A southward shift of the tropical rain belt has been observed throughout the second half of the 20th century. While such large-scale changes have been linked to anthropogenic aerosols, a complete understanding of this mechanism has been hindered by the lack of explicit information on aerosol radiative effects. In this study, we quantify the relative contributions of the instantaneous and cloud-mediated radiative effects of anthropogenic aerosols to the interhemispheric asymmetry in temperature and precipitation change for historical and future climate change simulations. Our analysis indicates that in model simulations the vast majority of the precipitation shift does not result from aerosols directly through their interaction with radiation, but rather indirectly through their modification of cloud radiative properties. Models with larger cloud responses to aerosol forcing are found to better reproduce the observed interhemispheric temperature changes and tropical rain belt shifts over the 20th century. These results suggest that reducing the uncertainty in predictions of future interhemispheric climate shifts will depend upon improved representation of aerosol-cloud interactions in climate models.