softball nature of the six questions (Keith being a part of SEAS). The issues of precipitation and ocean acidification (and a concrete plan to get off of SRM) need responses from all promoting SRM. To sum up: I think SRM proponents are on a self-defeating track when they say theirs is the “only way.” Ron From: [email protected] [mailto:[email protected]] On Behalf Of Ronal W. Larson Sent: Tuesday, April 14, 2015 1:11 PM To: Andrew Lockley; Geoengineering Subject: Re: [geo] Climate engineering, no longer on the fringe | Harvard School of Engineering and Applied Sciences Andrew and list: I write to take issue with the sixth (last) Q/A below, which reads: "Some climate engineering proponents argue that approaches like solar radiation management have the potential to buy time to make real progress on reducing carbon emissions. Is that the strongest argument for pursuing SRM? KEITH: Absolutely not. I think this is one of the weakest arguments. The strong argument is that solar geoengineering provides the only known way to substantially reduce climate risk over the next half century. a. I am OK with Prof. Keith’s responses to the first five questions. b. Nowhere in this sequence do we learn that geoengineering has both an SRM and CDR component. Intentional or inadvertent? c. The (SEAS Department) questioner only mentions “reducing”, not “removing”. Was CDR meant to be included or not in this question and answer? d. Which interpretation of “reducing” was Prof. Keith responding to? (The response is only for “risk”) e. Is the word “substantially” critical here? Is there any chance in this Keith scenario of having peaked in atmospheric CO2eq prior to 2065? Can we anticipate a slow or rapid decline after that peak? f. There is no question here about ocean acidification or the possibility of inadvertent stoppage of SRM . How serious does SEAS take those issues to be? g. Jim Hansen has shown afforestation, coupled with an early peak in atmospheric CO2eq, to allow a return to 350 ppm well prior to 2065. Is that scenario considered to be “unknown”? h. Where can advocates of CDR (such as in Andrew’s forwarding yesterday just prior to this message Noah Deich’s CDR blog) go to learn why CDR doesn’t qualify as being a “known way to substantially reduce climate risk over the next half century”? i. Would SEAS/Keith recommend funding now for CDR research at what level compared to SRM funding? j. Are the “weakest argument” and “only known” views supported by other SRM supporters on this list? Ron On Apr 13, 2015, at 9:10 AM, Andrew Lockley < <mailto:[email protected]> [email protected]> wrote: <http://www.seas.harvard.edu/news/2015/02/climate-engineering-no-longer-on-fringe> http://www.seas.harvard.edu/news/2015/02/climate-engineering-no-longer-on-fringe Harvard School of Engineering and Applied Sciences Climate engineering, no longer on the fringe DAVID KEITH RESPONDS TO NAS REPORTS ON GEOENGINEERING IN THIS Q&A February 18, 2015 When the National Academy of Sciences released a pair of reports earlier this month on geoengineering—deliberate intervention in the climate system to counter global warming—it moved discussion of the controversial topic into the mainstream science community. The NAS-convened experts concluded that geoengineering is no silver bullet, but that further research is needed. David Keith, Gordon McKay Professor of Applied Physics at Harvard School of Engineering and Applied Sciences and Professor of Public Policy at Harvard Kennedy School, has been a leading voice for assessing the risks and implications of large-scale deployment of geoengineering to help cool the planet. Keith’s 2013 book, A Case for Climate Engineering, lays out how geoengineering might fit into a larger program for managing climate change (complementing steps to reduce carbon dioxide emissions and devise adaptation strategies). He recently detailed a potential small-scale solar radiation management experiment in which chemicals would be dispersed in the high atmosphere to reflect sunlight away from the Earth’s surface. He has also suggested a scenario for analyzing the risks and benefits of geoengineering, and proposed frameworks for the governance of geoengineering testing by nation states. [1] Keith spoke about what impact the new NAS reports may have on the policy and science of geoengineering. What is the significance of the National Academies taking up this topic? KEITH: The Academy has dealt with geoengineering as a part of broader energy and climate studies since the late 1970s, but this is the first report devoted to the topic. It serves as a marker of the extent to which solar geoengineering is becoming a more normal part of the science and policy of climate change. [2] Do the NAS studies bring us closer to deployment of small-scale geoengineering experiments? KEITH: By endorsing research on solar geoengineering and explicitly including a discussion of small-scale experiments along with a discussion of their scientific merits and possible regulation, I believe the Academy has made it easier for government agencies to fund such research. Many program managers in U.S. government science agencies have been favorably inclined to fund research on solar geoengineering but have been held back by a sense that they needed a high-level political okay. My hope is that this report will, de facto, give program managers the confidence to move ahead with science funding even in the absence of an explicit new program. [3] You’ve made the point that governance of geoengineering is paramount. Do you see a path for establishing international consensus on how to regulate efforts in this area? KEITH: Consensus, no. But little or nothing is done in the international arena with full consensus. A more reasonable goal is alignment of a coalition of countries that represent a reasonable cross-section of the world, north and south, east and west. Such a coalition might support a broad research program through various mechanisms from a simple memorandum of understanding to information exchange which could be a useful first step on the road to multilateral control. [4] Geoengineering opponents cite the moral hazard argument—that pursuing these approaches will shift the focus away from efforts to reduce emissions of the greenhouse gases that cause warming. Do the NAS reports address this? KEITH: Not in a deep way, but that is a hard ask. The fundamental job of the Academy is to provide assessment about the state of science, including social science, and about the prospects for research. [5] To what extent are the obstacles to an informed policy on geoengineering technical and to what extent are they social or political? KEITH: I think the fundamental obstacles are social and political. There is deep concern that any attention to geoengineering will inevitably weaken the political force needed to cut emissions. This is a sensible concern, but not an excuse for deliberate ignorance. If solar geoengineering can provide a meaningful reduction in climate risks for the most vulnerable people and ecosystems, we must take it seriously. It is plausible that the combination of emissions reductions and geoengineering will provide a substantially better environmental outcome than emission reductions alone, and that this fact will make it easier to develop a sustained commitment to reduce emissions. [6] Some climate engineering proponents argue that approaches like solar radiation management have the potential to buy time to make real progress on reducing carbon emissions. Is that the strongest argument for pursuing SRM? KEITH: Absolutely not. I think this is one of the weakest arguments. The strong argument is that solar geoengineering provides the only known way to substantially reduce climate risk over the next half century. 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