What motivates and hinders municipal adaptation policy? Exploring vertical and horizontal diffusion in Hessen and Finland

Municipalities across the globe are seeking to adapt to increasing climate change impacts, such as heavy rainfall, drought, heat waves, and floods. An important question is how to support the diffusion of innovations in local adaptation policy-making. Responses often lack consideration of the diversity of municipalities and their varying needs and capacities. This article addresses this gap by analysing how internal and external motivations for and barriers to adaptation policy and diffusion vary across municipalities of different sizes in the federal State of Hessen in Germany and in Finland. Hessen and Finland have comparable population sizes and settlement structures, but their municipalities are embedded in different multilevel governance architectures and climatic geographies. The analysis builds on quantitative data from two independent surveys among Hessian and Finnish municipalities. The results show that while there are similarities and some differences among the motivations, with municipalities in Hessen focusing more on extreme weather events and Finnish municipalities more on well-being, the barriers are strikingly similar, focusing on lack of resources as well as unclear responsibilities of different governance levels and within municipalities. Size is an important factor determining the adaptation needs and capacities of municipalities in both surveys. The findings highlight the need for a clearer adaptation governance framework, support from the closest governance level and more resources, but also context-sensitive policy support that has been discussed in theory and practice.