Global citizenship education (GCE) as developed by UNESCO in 2015 is a pedagogy that aims to foster learners who contribute to a more just and peaceful world. UNESCO's framework for GCE is based on three dimensions: cognition, socio-emotions, and behaviour. Freire (2017) stated that learning about oppressive structures in the world cannot only be an intellectual endeavour but must include action to accomplish a more just and peaceful world. In Pedagogy of Hope, Freire (2014: 80) wrote about the importance of hope as a catalyst for change: 'there is no change without dream, as there is no dream without hope'. For young people, however, the ability to dream becomes harder when they feel a collective sense of anxiety and distress around global problems, such as the climate crisis (Hickman et al., 2021). Actions towards solving complex global problems should address the intertwinement between individual acts and state-corporate behaviours (Bryan, 2022). This article reflects on a study that implemented such a justice-oriented GCE during three consecutive academic years in one Grade Nine class, as students participated in a ten-week action-oriented unit on the climate emergency. The outcome of the Action Research shows the importance of taking collective action as a part of GCE, since students derived hope from experiencing a sense of success when engaging in civic action. Social media, furthermore, was highlighted by students as their main form of civic engagement and could therefore be utilised as means for civic action within formal education. Lastly, the article suggests that insights from citizenship education into strategising and organising collective actions might help to address the complexity of global issues.