If we're to believe the Philosophical Transactions of the Royal Society, or the Copenhagen Consensus Center, or apparently any of the individual geoengineering researchers who've modelled it, it's possible to halt all warming by building a fleet of autonomous wind-powered platforms that do nothing more sinister than spraying seawater into the air, in a place no more ecologically sensitive than the open ocean, and for no greater cost than 10 billion USD

(edit: I'm not sure where the estimate of 10B came from. I saw the estimate of 9B in a lot of news reports relating to CCC, and I rounded up to be conservative, but I couldn't easily find CCC materials confirming this number)

If this works, no significant warming will be allowed to occur after the political static friction that opposes the use of geoengineering is broken.

Isn't any amount of mean warming bad? So shouldn't we deploy something like this as soon as possible? Shouldn't we have started deploying it years ago?

Side effects seem minimal. Relative to seeding clouds with sulpherous chemicals (which will also be considered, once the heat becomes unbearable), it leaves no ozone-eliminating residue, it produces no acid rain. It may disturb rainfall in some regions, but it seems that it may be viable to just avoid seeding too close those regions.

I want to make it clear how little support this needs in order to get done: 10 billion USD is less than a quarter of the tax income generated by the nation of just New Zealand one year. A single tiny oecd government could, in theory, do it alone. It wont need the support of a majority of the US. It probably wont require any support from the US at all.

What should we do with this information?

I do buy the claim that public support for any sort of emission control will evaporate the moment geoengineering is realised as a tolerable alternative. Once the public believe, there will never be a quorum of voters willing to sacrifice anything of their own to reduce emissions. I think we may need to start talking about it anyway, at this point. Major emitters have already signalled a clear lack of any real will to change. The humans will not repent. Move on. Stop waiting for humanity to be punished for its sin, act, do something that has some chance of solving the problem.

Could the taboos against discussing geoengineering delay the discovery of better, less risky techniques?

Could failing to invest in geoengineering research ultimately lead to the deployment of relatively crude approaches with costly side effects? (Even if cloud brightening is the ultimate solution to warming, we still need to address ocean acidification and carbon sequestration, and I'm not aware of any ideal solution to those problems yet, but two weeks ago I wasn't aware of cloud brightening, so for all I know the problem isn't a lack of investment, might just be a lack of policy discussion.)

Public funding for geoengineering research is currently non-existent in the US (All research in the US is either privately funded or funded by universities), and weak in China (3M USD. 14 members, no tech development, no outdoor experiments.)

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I'll give an answer that considers the details of the Copenhagen Consensus Center (CCC) and geoengineering, rather than being primarily a priori. I've spent a day and a half digging around and have zero prior knowledge. I spent too much time reading Lomborg and CCC in retrospect, so I mention him disproportionately relative to other sources.

Cross-posted to my blog.

Here's what I notice:

1. Lomborg and his CCC seem very cost-benefit focused in their analysis. A few others are too, but see point 4. Basically, it's easy to compare climate interventions to other interventions, but hard to figure out how much damage warming and other climate change will cause, so you can't really figure out the benefit part of the cost-benefit analysis.

2. Lomborg and his CCC has recieved a ton of criticism for systematically making errors that underestimate the effect of climate change, and never making errors that overestimate the effect of it. One detailed account of him making such an error that could not have been made in good faith, is given here. He also literally lies in his cost-benefit analysis (by more than 10x).

There's a lot of articles about Lomborg e.g. taking a 700k salary and getting donations from Koch and Exxon, which showed up before I found the above examples of him lying about data. I reacted to the info on his salary/funding by saying, "this is indicative of him being sketchy, but instead of just changing my estimate of how likely he is to be sketch by however much ("updating") and calling it a day, I'm going to take this as a cue to dig into things until I have a firm understanding of whether this guy is systematically lying or not". Turns out he's a liar (see previous paragraph).

3. Page 33 of this CCC paper notes that,

To place SRM 1 [a plan which, by definition, reduces the amount of heat from the sun that stays in the earth's atmosphere by 1 watt per square meter] in perspective, 1 W m-2 is about 0.3% of the [average over the earth] incoming solar radiation of 341 W m-2 (Kiehl and Trenberth, 1997; Trenberth et al., 2009).

