This challenging book takes a broad and thought-provoking look at the precautionary principle and its implementation, or potential implementation, in a number of fields. In particular, it explores the challenges faced by public decision-making processes when applying the precautionary principle, including its role in risk management and risk assessment. Frameworks for improved decision-making are considered, followed by a detailed analysis of prospective applications of the precautionary principle in a number of emerging fields including: nanotechnology, climate change, natural resource management and public health policy. The analysis is both coherent and interdisciplinary, employing perspectives from law, the social sciences and public policy with a view to improving both the legitimacy and effectiveness of public policy at national and international levels.