A Functional Approach to Risks and Uncertainties Under NEPA

The National Environmental Policy Act (NEPA) mandates that federal agencies evaluate the environmental impacts of their proposed actions. This requires agencies to make ex ante predictions about environmental consequences that often involve a significant degree of factual risk or uncertainty. Considerable controversy exists regarding how agencies should address such risks and uncertainties. Current NEPA law adopts a largely ad hoc approach that lacks coherence and analytical rigor. Some environmentalists and legal scholars have called for a greater emphasis on worst-case analysis in environmental planning, especially after the recent Deepwater Horizon oil spill in the Gulf of Mexico and the meltdowns at the Fukushima Daiichi nuclear reactors in Japan, both of which involved the eventuation of risks dismissed ex ante as improbable. This Article proposes a functional approach to environmental risks and uncertainties under NEPA as a preferable alternative to both a worst-case analysis requirement and the morass of existing approaches. A functional approach that is sensitive to context and analytically focused is better suited to the complexities of environmental planning. It is consonant with current NEPA law, but also can refine existing law to develop requirements that focus on effectuating NEPA’s purposes by producing useful environmental information.