The post-normal sciences of precaution.

After centuries of optimism, science has become problematic and compromised. We can no longer assume that innovations are safe until proven dangerous. The 'technocratic' approach to science, with its reductionist methodology and its corporate control, is no longer appropriate. We need a 'precautionary' science that will be 'post-normal' in character. For this, we contrast 'applied science,' like the 'puzzle-solving' of Kuhn's 'normal science' and the 'professional consultancy' like the practice of the surgeon or engineer. Rather, we have a situation where 'facts are uncertain, values in dispute, stakes high, and decisions urgent.' For high-quality decision-making, we need an 'extended peer community' who will bring their 'extended facts' to the dialogue. There are a number of initiatives that advance the post-normal programme, including the endeavours of Poul Harremoës and the conference on Uncertainty and Precaution in Environmental Management.