One of the biggest challenges with technologies that reduce greenhouse gas emissions is that they require mass adoption. Solar radiation management (or SRM) has the opposite problem.
By Stardust Solutions’ estimate, dispersing three million tons of reflective particles into the stratosphere could cool the planet by 1.5 degrees Celsius for the relatively small price of $30 billion; that’s less than the cost of a single hyperscale data center.
Despite concerns about such an endeavor, the company is building a proprietary particle injection system with the goal of being deployment-ready this decade. While Stardust says they won’t deploy without the explicit authorization of multiple governments, questions nonetheless remain around the safety and ethics of SRM.
In this episode, Shayle sits down with Yanai Yedvab, CEO and co-founder of Stardust, to unpack how the technology works, its potential risks, and when to deploy it.
Shayle and Yanai discuss topics like:
- Why Stardust is eschewing sulfur dioxide in favor of naturally occurring, biodegradable amorphous silica and calcite particles
- How Stardust’s technology incorporates real-time testing
- Stardust’s commitment to only deploying under strict international regulation
- How the company balances the risk that solar geoengineering will reduce the economic incentive to decarbonize heavy industries with the imperative of an immediate climate solution
- Why Stardust structured itself as a private company rather than an academic or non-profit lab
Resources
Credits: Hosted by Shayle Kann. Produced and edited by Max Savage Levenson. Original music and engineering by Sean Marquand. Stephen Lacey is our executive editor.
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Transcript
Shayle Kann: I’m Shayle Kann. I invest in early stage companies at Energy Impact Partners. Welcome to Catalyst. So the biggest issue with the whole suite of technologies that are needed to reduce or remove global greenhouse gas emissions is that they’re kind of a collective action problem. Essentially, everybody has to act or it barely works. Solar radiation management or solar geoengineering is kind of the mirror image of that. By one estimate, dispersing about three million tons of reflective particles into the stratosphere could cool the planet by one and a half degrees Celsius for around $30 billion. One and a half degrees Celsius is a ton. And to put that in terms that we use a lot, that is less than the cost of a single hyperscale data center these days. But that number is exactly why a lot of pretty serious people are alarmed about the whole concept.
If cooling the entire planet costs what one hyperscale campus costs, this stops being something that only a coalition of governments could possibly attempt. In theory, one country could do it alone or on company or one billionaire, or dare I say trillionaire. The economist Scott Barrett called climate change a free rider problem. Everyone has to wait for somebody else to pay. Solar geoengineering, he said, is a free driver problem. It only takes one. The cheapness isn’t a footnote. It’s the whole governance question. To say nothing of all the technical questions, does it work and the side effect questions, what effects does it cause? Which is what makes my guest today unusual. Stardust is a private company building a proprietary particle in the system to put it into the stratosphere aiming to be ready this decade. They say they will not deploy without governments, plural. And the question is whether a technology this powerful and really this cheap should be built inside a company at all?
And if so, what are the guardrails we should put around it? Yanai Yedvab is the CEO and co-founder of Stardust. How the tech works, what it might cause, and who gets to decide. That’s coming up next.
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Shayle Kann: Yanai, welcome.
Yanai Yedvab: Thanks. Excited to be here.
Shayle Kann: All right. Let’s start with a walkthrough of the technology itself. What are you actually planning to do and how’s it going to work?
Yanai Yedvab: Okay. So first of all, let’s start by saying, Shayle, this is not a new concept, right? I know that you had several episodes discussing it. We didn’t invent the concept. So maybe taking one step back, I’ll walk through the concept very quickly and then what we believe is unique about our technology and our approach. So the idea essentially is to create a shielding layer. I often like to think about it kind of like the ozone layer, which is protecting air and composed of the ozone molecules and protecting us from malicious sun rays. So to add one additional layer, which we plan that will be composed by Stardust particles and will protect us from overheating by reflecting a tiny portion of incoming sunlight. Less than 1% is enough to essentially stabilize temperature and you can even take temperature down a little bit. So this is the fundamental concept and when we came across it the first time it was like four years ago, first of all, we were very curious at that time the option that people were discussing was sulfuric acid.
And the reason is that this is what volcanoes emit and whenever there is a volcanic eruption, which is powerful enough, it creates a similar effect naturally. These tiny particles go above the weather layer, create the shielding layer in this way, a stabilized temperature. I think the first question that we are asking ourselves is, can we do better? Because sulfuric acid comes with … It is known to do the effect we want to do, but it comes with a very long list of unintended consequences. It’s toxic, it induces acid rain, it impacts those on there and also the uncertainties are very high. We were asking ourselves, maybe there is a better approach. And I think that the way we looked at it is kind of I would say to look it from the end backward. We were asking ourself a question back then, which we didn’t know the answer, but let’s say we will be successful in developing this technology.
