This handbook addresses the new watershed moment in youth environmental activism: the collision of the historic and globally prominent youth-centred movements on the one hand, with established, consolidated power in opposition to environmental action on the other. The central goal of this handbook is to explore the state of the research literature on young people’s environmental activism, not just as a global network of movements involving young people, but as a global exchange of ideas, sentiments, and solidarities. The book explores how young people attempt to address the global injustice of environmental damage, take action on environmental issues including climate change, and imagine the world of social and environmental justice that they would like to build. The handbook borrows a slogan seen at Fridays for Future strikes around the world – “Systems Change, not Climate Change” – and asks: what systemic change do young environmental activists envision, and how do they conceive of, and take opportunities to, enact that change? Spanning six themes, Sadiya Akram and Benjamin Bowman have curated a diverse range of experts to interrogate this question, exploring topics such as emotions and identity; creative methods; activism and pedagogy; and institutional perspectives, while combining a global and a specific-movement focus. These expert contributions include reflections, conversations, and co-writing with young environmental activists while drawing on arts-based and creative methodologies. This innovative handbook is a key resource for students, scholars, and practitioners who are researching and working in the fields of environment and climate justice, climate change and society, climate research, young peoples’ activism, and young peoples' political participation.