A global typology of cities supporting coordinated climate action

Cities are central to climate action, yet the highly local nature of urban case studies limits the generalizability of climate solutions across diverse contexts. Here, we develop a data-driven typology of 11,000 cities based on 12 structural characteristics and statistically identify four types of cities that focus on development, urban planning, mitigation, or are megacities. Linking this typology to more than 100,000 scientific case studies reveals strong regional patterns and substantial evidence gaps, particularly in cities with planning needs, despite high potentials for solution transfer learning. Using ten type- and region-representative cities, we exemplify how the typology enables systematic learning: cities with development and urban planning priorities primarily draw on adaptation and basic need solutions for water security, heat management, and resilient spatial planning; Wealthier and mature global north cities can rely more balanced solution portfolios involving, for instance, building retrofits, low-carbon mobility, and technological solutions; Megacities require coordinated, cross-sectoral strategies that combine infrastructure renewal with nature-based and socio-institutional approaches that are reflected in available solution evidence. Our typology offers a scalable basis for matching climate solutions to city needs, improving evidence synthesis, and IPCC assessments.