Which corresponds to a 0.6 C average temperature change. This should put in perspective what a huge effect a 0.3% change in how much heat gets stays in earth's atmosphere has on global temperatures. If all the glaciers melted, the earth's temperature would rise 10 C, because glaciers are good at reflecting heat back away from the earth (back of envelope, me); if the earth became totally frozen, the temperature would drop by 55 C (see this page), which is why the thing this post is about, MCB, can realistically change global temperatures by a couple degrees C. Note that 1/2 of the global temperature change that already happened was because some glaciers and snow already melted and stopped reflecting heat away from the earth. Basically, the science behind MCB is pretty solid and I'd expect it to basically work.

AFAICT the IPCC estimates of how much warming there will be in the future seem to take into account the fact that the melting of the glaciers will further speed warming in itself, in addition to the warming you get from rising CO2 levels. Except they don't ever explicitly say whether that was considered as a factor, so I can't be totally sure they took that into account, even though it sounds like the most obvious thing to consider. (I skimmed this whole damn thing, and it wasn't said either way!) I guess my next course of action could be to annoy an author about it, though I think I'll be lazy and not.

4. We have little enough data on "how much economic damage has global warming done so far" that we can't make decent extrapolations to "how much economic damage will global warming do later". Like, you have papers saying that the economic damage from 3 C of warming could be 1%, 5-20%, 23%, or 35% of the GDP. When you have zip for data, you fall back on your politics.

5. The obvious game theory consideration of, "it's better if someone other than you spends money on global warming". The normal lefty position of, "our institutions aren't set up to coordinate well on this sort of problem, and every action against climate change, until we change, will predictably be a stopgap measure". The unusual conservative position of, "just do the cost-benefit analysis for MCB". How much damn energy I've spent filtering out the selectivity in what scraps of data scientists and economists want to show me. /rant

Here's what I'm taking away from all that:

CCC isn't reliable in general, but others have made estimates of the cost of worldwide MCB. I'm inclined to believe CCC about MCB in particular, as their numbers match up with others'. MCB is the most cost-effective climate intervention by a ~50x margin, and the estimated cost of worldwide MCB is 750M-1.5B USD annually. The exact technology needed to do MCB hasn't been fleshed out yet, but could be engineered in a straightforward way.

By CCC's own analysis, deploying worldwide MCB is >10x more cost-effective than standard global poverty interventions, and the fact that OPP and Givewell have far more funding than they know what to do with (even though they're lying and saying they don't), makes MCB even more attractive than this in practice.

Personally, I suspect that fleshing out the details of how MCB could be done in practice, would be more cost-effective than instituting a full-blown implementation of MCB, as having a well-defined way to implement it would reduce the friction for other(s) to implement it. Once I have hella money, it's something I'd fund (the research on how to do it, but certainly not the actual MCB). Like, to get things to the point of having a written plan, "hey government, here's exactly how you can do MCB if you want, now you can execute this plan as written if/when you choose". I expect other interventions (re: factory farming) to be more effective than the actual MCB at preventing suffering.

Thanks for reading, and thanks for bringing MCB to my attention. Stay awesome.

Thank you for looking into this! <3

I do think you might have put too much energy into thinking about the CCC though, haha. Maybe I should apologise for having mentioned them, without mentioning that I knew they'd taken money from dirty energy and I never got good epistemic vibes from them.

When I saw that stuff, I just read that as one of the many things we'd expect to see if MCB was legit, like, there would be a think-tank funded by dirty energy singing its praises, and even if that thinktank were earnest, I would still expect anyone who actually gave a shit about solving the problem to take the dirty money, because this kind of research ought to be rateable on the basis of whether or not it is true, rather than who paid for it, an extravagantly costly purity allegiance signal such as rejecting money from the richest people who benefit from your research should not carry a lot of discursive weight (and I'm still fairly sure it wouldn't have).

What set off alarm bells for me was when I realised just how much the individuals in the CCC were taking in salary for the kind of work they're doing. It would seem to me that genuine activists never get paid like that. I'm still not sure what that means, though. They live in world I don't know much about.

I suppose part of the reason I mentioned them is that they seemed to be gathering a lot of interesting heresies that our friends might like to know about, not just MCB. Did you find that was the case?


He also literally lies in his cost-benefit analysis (by more than 10x).

What's the literal lie, here? The link seems to say that a group led by Lomborg made misleading statements about how they made their prioritisations, but I can't see any outright falsehoods.

b/c of doing the analysis and then not ranking shit in order. do your own research if you disagree, but if you use "apparently because it is deemed rather uncertain if this will actually work as intended." as an excuse to rate something poorly because you wanted to anyways rather than either do more research and update it, or even just make a guess, then wtf? We are not playing, "is this plausibly defensible", we are playing, "what was this person's algorithm and are the systematically lying".

