The present mixed-method research examines the rise of the #FridaysForFuture movement in Norway during 2019. We investigated the youths’ motivations for participating in climate school strikes in Norway using a cultural psychological approach. In Study 1, we document findings from in-depth ethnographic fieldwork at major strikes and smaller demonstrations. In-depth and shorter on-site interviews of young participants of the strikes were collected (N = 93, age = 13-30 years). Thematic analysis of participants' interviews indicated the protestors have a sense of shared responsibility for causing and addressing climate change stressing the importance of implementing changes at the structural level. The school strikers construct a shared identity as “the future” motivating for engagement as they see striking as their only legitimate and effective tool to push politicians for policy change. Subsequently, in Study 2 we tested a model of collective action based on these findings from Study 1 and the adjusted Social Identity Model of Collective Action (SIMCA; Rees & Bamberg, 2014; van Zomeren et al., 2008). The survey sample consisted of high school students (N = 362, age = 16-19) recruited at high schools and online. Results of our path model showed that collective guilt, environmental threat, past protest participation, organized environmentalism, political orientation, and social capital positively predicted future protest intentions mediated by group identification, and, in turn, group efficacy. We discuss the results across both studies in light of past research on collective action to better understand environmental collective action in youths.