Assessing and Reducing Uncertainties in Stratospheric Processes Relevant to Stratospheric Aerosol Injections (SAI): what have we learned with climate modeling so far? (Invited Presentation)

For the last 20 years, there have been multiple and growing efforts to simulate through climate modeling the effects that the artificial injection of aerosols or their precursors (Stratospheric Aerosol Injections, or SAI) would have on climate. The use of climate modeling, and in particular the use of climate models capable of coupling atmospheric composition and surface climate, is fundamental to explore questions of risks and potential benefits of SAI. Standardized experiments, like those performed under the Geoengineering Model Intercomparison Project (GeoMIP), performed with multiple models, can help highlight areas of agreement and uncertainties.

However, as Earth System Models get more complex, and more interactions are added in different realm, diagnosing -and reducing- specific sources of uncertainties becomes harder, suggesting the need to couple comprehensive modeling studies using realistic scenarios with more focused simulations aimed at narrowing down specific processes.

Here I will review some of the most recent modeling efforts aimed at better identifying these sources of uncertainties, talk about what have we learned from the most recent GeoMIP simulations and how we are developing future modeling experiment to better answer some of the most pressing questions.