The Routledge Handbook of Grassroots Climate Activism introduces contemporary forms of grassroots climate activism from around the world through the lenses of a variety of academic disciplines, methodologies, and perspectives. Focusing on bottom-up case studies, it showcases innovative and creative approaches, as well as the knowledge of those working towards swift decarbonisation, just transitions, and climate justice. Grassroots climate activism presents a rich body of material to be studied not only by anthropologists, sociologists, geographers, and political scientists but also by scholars in the humanities and the creative arts. This timely handbook explores climate activism across six continents, and it provides perspectives from climate activists themselves. The authors interrogate a range of key questions: what forms of mobilisation, organisation, and practice constitute grassroots climate activism, and how have these changed over the last decade? What are the boundaries of the climate movement and how does it interact with, or differ from, other social movements? How do activists engage with the moral dimensions of the climate crisis? How do grassroots engagements with climate struggles give shape to plural, site-specific, but nonetheless interconnected, forms of climate activism? What tools do climate activists use to create functioning and effective local, national, and transnational networks? How has climate activism been impacted by the Covid-19 pandemic? What is the relationship between critical scholarship and climate activism? What methodologies are particularly effective for studying climate activism, and why?This handbook aims to inspire others to devote more attention to grassroots climate activism. It brings together established and up-and-coming scholars, scholar-activists, and practitioners who present novel, cutting-edge research and new findings exploring current developments in different parts of the world. This book will be of particular interest to students and scholars of climate activism, climate solutions, climate and society, human-environmental crises, grassroots activism, and social movements. It will also be of interest to practitioners involved in climate action and to all those who are ready to launch their own grassroots initiatives, or support one of the many already underway.