The Race to Refreeze the Planet: Private Startups Push Solar Geoengineering Forward

Key Developments

Stardust Solutions, a US-Israeli startup, has engineered a novel particle for solar geoengineering and is preparing for outdoor testing—while calling for government regulation of the field. The company has raised a staggering $106 million, a sum that exceeds the entire global budget for solar radiation management (SRM) research.

Meanwhile, Make Sunsets, a rival startup, is already operational. The company sells "cooling credits" by releasing sulfur dioxide balloons from U.S. soil, claiming each $2 credit offsets one tonne of CO₂.

"If Stardust's particles are proven safer, we will adopt them. Otherwise, we will continue using sulfur dioxide without waiting for government approval."
— Luke Iseman, CEO of Make Sunsets

A Regulatory Vacuum

The world currently has no international regulatory framework for SRM. While the European Parliament and African Union have called for bans, no specific regulations have been developed.

Mexico took unilateral action in 2023, banning SRM within its borders after Make Sunsets launched balloons without permission.

India's NITI Aayog has become the first Asian government body to outline plans for regulating SRM, specifically citing risks to the country's critical monsoon rains.

The Science of Sun-Dimming

SRM technology mimics the cooling effect of major volcanic eruptions. When Mount Pinatubo erupted in 1991, it released millions of tons of sulfur dioxide into the stratosphere, cooling the planet by 0.5°C for two years.

The technology does not remove greenhouse gases and requires continuous, indefinite replenishment to maintain its effect.

Voices from the Global South

Andy Parker, an NGO leader, frames the dilemma starkly:

"Developing countries face climate risks whether SRM is used or not. Decisions will be made in geopolitics, not universities."

Vaibhav Chaturvedi of the Council on Energy, Environment and Water (CEEW) warns of specific dangers for India:

"SRM could significantly affect Indian monsoons, with potential catastrophic impacts on agriculture-dependent livelihoods."

Governance Concerns

Shuchi Talati, a policy researcher, criticized Stardust's approach, citing fundamental conflicts of interest:

"The company lacks transparency and has profit incentives that would benefit from indefinite SRM deployment."

Industry Responses

Stardust CEO Yanai Yedvab maintains a cooperative stance: "We will engage with global policymakers, including India and Australia, and seek regulation before outdoor testing."

The coming months will reveal whether private capital or public governance leads the world's most controversial climate intervention.