This chapter reviews the history of global environmental conferences, and draws political lessons about their broader role in constructing efforts at global environmental governance, and in particular regarding the future of such global conference diplomacy for the environment. It focuses on Rio+10 in Johannesburg in 2002 and the prospects for reaching UN Conference on Environment and Development (UNCED) goals for sustainable development. Generally, the global UN conferences on the environment have produced declarations and action plans for subsequent activities. UN environmental conferences have helped contribute to a broader shift in international environmental governance through educating governmental elites, exposing them to new agendas and discourses, and providing them with added resources to pursue sustainable development. Rio+10 provides a major opportunity for reforming and streamlining multilateral environmental governance. It is intended to refocus international attention on sustainable development and assess accomplishments since 1992.