ABSTRACT
Today's complex environmental problems exhibit a number of characteristics that make them hard to tackle with normal scientific procedures. Models, scenarios and assumptions dominate assessment of these problems, and many value loadings reside in problem frames, indicators chosen and assumptions made. The available knowledge base consists at best of a mixture of knowledge, assumptions and ignorance. It comprises bits and pieces of knowledge that differ in status, covering the entire spectrum from well-established knowledge to judgements, educated guesses and tentative assumptions. The positivist interpretation has a tendency to lead people to expect that science can deliver certainty for every problem that can be phrased scientifically and that uncertainty can be remedied by better science and more research. The Guidance is intended to help scientific advisers to be as transparent as possible in their treatment of uncertainties. It addresses explicitly institutional aspects of knowledge development and deals openly with indeterminacy, ignorance, assumptions and value loadings.
