Confronting Uncertainty under NEPA

Climate change will require innovative solutions – new energy technologies and new adaptation strategies. These innovations will inevitably pose risks, often in the form of possible harm to human welfare or the environment. Climate change itself involves uncertainties. Evaluating these risks and informing decision makers and members of the public will be challenging. An environmental impact statement does not dictate the substance of regulatory decisions but is at least supposed to force the agency to take a "hard look" at the relevant factors. Unfortunately, it has been difficult to codify this directive in the context of catastrophic risks, which generally have low probabilities but extreme consequences. The problem of how to handle potentially catastrophic risks has vexed the courts. Dam safety and nuclear power have been particularly fertile sources of disputes over risk assessment, and are used here as case studies. This article suggests six improvements in current NEPA practice.