SAI Research Roadmap
PHASEFoundational knowledgeWhat can existing evidence tell us, and where does it fall short?Time2–3 yrsCost~$30M–$75M
PHASEAerosol microphysicsDoes data from small outdoor experiments validate the processes in our models?Time4–8 yrsCost~$70M–$150MEst. uncertainty reduction (cooling efficacy)~25%
PHASEStratospheric distributionDo sulfate aerosols mix and distribute, globally, in the way our models predict?Time4–11 yrsCost~$270M–$1.14BEst. uncertainty reduction (cooling efficacy)~66%
PHASEMonitored coolingAs cooling begins, do observed effects match predictions? Are any unexpected effects emerging?TimeOngoingCostTBD
ImpactsClimate response, impacts, and risks
AerosolsMicrophysics, chemistry, transport
ObservationsMonitoring systems, instruments, and data
EngineeringAircraft R&D, materials handling, operations
Step 1: SAI Research Roadmap
SAI Research Roadmap walkthrough: A plan for reaching an informed decision.
Stratospheric Aerosol Injection (SAI) could cool the planet by releasing reflective sulfate particles into the stratosphere, where they reflect sunlight back to space. It is now the most-researched approach to sunlight reflection. Yet we still don't have the evidence required to decide whether it could ever be used responsibly. This is a plan to build that evidence base: which questions must be answered, in what order, and at what cost.
The Roadmap is not a framework for governance. That work is vital, and it needs to run in parallel with the research.
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