"Limiting the risks of severe climate change requires swift and deep reductions in emissions of heat-trapping gases, safe and sustainable removal of carbon dioxide from the atmosphere, and accelerated investments to prepare for unavoidable impacts. It is possible, however, that these essential measures may not be enough to avoid substantial climate disruption. Should societies also assess the potential and risks of using solar geoengineering (SG) technologies to rapidly cool Earth? SG presents profound environmental, ethical, and geopolitical risks and uncertainties. With some researchers now designing atmospheric experiments to assess SG’s efficacy and risks, the question of whether and how such research should proceed deserves timely public scrutiny and debate. Researchers and research funders must build inclusive public participation into decisionmaking concerning SG research."