Assessing extreme weather-related vulnerability and identifying resilience options for California's interdependent transportation fuel sector

California’s transportation fuel sector (TFS), whose assets supply crude oil from its source to end fuel users, will increasingly be exposed to extreme weather events including flooding and wildfire under climate change. Prior studies have not considered the TFS as one sector and its exposure and vulnerability to these weather events, nor have they projected and analyzed the exposure at spatial resolutions that are fine enough to inform stakeholders about the vulnerability of individual assets that are interconnected to reliably supply and distribute fuel. Therefore, we conceptualize the TFS into a physically and organizationally connected, multi-sector network. Using this network, we project and analyze climate-change-induced flooding and wildfire exposure at both coarse and fine spatial resolutions, across multiple temporal horizons and climate scenarios. We then assess the statewide TFS’s exposure with the coarse resolution projections and discuss with various stakeholders about their assets’ vulnerability using the fine resolution projections in areas of interest.We find that transportation fuel product pipelines and central product distribution terminals are the most critical assets within the TFS network, and that the network is dependent on supporting sectors such as electricity and natural gas. Our statewide analysis identifies docks, terminals, and refineries as the most exposed TFS assets to coastal flooding, whereas roads and railroads are the most exposed assets to wildfire. The fine resolution models and the focus on different planning horizons (i.e. every 20-years between 2000 and 2100) facilitate our discussion with the stakeholders, which shows that they have implemented and plan to adopt hardening measures (improvements to physical infrastructures) and resiliency actions (improvements to behavioral responses at the organizational level) to adapt their infrastructures to these weather events, and that the fine resolution exposure projections are effective tools to facilitate stakeholder discussions. Overall, we find the TFS’s vulnerability to flooding and wildfire is three-fold: the direct exposure and potential disruption of operations, the impact on its supporting assets, and the increased pressure on California’s emergency management infrastructure. These findings will assist the TFS in adapting to the changing climate