As the International Union for Conservation of Nature (IUCN) World Conservation Congress opens today, Members are preparing to vote on a historic motion that could redefine the future of global conservation by tackling the world’s biggest threat to nature: fossil fuels. Motion 42: ‘Addressing the climate and biodiversity crises through fossil fuel supply-side measures and a just transition’ calls on the IUCN to develop guidance, analysis, and pathways for a fair and funded phaseout of coal, oil, and gas- placing fossil fuel supply at the heart of conservation for the first time in the IUCN’s history. If adopted, the motion would make the IUCN the first major environmental body to formally call for international cooperation toward a Fossil Fuel Non-Proliferation Treaty-a new global framework to stop fossil fuel expansion, equitably phase out existing production, and enable a just transition for workers and communities.