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| 00:01 | who's also also on our steering Circle and uh Mike take it away the meeting is is yours and Doug's okay well um I'm very pleased to welcome Doug today um he's uh up at Cornell and his background sort of in the in the notice that was distributed um he has a strong background in uh climate modeling particularly sort of human impacts and other things we we're doing M um I might say that the early focus on this climate intervention uh effort was in rather large sensitivity studies so could you |
| 00:39 | offset a CO2 doubling or even a CO2 quadrupling with it they were really not very plausible uh kinds of studies it was all a sensitivity study to sort of see if you could do it um and then sort of gmip geomip an intercomparison project stepped in and sort of standardized a lot of runs and they started to run some more realistic scenarios but over the past couple of years there been much more effort trying to look at at trying to do what something that might actually be plausible in a in a POC sense policy sense or trying to stabilize the climate |
| 01:16 | and and keep it steady prevent further warming or maybe take it up a little bit or down and Doug and his activities have been pretty instrumental in that and so that's sort of the focus we talked about as uh for this uh presentation so with that um Doug glad to have you here and feel free to go forward right thank you um I see lots of moderate number of faces that I know and a bunch of people that I don't know or or um have seen have seen emails from and now I can put a put a face to some of the emails as well um so um I'm going |
| 01:58 | to I'm going to talk for a while there's a bunch of things that I want to say but by and large I you know discussion is good ask me whatever questions you're interested in um I'm going to try to keep my remarks mostly fairly high level so I'm not going to drill super deeply into any one aspect in particular um let me actually share my screen for a little bit um I realize I have my um at home I have my display my display rotated in the wrong axis so hopefully uh that looks crappy let me actually move my screen share to |
| 02:45 | the uh monitor that's more correctly sized um how do I do that easy I'll just unplug that monitor um pardon me for a moment um let me go back to here and uh back to share screen um right there okay so that come through um so I have a slightly weird background in this space was originally a mechanical and aerospace engineer I was working in industry in the 90s doing program management uh uh primarily feedback control type stuff Dynamics and control um wound up doing a little bit of work in climate science and then I met David |
| 03:48 | Keith in about 2004 um and he introduced me to this subject um I'm like well that's kind of interesting um there was a workshop at Nasa ases in 2006 that I was at that I think was the first US conference specifically about solar geoengineering um although they weren't allowed to use that word and so Ken Caldera came up with this uh solar radiation management term um to deliberately obfuscate that the meeting was about geoengineering um and then I've basically been working on this a little bit starting then and more or less |
| 04:27 | full-time for at least uh 10 or 12 years um I don't really care what we call it solar geoengineering ipcc calls it solar radiation modification um my personal preference is just to call it sunlight reflection methods that keeps the ipcc acronym but I basically just uses plain English and um rather than terms that people don't understand what what it means necessarily um and I actually want to start there's a couple of problematic aspects to this this slide but it's the usual starting point for most people um |
| 05:04 | and certainly people who have not been familiar with the conversation with SRM there's a sort of a slide that's sort of a useful way to help articulate the position we're in um which is that of course we have to cut CO2 emissions to zero when we cut Co get Co2 emissions to zero everywhere on the planet is when roughly speaking things stop getting worse so that doesn't solve the problem anybody who says cutting emissions is a solution to climate change that's the wrong word to use it's a piece of a |
| 05:36 | solution um you then go say all right well we can solve the problem by putting pulling the CO2 out of the atmosphere lots of ideas for how to do that um you know somebody else here probably has a better answer than me on how much of that we're currently doing but we're off by several orders of magnitude still relative to the scale we need um and I so you know I think it's clear to me that eventually we should be able to do that but it's very unclear to me when we're going to be able to do that and |
| 06:10 | how rapidly we're going to be able to do that so the critical thing with all of these is that there's huge error bars on them there's error bars if I told you the emissions we don't know how much the planet warms we have no idea what future policy looks like well we can guess it's probably going to look anybody who thinks we're going to go zero emissions globally in the next 20 years I think is probably smoking something um and huge emiss uh uncertainties on the technology side as well uh which would basically put us in |
| 06:43 | a position of saying um the future is going to be worse than today today already has climate impacts and we do not have a guaranteed strategy um to avoid significant climate change so you know even for the people who are find the idea of geoengineering to be distasteful at a minimum if you said we shouldn't even be doing research on this topic I'd say you're gambling with everybody else's future you're gambling with the idea that if we can cut emissions fast enough and pull CO2 out of the atmosphere that's going to be |
| 07:22 | good enough and the reality is I think we can all hope that it's good enough but I don't think you can guarantee that um and some of us might have different estimates for that probability but the probability that that's good enough is clearly not zero um so uh there's at least three problems with this slide um first is the that this time axis is potentially long depending on how much you overshoot and how fast you can pull CO2 out that time scale could be quite considerable um second I sort of Drew |
| 08:00 | this well first of all that that y AIS climate impacts for uh CO2 and you know mitigation and CDR you can kind of just scale everything as a proxy using Global mean temperature as a proxy for a whole bag of climate impacts but we don't really care about global me temperature we care about all sorts of other stuff um and solar geoengineering does not cool the planet the same way that CO2 warm it so you don't get back to the same place so Point 2 on this diagram is cooler than 0.1 but it's not the same as |
| 08:38 | 3 um and then two other things first of all I think there's a number of people on this call would point out that uh drawing a flat line um sort of implicitly at a temperature higher than we're at today is not necessarily the right answer um we're already have climate impacts today um that's a design choice right if you decide to do some amount of solar geoengineering you get to decide how much to do and you get to evolve that over time and you know maybe decide 20 years in that it's like no we actually |
| 09:12 | want the planet cooler um or something like that the other big issue on this whole thing is if you said oh the purpose of research is to decide whether the green line is less risky than the Blue Line the implication is that those choices are uncoupled and I would say the number one concern that people Express around the planet uh is the question of you know referred to as moral hazard right so if the planet if people decide to start doing solar geoengineering does that lead to a reduction in how much attention you pay to uh um |
| 09:54 | mitigation my personal view is that that's a pretty small risk um other people disagree um but that's you know if you talk to different people and you get different perspectives on the value of research that's usually where the sticking point is um whether they explicitly acknowledge that or not um so as a as a Prelude to everything else I would more or less say I'd be from a purely physical climate impacts perspective I would be pretty damn confident that it's less risk to do some amount of |
