To achieve sustainable development, governments must balance protecting nature with supporting farmers’ livelihoods. These two goals often require decision-makers to evaluate tradeoffs between multiple policy approaches. Computer models that explore interactions between human and natural systems can help identify such tradeoffs and win-win solutions that satisfy different types of decision-makers.

Here, we develop such a model in collaboration with environment and agricultural policymakers in the Brazilian Amazon. Our model simulates how ranchers choose whether to turn their lands to pasture (and how many cattle to raise) or conserve land. We use regional economic and climate data, along with local policymakers’ expertise, to evaluate how ranchers’ land use choices may respond to multiple policy strategies under different climate and economic futures.

Our modeling identifies both tradeoffs and win-wins between policy approaches. On the one hand, combining enforcement of existing conservation laws with increased payments to farmers for conservation practices maintains a good near-term balance between meeting regional conservation goals and supporting high farmer incomes. On the other hand, this approach may lead farmers to rely on a few high-density ranches with lots of cattle, which can lead to long-term decline in pasture conditions, leaving farmers vulnerable to economic and/or climate shocks.