Factors Explaining Municipal Climate Adaptation: Insights from Two Assessments of over 100 German Cities in 2018 and 2022

Climate adaptation is becoming increasingly important for municipalities. Yet, key questions remain about why they engage with this agenda, particularly at different stages of the adaptation cycle and over time. This study examines how 17 different factors, grouped into four principal components (city size & scale; land use & compactness; socio-economics; and regional climate & exposure to extreme weather), influence municipal adaptation activities. It examines how these variables played out in 104 German cities, using the results of two assessment frameworks: one analysed municipal adaptation activities across five dimensions in 2018, while the other mapped them against three dimensions in both 2018 and 2022. Regression analysis indicates that larger, more compact and more exposed cities are generally more active in adaptation, whereas socio-economic factors have a minimal impact. City size & scale shows significant effects consistently across all assessment dimensions. All four components, including socio-economics, influence adaptation plan-related dimensions, whereas implementation of adaptation measures is primarily shaped by land use & compactness. The influence of city size & scale and regional climate & exposure declined between 2018 and 2022, suggesting a policy diffusion process. These findings reveal different nuances in factors influencing municipal adaptation, highlight the importance of including implementation in assessments of adaptation, and echo calls for further research into causal mechanisms and longitudinal studies.