Environmental movements are networks of informal interactions that may include individuals, groups, and organizations engaged in collective action motivated by shared identity or concern about environmental issues. This article reviews literature on environmental movements (including antinuclear energy movements) according to four main aspects: the social bases and values underlying the movements' mobilization, the resources support- ing their mobilization, the political opportunities channeling their mobilization, and the cultural framing processes through which environmental issues are defined as social and political problems to be addressed through mobilization. In addition, we consider the historical antecedents and roots of environmental movements. Finally, we discuss the interplay between the local and the global levels and the movements' impacts, a long neglected issue in the social movement literature. Our review highlights three main features of environmental movements: they are heterogeneous; they have profoundly transformed themselves; and they have generally become more institutionalized.