| 10:33 | of Geo engineering some amount of of reflecting sunlight than none provided that you're assuming the same emissions pathway um so uh this is just a picture from the National Academy report which only looked at atmospheric approaches um so it did not look at space based which is probably pretty far out right now it's more expensive of um certainly plausible in the long term but it's not going to happen in the next 10 or 20 years and it didn't look at surface-based approaches simply because it's actually really hard to get enough |
| 11:12 | surface area reflecting on the surface of the planet to do something meaningful um so the idea that's best understood put stuff in the stratosphere put aerosols in the stratosphere that's the idea I would talk about the most um so and we know that it works so um large volcanic eruptions do this periodically that's the Mount Pinatubo which erupted in 1991 cooled the planet by a little less than half a degree celsius um so I have 100% confidence that if you took a bunch of airplanes and you flew them up to the stratosphere |
| 11:44 | and you reled sulfur dioxide you're going to cool the planet um and actually the existence of that volcanic analog also sort of says you know there's some unknown unknowns but you know we at least have some way to calibrate our models um then uh yeah sorry that's just temperature plot from volcanic eruptions the idea that's next best understood would be but is much more uncertain is Marine Cloud brightening so those are ship tracks that you see in that satellite picture interaction between the pollution from the ship um and |
| 12:19 | basically creates clouds or can sustain make clouds brighter so you see it particularly where there wasn't a cloud and the pollution created a cloud but even if there are existing clouds it can make them brighter um we you don't need pollution you do that with sea salt spraying up into the clouds um Cloud we know for sure that there are lots of conditions where if you add aerosols the cloud will get brighter we also know for sure that there are conditions where if you add Aerosoles to clouds the opposite |
| 12:51 | happens um you cause the cloud to rain out I think the boundary between those is not perfect perfectly well understood uh so there's sort of a little bit more research uh needed on that um but I'll say a little bit more about that later I'm not gonna say anything about Sirus Cloud thing um I noted Dave Mitchell's on the call so um if there was a question about that he's probably better suited to answer it than I am um so one slide from modeling this one's a little bit old uh but just scale |
| 13:24 | to illustrate kind of what models show on the left is the pattern of temperature and precept Maps if you allow the planet to warm by a degree with CO2 and on the right is those same Maps um if you offset that warming with stratospheric aerosols so you don't get back to exactly where you are the prip response is not as well compensated as the uh temperature responses but this is sort of the argument you know it's pretty hard to look at those two maps and not conclude that there's very strong evidence that the maps on the right |
| 14:07 | would be less risk than the maps on the left um that of course is not the full story um so what do we know um stratospheric aerosol injection at least is pretty straightforward to do cost is somewhere in the billions doesn't really matter broadly whether it's 5 or 10 or 15 billion um it's basically free relative to the costs of climate change or anything else we do um with a slight caveat there's probably not very many countries that are actually capable of doing it uh contrary to a lot of what |
| 14:45 | you might read um and that's just because you need specialized aircraft to get up high and the challenge there is getting the engines and nobody is going to sell you an engine no there's only a couple of countries that make engines pratton Whitney is not going to sell you a jet engine unless the US government at least tacitly approves for example um we know it would cool lots of climate impacts get better right if you're interested in Arctic sea ice sea level rise heat extremes we know for sure what |
| 15:17 | the sign of the effect is on all of that um or permafrost loss or Greenland ice sheet loss for example um Antarctic is a slightly more complicated story um it doesn't simply reverse climate change I mentioned that there's residual changes in precipitation they're probably fairly small relative to they're certainly on average smaller than the changes in precept from climate change um but you know there may be places in the world that don't care that much about temperature changes and do care about precept |
| 15:49 | changes um and they might object um uh outcomes depend on how it's done it's not just this o do we do stratospheric Aerosoles or not for example depends on where you do it same with Marine Cloud brightening it depends on where you do it um Strat other things with stratospheric aerosols they do affect ozone honestly that's gots a lot of press but it's not obviously a big deal um acid rain deposition again you'll see some press on that relative to what we currently dump into the atmosphere um |
| 16:29 | you know relative to our current uh acid rain issues you could cool the planet practically back to pre-industrial for about 10% of that um changes you don't just reflect sunlight back to space you change direct diffuse sunlight ratio um the asterisk on the relatively few countries with capability I'll get back to later um but uh you the tropopause so so stratosphere is basically sorry brief bit of atmospheric physics um troposphere is heated from the ground you know sunlight is absorbed at the surface it Heats it from the |
| 17:11 | ground hot air rises so that's convectively unstable so if you put pollution into the ground it's all mixes out mixes gets rained out pretty quickly um high enough up in the atmosphere you get the tropopause above that it gets warmer with altitude um in the Stratosphere because UV the the ozone absorbs UV from the Sun um and so that's since it's warmer at the top of the stratosphere than the bottom that's stable right because hot air rises you put stuff in the stratosphere it lasts for order a year |
| 17:45 | instead of putting it in the troposphere that lasts for order a week so it's way more effective that's why it takes that's why it's essentially plausible to put enough material in the stratosphere um but the tropopause is lower at High latitudes um and so it turns out that it's plausibly a lot easier to do this at high latitudes and that's where a there are a lot of climate change impacts that might be of concern um societal Dimension if you do this it affects everyone on the planet um how you make those decisions is |
| 18:19 | unclear my personal view would be as long as most people on the planet think oh my gosh climate change it's going to be bad it's not bad now it's going to be really hard to get support to deploy if climate change gets to the point that everybody's like holy crap this is catastrophic we have to do something now my guess is you know that situation around the ability to make decisions will be um um change um I already mentioned the effect on mitigation clearly there's some potential for conflict |
| 18:59 | um if you were deploying it for a really long time and relying on it for cooling and you ever stop you kind of go back to where you were over 10 or 20 years it's not instantaneous um and then in terms of research yeah I think it's still fair to say it's mostly in the developed world it's mostly climate modeling um and I'd actually say to date a lot of the research has been curiosity driven rather than Mission driven that's sort of one of the things that I and a few other people are trying to change and |
| 19:29 | say you know this is you know we need to actually get answers that are relevant to society um what do you uh sorry I haven't been following the chat um um okay so what do we need to know from a science perspective what nobody you know I can sit here and say you know look I've read piles of papers I've looked at piles of simulation results I think it' be less risk if we deployed this nobody is going to deploy it based just on Doug saying that um you're going to need some broadly legitimate International assessment |
| 20:10 | report that uh comprehensively looks at the science um before it you're likely to get a reasonably legitimate Global decision towards deployment I think that holds regardless of whether you're talking about strateg sper aerosols or Marine Cloud brightening with a few caveats in that Marine Cloud brightening could be done on a much more Regional scale um so basically what do you need to know essentially what do you think would happen to all of the stuff we care about um and how do those answers depend |
