Commodity agriculture continues to spread into tropical dry forests globally, eroding their
social-ecological integrity. Understanding where deforestation frontiers expand, and which impacts
this process triggers, is thus important for sustainability planning. We reconstructed past
land-system change (1985-2015) and simulated alternative land-system futures (2015-2045) for the
Gran Chaco, a 1.1 million km² global deforestation hotspot with high biological and cultural
diversity. We co-developed nine plausible future land-system scenarios, consisting of three
contrasting policy narratives (Agribusiness, Ecomodernism, and Integration) and three agricultural
expansion rates (high, medium, and low). We assessed the social-ecological impacts of our scenarios
by comparing them with current biodiversity, carbon density, and areas used by forest-dependent
people. Our analyses revealed four major insights. First, intensified agriculture and mosaics of
agriculture and remaining natural vegetation have replaced large swaths of woodland since 1985.
Second, simulated land-system futures until 2045 revealed potential hotspots of natural vegetation
loss (e.g. western and southern Argentinian Chaco, western Paraguayan Chaco), both due to the
continued expansion of existing agricultural frontiers and the emergence of new ones. Third, the
strongest social-ecological impacts were consistently connected to the Agribusiness scenarios, while
impacts were lower for the Ecomodernism and Integration scenarios. Scenarios based on our
Integration narrative led to lower social impacts, while Ecomodernism had lower ecological impacts.
Fourth, comparing recent land change with our simulations showed that 10 % of the Chaco is on a
pathway consistent with our Agribusiness narrative, associated with adverse social-ecological
impacts. Our results highlight that much is still at stake in the Chaco. Stricter land-use and
conservation planning are urgently needed to avoid adverse social-ecological outcomes, and our
results charting the option space of plausible land-system futures can support such planning.