What will be questions that people like you, the policy makers, that the general public will come and ask us, right? How can we make sure that this is safe? What happens when these particles eventually fall on the ground? How sure are we that we are not solving one problem, but then bringing two or three other problems that weren’t where to begin with to the table.
Shayle Kann: Okay. So where did you land? What’s better than sulfur?
Yanai Yedvab: Yeah. So we believe there is a better solution than sulfur and essentially we came up, we designed two kinds of particles, one of them is composed of amorphous silica. Just to give you a sense, amorphous silica of the type that we’re using is used in toothpaste, is food additive, is naturally occurring. And the other one is a composite particle composed of a core of amorphous silica surrounded by a shell of calcite. Calcite is material that you can find in limestone in eggshells. So the idea was to develop particles that are composed of materials that are naturally occurring, that are known to be safe.
A few additional features that they have is that they are much better than sulfur in making sure that you don’t negatively impact the ozone layer. They are much more inert and they’re biodegradable, which means that once these particles fall on the ground, essentially they recycle back into the natural cycle becoming against structure material for these natural creatures because one of the things you want to make sure is that you don’t end up with bioaccumulation after 50 years understanding that these things piled up and you have no good way to get rid of it. So we believe that having something that naturally biodegrades is very important.
Shayle Kann: What do we know about effectiveness? Obviously we won’t know until you do it at scale entirely, but in principle, relative to sulfur, should you be able to get the same amount of reflection with more particles, less particles? How should we think about that? Yeah.
Yanai Yedvab: Yeah. So the short answer is that this is pretty similar. Our particle to be very straightforward is not much better than sulfate with respect to the effectiveness and not much worse…So up to, I’d say a few tenths of a percent, which is not … It’s kind of similar. One feature which is different in terms of the optical properties is that one of these particles, what we call this core shell particle is much better in the sense that it does not hit the stratosphere. One of the features that you have with sulfate is that…it acts itself as kind of an absorbing material to the infrared radiation that is outgoing from earth. So the reason we came with the more, I would say, sophisticated core shell particle is to avoid this phenomenon, which enables you if needed to go to a higher level of cooling.
We believe that for, I would say, to provide cooling which is comparable to the heating of the last 50 years, our simpler particle, the one which is composed of amorphous silica by itself is enough, but if you need to go higher, the second more complex particle is favorable.
Shayle Kann: Okay. So you mentioned that the reason everybody has been pursuing sulfur is because we have this natural analog, which is that volcanoes erupt and they put sulfur in the stratosphere. It has cooled the planet multiple times. There are a bunch of eruptions in history that have been measured Mount Pinatubo 35 years ago, Mount Tambora in 1815 in Indonesia, which famously resulted in Mary Shelley writing Bride of Frankenstein the following year on a summer vacation that was gloomy in Europe. But one thing I’ve always wondered about it is when I’ve heard about the stories of those volcanoes erupting and the effects that they’ve caused, the effects seem to be regional. They can be pretty big, obviously you can see an effect that crosses from one region of the world to another. But in practice for you, if you want to create this global cooling effect, do you need to be injecting at a series of locations simultaneously around the world to get the global blanket? Is that actually how it would work in practice?
Yanai Yedvab: Yes, you’re right. The short answer is that it’s preferable to, if at some point we do deployment and again, we’ll probably talk later on who decides on deployment…but you’ll probably want to do it from, I would say, more than one location exactly for the point that you’re making to get more optimal coverage. In fact, ideally, Shayle, you’d like to cancel as accurately as you can the warming effect of greenhouse gases because if you’re doing this, you are, I would say, restoring past conditions and this is a very good way to either eliminate or mitigate some of the unintended consequences. So bottom line, yeah, you don’t need many places or many points of injections. You’d probably like a few in the northern hemisphere, if you’re in the southern hemisphere, I would say two or three on each hemisphere and maybe one around the Equator should be enough.
There is another point which I think is worth mentioning, which has to do with it, one of the problems with sulfates apart from what we’ve been discussing is the fact that you cannot do testing at small scale of sulfates. And the reason for this, and this is something sometimes people overlook is the very high background that you have currently at the stratosphere, you have like few hundred thousand tons of sulfates and it’s fluctuating, which means if you think about it for a second, that the smallest scale experiment you can do is more or less one million ton, which is not an experiment, it’s deployment, right? I think one of the things which is unique about our technology is the fact that you can start very low and do this ramp up process kind of similar to how you do clinical trials with new, I would say, life saving drugs or vaccines where you start with a very small ensemble, you test for safety, you have very clear success criteria, only when you meet them, you go higher and you do it stepwise.
