A San Francisco nonprofit has published a detailed road map of experiments and infrastructure needed to make informed decisions about solar geoengineering. Scientists have spent half a century exploring the possibility of counteracting climate change by releasing reflective particles into the stratosphere, mimicking volcanic eruptions. However, big gaps remain in understanding how well it would work and what side effects it might cause. Reflective, the research organization behind the initiative, aims to equip the world with data and tools for informed decision-making. Their Sense is the world may need to make consequential decisions on timelines shorter than the research system is prepared for. If all work is done in a coordinated way, it would take about a decade and cost around 370 million dollars; if not, it would require roughly 20 years and nearly 1.4 billion dollars. The report makes the case for conducting outdoor experiments, which would release successively larger amounts of sulfur dioxide to observe effects. This is a controversial standpoint, as hundreds of academics have signed an open letter calling for a ban on outdoor experiments and an international non-use agreement, arguing the technology could never be governed in a globally equitable way. The core question, experts argue, is who would control a planet-altering technology. Since incorporating in late 2023, Reflective has quickly become an important player in the field, raising more than 20 million dollars from prominent charities and individuals and providing around 4 million to several dozen research groups.

The organization has also undertaken its own projects to promote research, including developing an open-source solar geoengineering simulator and an online hub for collaborative research. Earlier this year, Reflective released its SAI Uncertainties database, which identified a long list of scientific unknowns and engineering obstacles that would need to be addressed before any small-scale effort could move ahead.