Traditionally, the study of public policy focused on the consequential effectiveness of a policy but ignored the broader historical conditions of the emergence of 'policy' and its effects on individuals' subjectivity. The concept of 'governmentality' developed by Michel Foucault (1926-84) allows us to address these points. 'Governmentality' encapsulates three components of the deployment of power in Europe since the sixteenth century: institutional centralisation around the state; intensification of the effects of power on the entire social body (individual and collective subjectivity); and the emergence of new forms of knowledge ('power/ knowledge'). This article argues that the concept of governmentality is relevant to the study of environmental policy. A study of Canada's Green Plan shows that it constitutes a clear attempt to discipline the population by instilling new norms of environmental conduct and, thus, constructs a new subjectivity based on 'environmental citizenship'. An interpretation of the Green Plan as a 'failure' only makes sense within a narrower and traditional understanding of policy. On the contrary, the Green Plan is an example of resistance against other prevalent kinds of subjectification - such as the market - and could constitute one of the conditions for the emergence of a green 'self with all the dangers that this entails.