I prefer to reserve "literally lying" for when people intentionally say things that are demonstrably false. It's useful to have words for that kind of thing. As long as things are plausibly defensible, it seems better to say that he made "misleading statements", or something like that.

Actually, I'm not even sure that this was a particularly egregious error. Given that they never say they're going to rank things after the explicit cost-effectiveness estimates, not doing that seems quite reasonable to me. See for example givewell's why we can't take expected value estimates literally. All the arguments in that article should be even stronger when it's different people making estimates across different areas. If you think that people should "make a guess" even when they don't have time to do more research, that's a methodological disagreement with a non-obvious answer.

I still think it's plausible that some of the economists were acting in bad faith (it's certainly bad that they don't even give qualititive justifications for some of their rankings). But when their actions are plausibly defensible in a... (read more)

If you want to spend time predictably spinning in circles in your analysis because you can't bring yourself to believe someone is lying, be my guest. As for the specific authors: the individual reports written seem fine in themselves, and as for the geoengineering one, I know a guy who did a PhD under the author and said he's generally trustworthy (I recall Vaniver was in his PhD program too). Like what I'm saying is the specific reports, e.g. Bickel's report on geoengineering, seem fine, but Lomborg's synthesis of them is shit, and you're obscuring things with your niceness-and-good-faith approach.
3Alexander Gietelink Oldenziel4y
Less of this, please. From what Lanrian is citing Lomborg does not come close to outright lying. (there might be more in the link, I have not read anything but the comments.) Accusing somebody of literally lying is a very strong accusation and should only be done in the egregious cases for all the usual reasons. You are clearly well-informed about this matter. Your earlier comment was helpful and updated me in various directions. You could make me update me even more by applying the Principle of Charity.

Raw answer: no. Law and politics work on https://blog.jaibot.com/the-copenhagen-interpretation-of-ethics/ , and the legal liability will outweigh any actual costs by orders of magnitude. And the actual costs are probably WAY underestimated, ignoring inefficiencies and overhead of any real-world group that could undertake it.

There is also good reason to be cautious about the undertaking itself. We have no data on what actual weather shifts will occur with this scale of geoengineering, and the models have pretty large error bars. I don't know enough to say whether we CAN undertake small-scale projects to measure, or whether it's just impossible to know until we can model global weather in detail.

All that said, I suspect we're near the point where failing to take control via geoengineering will doom us anyway, so the risky attempt is likely justified.

Is there such a thing as “EA, but for carbon offsetting”? I can imagine an organisation that would invest in a weighted mix of direct carbon capture, lobbying, geoengineering, funding renewable energy, research, ...

All I can say about offsetting is that ~~most international flights will be offsetted by 2020~~, and it seems like that amount of carbon would only cost about 20$ per passenger per flight, which is to say, offsetting seems to be shockingly cheap.

Is this based on https://www.wired.com/story/airline-emissions-carbon-offsets-travel/ ? I think https://slatestarcodex.com/2019/08/05/links-8-19/#comment-783425 might be relevant - it seems only the increase compared to 2019 is being offset, not the whole flight.

No, with ~95% confidence.

The central problem of geoengineering projects is that there is no reason to even entertain the notion that they will perform differently than regular projects. They will be over budget by about the same amount, miss their timelines by about the same amount, and miss their performance targets by about the same amount. This last point is the real crux of the matter, because we are talking about large scale, irreversible changes to the environment. The only way to remedy an error is by using the same error-prone process that caused it in the first place.

That being said, there are new methods available for managing huge and complex projects. Then it is a matter of adopting the methods.

If the true cost were double or triple the $10B estimate, this wouldn't significantly change the implications; $30B is not significantly less feasible.

The implications are significantly different if $10B turns into $30B while the project is underway, which is the norm. The timeline is also significant, and delays of 2-10 years matter a great deal to how successful the project is going to be.

The things you're saying are true of estimates in civic engineering, but I don't know that they're true of estimates in climate science.

Estimated effects of climate change seem to have been drastically below the real outcomes, in many respects, we're 40 years ahead of schedule (and even when I say that, I am removing 10 years from the claim just to make sure I'm not overstating the effect; this is how reluctant people are to acknowledge the full insane reactivity of the climate).

