The United Nations Conference on Sustainable Development, held in June 2012 in Rio de Janeiro, was probably the largest event in a long series of megasummits on environmental protection and sustainable development. Roughly 44 000 participants descended on Rio de Janeiro to take part in ten days of preparatory committee meetings, informal consultations, side events, and the actual conference. Yet despite this unprecedented high attendance by participants from governments and civil society, the outcome of the conference is less than many had hoped for. In this paper I review the outcomes of the 2012 Rio conference in detail, with a special focus on its contributions towards the reform of the institutional framework for sustainable development. Following this review, I discuss the way ahead and options for structural reform to restrengthen earth system governance. © 2013 Pion and its Licensors.