On June 3 and 4, 1992, the Earth Summit (formally the United Nations Conference on Environment and Development or UNCED) met in Rio de Janeiro, Brazil, as a twenty-year follow-up to the United Nations Conference on the Human Environment (UNCHE, held in Stockholm). The goal of the 120 heads of state, over ten thousand government delegates, and hundreds of officials from UN organizations was to refocus global attention on the planet's degradation. It was the largest gathering of heads of state in history.

Although the post-Stockholm years were marked in many industrialized countries by the incorporation of environmental protection in their policy-making processes, change in economically less developed countries was much slower. There, although, environmental protection objectives were understood as inseparable from economic development, they were often subordinated to it. In this context, with the winding down of the Cold War and such high-profile environmental problems as the Chernobyl nuclear...