You could, if you really wanted to, describe climate ... (read more)

It does not follow that because climate models are bad to an unknown degree, geoengineering projects will overperform to a symmetric degree. This is a common assumption among large projects, but it is also a specific failure mode.
1mako yass4y
I'm not doing syllogisms here. The heuristic might not dominate the effects but it seems like a valid heuristic. In which larger projects has the assumption "climate models are bad, so geoengineering may overperform" been at play? I'm not familiar with any historical geoengineering projects, I'm not aware there's been any, unless you count all of the accidental cloud seeding that occurred as a result of sulphur in cargo boat emissions, which seemed more like an unexpected success.
To my knowledge, none. This is because to my knowledge there has never been such a project. I claim that there is no reason to expect geoengineering to be different than any other field in project outcomes. I claim further there are strong causal reasons to expect them to be the same. Large projects behave similarly regardless of whether we are talking civil infrastructure, oil & gas, energy, mining, aerospace, entertainment or defense. There is no trait of geoengineering which can differentiate it from this pattern. This is because the problems are not driven by the field from which the project originates, but by the irreducible complexity that comes with size. Absent a specific commitment to dealing with irreducible complexity problems, we should expect budget and timeline estimates to be badly wrong. Note this doesn't make geoengineering a bad field or their projects worse than other projects; the thing I am pointing to is that we need separate expertise to make it work the way we need. We cannot afford to spend multiple projects worth of budget on only one project, and we really cannot afford to be surprised by a 10 year delay.
The industrial aspect of MCB seems to be "numerous, autonomous boats spraying water". Building a lot of adequately-reliable boats doesn't sound like your typical megaproject, but more of an assembly-line job, something like liberty ships. Adequately developing the process of managing large numbers of drone ships might be a pre-requisite, and doubtless has other military and civil applications. (Of course, whether MCB affects the climate as hoped is another question altogether).
As it happens, coordinating a large assembly-line project is fairly standard megaproject material. Ships, aircraft, and semiconductors are good examples. The hitch is your example assumes a WWII-grade of funding and coordination. Do you think that can be achieved quickly enough, cheaply enough, and reliably enough to be ignored when proposing such a project?
I think a very significant (probably even dominant) fraction of this geoengineering project would not be the industrial aspect but the organisational and political aspects. Building some ships sounds very doable (although I don't know to what extend "spraying water" and "autonomous" are assembly-line projects, do we already have industries that make ships like this?) , coordinating around letting them sail around and alter the atmosphere less so.
1mako yass4y
Maybe I could be clearer. I'm proposing that we will need to do less of it than we thought, that we will get halfway when we were supposed to be all the way, but then maybe tests will reveal that this is enough. Geoengineering is a megaproject where, yes we may underestimate the amount of time it will take to get them to the stage of completion we thought we needed, but we may also overestimate how far we needed to get. As Greylag mentions, producing the boats will be a continuous process, it will be possible to stop halfway if that turns out to be sufficient, although I suppose most of the cost will be at the beginning so I'm not sure how significant that is here.
I think that is plausible, and I think the factors you mention are definitely a virtue of the MCB approach. A further one is that even if we were to produce too few, the ones we did produce would still result in marginal gains. I also agree that most of the cost will be at the beginning; even more so if it is done correctly. But I point out the error in estimating how many boats will be needed is completely independent of the error in estimating the timeline and costs for setting up production; we aren't at liberty to assume they will even approximately balance out. I think it is reasonable to infer that the longer the delay until operations start, the more boats will be needed to achieve the goal. This means the risk is lopsided primarily on the side of costs increasing; there's no particular likelihood of things being much cheaper or faster than expected, like we expected production to start in five years and it mysteriously happened in three. These are all solvable problems, mind; the core of my criticism is that there are specific issues that arise from the bigness of challenges alone, and that we need to account for them deliberately. This is not done in baseline cost or time estimates, and rarely done even among people who are experienced in tackling big challenges, so we aren't at liberty to assume that we can hand it off to experienced practitioners and they will handle it.

