Co-producing Coastal Adaptation Plans with Pacific Northwest Stakeholders: Applying Alternative Futures Analysis to Quantitatively Envision Policy and Climate Scenarios

Coastal communities throughout the US West Coast and elsewhere are facing the daunting task of preparing for climate change impacts, particularly the hazards from increased flooding and erosion. With sea-level rise, changing storminess patterns, and possible changes to the frequency and severity of major El Niño events, communities are already implementing emergency responses in order to protect infrastructure, beach access, and property. Recent studies show that despite the vast information available on coastal hazards and expected risks, few coastal adaptation plans with long-term climate change planning have been successfully implemented. Most likely, this lack of implementation is due to a disconnect between scientists and decision-makers; despite the availability of relevant science and tools, local decision-makers are burdened by not only deciphering the scientific information but also executing complex and costly coastal adaptation strategies without clear quantitative analysis at a regional level. Our approach to increasing the usability of coastal adaptation planning is to co-develop decision-support tools with `Knowledge to Action Networks' (KTANs) and use Envision, a multi agent-based framework for modeling alternative futures. In this study, we review the co-produced coastal adaptation policies being explored by KTANs in both Tillamook County, OR and Grays Harbor County, WA, two regions of the US West Coast that have experienced vastly different coastal evolution in the last few decades and therefore have significant differences in their exposure to coastal flood and erosion hazards. We examine how variations in local priorities drive the co-development of different policy scenarios across the two locations, and how metrics of importance to local stakeholders (e.g., the number of buildings impacted by flooding) change over time under different climate and policy scenarios. We also compare the influence of human-decision making via policy implementation to future climate change uncertainty. By collaborating with regional decision-makers on the project from the beginning, our aim is to co-develop usable, quantitative information and alternative adaptation policy scenarios for local communities that will promote coastal hazard resilience.