Improving the Quality of Climate Change Adaptation Planning Through State Mandate: The Case of California

As communities everywhere experience accelerating climate change impacts, local governments must proactively plan and implement adaptation or resilience strategies. A significant challenge is effectively scaling up these efforts in diverse communities. In 2015, the State of California passed Senate Bill 379 (SB379), requiring climate change adaptation and resilience strategies in local plans, making it the first U.S. state to broadly mandate such requirements locally. Our study measured the effects of SB379 on the quality of local plans that address climate change adaptation or resilience and assessed which types of plans jurisdictions selected to meet the requirements. Using a longitudinal study, we analyzed plan quality before and after SB379 took effect using criteria developed for earlier studies of voluntary climate adaptation plans. We found that California plans have significantly improved when assessed against theoretical criteria, and most jurisdictions have chosen their local hazard mitigation plans to meet the requirements. The flexible and cooperative design of the mandate and its loose enforcement suggest local jurisdictions are willing to address climate change, even when challenged with more stringent requirements if incentives align. As a natural policy experiment, California’s experience offers a unique opportunity to examine the effects of a state planning mandate and the choices local jurisdictions make to comply. Cooperative mandates that require local governments to address climate change adaptation and resilience in their plans but offer flexibility in how they do so may improve the quality of plans. Practitioners should seek to leverage flexibility in such mandates to the advantage of their local communities.