The Arctic is warming 4x faster than other parts of the world, increasing interest in the region for geopolitical and industrial purposes. Encountering these discourses from both local and international sources, worried residents have been inventive in their creation of climate justice movements, balancing pragmatism with aspirational, democratic, and utopian thinking. Drawing on extensive fieldwork between two case studies, a campaign seeking to make a glacier the president of Iceland and a group of Finnish Extinction Rebellion activists who have formed an organization to promote research into geoengineering, I show how these organizations have innovated legally and politically in their quests for intergenerational, pluriversal, and more-than-human environmental justice in the Arctic amidst increasing interest in the region for strategic geopolitical purposes. The former has drawn on Icelandic history and culture, popular proposals for a new constitution, and scientific data about the link between melting glaciers and ecosystem collapse to push for an amendment that would enshrine the rights of nature in Icelandic law. The latter, meanwhile, has made the argument from the perspective of intergenerational, more-than-human/multispecies, and indigenous justice for geoengineering, a technology that is controversial because of the challenges it poses to traditional forms of governance. To conclude, I reflect on the novel opportunities and challenges I have encountered while engaging with these organizations as an anthropologist and youth environmentalist, navigating competing claims to justice, a nascent field in which the science or governance is not at all clear (geoengineering), and exclusions of local and traditional ecological knowledge.