Flaws in subjective assessments of ecological risks and means for correcting them

Abstract

Environmental management involves assessments of the costs and benefits of stochastic processes. Judgements about the likelihoods and consequences of these processes depend on a broad range of uncertainties, most of which are unacknowledged in current approaches to qualitative risk assessments such as the Australian standard (AS/NZS 4360–1999). This article outlines some of the major sources of uncertainty in ecological risk assessments and provides a case study of the magnitude of the uncertainty associated with subjective assessments. It demonstrates the extent to which uncertainties may be reduced by consideration of a few kinds of uncertainty. And it suggests alternative approaches to ri..