1 Related Questions

Yishan Wong, the former CEO of Reddit, already has, so you might ask him - but I suggest you read all his blog posts on the subject first so that you don't ask anything that he's already covered.
3Answer by BastardAcademic4y
Start like everyone else does: work out your business plan. Understand exactly what it is your business will be doing, what it will involve, who else (personnel and other companies) it will involve. What resources do you need to begin, and what will you need to actually implement your service/product. What is your revenue stream and what are your outlaying costs? Will you need to borrow any capital to start with? What will you charge for your service/product, and how long will it take you to earn back and pay off your borrowing? You will also need to consider regulation and legislation: how much of it is there, what applies to you, will you need to register with a professional or national body, do you need certification, do you need permits or licences? What stage is your offering at: is this just an outline of an idea, of do you have a proof of concept? How much will it cost to prototype or test this concept? How and to whom will you market this offering? What are it's USP's? Can you back-up your claims for it with data and evidence? Have you done the research to show there is a space for your offering?
Maybe chat with the folks from Marine Cloud Brightening Project and ask which obstacles they faced?
Maybe consider starting something less ambitious first, but where you have a good handle on what you can achieve, a unique idea and an advantage over those who would want to compete against you and over political interests who would want to destroy you?
31 comments, sorted by Click to highlight new comments since: Today at 10:50 AM

Next steps are connecting an interested funder, the most competent researcher in the area, and someone who has some relevant engineering knowledge to figure out which experiments would maximize further information to tackle the biggest uncertainties in the model. Mainstream philanthropy will only take interest once someone does the weird thinking and logistics for them.

I would guess ~zero chance of any public funding for this. Professional hand wringers aren't incentivized to solve problems. If before any charities had already scaled it you had approached people and told them you thought distributing insecticide sprayed bed netting might be the most important thing in global welfare you would have gotten a mix of polite interest and scoffing that never would have gone anywhere.

Edit: looks like I'm wrong. The project is housed at a public university which presumably means it has received some grants. I'd still expect a motivated team to outperform the entire org. Looks like they produce <1 paper per year on average. All the collaborators probably have other things that are their main projects.

It's worth noting that projected costs are as high as 1 billion per year per W/m^2 of reduced forcing. Still trivial in the grand scheme of things, but quite a bit different than expected total cost of 10B.

1 billion per year per W/m^2 of reduced forcing

For others who weren't sure what "reduced forcing" refers to: https://en.wikipedia.org/wiki/Radiative_forcing

And to put that number in context, the "net anthropogenic component" of radiative forcing appears to be about 1.5 W/m^2 (according to an image in the wikipedia article), so canceling out the anthropogenic component would have an ongoing cost of 1.5 billion per year.

With regard to funding, I wonder if you could make it into a for-profit by finding municipal regions which experience periodic flooding and getting the city to pay you to pump the floodwaters up into the air as mist?

I believe global warming is supposed to increase flooding, so flood mitigation will probably be a booming industry soon.

By the way, my dad told me someone at his research lab (Xerox PARC) is doing research on Marine Cloud Brightening. If you send me a personal message via my user page, maybe I can get him to introduce you.

No need for him to contact me, better if he came and left a comment here (I'd also be happy to email him and relay the comment)

(sorry for taking over a month to reply)

Expected cost of 9B seemed to come from reports on the work of Copenhagen Consensus Center, but, if so, I couldn't see which CCC document it was coming from, didn't seem like a salient figure in CCC leader Bjorn Lomborg's angry blog either.

Between this and the viability of other geoengineering projects I'm expecting that the biggest blocker will actually be how to make sure we don't overshoot in the other direction, or just introduce chaotic variance.

(Even if cloud brightening is the ultimate solution to warming, we still need to address ocean acidification and carbon sequestration, and I'm not aware of any ideal solution to those problems yet, but two weeks ago I wasn't aware of cloud brightening, so for all I know the problem isn't a lack of investment, might just be a lack of policy discussion.)

There is also http://projectvesta.org which claims that it is possible to remove CO2 from the ocean and atmosphere via olivine weathering reasonably cheaply.

They propose mining and transporting 11 cubic kilometers* of olivine per year, at $10 per ton when scaled up, which comes out to $365 billion per year assuming that's metric tonnes. Might or might not be considered "reasonably cheaply" depending on what you think of the alternatives.

*they also mention 7 cubic miles, which would be almost a trillion dollars per year, but this would be a lot more than would be needed to offset world carbon emissions if their claim of 1.25 to 1 ratio of CO2 to olivine is correct - so I think that's a misconversion from the 11 cubic km figure rather than the other way around.

For some further perspective, $10 per ton at 1.25 times removal of CO2 would be $8 per ton of CO2. So, we could theoretically pay for it with a relatively affordable $8 per ton global carbon tax if that could somehow be made to work politically.

I have a few technical quibbles here.

  1. It's not quite accurate to imply Philosophical Transactions of the Royal Society B itself has made a claim about the robustness of MCB. Generally only an editorial endorsed by the editorial board should be taken as a statement about the journal's position in particular. Generally academic journals provide a forum for academic debate. Only the authors of an article are really standing behind the position. The journal only publishes work of a certain standard, and publishing a paper is somewhat an endorsement of the quality of work in the paper, but not of the finding itself.

