<p>Indigenous and community lands store a third of Earth’s irrecoverable carbon and provide habitat for a majority of its terrestrial mammals. However, few studies have considered the Indigenous or traditional ecological knowledge that sustains these environmental outcomes. Here, we use an interview-based approach to illuminate the specific ways in which Indigenous worldviews and cultural practices underpin these results. This study contains the perspectives from 49 interviews with Indigenous experts from 43 distinct communities across all six habitable continents. We describe the myriad ways they care for their land using traditional land use practices and rules, land-use planning, territorial monitoring, and ‘set-aside’ areas. These practices are grounded in Indigenous knowledge based on close observation of nature and multi-generational connections to place. They are both a source of resilience and vulnerable. All interviewees said climate change was directly impacting their lands and ways of life; 61% faced threats such as mining, commercial agriculture, and logging. Confronting an unprecedented pace of global change, many Indigenous Peoples call for support to carry their cultures and lands into an uncertain future.</p>