Exploring the Impacts of Both Climate Change and Decision Making Uncertainty on Coastal Community Vulnerability Assessments in a Policy-Centric Framework

Abstract:

Coastal communities throughout the U.S. Pacific Northwest face heightened risk due to sea level rise and increasing storminess resulting in coastal flooding and erosion hazards. Incorporating uncertainty with respect to both climate change and policy decisions is essential for projecting the evolving probability of coastal inundation and erosion, and the associated community vulnerability, through time.

 Through collaboration with a group of stakeholders in Tillamook County, Oregon, we are co-developing a scenario analysis and modelling tool to explore strategies that may reduce vulnerability to coastal hazards within the context of uncertainty and climate change. We use Envision, a spatially explicit multi‐agent modelling platform that provides a scenario-based, policy centric framework for examining interactions between human and natural systems across a landscape. Probabilistic simulations of extreme total water levels along the shoreline allow us to capture the variability of sea level rise, wave climate, and the El Niño Southern Oscillation under a range of climate change scenarios through the end of the century. Additionally, we explore a range of alternative futures related to management decisions and socioeconomic trends as defined with input from stakeholders. Here we quantify the relative contribution of uncertainty from both climate change and policy decisions in terms of multiple landscape metrics including damage to property (e.g. the number of buildings impacted by flooding and erosion). Quantifying uncertainty within the Envision framework will help to improve the usefulness of the model and determine the relative impact of policy and management decisions on the adaptive capacity of Pacific Northwest communities under a range of future climate scenarios.