When cities take control: Explaining the diversity of complex local climate actions

Abstract

AbstractCities face substantial risks of economic and physical losses from repeated exposure to climate hazards exacerbated by climate change. Drawing from the climate action and policy mix literatures, this study conceptualizes “climate action mix” defined as the diverse policy actions adopted by city governments to adapt to and mitigate the effects of climate hazards. This study makes a key contribution by analyzing the relation between the variety of hazards and the diversity of cities' climate action mixes. Deploying a modified Shannon diversity index, we develop a new measure of climate action mix by considering the breadth across different actions, and the depth of these efforts as measured by the progress along the policy cycle. We study an expansive range of mitigation and adaptation actions without imposing any domain or jurisdictional limitations in 162 cities across the United States. The analysis reveals a bifurcation in approaches where some cities have not adopted any policies, while others have a diverse mix of adaptation and mitigation actions in various stages of policy progression. We find that climate hazards drive local action—cities that experience multiple threats react by taking a diverse mix of climate actions. Cities broadly utilize global climate networks that offer policy learning opportunities and local networks that might promote a shared understanding of environmental threats leading to diverse climate action mixes. Finally, a city's capacity to develop climate adaptation and mitigation plans is positively related to a diverse portfolio of climate actions.