Twenty years ago, the first Earth Summit in Rio de Janeiro marked the arrival of environmentalism as a potent force in international affairs. That 1992 conference produced the United Nations Framework Convention on Climate Change, which aims to set limits on global emissions of greenhouse gases, and the Convention on Biological Diversity, which promotes ecosystem conservation. At the time, Chris Flavin of the Worldwatch Institute crowed, "You cannot go to any corner of the globe and not find some degree of environmental awareness and some amount of environmental politics." With socialism in disrepute, Flavin said, environmentalism had become the "most powerful political ideal today."
Two decades later, reports Science Correspondent Ronald Bailey, that ideal is in disarray. A 20th anniversary conference in Brazil last June, the United Nations Conference on Sustainable Development—nicknamed Rio +20—was an undisguised flop.