There is a growing consensus that climate change is occurring and will worsen. To address this global environmental challenge requires not only mitigating greenhouse gas emissions but also strategies for adapting to a changing climate. Given that the climate impacts are highly localized, subnational governments are on the frontline of adaptation and need to plan and prepare for the various impacts they face. In fact, formal planning for climate adaptation is emerging rapidly across the world as well as in the United States. This research focuses on the adaptation planning efforts by state governments in the United States. Drawing on the policy innovation framework, I examine the factors that drive state governments to develop and adopt a comprehensive climate adaptation plan, which is identified through either focused adaptation efforts and broader climate action plans. I also consider the policy diffusion process, by exploring how state governments learn from and influence each other in adaptation decisions.

The empirical analysis uses a discrete time-survival model and considers both internal state characteristics (e.g., climate risks and prior disaster exposures, fiscal stress, social capital, political ideology, and adoption of other climate policies) and external factors (e.g., other states that have completed adaptation planning)  that may affect the development of statewide adaptation strategy. Specifically, I define a comprehensive adaptation plan as it has to outline projected climate impacts and vulnerability for a state, cover a range of sectors and call for real actions. Data on state plans are compiled from a variety of sources including the Center for Climate and Energy Solutions, Georgetown Adaptation Clearinghouse and Environmental Protection Agency. As of early 2014, at least 16 U.S. states have completed climate adaptation plans; and six states have recommended adaptation in their climate action plans. The preliminary result shows that coastal states are more likely to formulate an adaptation plan, in part because of the increasing concern on sea level rise and coastal flooding. Land-locked states are relatively inactive, although many of them are also at high risk of other climate impacts such as droughts and heat waves. Moreover, states with more progressive GHG mitigation policies are more likely to develop adaptation strategies.

By reviewing the current status of state adaptation planning, this research will add to the understanding of the motivation and capacity for undertaking adaptation as a collective action. It can also serve a basis for monitoring and evaluating the effects of adaptation planning, and identifying the “best practices”.  Moreover, by examining adaptation initiatives at the “laboratories of democracy,” this paper may inform the development of a national adaptation strategy.