Trade-offs between nature and people in Ethiopia's protected areas demonstrate challenges in translating global conservation targets into national realities.

Achieving global biodiversity targets, such as the commitment to conserve 30% of the planet by 2030, depends on the ability of individual countries to translate targets into reality. While there has long been recognition that protected areas can bring costs as well as benefits, the implications of this for delivery of global targets have not been fully explored. We focus on Ethiopia, a country supporting globally important biodiversity but facing substantial poverty challenges. We characterize the extent and representativeness of Ethiopia's protected area network, demonstrating that a threefold expansion-particularly into ecoregions with higher opportunity cost-would be required to meet the Kunming-Montreal Global Biodiversity Framework Target 3. Using a quasi-experimental approach (accounting for known confounders and exploring sensitivity to potential unobserved confounders), we show that the existing protected area network has reduced forest loss and agricultural expansion, and helped to maintain grasslands. Yet, this has brought social wellbeing costs equivalent to 3.9 million fewer household-months of adequate food. Surveys show that national conservation stakeholders recognize these challenges and prioritize improving effectiveness of the existing network over expansion. Our findings highlight that trade-offs between environmental and social outcomes are not simply challenges to be managed, but are central to whether global biodiversity commitments can be delivered.