So I think that this is something which is critical because if you’re thinking about realistically going to whomever decision maker there will be and asking a permission to start with putting million tons of anything, let alone toxic material will be a very high bar saying we want to start low, gain confidence by collecting data and doing it stepwise seem to us as a much more reasonable approach.
Shayle Kann: That’s related to, I guess, my next question, which is I think we should head on. The reason that SRM has been controversial is that there’s a whole host of potential and somewhat unknown side effects that people are concerned about. I’m sure there are other reasons. It’s controversial too, but that seems like the one that to me is legitimate and those side effects can range from impacts on vegetation to impacts on carbon stores that we already have. Might you see some kind of a rebound effect to toxicity to weather and livestock. I mean, any number of things you can imagine if you’re doing this at scale are concerning. Which of those do you view as the biggest deal, which are the ones that we really do need to watch out for that you’re the most concerned with and relatedly, how are you planning to address and avoid those as you consider deployment? We’ll get back to what it would take to actually deploy, but what should we be worried about?
Yanai Yedvab: The short answer is all of them. I think that only if you’re able to eliminate or significantly mitigate all these side effects that you’ve mentioned and few others, this should be worth the consideration of policymakers and I’ll elaborate with your permission a little bit. We released a series of eight papers. The first one had to do exactly with the question you were asking. What is the set of requirements or what is the set of concerns you need to address in order to be able to establish the safety of this technology? And going to your list, I think it falls in three buckets. The first one you’ve mentioned toxicity, I would say more generally impacts on human health and the biosphere and there are a bunch of them. The good news about them is that we have well established criteria for other use cases and protocol on how to establish safety.
So you don’t need to invent new criteria, you can use the existing one. The second one is I would say impact on the chemistry or the composition of the stratosphere. You don’t want to deplete the ozone layer, you don’t want to end up with the stratosphere that is composed of other gases than you started with and few other considerations. And the third one as you’ve mentioned is climatic impacts and you’ve mentioned some of the impacts on crops, changes in precipitation patterns and other. We argue that in order for this technology to be seriously evaluated by policy makers, you need to make sure that you check all these boxes. And in terms of where we are in this process, as for the first bucket of human health, I would say that when you’re looking at existing regulation for other use cases, it will need to be, I would say maybe there will be changes to this use case, but it’s a good starting point to see if this is considered a safe material.
So the short answer is that yes, we are meeting this criteria. And as they were saying, these similar particles are used in a variety of use cases from tooth space to food additives and occur naturally and we went through the process formally as to the other part of essentially when you’re looking at the composition of the atmosphere, you’d like ideally an inert particle. Sulfate, by the way, is very un-inert, right? It’s very reactive. It changes with time. I would say that lab tests that we’ve done show that our particle is at a very high level of units, but definitely better than any other alternative that was provided so far. So again, there is more testing to be done, I’d say on all aspects, but definitely here you want to go from lab tests to doing tests in the field, but we feel that we are on a promising path.
With respect to climatic impacts there, you cannot do lab testing because as you said, this required large scale testing. I think that the method that we are proposing is combined of I would say three pillars. One is this clinical trial approach saying you start orders of magnitude below the level that brings any climatic or environmental effect. This is one. The other thing is the ability to monitor the particles in terms of how they move around and what are the effects they’re creating. We have developed a unique tagging technology which enable us to track in real time each batch of particles as they move across the globe. Think about it conceptually, Shayle, as similar to a constellation of satellites where we have this global dashboard and you can see how its satellite is moving around. Essentially we have this ability, we have a unique fingerprint for each batch of particles.
You’ve mentioned that there will be different injection locations. So each one of them will have a unique fingerprint or QR code that you can actually track as they move across the globe and the ability also to track the radiation balance and a few other [factors] to monitor it. And the third aspect is that we believe that we will be able to tailor the shielding layer much better than what you can do with sulfates. So the bottom line when we are discussing, we are still in the process. The testing is not done yet. We’ve just released a series of papers which essentially goes through all this process and provide all the information that we have so far for people to understand where we are in this process and the idea is to allow the scientific community to review them to do external validation, which we think is critical.
But the bottom line is that we believe that for the first time you have a foundation for what may be a safe and controllable option for solar geoengineering. This is the reason we started Stardust and again, still a lot of work to do and I would say ideally in two or three years you’ll have also three or four other entities, either universities or companies or hybrid that will develop their own option because you want to make sure that whenever governments will come to the point they’ll need to seriously consider options to stabilize temperature, they have more than one option and that they have safe options.
