U.S. Department of Commerce


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Published in ENVIRONMENTAL MODELLING, SOFTWARE AND DECISION SUPPORT: STATE OF THE ART AND NEW PERSPECTIVES, edited by A. J. Jakeman, A. A. Voinov, A. E. Rizzoli, & S. H. Chen (Amsterdam et al.: Elsevier, 2008). This article is a U.S. government work and is not subject to copyright in the United States.


Recent emphasis on uncertainty in environmental decision making reflects numerous changes in environmental science and policy making over the past few decades. Firstly, environmental policy problems increasingly involve large, interconnected and complex social choices. For example, climate change, ozone depletion, biodiversity loss, genetically-engineered crops, environment-related diseases and health risks involve large scale, long-term impacts, whose precise causes and consequences are often poorly understood. Given these uncertainties and the risk of irreversible environmental changes, different perspectives about the nature, policy implications, or even the existence of a problem, are inevitable (Rittel and Webber, 1973; Sarewitz, 2004).