Accounting for risk and uncertainty in determining preferred strategies for adapting to future climate change

Abstract

Individuals, businesses, and policymakers face the problem of selecting a preferred strategy for adapting a managed ecosystem to future climate change when there is risk and/or uncertainty about future climate change and its ecosystem impacts, and the conditional outcomes of adaptive strategies (i.e., performance of an adaptive strategy given a particular future climate change scenario occurs). Evaluation methods for this purpose are described for two cases; one in which the decision-maker can (climate risk case) and cannot (climate uncertainty case) assign probabilities to future climate change scenarios. Fuzzy sets are used to characterize uncertainty regarding both future climate change, and the conditional outcomes of adaptive strategies. The preferred conditional adaptive strategy for a future climate change scenario is determined by ordering the adaptive strategies for that scenario using a fuzzy set operation. Two methods are described for determining the adaptive strategy that is preferred across all climate change scenarios. The preferred overall adaptive strategy for the climate risk case is determined by maximizing a performance index for strategies. The preferred overall adaptive strategy for the climate uncertainty case is determined using the minimax regret criterion, which selects the strategy that minimizes the maximum loss in performance that can occur across all strategies and climate change scenarios. Ways for making the evaluation methods dynamic are considered.