American states have taken the lead in US climate policy over the past decade, implementing the goals of the Kyoto Protocol in the absence of ratification by the federal government. These developments serve as practical models for post-Kyoto climate policy and have theoretical implications for the treatment of atypical non-state actors in the study of global climate governance. The entrance of sub-national actors into foreign policy, or paradiplomacy, is examined in this study to highlight the international implications of climate policy adoption among the American states. A typology of American state actions is presented, and future options for bottom-up climate policy in the United States are considered.