I n June 2012, Rio de Janeiro will host the United Nations Conference on Sustainable Development, more commonly referred to as Rio 2012 or Rio+20. The meeting marks the twentieth anniversary of the U.N. Conference on Environment and Development in 1992, also held in Rio. That landmark gathering adopted the Framework Convention on Climate Change and opened the Convention on Biological Diversity for signature. The conference was itself a milestone in the evolution of international environmental diplomacy, taking place two decades after the 1972 Stockholm Conference on the Human Environment.