| 20:47 | on choices like what latitudes do you put things in on how much do you cool and so forth um and then equally critical how confident are we and what are all the risks um that's not just the physical climate uncertainties but also you know like what is the risk of moral hazard is that something we can do research about um and what can we do to reduce those risks um I think I said all the rest of that um but I will also say you know to me coming from engineering this is you know you know Engineering in the true sense of the |
| 21:29 | word of applying scientific principles towards a specific end this isn't just oh let's go put aerosols in the stratosphere in our climate model and see what happens you know you go do things like say all right what latitudes what happens if I put them in at this latitude what happens if I put them in at that Latitude can I mix and match right there's some Design Elements to it there's some specific aspects of how do I go about reducing uncertainty and qu um doing risk management and so forth um so how do we get |
| 22:03 | there uh one Mike I think mentioned this a lot of the research that W has been done was just kind of like oh this is an interesting idea I'm going to go take my climate model and put a pile of aerosols in it and see what happens that's not directly relevant for doing riskrisk comparisons of the sort that you would want to do in like a big ipcc assessment report that says okay if we follow this path here's what the impacts are if we follow that path that uses some amount of SRM that's what the impacts would be right so you want |
| 22:37 | scenarios that are plausible you want to repeat those in piles more climate models than we have to date a lot of this stuff is still done in just a handful of climate models you want to pass that down to every single climate impact uh ideally um and you want to do all of that in a way where the people in the developed developing world and so forth trust the research so there's some challenges that need to be careful about the research effort itself um this is just from paper a few years a uh few years ago last year |
| 23:19 | um and this gets at a comment that a few people have actually made as well which is so we sort of started as a default we're going to start to employment roughly when our climate model roughly when the world would pass 1 and a half degrees um 20 you know maybe it'll be earlier than 2035 but that was sort of a reasonable estimate um also look at what happens if you cool further than that back down to one degree or a half degree if you care about something like Antarctic ice shelf collapse and Associated sea level rise |
| 23:57 | you might want to do that um and also things like what happens if you just delay for 10 years um and hold off on a decision um what are the impacts of that so looking at scenarios that you can more directly compare the other big thing that we've been working on is looking at the latitudes of deployment um yeah I'll just go to the next slide so trying to basically say like okay and and we haven't done all of this work for marine Cloud brightening yet but it's in progress um uh by a piece that by Me by lots of |
| 24:40 | other people as well um but just sort of take take a look at all of the different places that you could put aerosols into the stratosphere they mix longitudinally so you don't have to worry about that um if you put them in over itha or you put them in 10 miles north north of here nobody's ever going to be able to tell the difference so this is sort of like a reasonable set that was sufficiently distinguishable I'd really say the main things are you could put them at high latitudes you could put them in at Mid |
| 25:12 | latitudes you could put them in in the tropics all of those things do a little bit different if you put them in in the tropics you kind of overcool the tropics and undercool the poles if you put it in at high attitudes unsurprisingly you some level you focus more effort on the pole so under overcool the poles if you will um and undercool the Tropics um or you going just think of that as like where where is it that I'm most worried about um there are issues if you put too much forcing in one place versus another you |
| 25:46 | change you know the atmosphere is trying to move heat around so you can't like just cool the Arctic try to cool the Arctic the planet will move a lot more heat northward into the Arctic um and and if you can change the temperature gradients and that has impacts on precipitation and so forth you have to be a little um mindful of all of that um so what do we know don't do it in one hemisphere uh at least not very much because that'll shift uh intertropical Convergence Zone um I said that um I said that uh I did not |
| 26:21 | emphasize too much that simpler to implement but you could potentially even start a small deployment with existing aircraft at high latitudes I'll say a little bit more about implementation later um and then once again this is uh uh from the scenarios on the previous plot um in principle if you're if you're quote only cooling the planet by a little over a degree um that bit about oh it doesn't you know you're warming the planet with CO2 and now you're cooling it by a different mechanism that leads to some |
| 26:57 | novel climate for the most part most of the surface is actually indistinguishable from the reference climate that is to say for the most part if you view this as a magic undo button that's actually not that far off um for a small amount of cooling um in climate models and then of course there's a big question of we you know there are uncertainties in climate models there you know we can calibrate a little bit with volcanic eruptions um but we don't have observations of what happens if you P the planet and so we don't have a um |
| 27:38 | proof that that's what would uh actually happen if you were to deploy um this was uh uh just a little bit more on the Arctic one um so couple of papers I've noted here um the one on the top right which is what that plot is from that's Walker's results basically inject at 60 North um the tropopause is much lower so it's much easier to get airplanes to do that um we actually to have a paper with wake Smith who actually looked at that kind of do it with existing airplanes but you're still high enough |
| 28:19 | that if you actually wanted to sustain it do significant Cooling and sustain it you probably want to design dedicated airplanes to do that um bottom line is you want to restore Arctic sea ice you could then the question is what are all of the rest of the ramifications from that um and then we have a paper that's not yet out uh so technically still embargoed but should be out next week or so uh by Paul go Godard uh at Indiana looking more carefully at what happens to Antarctic um under some of these strategies um a little bit more |
| 28:56 | complicated just just because of the there's some Dynamic effects that that you know the big issue with the Antarctic is you have these floating ice shelves that are holding back all the sea ice and they're being warmed from the bottom and the temperature at the bottom of that is uh influenced by ocean currents as well and so you need to spend a lot of time paying attention to how does the deployment of Stratus aerosols for example affect ocean currents I think the bottom line is uh yes as long as you're a little bit more |
| 29:36 | careful about how you do it you can clearly reduce the risks we're not at a point of saying here's exactly how much you would need to do to prevent a Tipping Point in Antarctic um implementation um this slide is actually a couple of years old wake Smith and some of his colleagues did a really good job sitting down and saying okay if you want to do this in the tropics people have been doing climate model simulations where you put stuff in at 21 kilometers no airplanes can fly at 21 kilometers with a useful |
| 30:15 | payload and so they went and did a paper design study and essentially said you can go buy airplane engines from GE not fun not fundamentally hard to go design the airframe you could go do it if you wanted um it would probably cost5 billion in five 10 years to develop the airplanes so keep that number in mind a little bit you cannot just say oh we're going to go deploy this tomorrow because you're limited by uh you're limited by this ability to make a decision to deploy that is limited by not really |
| 30:58 | having an adequate scientific basis to give people a sufficient Comfort to make that sort of a decision and you're limited by whatever time scales it takes to develop the engineering Hardware you need to deploy the caveat to that is again this High latitude option that you could at least do a little bit at high latitudes with existing aircraft you probably couldn't get very much cooling with existing aircraft but you get a little bit while you were trying to figure out how to ramp that up um I'm not going to talk |
