Thresholds and Adaptation Pathways of Nature-based Solutions for Sea-level Rise

Abstract

Nature-based solutions serve as flexible, multi-functional, and adaptable actions aimed at promoting human well-being and socioeconomic benefits from climate risks by restoring natural ecosystem structures and functions. Due to uncertainties such as the magnitude/rate of sea-level rise (SLR), social politics, economic investment, etc., those strategies might be unfeasible and reach the tipping points of socio-ecological performance. The design of dynamic adaptation pathways contains a broad suite of actions that should be adopted in different SLR scenarios based on each method's thresholds to better manage uncertainty. The research question is, how to know the thresholds of nature-based strategies and create pathways to preserve multiple options in an uncertain future? To facilitate it, the paper defines the metrics to assess nature-based solutions performance under SLR and unpack the thresholds of each strategy based on case study analysis of the US, to design adaptation pathways over time. Results indicated that the feasible combination of nature-based strategies/pathways could bring more socio-ecological benefits. The number of adaptation options/pathways would decline with the extreme SLR, which shows coastal adaptation needs to start earlier than expected. These findings explore alternative sequences of decisions and illuminate the paths of alternative strategies to better adapt to SLR.