This book examines how the global environment is regulated and, in particular, the diversity of actors involved in addressing the problem of climate change. It considers the role of private actors, such as nongovernmental organizations and transnational networks, in global environmental politics. It shows that private actors are increasingly assuming duties normally associated with governments. They are taking on the role of regulators, as they create, implement, and enforce rules to manage global environmental problems. The book asks when and why private actors perform these regulatory roles. It cites three examples to demonstrate the diversity of private authority and the ways in which nonstate actors are serving as rule makers: the first deals with Walmart, the second is about the ruffed lemur, and the third relates to the Kyoto Protocol. The book distinguishes between two different types of private authority: delegated authority and entrepreneurial authority.