The activation of giant aerosol particles (r >1 μm) alters the warm rain formation process and decreases the lifetime of liquid clouds as giant particles can form large cloud droplets and quickly initiate the warm rain process. Previous work applied cloud parcel models or large eddy simulations to study the impacts of these particles, but there is still limited research on assessing the effects of giant aerosols at global scale. In this study, we assess the effects of giant aerosols using the U.S. Department of Energy’s Energy Exascale Earth System Model (E3SM). We diagnose the abundance and physical properties of giant particles in the 4-mode version of the Modal Aerosol Module (MAM4) and allow these giant aerosol particles to be activated directly to form drizzle droplets. Sensitivity tests are performed to quantify the effects of giant aerosols on cloud and precipitation characteristics. We also perform global simulations to investigate their effects on the energy budget, aerosol-cloud interactions, and the simulated climate.