Within an educational system increasingly focused on test-based accountability, how can a local education authority adopt an interdisciplinary environmental and sustainability education (ESE) policy? What local and global factors and actors shape and inform the creation of such a policy? In answering these questions, this article examines the formulation of ESE policy in the New York City Department of Education. Based on an analysis of archival documents and 20 expert interviews, the study draws on the Advocacy Coalition Framework and extends its application by adding global and social movement perspectives. In doing so this study find that external events enabled the initial enactment of the policy in 2009, while the practice and local pilots of ESE programs substantially informed the reformulation of the policy in 2012.