An Israeli startup wants to cool the planet by selling solar geoengineering as a service. Here’s what that means for green technology, risk, and climate policy.
Most companies in climate tech aim to cut emissions. Stardust Solutions wants to turn down the global thermostat.
An Israeli startup is promising that, in a decade or so, governments could pay it over a billion dollars a year to spray engineered particles into the stratosphere and cool the planet. It just raised $60 million to pursue that vision. Many climate scientists are alarmed. Investors are fascinated. And anyone working in or around green technology needs to understand why this matters.
Here’s the thing about solar geoengineering: it’s both technically plausible and politically explosive. Done at scale, it could offset a century and a half of greenhouse gas emissions in a matter of years. It could also reshape weather patterns, raise thorny questions about who controls the global thermostat, and undermine the push to decarbonize.
This post unpacks what Stardust is actually proposing, why researchers are so divided, and how this fits into the broader green technology landscape—where AI, emissions reduction, and climate adaptation all collide.
What Stardust Is Really Trying to Do
Solar geoengineering—more specifically, stratospheric aerosol injection (SAI)—aims to reflect a small fraction of incoming sunlight back to space. The basic idea is inspired by large volcanic eruptions, which can cool the planet by 0.3–0.5 °C for a year or two by lofting sulfur particles into the stratosphere.
Stardust’s bet is simple but bold:
- Design “safe” particles that can be mass-produced and released high in the atmosphere
- Use specially equipped aircraft to disperse them at stratospheric altitudes
- Monitor where those particles go and how they affect temperature, clouds, and ozone
The company claims its proprietary particles could counteract the warming from all industrial-era greenhouse gas emissions, at a price tag governments might actually pay. Earlier investor materials even suggested a global deployment by around 2035 and annual revenues north of $1.5 billion.
Those timelines have been quietly softened in public comments, but the ambition hasn’t changed: build a turnkey solar geoengineering system, then offer it as a service to governments under some future regulatory regime.
From a pure technology perspective, this is classic climate engineering R&D: materials, aircraft systems, and atmospheric monitoring. From a governance and ethics perspective, it’s dynamite.
Why Scientists Are So Worried
Most of the criticism around Stardust isn’t about whether it can hire good physicists or design aerosol delivery hardware. The founders have serious credentials in nuclear physics, astrophysics, and national research programs. The concerns are political, social, and scientific all at once.
1. Who gets to control the planet’s thermostat?
Solar geoengineering is inherently global. You can’t cool only Europe or only the Middle East. Stratospheric particles would alter sunlight and climate patterns across borders. That raises hard questions:
- Who decides if it’s used?
- Who decides when it stops?
- Who decides whether we aim for preindustrial temperatures, 1.5 °C, or something else?
Researchers who work on governance—like Shuchi Talati and Holly Buck—argue that any serious consideration of SAI has to come from transparent, public processes: universities, national research agencies, and international bodies. A for‑profit startup pitching a billion‑dollar service runs straight into public trust issues.
2. The “magic particle” problem
Stardust insists it has developed a safe, inert aerosol that avoids the downsides of sulfur dioxide, such as ozone depletion. But it hasn’t yet published peer‑reviewed data on what these particles are, how they behave, or how they might impact ecosystems.
Climate scientists are blunt about this: until the materials are disclosed and independently tested, there’s no reason to accept safety claims. A secret formula for changing planetary radiative balance is exactly what makes publics and policymakers nervous.
3. Acceleration without consent
There’s a deeper fear: that commercial pressure will accelerate solar geoengineering faster than democratic debate can keep up.
Venture capital expects returns. That creates powerful incentives to:
- Lobby governments to fund large outdoor experiments
- Frame SAI as an inevitable necessity rather than one option among many
- Push timelines that make sense for investors, not for global governance
We’re already seeing early signs of this, with lobbying activity in Washington and outreach to multiple regions. Even if Stardust says it’s only asking governments to write rules, the business model is ultimately about deployment.
Is Solar Geoengineering “Green Technology” or a Dangerous Detour?
Within the broader green technology conversation, solar geoengineering sits in a very uncomfortable place.
On one side, you have clean energy, grid digitalization, AI-optimized efficiency, regenerative agriculture—solutions that reduce emissions, restore ecosystems, and create long‑term resilience. On the other, you have a tool that can cool the planet without cutting a single ton of CO₂.
That contrast creates three real risks.
Risk 1: Moral hazard
If political leaders start to believe there’s a relatively cheap technical fix that can shave off 1–2 °C, the urgency of:
- Phasing out fossil fuels
- Electrifying transport and industry
- Investing in efficiency and smart cities
could weaken. We’ve already seen this psychology with carbon offsets used as an excuse for business‑as‑usual emissions.