Shayle Kann: We’ll get back in a moment to governments and who makes decisions and the governance of this whole thing, but just before we do that, I want to talk about cost. What is your estimate as to how much it will cost to get how much of a cooling effect?
Yanai Yedvab: Yeah. So in terms of giving orders of magnitude or estimates, and we have a very detailed breakdown for every million tons of particles that will be dispersed, the cost will be roughly $10 billion and you’ll get half a degree of cooling. This is like a figure of merit of how much this will cost. By the way, we are not claiming that our technology is the cheapest. We are not competing for cost. We believe that you may get with sulfur, I would say a little bit cheaper price. We argue that it’s much more important that technology is exactly as you were saying, will be safe and we see very low side effects. It’s much more important than whether it costs $10 billion or 8 or $7 billion.
Shayle Kann: I mean, there’s an argument that you could be an order of magnitude more expensive and it wouldn’t really matter, right? Just in the context of what, if we are going to need to solve climate change, any other intervention, whether it’s decarbonizing, whether it’s carbon removal, if you’re trying to get a half a degree of Celsius of cooling effect, it’s going to be at least an order of magnitude more than that. And I mean, to be fair, that is annual, right? Like you would have to do that annually.
Yanai Yedvab: This is annual. Right. Essentially, just to give you another … First of all, I couldn’t agree more: essentially at the current level to stabilize temperature, to stop warming at the current level. And again, the level is changing all the time, but essentially you’ll need, I would say two million tons of our particles, just to give you –
Shayle Kann: $20 billion, plus or minus.
Yanai Yedvab: Yeah. And again, you want to say you want more cooling, but again, this would be for government, but this gives you the orders of magnitude. It’s like a small thing. I agree with you: cost is not the prime concern here.
Shayle Kann: Yeah. Okay. So then let’s talk about governance. The double edged sword of solar geoengineering is that it is so cheap in principle, which means that there is some risk that anyone could do it. Any government, any very wealthy individual possibly … The challenge with this is you have this tragedy of the commons thing. How do you think the governance should proceed? Who should dictate whether you are able to both test and as you said, you’re going to try to test in a manner that is responsible and starts at small scale, et cetera. But so who should be setting your path first of all and second of all, who should be determining whether we inject at the million ton scale at some point?
Yanai Yedvab: Yeah. The short answer for both is governments in plural. I think that all decision making exactly as you’re saying, both with respect to the R&D and testing phase and with respect to deployment should be done by governments. I don’t believe there is any other way this could work. We would definitely not participate in any endeavor that won’t be conducted under, I would say, clear and strict regulation and adequate governance by governments. This is stated at their website. I keep saying it every interview, our investors are aligned with this. This is a very … As much as it is important to us to develop a safe technology, it is important to us to make sure that this will be done the right way. By the way, I think it’s also the prudent way to run this company, but also on the value perspective, I think this is the right way to do it.
I want to mention something short with respect to the beginning of your question saying it’s very cheap, not anyone, but many players can do it. I’d say there are many ways you can deploy this technology the wrong way. We started startups because we believed that governments need good options, right? If you want to start dispersing toxic material in the sky, you don’t need status, you don’t need all the sophistication, you don’t need governance.
I believe that having a safe option essentially lowers the risk that people will go the wrong way because there is an alternative. Or to say it otherwise, if we didn’t have options, I would say that the likelihood that someone would go the wrong way would be much higher.
Shayle Kann: You said plural governments, that seems obviously correct to me as well. Is there an obvious governing body? Is this a UN sub body or something like that? Does something new need to be spun up? What are we actually talking about?
Yanai Yedvab: Yeah. So a couple of comments. One is I’m not sure what this government body should be. I will say also that it’s not our … We are technology enablers, right? It’s our role to educate policymakers to push them to build this regulatory framework, but we should be very careful not to try to shape it one way or the other because this will be something which will be bad for any number of reasons. I would say, again, we’re speaking to policymakers in the US, in Europe, in our region, in other places of the world, but eventually I’ll say, Shayle for this to work, it should be an all ends effort and our role is to develop the best technology we can to provide the toolkit to provide the information. Other smart people or smarter people need to figure this out. I will say that there are good precedents that you can look up to.
One of the precedents, which I think is very relevant is the way the world dealt with another global environmental problem, which was all in the other layer back in the late 80s- Montreal protocol.
Shayle Kann: I was just thinking about that as well.
