risk of a nuclear war, and investments in civil defense were justified as reducing the risks of catastrophic outcomes in case a war did occur.
In the case of climate change, appropriate strategies for reducing risks will change over time in light of new information, and so too will investments in different types of action. The committee suggests that some essential elements of a sound risk management strategy for responding to climate change include:
To some extent, it is possible to make substitutions or trade-offs among investments in different elements of climate change response. For instance, substantially limiting the magnitude of climate change could make it less important to invest in adaptation efforts (recognizing that the outcomes of these different types of actions can occur over widely differing temporal and spatial scales, thus complicating direct trade-off relationships). In general, however, because the long-term benefits of investing in any particular response (e.g., R&D investments, emissions mitigation efforts, adaptation planning) are uncertain, a strategy of diversification across different types of responses will reduce risk more and be more robust than pursuing a single approach at the expense of all others.
Decision Frameworks for Addressing Climate Change
Historically, humans have responded to changing environments by a process of muddling through; that is, by taking an ad hoc approach to decision making as choices arise.2 In the modern era, techniques and approaches have been developed that allow decision makers to think through complex issues systematically. One prominent approach is the precautionary principle,3 which emphasizes avoidance of potentially serious or irreversible environmental harm, even when scientific uncertainties may be substantial. At the other extreme is what might be called “staying the course,” or not taking any action until the need for action is fully established and the consequences of any action are fully understood. Another common approach is cost-benefit analysis