From Fossil to Clean: Aerosol–Cloud Radiative Forcing in Transition

Aerosol–cloud interactions (ACI) remain a major source of uncertainty in climate projections. Within the CleanCloud Project, we quantify present-day ACI radiative forcing and its evolution toward a post-fossil energy regime, including associated variability and rapid adjustments. Using improved Earth System Models (EC-Earth and ICON-HAM), updated with refined parameterizations for mineral dust emissions, wildfire smoke, and Arctic marine aerosols, we perform 30-year fixed-SST simulations to assess the radiative impacts of both anthropogenic and natural aerosol sources. Our results provide key insights into the role of ACI in climate feedbacks and establish a baseline for near-term projections of high-impact weather events, improving the reliability of climate model predictions under changing emission scenarios.