Climate Change and Decision-Making Under Uncertainty

Abstract

This paper highlights the main risks and uncertainties associated with climate change in forest management. The overarching challenge is the deep uncertainty about the future direction of changes in climate denoted by representative concentration pathways (RCPs). Moreover, climate change poses new sources of risk from frequent, more intensive, and even novel disturbances in forest ecosystems. Adaptation strategies have been developed to guarantee resistance of forests to climate change and impacts, but they are mostly valid for a restricted set of climate outcomes in the future. Therefore, alternative decision-making approaches should be found to overcome the deep uncertainty about future climate development and adapt forests to future environmental conditions. We propose two decision-making approaches; portfolio diversification and robust decision-making (RDM) to solve both problems. Portfolio management is an established concept in forest utilization and requires diversification of forest structures by e.g., admixing new species, or applying different sets of silvicultural interventions. Robust decision-making is a unique approach to deal with the deep uncertainty in general, but has rarely been applied to forest management. Recent adaptations of RDM to risk management under climate change provide a good basis for application in forestry. We outline the details of RDM to this end with an example, and highly recommend its application. Finally, a consensus among politicians on a climate target, e.g., Paris agreement, may diminish the deep uncertainty about the degree of climatic change at the end of the century. However, actions pathways, i.e., scenarios to meet the climate target would stay deeply uncertain for long.