Dear Colleagues, 1) At a recent 3/6/2023 NOAC meeting there was an extra ordinarily lively and fruitful discussion on this topic that featured representatives of a very broad spectrum of views that (as one participant remarked) was unusual in that it was a respectful discussion and airing of view points rather than a debate. Unfortunately, I was unable to attend this meeting but was able to view the recording of it, and strongly encourage all who are able to, to access this recording to view it. As recordings of NOAC meetings are not generally distributed more broadly than the NOAC list I don’t feel at liberty to include a link to this recording in this post to other lists. For this reason, and also because I will likely misinterpret or not do justice to them, I will refrain from attaching (my understanding of) viewpoints discussed to particular persons at the meeting.
2) The letters supporting SRM research (letter #1 <https://climate-intervention-research-letter.org/> and letter # 2 <https://www.call-for-balance.com/letter> are commendable developments that should be welcome by all direct climate cooling (DCC) advocates. However (as noted by some in the NOAC meeting) they are: a) Cautious to a fault on quick or gradual piloting and deployment (depending on method see below), given the urgency of triggering irreversible tipping points <https://www.google.com/search?client=firefox-b-1-d&q=lenton+NAS+workshop+on+tipping+points2022#fpstate=ive&vld=cid:2d77e4e5,vid:4ppkTB4_fyk> potential to prevent or reduce increased catastrophic harm to humans and the fact that (mentioned by some participants) that the Mt. Pinatubo volcano <https://earthobservatory.nasa.gov/images/1510/global-effects-of-mount-pinatubo> for example lofted about 17 million tons of SO2 to the stratosphere (far more at one time than any SAI planned deployment that I am aware of) and cooled the globe by roughly 0.6 C for 15 months without any (at least prominently publicized) adverse impacts. b) Too narrowly focused on SRM and particularly (global) SAI to the exclusion of other generally lower-leverage and lower-risk possible direct climate cooling methods <https://pdfhost.io/v/kUvEpsGdb_Understanding_the_Urgent_Need_for_Direct_Climate_Cooling_0209233> (DCC), in spite of emphasizing (in the spirit of “not placing one’s eggs all in one basket”) the need to study MCB and CCN as well as SAI as “outcomes might be optimized if multiple techniques are used in combination” (Letter 1). Letter 2 is less specifically directed at these three species of SRM but still exclusively focused on SRM and from the points made on p. 7 for example that “the provision of SRM is organized by a globally legitimized body, and not based on private interests” on high-leverage SRM with global scope. For example, as recent modeling suggests that if and when we achieve (human and natural) net-zero GHG emissions global temperature will not significantly drop <https://www.carbonbrief.org/explainer-will-global-warming-stop-as-soon-as-net-zero-emissions-are-reached/> for at least another 50 years due to legacy heat from the Ocean (where 90% of it is being stored), and even more recent modeling suggests that 7-10 C may be “in the pipeline <https://arxiv.org/ftp/arxiv/papers/2212/2212.04474.pdf>” (most of which is undoubtedly related to ocean warming where 90% of legacy warming is being stored) even if net-zero were achieved today, it would seem that we should urgently begin researching and when prudent implementing methods to reduce (and possible use for economic benefit) this excess ocean “heating from below” in addition to doing the same for “heating from above (see OTEC summary here <https://docs.google.com/document/d/1TowThwi6j6cX3iLGBRrj22D30cYhKa_9/edit> ). Another example is cooling based on efforts to enhance water cycle cooling through evapotranspiration and convection that may also regenerate nature (just as important as reducing GHG’s in the long run <https://www.cpegonline.org/post/our-two-climate-crises-challenge>) and provide economic benefits (see for example Seatomizers summary here <https://pdfhost.io/v/kUvEpsGdb_Understanding_the_Urgent_Need_for_Direct_Climate_Cooling_0209233>). c) Assume an overly binary view of (and direct climate cooling) “global SAI deployment or not” (my guess is with a now outdated (per research in b) view of SAI “shaving the peak” (Shepherd and Long napkin diagram <http://jgshepherd.com/wp-content/uploads/2011/01/Napkin-diagram.pdf>) deployment that may be necessary in the future), and “research and deployment” of direct climate cooling in general. Regarding the first binary there is no reason why any of the less risky direct climate cooling methods discussed in b) should not (if found to be indeed effective and with little risk) deployed asap, and (as mentioned by at least one participant per the “Cornell SAI group”) the most prudent roll-out of SAI not be based on “nailing down the research” and then deploying, but rather researching as much as possible while gradually deploying and evaluating and researching further depending on outcomes in the spring in polar regions where the stratosphere is lower so that lofting with more conventional aircraft may be possible , and the aerosol is likely to drop out of the Stratosphere more quickly in months rather than years reducing “termination shock” risk (see SAI summary here <https://pdfhost.io/v/kUvEpsGdb_Understanding_the_Urgent_Need_for_Direct_Climate_Cooling_0209233>). And with regard to the “research and deployment” binary, assume (as one NOAC meeting participant opined) that controlled experiments in laboratories are inherently more valuable than field experiments as causal factors can be elevated to extreme levels to facilitate signal (or outcome) detection. But it seems to me that, as many have opined, atmospheric processes and chemistry are so complex that we will never be certain that we have adequately pinned it down with laboratory or small-scale empirical research. One participant asked a key question in this regard. At what empirical scope do we need to