Effectiveness of California earthquake scenarios in motivating mitigation

Scenarios of potential earthquake damage have been prepared and used in California for over 50 years. We investigated the effectiveness of earthquake scenarios in motivating, supporting, and guiding earthquake risk mitigation through semi‐structured interviews and literature review. As part of California's earthquake resilience ecosystem, scenarios have had a significant role in the development or adoption of major mitigation programs for buildings and infrastructure. Scenarios were often paired with damage from real events to advocate for mitigation measures, with the role of scenarios being to communicate the potential for future losses. Scenario processes and findings were used to build community and political support. Interviews in particular point to the often complex and interdependent relationships between scenarios, other significant sources of influence, and contextual factors in motivating, supporting, or guiding subsequent mitigation actions. Significant, focused effort building on a foundation of sustained advocacy by the professional community and a supportive policy context are required to move from even the best‐prepared scenarios to actual implementation of mitigation measures. Future scenario projects should have adequately funded stakeholder engagement and a component to create a pathway to implementation for scenario findings, such as a mitigation planning process.