| 31:33 | about Marine Cloud brightening implementation because there really isn't uh I would say there's not yet enough understanding of the details of the cloud aerosol interactions and where you'd want to do things and how much you need to inject and so forth to get a robust a really robust estimate but you know I I would say once again Marine Cloud brightening is probably not expensive to implement compared to climate change damages um I think when you're thinking you know uh an important way to think |
| 32:07 | about this in general is that some level you're weighing what are the impacts and risks of climate change against the impacts and risks of SRM um lots of us can probably you know you spend 24 hours giving a talk on that uh climate change side on the SRM side you can sort of think of it as four different categories this is sort of my grouping the physical effects of a responsible well-designed deployment is primarily what we've modeled in climate models that I would essentially say it is extremely high |
| 32:41 | confidence that those risks are themselves less than the risks of climate change um however you also have to worry about the physical effects of like poorly managed deployment including what would happen if some were to terminate during a deployment you do have to worry about is there a real substantial risk of moral hazard or mitigation deterrence or whatever you want to call it and is there a substantial risk of conflict because you know perfectly well I already get emails all the time from crackpots accusing me of of being |
| 33:18 | responsible for every single storm that happens and by the way apparently I caused the forest fire caused the forest fires in Maui um a few months ago um you know perfectly well that if there actually really was a deployment um every weather event in the planet has the potential to be blamed on that deployment um so I think those risks of the human Dimension need to be taken seriously doesn't mean that that's a showstopper it just means they need to be taken seriously um second broad comment about risk this |
| 33:55 | is the engineer in me doing program management um I'm still involved in 30 m telescope project that I've been involved with for now 24 years 23 years um we have a massive risk registry every large engineering project has a massive risk registry where you look at every single uncertainty or risk and you quantify how wrong could we be or what's the risk of this particular thing happening and what are the consequences of being wrong I have uh seen scientific talks where people are like oh in this climate model |
| 34:31 | ozone goes up by two dubs and units and in this climate model it goes down by two dubs and units and that's totally uncertain and the answer is with a baseline of a couple hundred plus or minus two is irrelevant who cares whether sure you don't know what the sign of the effect is but if it's zero practically zero it just doesn't matter right so there's a there's a way of thinking here that is maybe uh I don't want to be too critical of science s but sometimes they get like hung up on uncertainties without being |
| 35:01 | careful to quantify them how important they are and conversely when somebody Tunes a climate model they pick a set of parameters and then they say okay with this set of parameters do we match Pinatubo observations for example but they don't then typically say well how much can I vary these parameters and still match pinba right so how well are my observations constraining it and then you have one version of the climate model that's been tuned but you don't have like sort of a the the only way in some sense that |
| 35:36 | you're looking at uncertainty formally then is by saying well you know n cartooned their climate model and here's the answer they got and the UK people tuned their climate model and here's the answer they got and they're different um so there's a way that we have not been very systematic about sampling that space and saying how wrong could we be and what are the consequences of being wrong the other broad comment I would make about uh deployment and uncertainty is that I feel like a lot of |
| 36:10 | the discussion globally has this sort of brain mindset of like the decision to deploy is like jumping out of an airplane right you have a somehow you just make this decision and you jump and you can't unj jump that's just not the right way to think about this right the way you would actually do this is you do a bunch of modeling at some point you may or may not you know I don't get to make the decision nobody in this room gets to make this decision at some point somebody says well maybe we should go |
| 36:40 | proceed to the next scale you then you know buy a bunch of Gulf Stream aircraft or whatever and you strip out the seats and put some tanks in and put a bunch of stuff in the stratosphere um broadly you know you can imagine SAR steps for something like Marine Cloud brightening uh for Stratosphere you could put in enough that you would sort of follow the aerosol Cloud not enough to affect the climate and you'd then say at least does my aerosol Cloud match the models if it doesn't match the models then you might say something's wrong um |
| 37:16 | maybe we should go back if it does match the models you say okay well I've got at least some confidence I can start scaling things up right and you start it's not like you're getting to one degree cooling over you're gradually ramping things up that gives you lots of times to check to see whether your models are correct and to potentially adjust your strategy including to the point of saying H okay we're going to stop trying to cool the planet so a lot of the you know there's risks that people |
| 37:48 | imagine that are not necessarily actually risks that you would encounter in the real world um I'm I'm not going to say very much about Marine Cloud brightening most of my focus has been on stratospheric aerosols I'm just going to show one plot here this was um Sarah doy at University of Washington sent this to me um showing the observation stratocumulus Cloud deck um not the model but the actual observations and then highlighting regions where one would expect Marine brightening might be effective um and the game plan right now |
| 38:33 | is to sort of follow a little bit of a similar strategy of what we've done with stratospheric aerosols which is go perturb each of these regions separately look at what they do to the climate um and say okay well you know can we combine forcing in different regions op in some optimal way that that uh to achieve different objectives one of the observations of course if you looked at what the radiative forcing was with stratospheric aerosols if you put them in in both hemispheres you can get a pretty uniform |
| 39:14 | distribution of aerosols around the entire planet and you can get a fairly uniform radiative forcing and that roughly compensates the radiative forcing from CO2 with Marine Cloud brightening you've got a patchy forcing um yes the atmosphere moves heat around but it isn't perfect you are going to get a more spatially heterogeneous response that's what models say that's what basic physics would say um and let's just it's not to say one is better than the other they're tradeoffs right rine Cloud brightening |
| 39:46 | is not you know it's not going to perturb atmospheric chemistry in the same way um and it doesn't have the same Fear Factor necessarily um you tell people you're going to put sulfate aerosols over their heads and they might say you're nuts you're out of your mind you tell people we're going to go spray saltwater in remote Marine clouds they'll be like sure sounds fine to me um I haven't heard any you know Australia started trying to do this in the Marine Cloud over the Great Barrier Reef and I |
| 40:13 | haven't heard a single person say that's a bad idea um but there are tradeoffs um you know if you were truly objectively looking at the at at these things the climate response part the shifts in temperature and precipitation are almost certainly going to be less risk from stratospheric aerosols anyway um I think that's sort of the main things that I wanted to like highlight at least um and make sure we leave lots of time for discussion and comments and and so forth I you know I can probably find slides on all sorts of |
