This chapter examines how emotions influence the formation and dynamics of environmental movements. It begins by analysing emotional repertoires, including narratives and slogans, that help build collective identity. Activist tactics and strategies are explored alongside framing methods and mobilizing structures that shape how people express demands. The chapter also discusses the role of networks and Environmental Movement Organizations (EMOs) in fostering collective action and solidarity, highlighting their contribution to the institutionalization of movements worldwide. Emotions are grouped into three types to explain how they spread, unify, and drive activism. Both historical and current movements are discussed, with particular attention to Earth Day and the post-2018 school strikes. These examples illustrate how emotions sustain momentum and shape environmental agendas across different periods and geographies.