  2. Generally I understand it is not a given that MCB will work. Only the sulphur dioxide solution is really proven, and "sulphur" makes me nervous (I don't know if there are good grounds for that). More research is needed on MCB, which a point in favour that the research should be funded and carried out as soon as possible.

  3. It may be that researchers could do research into MCB without it being seen as an endorsement by the entire field that we don't need other solutions. MCB can and should be presented as important experimental work that needs to be done, as a last resort. When it is actually proven, I think that's when we have the dilemma about what to tell the public. But at that point, looking at the status quo, it may be our only option left.

The 2015 report "Climate Intervention: Reflecting Sunlight to Cool Earth" says existing instruments aren't precise enough to measure albedo change from such a project, and measuring its climate impact is even more tricky. That also makes small-scale experimentation difficult. Basically you'd have to go to 100% and then hope that it worked. As someone who ran many A/B tests, that makes me hesitant to press the button until we have better ways to measure the impact.

we still need to address ocean acidification

And changes in precipitation patterns (I've seen evidence that reducing solar incidence is going to reduce ocean evaporation, independent of temperature).

There's also the "double catastrophe" problem to worry about. Even if the median expected outcome of a geoengineering process is decent, the downside variance becomes much worse.

I still suspect MCB is our least bad near- to medium-term option, and even in the long term the possibility of targeted geoengineering to improve local climates is awfully tempting, but it's not a panacea.

As an unrelated aside, that CCC link rates "Methane Reduction Portfolio" as "Poor"; I'd have marked it "Counterproductive" for the moment. The biggest long-term global warming problem is CO2 (thanks to the short half-life of methane), and the biggest obstacle to CO2 emissions reduction is voters who think global warming is oversold. Let the problem get bigger until it can't be ignored, and then pick the single-use-only low hanging fruit.

(I've seen evidence that reducing solar incidence is going to reduce ocean evaporation, independent of temperature)

Of course, it may help that the way MCB reduces solar incidence is mainly through artificially increasing ocean evaporation. But it would be good to make sure of that.

I do buy the claim that public support for any sort of emission control will evaporate the moment geoengineering is realised as a tolerable alternative. Once the public believe, there will never be a quorum of voters willing to sacrifice anything of their own to reduce emissions.

I wonder if the possibility of geoengineering has already significantly reduced support for emission control, since the idea has been written about in popular science media for a while and isn't exactly a state secret. Also, if we don't put more effort into studying the actual cost and feasibility of geoengineering, it will be really disastrous if the cost turns out to be much higher than current expectations, or the idea turns out to be infeasible (without causing other serious side effects).

Yeah, I sometimes wonder if the sorts of people with the competence to get any real climate policy through also tend to have much more of an awareness of geoengineering than the general public, and that's why we're seeing so little productive energy. (Probably not though, afaict!)

Having more awareness then the general public is a very low bar. The general public doesn't know about it at all.

I would be surprised if that's the case. I remember talking with someone who did lobbying for the German energy sector. When I asked him about Thorium-Moltan-Salt reactors he didn't know what I was talking about.

It seems to me that lobbyists generally aren't the kind of people who are up to date with futuristic tech solutions. They are rather occupied with the technologies that the companies that they lobby for actually develop.

"With Solar Radiation Management techniques specifically, it is not possible to be certain of the effects on ecosystems’ biodiversity, since it will create an entirely new ecological balance (or disturbance) (Alan Robock., 2016). The energy from incoming sunlight is an essential resource for life on the planet and is closely linked, for example, to supporting the oceanic algae that produce most of the world’s oxygen"
From the book "The Big Bad Fix", 2018

In our discussion and potential actions, we should not focus only on climate-related side-effects. We should take into account risks connected to the ocean ecosystem functioning. The ocean is full of living organisms that depend on each other's functioning, and some of which depend on light. Because of this interdependence, a whole ecosystem can collapse if a certain species would be eliminated (this called "tipping point" in biodiversity discussion). The conditions for such a collapse for ocean ecosystems are yet poorly understood. But this remains a risk of successful or unsuccessful deployment of any of Solar Radiation Management techniques.

Edit: I ended up spending a bit over a day looking into geoengineering and the Copenhagen Consensus Center after writing this, so go look at my answer for a more informed take that includes what I learned from doing that. My below 2 long-form comments are not exactly wrong, but more poorly informed than that answer.


