https://www.politico.com/news/2026/05/15/a-closely-guarded-plan-to-cool-earth-is-revealed-00920438
By CORBIN HIAR
Excerpt: A company that aims to make billions of dollars by cooling the Earth has lifted the veil of secrecy that until now has hidden its plans for preventing sunlight from overheating the planet.
It hinges on aerosol particles that are 125 times smaller than the tiniest grain of sand.
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-U.S. startup to spray millions of tons of sunlight-reflecting aerosols into the stratosphere. Its plans were so guarded that it required scientists to sign nondisclosure agreements before they could study its potentially planet-altering technologies.
On Thursday, the company revealed the makeup of its proprietary particles. They are made of what’s known as amorphous silica and are 0.5 microns in size — only visible with a microscope. The startup also shared information about the systems it could use to disperse the spherical silica particles some 11 miles above the ground and monitor them as they fall back to the Earth.
“Our premise from the start was that the only way sunlight reflection technology would be considered by governments is if we provided robust scientifically-based solutions to all the challenges and concerns and proved it to be safe, practical, and controllable,” Stardust CEO Yanai Yedvab said in a statement. “That is the mission we took upon ourselves, and the details we are releasing today represent a major step toward that goal.”
The company is a leader in solar geoengineering — the hypothetical pursuit of altering clouds or changing other characteristics of the atmosphere in ways that would interrupt sun rays before they hit the Earth. Other ideas envision building massive sun shades in space or creating bubbly mixtures of reflective sea foam to limit the amount of heat absorbed by the oceans.
