Multilevel Governance and Policy Diffusion in Climate Adaptation: A Comparative Analysis of National and Sub national Public Policy Responses

Climate adaptation policy presents a distinctive governance challenge because the physical impacts of climate change are experienced locally and unevenly, while much of the scientific, financial and technical capacity required designing effective adaptation responses is concentrated at national and international levels. This structural mismatch has produced highly varied multilevel governance arrangements across countries, ranging from centralized, nationally coordinated adaptation planning to devolved models in which sub national governments bear primary implementation responsibility with limited central coordination. This paper applies multilevel governance theory and policy diffusion frameworks to compare climate adaptation policy architectures in three contrasting cases: the Netherlands (a highly centralized, technically coordinated model), the United States (a fragmented, sub nationally driven model in the relative absence of binding federal adaptation policy), and Ethiopia (a nationally coordinated model operating under significant capacity and financing constraints typical of many low-income countries). The paper argues that policy effectiveness depends less on the degree of centralization per se than on the presence of formal vertical coordination mechanisms, such as mandated information-sharing platforms and conditional intergovernmental financing, that bridge the scale mismatch between where climate risk is experienced and where adaptation capacity resides. The paper concludes with implications for public policy design in multilevel and federal systems facing escalating climate risk.