research to be confident that risk is low enough to start deploying. It seems to be rather self-evident that the best and only way to reach this point would be to proceed with very small localized deployments in the poles and constantly monitor, adjust, and learn by doing, that is that a good part of the “research” is the “gradually deployment”. After all we’re not addressing nuclear radiation or the Manhattan project here, we’re primarily talking about a natural substance millions of tons of which have (and will be continued in the future) to be lofted into the atmosphere by natural methods! In this sense I would suggest that empirical research on, particularly atmospheric and cloud-based DCC, will likely require more “social science” non-controlled experiment statistical techniques in the “real atmosphere” that can only be accomplished with small-scale deployment. d) And as one NOAC meeting participant noted, Letter 1 includes a rather gratuitous (in the offering any evidence in support) swipe at the Make Sunsets effort particularly with regard to selling “cooling credits that I too think is unwarranted and counterproductive (see discussion of Make Sunsets initiative in 3) below): *“The state of scientific knowledge about SRM is also currently insufficient for it to be included as part of a climate credit system or other commercial offering, as some have started to propose.* Even for stratospheric aerosol injection (the most well-understood SRM approach), the amount of cooling achieved by the injection of a given mass of material and how SAI will affect the climate system are still highly uncertain. Even with improved understanding of these effects, since SRM does not address the cause of climate change, nor all of the effects of increased greenhouse gas concentrations, it likely will never be an appropriate candidate for an open market system of credits and independent actors.” 3) Finally, I believe that this entire topic of “how can best move the ball forward on urgently necessary DCC” should be considered in a broad political as well as scientific frame. a) If I may say so, as a social scientist, and especially as a radical economist, I believe that I am particularly a-tuned to the political dimensions of social change and “social ideology” as mainstream economics is a prime example of the latter (I wrote a book on this that I will send to anyone upon request). Similarly, I think the broad NOAC discussion that included members of our broader “climate cooling community” including but not exclusively climate scientists or climate change professionals who (consciously or not) understandably may have to be more careful and conservative in their public positions on these issues. All of us (people and organizations) are (again not always consciously) playing a strategic role in this sense. b) My own view (that comes without personal cost to my livelihood, status, and/or strategic and practical efforts to make the world a better place) is that anything that stimulates awareness, debate, and hopefully action on the need for urgent direct climate cooling, and that is physically or economically beneficial, or at the very least, does not cause harm, is a positive step forward. For example, I believe that all of us (including the founders of Make Sunsets) understand that an effective high-leverage (and therefore high-risk) direct climate cooling method like SAI should be researched and implemented publicly and transparently, or with extensive public monitoring and oversight, per the two recent letters on this topic discussed in 2) above. And since the Make Sunsets’ lofting of “de-minimis” amounts of SO2 to the stratosphere is not “effective” in terms of climate cooling <https://makesunsets.com/blogs/news/pricing-cooling-credits>, and thus does not cause any harm and has the same temporary cooling affect as a much large amount of GHG reduction would permanently (see below) it is on balance a positive step toward cooling. c) I believe that the Make Sunsets selling of DDC credits that can be roughly estimated in this case, as generally speaking (see below) global SAI cooling can be viewed (like GHG removal) as a pure “public good” that has the same result no matter where and when it is applied, has enhanced it’s political impact and has the potential to create a broad group of citizen/consumer climate cooling advocates among the general public. Hopefully, this will facilitate kick start this possibility for other (likely more local and geographically priced) legitimate private cooling credits. As I’ve said in prior blogs, I believe that we are in an “all hands on deck” for cooling moment, and therefore need to harness whatever institutional (public, non-profit, private) methods we can to ramp this up as fast and as much as possible. d) Finally, though what Make Sunsets is currently doing is not “effective” in terms of climate, it is (modestly) physically beneficial as each gram of SO2 actually lofted to the stratosphere is roughly equivalent to the removal of 0.476 metric tons of CO2 for 2.1 years (see blog <https://makesunsets.com/blogs/news/calculating-cooling>) as 1/2.1= 0.476), so that (as pointed by Make Sunsets in the NOAC discussion) lofting a kilogram of SO2 would be roughly equivalent to removing 476 metric tons of CO2 for 2.1 years. And this linking of temporary cooling to temporary GHG drawdown adds another useful “direct climate cooling” public education dimension to the Make Sunsets effort as it shows how much temporary cooling “bang for the buck” lofting a still “de-minimis” amount of SO2 can provide relative to temporary removal of GHG. e) Similarly, I believe that Andrew Lockley’s balloon lofting experiment, though unfortunately named, can be viewed as a politically positive DCC intervention. As I said, that NOAC meeting stimulated a lot of good discussion! Best, Ron , -- 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 view this discussion on the web visit https://groups.google.com/d/msgid/geoengineering/CAPhUB9Akk1t36bEeKQucsSw34udVsLKSQ_YVrFcxiH2sDpSmbg%40mail.gmail.com.
