New Study: Amazon Could Hit Irreversible Tipping Point by 2040s if Deforestation Reaches 22–28%

A major new scientific study published in May 2026 and covered extensively by Mongabay modeled threshold scenarios under which the Amazon's self-reinforcing water cycle breaks down irreversibly. Researchers found that crossing 22–28% total Amazon deforestation — combined with global warming of 1.5–1.9°C — could trigger a widespread shift from closed-canopy tropical forest to degraded open forest and savanna-like ecosystems across large portions of the basin, a transition that could unfold over decades but may become self-sustaining by the 2040s. Current deforestation stands at approximately 17–18% of the original Amazon extent. The study underscores the narrow margin before irreversible ecosystem transformation becomes locked in. Conservation organizations are using the study to push for ARPA Communities and other 60-million-acre protection initiatives as emergency buffers. The findings reinforce the scientific consensus articulated by Thomas Lovejoy and Carlos Nobre that the Amazon tipping point is not hypothetical but a near-term risk.