Stardust Solutions Has Raised $75 Million, Led By Former Israeli Nuclear Programme Physicists, And Wants $1.5 Billion In Annual Revenue By 2035 But The World Has No Framework To Govern What It Is Planning
According to Politico, a company called Stardust Solutions has lifted the veil of secrecy that until now has hidden its plan to spray millions of tons of sunlight-reflecting aerosols into the stratosphere; particles that are 125 times smaller than the tiniest grain of sand.
Stardust Solutions had been so guarded about its technology that it required scientists to sign non-disclosure agreements before they could even study the potentially planet-altering material.
What Stardust Solutions is proposing is not science fiction. Solar geoengineering, also referred to as solar radiation modification, includes several proposed methods to reflect sunlight back into space. Stratospheric aerosol injection adds aerosols high above Earth in the stratosphere using balloons or aircraft, attempting to cool the Earth at a global scale, mimicking the temporary cooling effect of some major volcanic eruptions.
The 1783 eruption of Iceland’s Laki volcano sent millions of tons of sulphur into the sky, dimming sunlight and cooling the planet for years. Stardust Solutions hopes to replicate that effect deliberately, precisely, and at commercial scale. The difference between that eruption and what Stardust Solutions is proposing is that nobody elected Laki.
Stardust Solutions is developing two types of amorphous silica-based particles. One is described as “fully bio-safe, manufacturable at scale today, and at a very advanced stage of validation.” A second version includes a calcium carbonate core that would more effectively block solar radiation.
Both designs are, according to Stardust Solutions, intentionally engineered to recycle into existing natural cycles after they settle to the ground. Amorphous silica is a food additive. Calcium carbonate is what you find in eggshells and limestone. Stardust has positioned this framing deliberately. It wants the public to understand its particles as benign, familiar materials, not experimental atmospheric chemicals.
The scale of what Stardust Solutions envisions is extraordinary. The company estimates that a starting project to begin cooling the atmosphere could cost around $10 billion, requiring some 10 million tons of particles dispersed over several years, with the stated aim of cooling the atmosphere by 1.5 degrees Celsius.
The company has previously pitched investors on “global full-scale deployment” as soon as 2035, with expected annual revenues of around $1.5 billion. That number deserves to be read again slowly. A private company led by former Israeli nuclear programme physicists is planning to earn $1.5 billion annually by modifying the atmosphere of the entire planet.
Stardust Solutions has raised $75 million since 2023 from investors who are betting that global warming could get so out of control that governments might decide to pay the Israeli-American startup to spray its aerosols into the stratosphere.
The $60 million round in 2025 was the largest-ever fundraising round for any company in the sector, led by Lowercarbon Capital and joined by the Agnelli family and former Facebook executive Matt Cohler.
What these investors are betting on is not that geoengineering will work safely. They are betting that the climate crisis will become severe enough that governments will run out of alternatives.
The scientific community’s response has been divided but predominantly cautious. David Keith, a professor at the University of Chicago and a leading voice in geoengineering research, stated bluntly: “Claims of an inert stratospheric particle are nonsense.” More than 600 scientists and academics have called for an international ban on such projects, while Tennessee and Florida have already banned geoengineering outright.
The US Government Accountability Office has identified potentially harmful effects including increased air pollution, damage to the ozone layer, and changes in rain and snowfall patterns, with other detrimental effects still unidentified.
The governance question is where the deepest problems lie. Shuchi Talati, executive director of the Alliance for Just Deliberation on Solar Geoengineering, was direct: “This announcement is a clear example of why self governance led by for-profit entities does not work.
They cannot create their own principles and then applaud themselves for following them. They cannot define safety according to their own standards and then self-certify that they meet them.”
Hannah Safford, a former White House climate policy adviser now at the Federation of American Scientists, added: “It rarely works out well when those who develop globally significant technology are also in charge of governing it. In the United States, government has shown more interest in banning climate science than in thoughtfully governing emerging technology.”
Efforts to establish international rules have so far faltered. The UN Convention on Biological Diversity has a non-binding moratorium. The US is not a signatory. A Swiss proposal for an expert group at the UN Environment Assembly failed to advance. There is no comprehensive global framework.
Prakash Kashwan, a professor of environmental studies at Brandeis University, has warned that solar geoengineering could alter weather patterns, impacting food production and economies, particularly for the two billion people in South Asia, East Africa, and Latin America who depend on annual monsoons for their crops.
The profound inequity of this technology is the most important thing about it. The people most exposed to the risks of geoengineering; equatorial nations, monsoon-dependent populations, the Global South are the same people who would have the least say over whether it is deployed.
Geoengineering is unlike other responses to climate change because, while it can theoretically reduce warming, it does not address the root cause: the burning of fossil fuels. That means the world would be effectively hooked on solar geoengineering until nations reduce their use of oil, gas and coal to safe levels.
This is the termination shock problem, which scientists have discussed for years. If geoengineering begins and is then suddenly stopped because the company goes bankrupt, because a government withdraws permission, because of a geopolitical crisis, global temperatures could surge catastrophically in a matter of years, faster than any ecosystem could adapt to.
Stardust Solutions is doing something genuinely important by publishing its research. Secrecy around planetary-scale technology serves no one. But publication is not governance. A 14-page voluntary code of conduct written by the company itself is not regulation. And $75 million in private funding from venture capitalists is not a democratic mandate to alter the chemistry of the Earth’s stratosphere.
The question this story forces is one that no one in power is currently equipped to answer: who gets to decide whether humanity dims the sun?
To check out our previous coverage on climate science and global environmental developments, read our articles here.
