This road map could help us decide whether to deploy solar geoengineering

A San Francisco-based nonprofit called Reflective has unveiled a comprehensive roadmap for solar geoengineering research and experimentation. Solar geoengineering involves releasing reflective particles into the stratosphere to counteract climate change, but significant gaps remain in our scientific understanding of the potential impacts and governance challenges.

Reflective aims to provide the necessary data and tools for informed decision-making, with the hope of accelerating research and ensuring responsible progress. The roadmap estimates that a coordinated effort would take about ten years and cost around $370 million, while an ad-hoc approach could take roughly 20 years and nearly $1.4 billion.

Reflective suggests conducting outdoor experiments to release increasing amounts of sulfur dioxide into the stratosphere for scientific observation. However, this approach is controversial, as over 300 scientists have signed a letter calling for a ban on such experiments, citing concerns about global inequity and control of a planet-altering technology.

Reflective acknowledges the controversy but emphasizes the need for high-priority research to address the uncertainties surrounding solar geoengineering. The roadmap outlines three stages: foundational knowledge, technology development, and monitoring. The first stage focuses on computer simulations and lab experiments to understand potential impacts on various regions, ecosystems, and phenomena.

The second stage involves releasing sulfur dioxide using modified aircraft, with the goal of reducing uncertainty about the cooling efficacy of solar geoengineering by approximately 66%. The final stage would be ongoing monitoring of full-scale solar geoengineering if the world proceeds with its implementation.