This policy brief examines the role of data collection, analysis, and use in supporting effective urban climate policy formulation and implementation. It draws on research conducted within the PAUL project (Pilot Applications in Urban Landscapes – Towards Integrated City Observatories for Greenhouse Gases, ICOS Cities). The study investigates how decision-makers in Munich, Zurich, and Paris currently use greenhouse gas emissions data to inform climate action and explores how improved or new data could enhance climate-related decision-making.

Guided by three core questions, the brief assesses the current state of urban climate data practices, identifies key data-related challenges faced by city-level policymakers, and explores opportunities to strengthen data provision, analysis, and management. By examining concrete examples from Paris, Munich, and Zurich—three comparatively wealthy European cities with advanced data infrastructures—the research provides insights into both existing good practices and remaining gaps in evidence-based climate governance.