Pinpointing Amazon forest tipping in global warming and deforestation pathways

Humanity is exerting unprecedented pressure on the Amazon forest through global warming, deforestation, land-use change, and large-scale infrastructure projects. As the Amazon may exhibit a tipping point beyond which detrimental changes become self-propelling, these pressures could trigger system-wide state shifts. We use a dynamical systems model to assess local transition risks and cascading transitions across the Amazon under different SSP-scenarios (SSP2-4.5, SSP3-7.0 and SSP5-8.5). For each scenario, atmospheric moisture transport is derived throughout the 21st century using an established moisture-tracking model.In the absence of deforestation, we identify a critical global warming threshold of 3.7-4.0 °C, beyond which around one third of the Amazon loses stability. When deforestation is included, however, our simulations indicate a near system-wide transition (62-77% of the forest area) at global warming levels of 1.5-2.0°C combined with 20-30% deforestation across the basin. Most transitions are driven by drought-induced knock-on effects, causing long-range cascading impacts through the lack of atmospheric moisture recycling. Overall, our results highlight the need to limit warming to as close to 1.5 °C as possible and, halt deforestation at current levels (~17% across the basin), while ideally restoring degraded areas to reduce transition risks across the Amazon forest.