Adaptation as a Decision Making Under Deep Uncertainty A Unique Challenge for Policymakers?

摘要

Climate change will fundamentally alter the nature of climate risks that we face as a society. The only viable approach to limit the impacts of climate change is to reduce global greenhouse gas emissions. But, due to the lags in the climate system, the world is already committed to further changes from historical emissions alone. The only way to reduce the impacts of this unavoidable climate change is through adaptation. Adaptation brings with it both new and old challenges for decision makers. This chapter describes the major new challenge introduced by climate change as deep uncertainty about the future evolution of climate. This means that policymakers can no longer rely on traditional approaches for managing uncertainty. The past can no longer be assumed to be an adequate guide to the future. Not considering the true nature of the uncertainties in decision making today can lead to maladaptations, putting lives at risk, and wasting investments. Long-term investments and policies, like public infrastructure and sectoral planning, with long lead times and high sunk costs, have the highest potential for maladaptation. Not considering long-term climate risks from the outset in these decisions can lock-in future vulnerability and unnecessary costs. This chapter suggests that, despite these challenges, in many cases, adaptation will be no more difficult than many other areas of public decision making. Many elements of adaptation plans, particularly in the near-term, are not necessarily highly sensitive to climate change uncertainties. Further, for long-term decisions, through employing a broad range of adaptation measures, considering flexibility up front, and sequencing measures to best cope with uncertainty, it is possible to build robust adaptation plans. By employing such principles in planning from the outset it is possible to reduce risk today and maintain flexibility to cope well with future climate changes.