Urban height-Aerosol synergy drives globally dampened urban rainfall

Urbanization modulates precipitation through thermodynamic, dynamical, and aerosol pathways, yet how the rapidly increasing three-dimensional urban height interacts with rising aerosol pollution to shape urban precipitation at the global scale remains unresolved. Here, we quantify the global urban imprint on precipitation using high-resolution satellite precipitation products and attribute its drivers with a glass-box explainable artificial intelligence (XAI) model, the Explainable Boosting Machine (EBM). After controlling for other factors, we find that higher aerosol burden and greater built-up height each tends to enhance urban precipitation when considered individually, but their interaction is antagonistic: at simultaneously high aerosol concentrations and urban heights, their combined effect suppresses precipitation. Simulations with the Weather Research and Forecasting model coupled with chemistry (WRF-Chem) for Delhi, Dakar, and Oklahoma City corroborate this pattern and indicate that the suppression arises primarily because the urban-height–aerosol interaction damps the circulation response associated with the aerosol direct effect. These results address a key gap in understanding how urban vertical growth and air pollution jointly regulate precipitation. They further suggest that, under continued vertical densification and anticipated emission reductions, the urban precipitation enhancement could intensify, with implications for future urban flood-risk management.