Nilabhra Mondal, Prashant Anand, Ansar Khan, Matei Georgescu, Dev Niyogi, M. Santamouris
Urban cooling demand (UCD) is shaped by the three-dimensional evolution of cities, where climate, morphology, and demographic pressures interact to determine thermal energy needs. However, urbanization is driving heterogeneous volumetric growth, spanning horizontal expansion, vertical densification, and infilling, whose combined effects on UCD remain poorly quantified. Here, we analyse 88 Indian and 52 global cities from 2003 to 2023 and reveal a divergence in UCD trajectories driven by growth typologies. Cities undergoing extensive, irregular expansion exhibit the fastest relative increases in UCD despite lower initial demand, whereas medium-sized cities sustain the highest absolute demand. Compact urban forms show moderated trends, indicating structural thermal advantages. Across regions, volumetric growth, particularly vertical development and volumetric densification, is strongly associated with UCD and exhibits substantial explanatory power after climate, suggesting that urban form is an important consideration in climate-responsive and energy-efficient urban transitions. The authors show that city growth patterns strongly shape future cooling demand, with sprawling and vertically densifying cities showing the fastest rise, highlighting critical risks for energy demand, heat exposure, and climate-resilient urban planning.