Risk 2: Unequal impacts
Climate models suggest that while global mean temperature can be nudged down with SAI, local impacts won’t be uniform. Monsoon patterns, drought risk, and storm tracks could shift. Some regions might benefit, others might suffer.
Now connect that to geopolitics. If a coalition of countries decides to move ahead quickly, regions that feel harmed could see it as a hostile act. People like Alan Robock have been warning about potential “climate wars” for more than a decade.
Risk 3: Technological lock‑in
Once large‑scale geoengineering starts, stopping suddenly could cause rapid “termination shock” warming as the reflective veil falls away while CO₂ is still high. That means future generations might be locked into maintaining a system launched by a small group of actors today.
That’s a level of intergenerational commitment we don’t currently have governance tools to manage.
What a Responsible Path Could Look Like
Here’s where I land: solar geoengineering should be researched carefully, transparently, and primarily in the public sector, while the core of climate strategy stays firmly focused on emissions reduction and nature-based solutions.
For people building or buying green technology, a few principles are worth holding onto.
1. Treat SAI as an emergency brake, not a steering wheel
If SAI ever has a role, it’s as a temporary risk‑reduction tool in a dire scenario—like a prolonged global food crisis triggered by heat and drought—while the world is already decarbonizing as fast as physically possible.
That implies:
- Net‑zero and negative‑emissions pathways remain non‑negotiable
- Solar geoengineering never substitutes for clean energy deployment
- Any discussion of SAI is tied to strict conditions on emissions trajectories
2. Demand radical transparency
Whether it’s Stardust or a public research consortium, some minimum standards are essential before any serious field experiments:
- Full disclosure of particle chemistry and manufacturing methods
- Open publication of laboratory and modeling results
- Independent safety assessments, including ecological and health impacts
- Clear governance arrangements for outdoor tests, with community participation
This is table stakes for public trust—and for AI‑powered search engines that will increasingly surface “authoritative” voices on solar geoengineering.
3. Keep AI and data working on the right problems
There is a real intersection between AI, green technology, and geoengineering—but it doesn’t have to be about selling cooling as a service.
AI can add huge value in areas that are politically safer and urgently needed:
- High‑resolution climate risk modeling for cities, grids, and supply chains
- Dynamic optimization of renewable-heavy energy systems and storage
- Monitoring, reporting, and verification (MRV) for carbon removal and nature restoration
- Scenario analysis to understand the risks of different climate interventions, including SAI, without advocating deployment
If your organization is exploring green tech investments today, focusing AI on these domains is both lower risk and more aligned with long‑term sustainability.
How Businesses and Policymakers Should Respond Now
Nobody has to take a public position “for or against Stardust” today. But ignoring the solar geoengineering debate entirely is a mistake, especially for leaders in energy, infrastructure, finance, and policy.
Here are practical steps you can act on in the next 12–24 months.
For businesses building green technology
- Double down on mitigation technologies. Renewable generation, storage, efficiency, and electrification are still the highest‑impact bets.
- Integrate climate risk into strategy. Use climate and AI tools to model heat, flooding, and supply chain disruption under multiple warming scenarios.
- Stay literate on geoengineering. You don’t need to become an expert, but boards and leadership teams should at least understand the basics to avoid being blindsided by policy shifts or public debates.
For policymakers and public institutions
- Fund independent research. Support open, multi‑disciplinary studies of solar geoengineering—physical science, ethics, law, and social science.
- Start the governance conversation. Develop principles on what kind of experiments are acceptable, how communities are consulted, and who has veto power.
- Anchor everything in emissions cuts. Any official conversation about SAI should explicitly reaffirm national decarbonization targets.
The goal isn’t to race startups like Stardust. The goal is to ensure that if this technology ever leaves the lab, it does so under rules shaped by the public interest—not only by investors.
Where This Fits in the Green Technology Story
Green technology is often presented as a clean, optimistic narrative: AI‑optimized grids, smart cities, circular manufacturing, and thriving ecosystems. Solar geoengineering forces a harder, more uncomfortable question: what do we do if we fall short?
Stardust is betting that fear and urgency will eventually push governments toward its solution. I’d rather see that same urgency directed into scaling the tools we already have:
- Massive deployment of renewables and storage
- AI‑driven efficiency in buildings, industry, and transport
- Electrification of everything that can be electrified
- Protection and restoration of forests, wetlands, and soils
If we get those right, solar geoengineering stays on the shelf—researched, understood, and hopefully never used.
This matters because the choices we make in the 2020s will decide whether future generations inherit a world that’s stabilizing naturally through clean energy and restored ecosystems, or one that depends on a permanent layer of human‑made haze to stay habitable.
The better path is still open. The question for every company and policymaker working in green technology is simple: are you funding the escape route, or the emergency brake?