Awesome! I'd wanted to know what the actually useful geoengineering stuff was.

I do buy the claim that public support for any sort of emission control will evaporate the moment geoengineering is realised as a tolerable alternative... Major emitters have already signalled a clear lack of any real will to change. The humans will not repent. Move on. Stop waiting for humanity to be punished for its sin, act, do something that has some chance of solving the problem.

From a game theory POV, "dont pressure emitters" is basically just "surrender". In theory, "emitters who don't want to change" can and should be coerced by force, whether that's within a nation by laws (which will ultimately be enforced with force if broken), or internationally, by threat of military force that's willing to follow through. Like, that's how you'd game theoretically not lose.

In practice, fuck me if you're able to get any coordination to work.

There's a case for, "don't do geoengineering until you have an actual solid international power alliance capable of doing regulation". Because then the emissions agreements are set.

In practice, what's the actual utilitarian thing to do? Well, the main unanswered question is, how much can cloud brightening be scaled? Can it keep temperatures constant if emissions levels go 5, even 20x? Secondly, what can be done about e.g. ocean acidification and other non-warming issues? I have zero knowledge here. But if it scales that well, then throw out the game theory and just do the geoengineering.

If you're a lone EA and you're trying to use this information, presumably your options are, "do startup and try to get >$10B", and "gain control of a tiny country, boost military, start threatening emitters".

added: or "do startup, make money, then fund research".

If we could draw the borders differently, so that we had longtermist/conservationist nations and shorttermist nations, then maybe the longtermist faction could impose enough sanctions and threaten enough annexings of enough rainforest to do something. Instead we just have a bunch of moderate liberal democracies who are institutionally incapable of doing anything significant. Perhaps next year the US will have a government that would be willing to really threaten to take the amazon from Brazil, but they would have to wonder what that would would add up to, if anything, when the other guys take power again and call it off.

My hope is that this is cheap enough that a group of nations can do it without needing very much political energy.

I feel like it's only a matter of time before China decides a drought-related loss of crop productivity (we should anticipate that eventually, yeah?) is unacceptable and does MCB unilaterally, but I wish they cared enough to move now. They do seem capable of projects of this level of weirdness and scale. Like, I can't imagine they had to wait for a grass-roots political movement to emerge and start pressuring politicians to Build a Space Mirror Over Chengdu Now, The People Demand It. If the Chinese govt needed the interest of a large group of distracted, unimaginative people to get a thing like that off the ground they wouldn't be doing it, surely.

what can be done about e.g. ocean acidification and other non-warming issues?

There are proposals for ocean acidification, but the ones I heard about don't seem cheap. For carbon sequestration, I'd be very curious about the prospects of genetically engineered plants or algae. Empress trees have recently received a lot of attention for having an efficiency of 103 tonnes of carbon per acre per year.

www.projectvesta.com proposes using crushed olivine to capture carbon and reduce ocean acidification. It seems doable on a large scale and not very expensive.

Another comment claims that this would be relatively expensive.

(reason for retraction: Occurred to me that I'm not sure how this compares in cost to other carbon capture and anti deacidification measures)

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Instead we just have a bunch of moderate liberal democracies who are institutionally incapable of doing anything significant.

Awesome burn! :D

a group of nations can do it without needing very much political energy.

I mean, if your plan is "convince people or governments to do a thing" rather than "do this thing myself", you're gonna have a bad time. It's probably within the scope of an individual NGO or maybe a hella determined individual to pull this sort of thing off, no? I guess you'd have to try, and see if anyone decided it was illegal after you started!

Hey, important question: I liked your first two links at the top of this post, were there any others you found helpful in your own research? I've been meaning to do my own research on what geoengineering stuff would be effective.

Added: Ok, I spent a few hours actually reading science and looking into it. So this says the "make clouds over the ocean, so light + warmth gets reflected back into space" strategy has "the capacity to balance global warming up to the carbon dioxide-doubling point". Which is like two to fourish degrees C. Which I can't find a figure on how long that's expected to take, except we went from like 355 to 415 ppm from 1991 to 2019. So this is roughly a century of warming you'd be undoing.

Further, the MCB seems like a very solid approach. I didn't get a good quantified feeling for how big of a deal various types of non-warming climate are though. Any info there?

