One Earth, Volume 1, 25 October 2019,
A new threat now confronts the Amazon in the form of a massive infrastructure program, the Initiative for the Integration of the Regional Infrastructure of South America, or IIRSA. This article presents results of a projection analysis showing that IIRSA could push the Amazonian forest past a “tipping point,” replacing it with tropical savanna. Such an event would degrade biodiversity, reduce carbon storage, and harm continental agriculture, dependent on moisture transport from forest-based rainfall recycling. The article considers environmental policy in Brazil and discusses its weakening over time. One short-term approach to conservation is provided by indigenous resistance to development forces. The article presents a case study of the Munduruku people, who recently stopped construction of a large dam on the Tapajós River in defending their territories. It argues that more research is needed to understand the impacts of IIRSA, which is proceeding in the dark.