ABSTRACT
Environmental sustainability is a destination that is reached at some point in the future. Efforts to both dene environmental sustainability and develop strategies to assess its status carry the implicit assumption that action or decisions made in the present can be extrapolated into the future and their outcomes understood. This chapter examines the nature of uncertainty, its connection to prediction, and how it influences sustainability assessment and decision-making. In the broad field of environmental management, the precautionary principle has been employed to direct rational decision-making by introducing careful consideration for the irreversibility of possible future consequences. Assessing sustainability based on the application of targets or preset thresholds for key environmental indicators suggests a nearly intractable level of uncertainty surrounding the correctness of any policy decision.
