Trade-Offs and Synergies between Climate Change, Biodiversity, and Agricultural Economy Across Various Future Land Use Scenarios in Brazil.

Land-use change is a major driver of biodiversity loss and a key contributor to greenhouse gas emissions, making it crucial to mitigate climate change and preserve biodiversity. This is especially relevant for Brazil, where agricultural expansion impacts biodiversity- and carbon-rich biomes. Achieving Brazil's commitments to the Paris Agreement and the Convention on Biological Diversity requires balancing agroeconomic development with biodiversity preservation and climate change mitigation. However, more comprehensive information is needed on land-use trade-offs and synergies across varying global change contexts. To address this gap, we quantified trade-offs and synergies among these objectives through 2050 under three land-use change scenarios in Brazil. We assessed the impact of each scenario by estimating spatial changes in carbon stock, mammal distributions, and agricultural revenue. Our results confirm that agricultural growth in Brazil occurs at the expense of biodiversity preservation and climate change mitigation, and vice versa. The primary drivers of these trade-offs and synergies are changes in natural vegetation cover and agricultural land, led by global demand for agricultural products. Under a SSP3-7.0 scenario, rising demand for agricultural products from 2015 to 2050 is projected to expand agriculture into natural areas. This pathway increases Brazil's agricultural revenue by $39.7 billion USD annually but reduces land carbon stock by 4.5 Gt and shrinks mammal distribution areas by 3.4%. Conversely, the SSP1-1.9 scenario projects declining agricultural demand over the same period, driving the reconversion of agricultural land to natural vegetation. This shift increases carbon stock by 5.6 Gt and expands mammal distribution areas by 6.8%, though it would lower agricultural revenue by $19.7 billion USD annually. Our findings further highlight that containing agriculture outside biodiversity- and carbon-rich areas, along with strategic ecosystem restoration, presents opportunities to harmonize agroeconomic development with biodiversity preservation and climate change mitigation.