Interactions among Amazon land use, forests and climate: prospects for a near-term forest tipping point

TLDR

Model experiments and rising biofuel demand predict that Amazon forest could be largely replaced by savannah‑like vegetation by century’s end, with fire, drought, and logging accelerating a potential near‑term dieback. Fire‑sensitive investments and protected areas are increasing fire control and limiting agricultural expansion. If current El Niño‑driven droughts persist, roughly 55 % of Amazon forests will be cleared, logged, damaged, or burned in the next 20 years, releasing 15–26 Pg of carbon.

Abstract

Some model experiments predict a large-scale substitution of Amazon forest by savannah-like vegetation by the end of the twenty-first century. Expanding global demands for biofuels and grains, positive feedbacks in the Amazon forest fire regime and drought may drive a faster process of forest degradation that could lead to a near-term forest dieback. Rising worldwide demands for biofuel and meat are creating powerful new incentives for agro-industrial expansion into Amazon forest regions. Forest fires, drought and logging increase susceptibility to further burning while deforestation and smoke can inhibit rainfall, exacerbating fire risk. If sea surface temperature anomalies (such as El Niño episodes) and associated Amazon droughts of the last decade continue into the future, approximately 55% of the forests of the Amazon will be cleared, logged, damaged by drought or burned over the next 20 years, emitting 15–26 Pg of carbon to the atmosphere. Several important trends could prevent a near-term dieback. As fire-sensitive investments accumulate in the landscape, property holders use less fire and invest more in fire control. Commodity markets are demanding higher environmental performance from farmers and cattle ranchers. Protected areas have been established in the pathway of expanding agricultural frontiers. Finally, emerging carbon market incentives for reductions in deforestation could support these trends.