Note that you could (maybe) just do a fifth of the full version of Marine Cloud Brightening (MCB): spend a bit less and do it over less of the ocean, and then be like " 'oops' I'm done funding this, but wow it lowered global temperatures by 0.4 C (hopefully a statistically significant difference?), guess someone else better fund it now", and then see if anyone takes the bait, and then use the rest of your money for something else.

But overall, MCB seems... like the effect size might be enough to justify unilaterally doing it even though it's not a great game theoretic idea. I'd have to think more about that part of it, but unless I come up with something better, I'll fund it once I have a spare couple billion.

My preferred approach would be seeding political pressure. Focus on the conservatives, who will, with a little convincing, be eager to believe that there is a way to continue living as they have without anything changing. Then disarm the liberals. Then finally help Extinction Rebellion to see this thing they've been neglecting (you might think there must be some twisted reason they haven't been talking about it, I suspect their discourse is just fairly centrally controlled, I can find no evidence of it having ever been discussed in the larger exposed body of the egregore, it simply hasn't come up). Then the politicians will hear them all. The soil does seem receptive. One would think that if it were, the fruit would have already grown by now, this technology has been on the table for at least 25 years, but if the medium has not been conductive, maybe we are the part of the medium that's been failing to respond.

I found most of my info by looking through news articles after hearing Bjorn Lomborg on econtalk. I think it was a critical post on an ideologue's blog that lead to the royal society.

There's some really wild stuff down this hole. I've barely started. Stephen Salter is a key individual, worth reading his files http://www.homepages.ed.ac.uk/shs/Asilomar%20Climate%20Intervention/

Found out about the salter sink yesterday and it's fucking bananas.

I'd say: stop wanting MCB to work out so much. Don't just hope that it's gonna get approved, mate. Convincing people of stuff if fricking impossible. I think you're seriously overestimating how likely this is.

I think we are talking about $10B/year. Which is according to Scoot roughly the total yearly private philanthropy budget.

That feels outside of the reach of startup funding. Funding research and PR is likely the more promising route.

It's 750m/yr, and that's including air capture costs as well. see p3 here

Before this, the only other low-budget method of planetary cooling that I knew, was dumping sulfate aerosols in the upper atmosphere (from rocket or balloon), in imitation of volcanic eruptions and dirty coal burning. The tactics have two things in common. One is that their immediate effects are regional rather than global, the other is that their effects quickly get washed out unless you keep pumping.

Carbon dioxide disperses through the atmosphere in a relatively homogeneous way. But these much larger particles will remain concentrated at particular altitudes and latitudes. So certainly when and where they are released will need to be carefully chosen.

As for the short lifespan of the particles, again it contrasts with carbon dioxide. Once a carbon dioxide excess is created, it will sit there for decades, possibly centuries. There will be turnover due to the biological carbon cycle, but a net reduction, in the form of uptake by natural carbon sinks, is a very slow process.

The carbon dioxide sits there and traps heat, and the sulfate aerosols or water droplets only alleviate this by reflecting sunlight and thus reducing the amount of energy that gets trapped. So the moment you stop launching sulfate rockets or turn off your seawater vaporizers, the full greenhouse heat will swiftly return.

That's why extracting and sequestering atmospheric carbon is a much more permanent solution, but it is extremely energy-expensive, e.g. you can crack open certain minerals and CO2 will bond to the exposed surface, but it takes a lot of energy to mine, pulverize, and distribute enough of the resulting powder to make a difference. Some kind of nanotechnology could surely do it, but that would be a cusp-of-singularity technology anyway. So there's a reasonable chance that some of these low-cost mitigation methods will begin to be deployed, some time before singularity puts an end to the Anthropocene.

The need for ongoing maintenance is a feature not a bug given that we don't understand the actual effects in high resolution.

... public support for any sort of emission control will evaporate the moment geoengineering is realised as a tolerable alternative. Once the public believe, there will never be a quorum of voters willing to sacrifice anything of their own to reduce emissions

More precisely, public support for emission control that requires personal sacrifice. Energy efficiency measures have been estimated to cost “substantially less than the cost of meeting electricity needs with new power plants”, for example.

Relevant point, but why did you post this in the answers section?

I think a lot of good is going to be done in the course of the shift towards electrification and renewable energy that's being driven by the fact that those things are just better and more efficient than the old things, rather than any heroic public sacrifice.

For more info about that, we should consider calling in Micheal Vassar. He's been pleased to find that his long-standing prediction that solar + batteries are soon going to out-price nuclear seems to be coming true.

why did you post this in the answers section?

Oh. By accident - sorry! Ah, there is a “move to comments” button. I will press it.