Yanai Yedvab: Exactly. Which by the way, it was a US-led process. Not everyone knows it. It was essentially a nexus of the US Academy obviously discovering the problem and researching it, US industry developing the substitute was Dupont at that case and the US government which within three or four years was able to consolidate this multilateral coalition, which eventually as you were saying, signed the Montreal Protocol, which on one hand bend the use of these malicious refrigerator gas, but at the same time put criteria to your question about governance for what should be an adequate substitute.
Shayle Kann: Yeah, I think that is the obvious analog. Unfortunately, that also has been the obvious analog for all of the other climate change efforts that we’ve seen. The Q&A protocol was sort of like a next generation Montreal protocol as well. I think that one, though it hasn’t been entirely unsuccessful, clearly hasn’t done the trick, hence the need to have the conversation about solar geoengineering in the first place, but that does seem right to me if you get recognition, broad recognition of the need, then something like that has to be the answer.
Yanai Yedvab: An again, not trying to dictate anything or trying to, but I would assume that it will start from, I would say, individual governments starting to look into this technology, starting to evaluate technologies and then hopefully kind of similar to what happened back in the late ’80s, something will come out in terms of consolidation. But I believe that I would guess that in the near future you’ll start seeing different governments starting to ask themselves, “Okay, so what are the pros and the cons of this technology we should get better in terms of understanding?” And as I was saying, also start thinking seriously, how do we regulate first of all the R&D and the testing and then think about the next stages?
Shayle Kann: How do you address the concern that I know some people have, which is if we start to seriously pursue solar geoengineering, even from an R&D perspective and it becomes increasingly clear that it is possible and that the costs are roughly what we think that they will be, that it creates sort of a disincentive to take the other actions to decarbonize that are necessary. Why would we figure out a new way to make steel or cement if we could just get a half a degree of cooling for $10 billion? How do you frame that?
Yanai Yedvab: First of all, I think it’s a very valid concern, to state it out loud and clear. This is the moral hazard: if we do this, the incentive to do other things goes down. I will add to this, there is also a moral imperative. The moral imperative and I want to balance both concepts, but the moral imperative essentially says, how do I make sure that if governments need to evaluate options, say in five or 10 years, they have good options on the table. And you need to balance these two. This is the real world. You need to deal with the moral asset. I’m not saying it’s an easy problem. I know that people are working on ideas, providing technology only to governments who are actually following emission reduction goals or other options of combining the two technologies one way or the other in a bucket.
But I would say you always need to … It’s always a game of alternatives and you need to balance this moral hazard which is a serious concern with the moral imperative, making sure you know that when our kids are at our age, they have a world which is more or less as good as the one we got from our parents. I would argue that having no option is not a good balance for this. You need to have options. You want to make sure that you are not stuck in a position that in 10 years from now, people are saying, “Why no one worked on giving us options?” And at the same time, I believe that the governments and regulators and NGOs as they were saying, this is an all-hands effort. [We] need to find ways to balance also the risks of moral hazard.
Shayle Kann: All right. Final question for you, one that I’m sure you’ve gotten many times. Why is this a company or why should this be a company? You could imagine pursuing the exact same path you’re pursuing right now via a university or a nonprofit or a government lab or something like that. Why do it as a private commercial enterprise?
Yanai Yedvab: So first of all, when people started working on this concept, they started doing basic research in academia. This is how it always works. This is how it works in medicine. This is how it worked in genome sequencing. Everything starts with basic research in academia. However, when you’re moving past this stage to the point that you need to actually build systems and develop technologies and again, all these precedents are relevant with life-saving drugs, with genome sequencing with space then you combine academy and private sector. And the reason for this is that there are two things the private sector is doing better. One is the ability to pull resources. The other one is the ability to incentivize top talent to work on this problem. And to me, it’s like asking why the COVID vaccine was developed by Moderna and BeyondTech. It started with basic research. It always starts with basic research, but when you’re working on a very multidisciplinary project and you need to build technology, the way it usually works is that the party which is developing the technology are companies.
And again, there is a major role definitely for academia, for a non-for-profit to do advocacy, to do education and eventually for governments. All of them need to work together, but developing technology, not bad, developing technology is something that usually companies do.
Shayle Kann: This was fascinating. Thank you so much for the time.
Yanai Yedvab: Thanks a lot. Really enjoyed it.
Shayle Kann: Yanai Yedvab is the CEO and co-founder of Stardust. This show is a production of Latitude Media. You can head over to latitudemedia.com for links to today’s topics. This episode is produced by Max Savage Levenson, mixing and theme song by Sean Marquand. Anne Bailey edits the video version of the show. Stephen Lacey is our executive editor. I’m Shayle Kann, and this is Catalyst.