| 40:56 | different topics um but um I would say you know just as a more General comment I first time I think I gave a presentation in about 200 you know after I went to this NASA as meeting in 2006 and I gave some presentation in 2007 saying hey you know the next thing I'm G to go work on is do engineering and I didn't get to my conclusion slide I got yelled down by so many people um who were so aass at the concept that anyone would research this that I couldn't actually even finish my talk now I have every single Dean at |
| 41:40 | Cornell the president of Cornell the head of the sustainability Institute of Cornell saying absolutely yes we need to go do this research tell me who you know can we go hire more faculty in this area how do we help you raise money to do this the situation has changed completely um other than a handful of people who signed that that um there's a non-use agreement that went out last year um virtually everybody I talk to is supportive of research and that's both the developed world and the developing world if you ask people in the |
| 42:16 | developing World by and large the answer is a little bit of skepticism of you know the global North has screwed us in the past they might screw us again but also look we're the ones who are going to die from climate change um if there's a technology that can address climate change um get out of the way um we need to pay attention to it so you do see a little little bit of those both of those from the developing World um but personally I see a lot more of the second than the first um um okay uh I one dire comment to me |
| 42:57 | about the the this bit about the milky white Sky yeah um yes the sky would be a little whiter um Ben Kravitz and I wrote a paper about that in 2013 um if you were doing enough stratospheric aerosols to cool the planet by something like 3 degrees Celsius you would probably you probably still wouldn't notice the effect if you were in a city but if you were in the countryside you'd sayou know when I was a kid I might I saw blue skies and they look just a little bit paler but I'm sorry if you're cooling |
| 43:35 | the planet by 3 degrees Celsius the alternative is probably so catastrophic um that it like okay we should accept that um and this is also one of these problems with um um I was involved in a study back in 2017 where the scenario was stupid um I didn't choose the scenario but I was involved with it and it wound up getting used in all sorts of impact assessment um and it involved cooling the planet by 4 degrees Celsius at the end of the century with and then they ran the climate model 20 times so and then you look at a 20-year |
| 44:17 | period and you so you essentially now have 400 years of observations of uh uh using stratospheric aerosols to cool the planet and you say hey look I can see this effect over here and I'm like look if you're cooling if the alternative is a planet four degrees warmer I don't care that we like reduce the Indian Monsoon strength by 5% right like so there's been a you know there's a lot of the media coverage has been really problematic and that's been partly driven by bat well-intentioned but poorly represented |
| 45:00 | science that has been more focused on hey I want to understand some detail rather than hey I want to con um convey an appropriate uh information specifically for policy um termination shock risk that's a damn good question nobody knows um if you were using this to cool the planet by half a degree yeah you warm back up by half a degree over the next 20 years that's not that different from our current rate of warming um if you're using this to Cool by two degrees and you turn it off that could be pretty bad so that you know |
| 45:50 | then is ask so you know there two questions there right what's the impact if there was a termination and what's the probability of a termination and how do you then design governance and design if you're deploying Stratus for your carousels don't do them out of one Airbase don't have a single supplier for your aircraft don't have a single country deploying it maybe that's okay if you're doing two10 of a degree cooling but if you're going to do a a degree of cooling don't do those things |
| 46:27 | and you can reduce the risks of ever having a GE engineering Doug yeah here Doug let me let me sort of what we what we've done in the past is I'll try and call on people on questions if they'll raise their hands or something like that so we don't have to do it all I'll read it but but no that's okay and so I want to take one prerogative and sort of asked the first question even though have it doesn't but the notion of that we would get there with an ipcc assessment sort of bothers |
| 47:00 | me because ipcc basically says its mission is to just report on what's in the literature rather than to drive a process of trying to really understand something enough to make a decision and so I guess I'm uh sort of curious if we should be starting to think about some other kind of process for doing that um you know some Mission directed process I don't disagree that we need a nice scientific recommendation but if all ipcc does a sort of report on what's in the literature and there's no effort to drive the literature by |
| 47:40 | governments will we ever really get to anything so should what the assessment process is or how that process works be something we talk about so yes and let me say two things first of all I think in PR you're you're right but I think you can solve those two things separately right so you can say we are going to go do mission-driven research and there's several efforts I'm involved with right now to actually fund that and ex you know write down a clear road map and execute according to that road |
| 48:16 | map and then if you do that you will have the literature that you can then use to assess the second thing of course is who's going to do that assess um right now of course there's a Cadre of senior lead authors in the ipcc that are a little bit of the Over My Dead Body um to the point of I've had conversations with one that was essentially willing to lie one and explicitly because of the view you know this absolute concern that if we allow this out to be mentioned if we allow the public to find out about |
| 48:55 | this it's going to detract from mitigation and so we're going to lie to the public yeah that's the Viewpoint that I've had from at least one person so you know we have to change that too one aspect also of the ipcc is it's driven by the scientific decisionmaking process which says I want findings of high confidence before I come to a conclusion as opposed to the relative risk kind of framing that one might want to use in an existential problem so it really seems to me that we need to come |
| 49:26 | up with a different way of thinking about how you get to a decision here and proposal or something like that so okay um I think absolutely yeah yeah yeah we need we need relative risk not and and which is why I would put a big emphasis in the research on you know uncertainties and risk and not just on yeah I mean I think it should be compartive one of the failures has been not having sort of a risk kind of assessment in the summary for policy makers instead of having scientists be able well and that's where I would like |
| 50:01 | you know I I quickly looked at Michael man's response to Jim Hansen and I was like totally no offense to Michael man but I'm completely appalled that he essentially ignored the entire concept of uncertainty he basically said you know I have my estimate and my estimate is correct no acknowledgement that that no actually you're at you know the correct way to convey stuff is to say you know you know you know here's my guess based on this but it might be wrong and as soon as you say it might be wrong you |
| 50:35 | know we don't need to get into an argument of whether Jim Hansen is correct estimate is correct or Michael man's is correct if it's even possible that Jim Hansen is correct we need to be doing something yeah if it's even PL you know we don't have to argue whether like amok shutdown is 5% likely or 90% likely right if it's 5 % likely you got to do something okay let's go to the question let's see in my lineup Jonathan Cole is first Jonathan hey thank you that was a really great presentation um I want to pitch |
| 51:12 | the idea that you include a slide about a groundbased reflection because um I build prototypes of foil reflection devices and I've shown them the of people and only one or two in all those hundreds have have actually understood the idea that photons move in straight lines and that if you reflect something back out to space and nothing it doesn't bump into anything on the way out it goes all the way out and that energy has gone with it the the level of understanding in the public even within science circles that |
