Jul 1, 2026 · 38m · catalyst
Inside the most sophisticated plan for solar geoengineering
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gold bands on the timeline = statements, start to end. Hover to read, click to jump. CC turns on captions
In this episode of Catalyst, Shayle Kann interviews Stardust CEO Yanai Yedvab about the company's engineering of proprietary reflective particles for solar geoengineering. They discuss the technical design, economic feasibility, governance frameworks, and ethical dilemmas of using private-sector innovation to cool the planet.
How this conversation actually went
Every chapter scored 0–10 on four independent dynamics. Hover any point for the reasoning behind the score. Shayle holds 21.6% of the talking time here. How this is scored →
Shayle as informed peer 5.0 Guest teaching 4.6 Guest disagreement 0.6 Shayle pushing back 2.1
speaking balance: gold is Shayle, purple is the guest (3 minute bins)
Sharpest disagreement ▶ 33:55 Reframing moral hazard as moral imperative
The guest directly counters the common framing that solar geoengineering research encourages moral hazard by asserting a countervailing moral imperative to ensure future generations have emergency tools.
Hardest push from Shayle ▶ 31:52 Host pushes back on Montreal Protocol analogyThe host pushes back against the guest's optimistic regulatory analogy by noting that the Kyoto Protocol followed the same model but failed to solve climate emissions.
Biggest teaching moment ▶ 12:35 Explaining sulfate testing constraints and clinical methodologyThe guest educates the host on the physics of high natural sulfate background levels in the stratosphere, explaining why small-scale sulfate testing is impossible and requires an alternative particle approach.
Shayle holds their own ▶ 10:42 Host cites historical volcanic analogsThe host displays extensive context by citing historical volcanic events like Mount Pinatubo and Mount Tambora to probe the mechanics of localized vs global stratospheric distribution.
the scores for every segment, with the reasoning behind each
| Chapter | Topic | Shayle as informed peer | Guest teaching | Guest disagreement | Shayle pushing back | Why |
|---|---|---|---|---|---|---|
| Commercial Break: Bloom Energy, Engie, Energy Hub | 4 | 5 | 0 | 1 | After an opening sponsor block, the host invites an overview of Stardust's technology. The guest explains how their engineered amorphous silica and core-shell calcite particles overcome the toxicity and stratospheric heating limitations of traditional sulfur. | |
| Injection Strategy and Small-Scale Clinical Trial Methodology | 6 | 6 | 0 | 2 | The host demonstrates domain knowledge by referencing volcanic analogs like Mount Pinatubo and Tambora to question injection distribution. The guest educates the host on why sulfates cannot be tested at small scale due to background noise while their particle allows clinical trial style ramp-ups. | |
| Addressing Environmental Risks and Particle Tracking Systems | 5 | 5 | 0 | 2 | The host presses on the legitimate controversy around ecological side effects, toxicity, and rebound risks. The guest systematically breaks the risk framework into three buckets and details their proprietary particle tagging tracking system. | |
| Commercial Break: Mid-Roll Sponsorships | 5 | 3 | 0 | 1 | Following mid-roll ads, the host drills into the unit economics of cooling. Both agree that at ten billion dollars per half degree Celsius, cost is negligible compared to traditional decarbonization or carbon removal interventions. | |
| Governance, Regulation, and the Montreal Protocol Analogy | 6 | 4 | 1 | 4 | The host probes who gets to govern deployment and challenges the guest's optimistic Montreal Protocol analogy by citing the failure of the Kyoto Protocol. The guest insists that governance must be multilateral and state-led rather than private. | |
| The Moral Hazard vs. Moral Imperative Debate | 5 | 5 | 2 | 3 | The host raises the moral hazard argument that cheap geoengineering creates a disincentive for industrial decarbonization. The guest reframes the issue by balancing moral hazard against the moral imperative of developing safe, tested options for future decision-makers. | |
| The Role of Private Enterprise in Climate Tech | 4 | 4 | 1 | 2 | The host questions why this research is housed in a venture-backed commercial company rather than an academic institution. The guest justifies private enterprise by drawing analogies to biotechnology and vaccine development where scale and talent incentives are essential. |
Statements from this episode (12)
Yedvab: Reflecting under 1% of sunlight stabilizes global temperatures
“Less than one percent is enough to essentially stabilize temperature, and you can even take temperature down a little bit.”
Yedvab: Stardust particles match sulfate cooling effectiveness within tens of percent
“Our article, to be very, very straightforward, is not much better than sulfate with respect to the effectiveness and not much worse than sulfate.
So up to, I'd say,
A few tens of percents, which is not a, it's kind of similar.”
Yedvab: Stardust silica particles can offset 50 years of global warming
“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 partic…”
Yedvab: Global solar geoengineering requires only five to seven injection locations
“You'd probably like a few in the, a northern hemisphere, a few in the southern hemisphere. I would say two or three on each hemisphere, and maybe one around the equator. Should be enough.”
Yedvab: Background stratospheric levels make small-scale sulfate testing impossible
“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, since this is something sometimes people overlook, is the very high background that you have c…”
Yedvab: Stardust lab tests show its particle is highly chemically inert
“Lab tests that we've done show that our particle is, I'd say, at a very high level of inertness, but definitely better than any other alternative that it was provided so far.”
Yedvab: Stardust developed tagging technology to track particle batches globally
“We have developed a unique tagging technology which enables us to track in real time each batch of particles as they move across the globe.”
Yedvab: 0.5 degrees of cooling costs $10 billion using Stardust particles
“So in, 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 ten billion dollars, and you'll get half a degree of cooling.”
Yedvab: Halting global warming would cost $20 billion annually using Stardust
“Essentially at current level to stop war, to stabilize temperature, to stop warming at the current level, and again, the level is changing all the time, but essentially you'll need Well, let's say you'd say two million tons of our particles, just to give you- …”
Yedvab: Stardust will only operate under strict multilateral government regulation
“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.”
Yedvab: Safe geoengineering alternatives reduce the risk of rogue deployments
“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 m…”
Yedvab: Having no geoengineering options is worse than moral hazard risk
“I would argue that, you know, 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, on giving us option?”