A closely guarded plan to cool Earth is revealed

Key Points:

• Stardust Solutions, an Israeli-U.S. startup, revealed its plans to combat global warming by spraying microscopic amorphous silica aerosol particles into the stratosphere to reflect sunlight and cool the Earth, having raised $75 million since 2023.
• The company disclosed details about its particles, which are 0.5 microns in size and made to be bio-safe and recyclable into natural cycles, along with its proposed dispersion and monitoring systems, aiming to prove the technology is safe, practical, and controllable.
• Solar geoengineering, including Stardust's approach, is controversial because it does not address the root cause of climate change—fossil fuel emissions—and would require ongoing deployment until emissions are drastically reduced globally.
• Stardust’s plans depend on international cooperation, especially from the U.S. and China, whose support or tacit acceptance is considered crucial for deployment, though the company states the timing of its announcement was unrelated to recent U.S.-China summit talks.
• Critics caution against allowing a private company to self-govern such impactful technology, calling for independent, coordinated research governance to ensure ethical standards and prevent misuse amid fraying international cooperation.