| 51:49 | are not climate science is so low in terms of the basic physics of cooling through you know radiating adjustment that um the benefit of of promoting the groundbased uh stuff even though it's maybe slow to deploy and maybe it does take you know thousands or millions of kilometers to do it the benefit is that when I give people these devices to take home they play with them the kids shine them in each other's eyes uh and they get the real tangible sense of how the cooling occurs and how much energy there is in sunlight so I would |
| 52:27 | just make that pitch that you include a little more about the ground BL based reflection because if it does roll out across the Farmland even 10% of the farmland or something like that you can get a very big effect on it as well as cooling the plants and stuff you um the biggest effect you would actually get is if you like cool buildings so that you reduce your air conditioning demand so that you reduce fossil fuels so so roughly speaking uh to get all the way back to pre-industrial from where we are today would be a little less than 1% sunlight |
| 53:02 | that you need to reflect but 1% is a hell of a lot of area right so you know the the advantage of stratospheric aerosols the reason that that's sort of plausible is because they're you're getting that area with lots of lots of tiny tiny things um so that you don't have a lot of volume the advantage of marine fly brightening is there's a hell of a lot of ocean and just using the clouds the problem with doing it on the surface is simply like the continental US is 2% of the world's surface area so if you want |
| 53:34 | to reflect enough if you want to reflect enough to get a significant cooling you're talking like a reasonable fraction of the Continental us and that's just a lot of area so that's the reason that I haven't talked about it um combined with you know you do get the from a climate response perspective if you're putting all your forcing in in small places you could there are you know if you if you tried to actually scale it you would actually be changing climate right one time was what you need |
| 54:04 | is a styrofoam continent floating on the Pacific but okay let's yeah you can manage outgoing long wave a little bit to man let me go to Robert hul yeah look that was just awesome Doug thanks so much a couple of things I wanted to raas uh first the the issue of urgency that you lagged in the amok uh context um just the fragility of Earth Systems seems such that with arctic melt and and various other tipping elements that uh that we really need to uh to move uh quickly on this uh but I wanted to um just refer to uh this chart from your |
| 54:46 | paper from uh last year uh showing that um with s with I think 20 million tons a year roughly it would be possible to get back below uh Point uh 05 and then just to take uh one example of abundant uh examples of of the problem is a paper coming out in nature just uh this week uh just saying that um looking at this carbon budget Concept in order to stay below one 1. |
| 55:23 | 5 and completely ignoring the question of albo and the the ability of albo to keep us below 1.5 and then uh finally there is some level of opposition to the MCB trial in Australia this is a paper from the earth and uh yeah so uh a couple of things there thank you ah thank thank you for pointing me on that last one for all people's anks you constantly get this angst to about oh we can't possibly do anything outdoors and it's like well where where's the opposition um but yeah but you're thank you for pointing me on that yeah know I you |
| 55:59 | constantly see stuff and constantly see stuff saying you know this climate impact is unavoidable this climate impact is unavoidable and none of them say Well it you could avoid it it's just okay let's see Peter do you wanna yeah yes so Doug wonderful presentation uh are you are you going to be providing the the slides to us uh I certainly can if you want them yeah yeah they're very good I haven't really studied this for almost 10 years and it's progressed phenomenally um one point and and a question uh the |
| 56:42 | the mon penbo I have a new paper out that's not looking for a place to publish I can send it to on the list here um about the Pinatubo Paws that in in addition to the cooling in 92 there was also uh we had Net Zero that year of uh CO2 that CO2 uh levels were stable they were going up one and a half parts per million per year went to zero in 92 and then in 93 went back one and a half parts per million per year the point there being that I think getting CO2 back to assuming that we are willing and interested in learning how that happened |
| 57:22 | um probably uh which is probably ocean fertilization iron fertilization then uh we may be able to replicate what happened in in C2 and then if you do that then the um termination shock becomes much less of an issue because you don't need to do two or three degrees and yeah and so just for everyone who knows me I never talk publicly about s SI about Sol about SRM because of that reason wa saying as soon soon as we talk about restoring CO2 levels then it becomes a total no-brainer anyway that's my comment my question |
| 58:04 | is um uh in terms of get getting social license for doing it we've put together our climate restoration safety and governance board which could cover uh and I probably will eventually cover SII but you thought about What mechanisms uh to use for getting social license um I certainly know people who've thought about it I think my broad reaction would be that the fundamental precursor to that is uh a sufficient body of legitimate trusted science and that you know me putting here's a plot from one climate model conducted by one |
| 58:52 | group on one scenario with one tuning of the parameters in the climate model I I doubt that people will base their acceptance on that um although I still think the reality is that social license is going to be driven far more by what happens with climate change than any research we do on Geo engineering um great but I don't think that Situation's going to change overnight but it's hard I I can't predict the future on that um there's lots of efforts to at least you know do a better job of communicating and then my |
| 59:32 | reaction is do a better job of being clear on the research doing simulations that are not for degrees of cooling um but are sort of more policy relevant and doing a better job on the riskrisk comparative Framing and not just saying oh look stratospheric aerosols would affect this or Marine Cloud brightening would affect that right yeah that's great C can we uh schedule a little offline chat about about the social license yeah yeah absolutely great thanks Doug fantastic job can't wait to have the slides all right thanks |
| 1:00:12 | Ron you Mike I think herb was before me but that's okay um so sorry yeah go go her yeah his hand is up on a yellow wall and I couldn't see it okay yeah yeah go ahead R Zoom sorts them for you a little shorter than you usually [Laughter] are okay herb go ahead oh you want me all right all right well again like everyone else uh Doug it's just a I thought it was the perfect combination of uh technical enough to get across important and detailed Concepts and not always intuitive ones and very accessible and um uh we uh I hope you I |
| 1:00:55 | hope you find the time to give this to many people in many different places you and your colleagues um that said a couple of just Qui quick comments one is um um I I Rebel when I even hear serious discussion of maral Hazard to me even discussing maral Hazard is a maral hazard um and and uh I think of it as as cooling deterrence rather than mitigation deterrence but and and I and I only just want to make that comment but you know you I don't know which of our lists you're on but we've had some discussion about that in the last couple |
| 1:01:29 | of days but I think that what surprised me um was your what sounded like you were fairly sanguin about opposition uh or Andor support for cooling particularly from uh the the global South and so forth and and while you're immersed in it every day and I I'm not but it's been my experience it's been just the opposite um the indigenous Community the contacts I've had with them um uh they just see it as completely imp I don't I don't want to overgeneralize but the folks we've talked to see it as completely |
