Patterns, Drivers, and Trends of Urban Cooling Demand across Global Cities

Urban Cooling Demand (UCD) in cities is shaped by patterns of urban form, including engineered three-dimensional characteristics of building and transport infrastructure, local to large-scale climate dynamics and demographic elements. While impacts of lateral expansion on UCD have been widely assessed for urban environments, the specific impact of volumetric urbanization, which refers to the simultaneous horizontal and vertical expansion of cities, remains largely unexplored. We present a set of city-scale indicators of urbanization by analysing changes in both horizontal and vertical urban extents, along with demographic factors such as population density which influence on historical patterns and trends of UCD. We estimated these indicators and UCDs across 88 Indian cities and 52 global cities from 2002–2023, clustering cities into four typologies: (Type I) large, irregular cities, (Type II) medium-sized cities, (Type III) smaller, irregular cities, and (Type IV) smaller, compact cities. While regional and coastal–inland climate-based classifications were examined, the typology framework provided a more intricate explanation of UCD variability, capturing the nonlinear interactions between urban climate and city structure. Type I cities show the sharpest increase in UCD due to extensive high-rise growth and sprawling urban canyons that trap heat, while Type II cities follow a similar but less pronounced trend. In contrast, Type III and IV cities exhibit moderate UCD trends, as their compact urban forms promote mutual shading and lower cooling demand. We also found that volumetric urbanization, particularly vertical development and infilling driven densification, is the primary driver of rising UCD and the second most important factor in predicting cross-city UCD patterns, after local climate. Our results highlight the role of volumetric urbanization in shaping cooling demand and the need for profile-specific, climate-responsive planning. As cities worldwide shift toward volumetric densification, understanding these dynamics is vital for mitigating urban heat and optimizing cooling energy in a warming climate.