Reflective releases solar geoengineering research roadmap, estimates $370 million cost

September 10, 2026 at 04:00 PM2 min

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San Francisco nonprofit Reflective published a roadmap of experiments and studies needed to inform decisions on solar geoengineering. The roadmap estimates coordinated research would take about a decade and cost $370 million. The report calls for outdoor experiments, a stance opposed by hundreds of academics who signed a non-use agreement.

Key Facts

Reflective, a San Francisco nonprofit, released its SAI Research Roadmap on September 10, 2026.
Coordinated research would take about a decade and cost $370 million; uncoordinated work would require 20 years and nearly $1.4 billion.
The roadmap calls for outdoor experiments releasing sulfur dioxide into the stratosphere.
Since 2002, hundreds of academics have signed an open letter calling for a ban on outdoor experiments and an international non-use agreement.
Aarti Gupta, co-initiator of the non-use initiative, argues the first-order questions are not technical but about governance.

The Roadmap

Reflective, a research organization that funds studies on solar geoengineering, published the SAI Research Roadmap to fill a gap in systematic planning. The roadmap outlines experiments, studies, and infrastructure needed to make informed decisions about stratospheric aerosol injection. Dakota Gruener, Reflective's cofounder and CEO, said the mission is to equip the world with data and tools for informed decision-making about sunlight reflection. Gruener said the world may need to make consequential decisions on timelines far shorter than the research system is prepared for.

Cost and Timeline

The report estimates coordinated research would take about a decade and cost $370 million. Uncoordinated work would require roughly 20 years and nearly $1.4 billion. The roadmap calls for outdoor experiments releasing successively larger amounts of sulfur dioxide in the stratosphere.

Opposition

Since 2002, hundreds of academics have signed an open letter calling for a ban on outdoor experiments and an international non-use agreement. Some signatories argue more studies cannot address the question of who gets to deploy solar geoengineering. Aarti Gupta, professor at Wageningen University, said the first-order questions are not technical but about governance.