| 1:02:01 | incompatible with their with their view worldview uh social justice Advocates people like Greta thunberg are you know vehemently against it uh um and and of course as you pointed out the the IC ipcc authors that are willing to lie um uh which is not the first time I've heard a similar anecdote to that um and even the White House when the um when the report that Congress had them do uh that they released at the end of June you know they they sort of had this off the Record Hot Potato like okay we had to do this report which is a report |
| 1:02:36 | basically outlining a research agenda but um we want to make it very clear anonymously we're not supportive of this we're not going to fund it um Etc which I took from the fact that there's no Lobby basically um making them be more open to it the only people they hear are the opponents of of cooling so I if you could just both respond to that and also just maybe briefly even though it's a a broader question if you were the sort of um philosopher king if you will of the planet what would be um uh kind of an |
| 1:03:10 | ideal Pathway to get from here to um deployment if you know if warranted uh you know past all of these uh political and governmental and institutional obstacles I know that's a lot to ask so you can pick Ando which you want to respond to H how how many hours do you have exactly yeah yeah I just we want to make sure Ron and Robert have enough time um I'd say there's a huge amount to unpack there on on moral hazard the reason that I mention it is that if you want to understand why people are opposed to geoengineering I think you |
| 1:03:52 | have to recognize and call out that that is actually the source of their concern right so why is why would you be strongly concerned about termination shock only if you thought that you were doing using this as a substitute right as Peter points out right if you do get emissions down and you manage to pull CO2 out of the atmosphere you're not necessarily talking about cutting you know cooling by a whole lot so if you you know why are you concerned about termination shock is primarily because your mindset |
| 1:04:27 | is thinking that this is a substitute so it's not always explicit in people's minds but sort of the like the Michael mans of the world um and the ipcc people lead author person that will go nameless um that's basically the source of their concern um personally I think it's nonsense I think it's so obviously not the uh situ you know if one gets to the point of actually deploying this stuff I think it's pretty blindingly obvious to everybody on the planet that that's not where we wanted to be right |
| 1:05:03 | we didn't want to be in a position where it's like cool now we can keep keep emitting nobody says great I'm gonna keep smoking because chemotherapy has been invented or or I'm G to run this red light because I've got airbags um it to me it's just total nonsense as an argument and the argument itself is morally problematic because if you really parse it comes across a little bit like if you don't watch enough poor people in Bangladesh dying you're not going to cut your emissions so personally I have a big |
| 1:05:35 | problem with the moral hazard argument but I acknowledge that that's why people have concern so what do I think needs to happen is we somehow we need to change the narrative and I think it is changing um I don't know I'm not sure I answered all your questions well I would just say the other the other reason of course is that now fossil renewable energies are becoming less expensive than than fossil and it's not like anybody's going to go back to Fossil I mean they might hold on to it a little bit because of their |
| 1:06:08 | assets but but they're not g nobody's gonna go back to the fossils given the dropping price of Ren in my at least in my view okay Ron just in terms of that changing the narrative my view basically is good good science will help but it's not sufficient so good science and good communication um and right now that's really hard to do when there's like zero money and nobody really pushing for it but as soon as you know there are several groups that are likely to start ramping up research funding and I think |
| 1:06:43 | as part of that recognizing that one needs to do a better job of articulating things is going to come along with that sorry okay Ron uh thank you Mike and and thank you Doug that was excellent It's it's just very refreshing we we've had you know numerous people presenting to hbac and I think you know we're we're as you know we're I I believe you know we're a community that believes very strongly in the urgent need for for cooling and uh I think you you're you're sort of uh you know been been the |
| 1:07:18 | closest to to that view as far as I can tell and on that note uh you know the urgency experimentation and deployment so I think you know we we have I agree with you we we have seem to have crossed a threshold where most of the community as far as I can tell believes in the importance of research uh the problem is you know we we had David Keith for example and he he he you know he said well probably about 10 more years of research I mean it was a it was a you know a video like this so I wouldn't I wouldn't you know pin him |
| 1:07:52 | on that it of you know in convers but uh you know and part of that was a skepticism about tipping points that you know if we cross 1.5 you know that was that's just kind of a political Target it's not going to be that bad and to the contrary you know I think uh I believe and I think many people many of us believe that that is a very serious risk that we need to consider and we don't really have 10 more years of research so on that note and I I I get this sense that you're you're you're you know |
| 1:08:26 | you're sort of at least you know thinking in this way we need don't we need to do actual test testing I mean and i' i' I I you know I proposed sort of a space station analogy start in the polls you know drawing on your work and and Mike who who had a paper early on to the you know the White House Office on the same same topic that you know just start very small steps in the polls you know you can even frame it as a Great Barrier Reef kind of thing you know we want to cool the poles and then try and get the |
| 1:08:58 | you the native people and the the uh the countries that have some Authority in the polls you know uh uh jurisdiction to just say let's let's just do a little bit you know we'll just start you know experimenting because I don't see you know if we don't start actual experiments real test deployments you know it it's it it will take 10 years I mean I just I I I to be honest you know I think I and many of us were quite despairing after we heard from David uh that you know we this this is just we we |
| 1:09:32 | need more urgency in the community and and and it doesn't seem to be uh on the agenda right now so you know anything you could you could say to that would be would be appreciated thank you okay um three things so first of all um with regards to tipping points my reaction is that there is certainly uh uh in some cases overhype um about one particular study without sort of balanced look at all sorts of things but my bottom line is this is risk so I don't need 100% confidence in the probability of a Tipping Point to act and I think you can |
| 1:10:13 | um the correct argument to somebody to say you know David Keith says I don't believe in tipping points um the correct argument really is much more about probability and risk right you don't have to convince them that it's 100% probability you have to convince them that it's not zero and that it's a not not a trivial number um with regards to timeline my guess is the I'd be very surprised if any form of SRM is deployed at any reasonable scale in the next decade um that you know quite frankly |
| 1:10:49 | even if we had the social license today and all the science today it's it Take Years [Music] um but you know how much research do you need is it's prob it's it's um you know it's it's risk right for me I'd say sure if if I was in charge of the world I and I got to make all of the decisions I might say I've made my risk calculus I think we should start putting a little bit of aerosols into the stratosphere but that's not my decision and it shouldn't be my decision um so how much research do you |
| 1:11:30 | need is Need For What need for whom right um exactly what you said effectively right it's a risk calculation um in terms of experiments my answer is wet four um I don't think we should be doing stuff just to be seen to be doing stuff I think you do stuff with a purpose so Marine Cloud brightening I think we should start doing experiments in about 2013 2014 um as proposed by Tom Akerman and others to actually do controlled perturbation experiments of marine of marine Cloud brightening I think it's absolutely blindingly nonsense that |
