High-latitude stratospheric aerosol injection to preserve the Arctic

In this study, we use the Community Earth System Model to simulate two Arctic-focused SAI strategies, which inject at 60 degrees N latitude each spring with injection rates adjusted to either maintain September Arctic sea ice at 2030 levels ("Arctic Low") or restore it to 2010 levels ("Arctic High").

Both simulations maintain or restore September sea ice to within 10% of their respective targets, reduce permafrost thaw, and increase GrIS surface mass balance by reducing runoff. Arctic High reduces these impacts more effectively than a globally focused SAI strategy that injects similar quantities of SO2 at lower latitudes. However, Arctic-focused SAI is not merely a "reset button" for the Arctic climate, but brings about a novel climate state, including changes to the seasonal cycles of Northern Hemisphere temperature and sea ice and less high-latitude carbon uptake relative to SSP2-4.5.