By far the most important way that the international community has sought to govern the global environment is through cooperation among nation states and the creation of multilateral environmental agreements (MEAs), or regimes. There are currently more than 140 MEAs in existence, most of which have come into being since 1972. Studying international environmental cooperation provides insights into exactly how states succeed or fail to work together to address complex transboundary and global problems. International environmental negotiations have been fraught with difficulties, and conflicts of national interests, values, and priorities. These clashes have often led to compromises that have disappointed many. These negotiations are also often remarkable for examples of political entrepreneurship, creative compromises, and last-minute solutions. They have attracted attention and participation from a wide range of actors, not only states and their representatives, but also scientists, activists, and business leaders.

International relations theories of bargaining and “cooperation under anarchy” have provided important insights into the complex factors that shape negotiation outcomes and regime formation. At the same time, the study of international environmental cooperation has brought to the fore important dimensions of these processes that had hitherto been less visible in this field of study, but have gained in importance across most, if not all, types of global governance regime in recent years. In later sections of this chapter, we examine the growing influence of the South in global governance, the role of scientific and technological expertise, and increasing demands for participation by non-state actors, notably civil society and corporate sector actors.