| 1:12:08 | those that weren't started 10 years ago um because we don't understand some of the processes well enough to constrain them for stratospheric aerosols if you said uh let's say we're going to go buy three Gulf Stream craft and put you know 50 tons 100 tons 100,000 tons of aerosols into the stratosphere I think that's something that you would do as a Prelude to deployment right you're going to put 100,000 tons in before you put a million tons in but I'm not quite sure that I could like I couldn't argue that that's |
| 1:12:45 | going to change the answer if you think about it from an uncertainty perspective a large uncertainty that you need to reduce is one where some izations of that uncertainty you would choose to deploy and others you don't right now I would not be in a position to say we have to do this experiment in order to reduce uncertainties part of that is because most of the uncertainties that people are really worried about aren't things that you would ever find out about with a small release but you know in principle I'm open to making the you |
| 1:13:17 | know doing that more quantitatively and saying okay here's exactly what you could learn with this amount of aerosol at this point in time and so forth um but in terms of actually putting enough in to actually start cooling the planet I don't write this instance I would say sure my personal view is I think that would reduce physical risks but I think it would increase societal risks and I think it would actually slow down stuff in the long term right if somebody was pushing too hard for deployment there's |
| 1:13:50 | going to be a backlash so you know some this is all weighing non-commensurate types of risks that none of us know anything about um so Doug I know you have to leave around five or something but there are a couple of questions still on last if you can stay as long as you can we're happy but if you have to leave let us know um probably about :2 is as late as I could push it and get to daycare before it closes oh okay all right maybe 503 if I'm if I hurry at the door okay all right well we'll go Robert |
| 1:14:22 | Christoper I trying to get my question really short you you glossed um across one quite interesting point rather quickly for me which was when you you talked about conflict as being one of the possible impediments um and but you but you then said it didn't need to be a showstopper now I find I find this whole issue there's a whole range of things that one could put in that caption or underneath the caption conflicts but one of the things that has always exercised me about C ation management is the fact |
| 1:14:55 | that because you're doing it in the Global Commons and there's no way that you can control the cross-boundary impacts the opportunities for Any Nation or any Community to say hey look um we've just had a flood we've just had whatever a drought it's entirely due to your experiment or your you know your your stratospheric aerosol injections you need to compensate us now one of the things that concerns me is whether is the extent to which our conservative with a small C uh politicians and the |
| 1:15:31 | legal advisors upon whom they rely for any form of treaty or legislation are going to look at the potential exposure from these sorts of claims whether spurious or otherwise and kind of really struggle to approve any kind of activity in this area um yes um I think if you wanted to imagine a deployment that was going to be successful right and successful means you know if you're actually trying to reduce climate risks you're actually deploying at some reasonable amount of scale for some period of time you want |
| 1:16:13 | to actually do that you know there's got to be reasonable consensus um and there may in order to get that reasonable consensus you may need to and might be morally appropriate to put some sort of compensation scheme in place right so that the direct costs of deployment might be completely irrelevant because the real costs of deployment are we're going to put a compensation Fund in place for people who view themselves to have been damaged by this right so this that and that's an active area of research as well um but |
| 1:16:47 | it's also why I would tend to say you know look you know lots of us might look at the risks and say oh we see big risks um but by and large most people on the planet do not currently see climate change as a risk certainly not a sufficiently existential risk to justify action um right so you know if you suddenly said whoops there's research that convincingly shows that if you're above one and a half degrees for more than a decade we're got we're going to get 10 meters of sea level rise or |
| 1:17:18 | something you know maybe that that might change the conversation um and if I have to jump off before I get to everybody's question feel free to email me yeah right I was gonna sort of ask that stress that maybe necessary um maybe Greg and Victor could you B perhaps ask your qu both ask your questions and then see if he has real time do it yeah sure well my question is I have a million questions but I'll just say is it not is it when in the modeling the in introduction of the aerosols is is fairly uh blunt uh I mean in a real |
| 1:18:02 | system it would be a control loop with different yep it would be you know like a real control system and I think yep that's me I I am a controls person I teach controls yeah yeah so essentially you can manage these um the the the problems that we've talked about of the non-uniformity Etc would be uh ameliorated by that by a real control system anyway that's the thing I'd made yes yes that's the short answer the long answer is an hour okay well I might I might email you Victor but that's basically what I |
| 1:18:40 | do um Victor do you have a quick I had some technical question but if you're in a hurry I can I can let you go but well ask it and I can always um give a very short answer if I can okay well I've been wondering um why it's uh more difficult to uh deploy SRM in the high latitudes I realize it's a bit the it's bit lower but it's it's yeah it's easier to deploy in high latitudes because the trophy pause is lower but don't don't you have to get to the stratosphere so you still have to have |
| 1:19:15 | like the purpose built aircraft and that's basically wake's analysis is that you still if you wanted do it with any reasonable cost effectiveness at scale you'll need purpose built aircraft but now they only need to get to you know you want to you don't want to like here's the trop PL right is not like a a paper thin boundary and you don't want to be right right above it because you're the reason is you want lifetimes you want to be some distance above it um which pushes you I don't know we haven't |
| 1:19:47 | been comprehensive about this whether you need like 13 kilm or 15 kilom but by the time you say I want to be at something like 13 to 15 kilometers with a payload you you know you can go do it with existing KC 135s but they're all at the end of their service life um for fatigue reasons so you fly them 10 Cycles a day for a year and they're all GNA break but you basically you're gonna need you basically need to build new airplanes anyway um it's a lot easier where the air is denser you don't need as much Wing area you |
| 1:20:25 | don't need as much and your engines flame out at at high altitude if you're not careful don't you just need the injection time though it to last a few months I mean during the peak summer season and that's all spring you want to put them in like like March April May well yeah once the snow starts to melt there's no purpose doing it before the snow starts to melt really um because you're going to be darker than the maybe maybe not I guess it's in the stratosphere but it's in yeah it's in the stratosphere and an |
| 1:20:56 | actual fact you get your predominant cooling not over the regions where there's snow actually you get your predominant cooling from being a little having forcing slight south of that um and therefore reducing the heat transport into the Arctic oh okay um but regardless yeah you want to put them in in like spring or something like that so that they're there during the summer during the peak of the insulation um through the fall um but yeah no you still need to get them to altitude okay thank you very much better |
| 1:21:33 | head out I don't want your children stuck somewhere y all right thanks all thank you very much thank you thank you thanks Doug thank you Doug good to see you good to see you all back thank you the steering Circle should stay on for our debrief thanks to everybody else |