This can make the difference between successful use of science and the failure of an action because of scientific constraints. It is important that science be part of the senior policy process, where understanding its implications may be crucial.
Of course, even very good science advice is often not translated into policy, for a very wide range of reasons. As noted above, the scientific dimension, although very important, must compete with many other considerations. However, there are an impressive number of important cases in which solid scientific inputs have made critical contributions to policy. Well-known examples are scientific understanding of ozone depletion and an early study by the US Institute of Medicine which first called attention to the urgent need for awareness and prevention programs related to AIDS. The case of the IPCC is also noted elsewhere in this report. The potential for high impact underscores the importance of publication, dissemination, and discussion of science advisory products with policy makers, groups that are affected by the policies in question, and the public.
The elements outlined above are synthesized from efforts around the world to find ways of ensuring scientific credibility on the one hand and interactions between science and policy on the other. They may therefore provide a foundation against which to assess the role of science advice in the United Nations system.