Reversed Future Drying‐Wetting Precipitation Patterns Over the Northwestern and Southeastern East Asia Driven by Reduced Aerosol Emissions

Abstract To investigate drying‐wetting patterns of precipitation trends in East Asia, we examine the past and future precipitation changes and their underlying control factors using observations and CMIP6 simulations. Over the past seven decades, greenhouse gases enhanced evaporation through enhanced net longwave radiation, raising dryland precipitation, while aerosols suppressed evaporation by reducing net shortwave radiation, lowering humid region precipitation, thereby weakening the dry‐wet contrast. Future CMIP6 projections show greater precipitation increases in humid region than in dryland under both intermediate‐ and high‐emission scenarios. Observation‐constrained projections indicate a slight decrease in dryland and an increase in humid region, strengthening the dry‐wet contrast. This shift stems from aerosol reductions that increased net shortwave radiation, enhancing evaporation in humid region and reversing the historical suppressive effect of aerosols on precipitation. These findings highlight the distinct roles of greenhouse gases and aerosols in modulating regional precipitation, providing insights for climate adaptation strategies in East Asia.