Amazon tipping advances and amplifies biodiversity loss through teleconnected precipitation declines

The Amazon rainforest is the most species-rich region on Earth, being home to approximately ten percent of all species worldwide. However, human influences such as global warming, deforestation, and land-use change are placing unprecedented pressure on the rainforest, endangering this unique ecosystem. Recent findings suggest that the Amazon rainforest could cross a tipping point within this century when deforestation and climate change are considered together. In this study, we project the impact of such a potential tipping point on the biodiversity of the Amazon basin and compare it with a scenario without tipping. To do so, we use climate data generated by a dynamical tipping point model which simulates the Amazon forest system using a moisture-recycling network under different climate and deforestation scenarios. To assess the impact on species we compare changes in climatically suitable areas for nearly 2,000 species in the Amazon basin using an ensemble of species distribution models. Our results show that the combined effect of deforestation and climate change leads to a substantially stronger decline in climatically suitable areas than climate change alone. Including deforestation results in markedly intensified biodiversity losses already early in the century (2030-2044). Notably, the largest differences in species richness loss between scenarios do not occur in deforested area but several hundred kilometres away. These teleconnected losses are driven by deforestation-induced disruptions of atmospheric moisture transport, causing precipitation declines in distant regions and pushing species beyond their climatic niches. Overall, our results indicate that limiting global warming together with halting deforestation is critical to preventing severe and widespread biodiversity losses in the Amazon within the coming decades.