In 2009, Rockström et al inaugurated a new approach to the study of environmental problems. The notion of planetary boundaries became a key instrument to assess the trajectory of environmental governance and, in a more profound way, the path of human civilization. The aim of this paper is to provide an overview and an analysis of Rio+20 using the global governance of planetary boundaries as main criteria. The role of Brazil in the Summit is also considered. The main conclusion is that the Rio+20 was a failure in terms of defining a safe operating space for humanity. That negative outcome reflects the main features of the international system: blocked and dominated by conservative forces. In this context, Brazil operates as an underachiever environmental power, combining a huge physical environmental capital with a poor social environmental capital.
