As is the case wherever the problem of environmental protection arises, the major issue for international negotiation is that of the interface between scientific research and policy making, and that was the case in Copenhagen. It is also that of the transformation of scientific truth into collective choice. Such transformation is never easy, nor natural. Regardless of their accuracy, scientific facts cannot conceal the complexity of decisions that must include other issues and take into account other interests.This is why it is so important to be able to examine the case of the Antarctic Treaty, which is both exemplary and, alas, unique.