A Climate Intervention Dynamical Emulator (CIDER) for Scenario Space Exploration

Abstract. Stratospheric Aerosol Injection (SAI) is a form of climate intervention that has been proposed as a way to reflect incoming solar radiation in order to provide a cooling effect and offset some of the impacts of greenhouse gas warming. Many possible scenarios for SAI implementation exist, ranging from steady, cooperative deployments across one or more injection latitudes to highly dynamic uncoordinated deployment with multiple independent actors with different aims. To explore the physical consequences across this wide range of possible SAI deployment scenarios, we develop the Climate Intervention Dynamical EmulatoR (CIDER), a climate emulator designed to emulate regional and global responses to a SAI deployment as the injection (or desired climate goals) vary in magnitude, latitude, and time. We train the emulator on existing sets of simulations from two Earth System Models. We then validate the emulator on a novel climate model simulated scenario of an example multi-actor uncoordinated SAI deployment. Our findings demonstrate that CIDER can be successfully used to estimate multiple climate variables of interest and across multiple climate models, including regional and global temperature and precipitation; it also successfully emulates results of an uncoordinated SAI deployment, rendering it an invaluable tool in exploring the climatic implication of a wide range of deployment scenarios, with the possibility of future coupling with regionally resolved integrated modeling frameworks in order to better quantify the potential societal impacts of SAI.