A San Francisco-based nonprofit called Reflective has released a detailed plan outlining the steps needed to study solar geoengineering, a controversial climate intervention strategy. According to MIT Technology Review, the plan, called the SAI Research Roadmap, maps out the experiments, studies, and infrastructure required to better understand the potential of stratospheric aerosol injection (SAI), a method that involves releasing reflective particles into the stratosphere to mimic the cooling effects of volcanic eruptions. Scientists have been exploring this concept for over 50 years, but major uncertainties remain about its effectiveness and risks. Reflective's roadmap aims to guide future research and encourage funding for high-priority studies, with the goal of "responsibly accelerating" scientific understanding, according to Dakota Gruener, the organization's co-founder and CEO. The report estimates that if research efforts are well-coordinated, it could take about a decade and cost around $370 million. Without coordination, it could take up to 20 years and nearly $1.4 billion. Reflective does not advocate for the deployment of SAI but supports controlled outdoor experiments that would release sulfur dioxide or related materials into the stratosphere to observe their effects. Since 2002, hundreds of scientists have signed an open letter calling for a ban on such experiments and an "international non-use agreement." They argue that solar geoengineering could never be governed fairly, given the global scale of its potential impacts. Aarti Gupta, co-initiator of the non-use initiative, emphasizes that the central issue is who would control a technology capable of altering the planet's climate. Despite these concerns, Reflective has raised over $20 million and funded around $4 million in research, while also developing tools like an open-source simulator and an online hub for collaborative study. The roadmap outlines a phased approach to research, starting with computer models and lab experiments, followed by small-scale outdoor trials. The first phase would last two to three years and cost between $30 million and $75 million. A later phase would involve releasing 10 metric tons of sulfur dioxide into the stratosphere four times over two seasons, costing $70 million to $150 million. This could reduce uncertainty about cooling effectiveness by 25%. Subsequent phases would involve larger releases, aiming to decrease uncertainty further, with the final stage focusing on long-term monitoring if SAI were ever deployed. Gruener notes that the roadmap is a "Version 1" meant to spark discussion and includes safeguards to halt research if experiments yield harmful results. Critics like Wil Burns, a signatory of the International Non-Use Agreement, argue that even large-scale experiments may not provide useful insights for full deployment, citing concerns about unintended consequences like "termination shock" and the rights of future generations. Others, like Ilan Gur and Sebastian Eastham, support the need for outdoor experiments to address unresolved uncertainties, even if they don't answer all questions. Gruener acknowledges the risks of solar geoengineering but argues that uncontrolled climate change could be more damaging, especially for developing regions, and that the proposed experiments carry minimal environmental risk compared to current industrial activities.