Road expansion risk predicts future hotspots of tropicaldeforestation

Jayden E. Engerta, Carlos M. Souza Jr., Fritz Kleinschrothd, F. Yoko Ishidaa, Stefany P. Costa, Jonas Botelho Jr. e William F. Laurancea. Proceedings of the National Academy of Sciences (PNAS), 2025. https://doi.org/10.1073/pnas.2502426122.

Abstract

Roads act as conduits for human incursions and hence underlie many of humanity’simpacts on nature, including deforestation, wildfires, and natural-resource overexploita-tion. Unfortunately, existing roadmaps often drastically underestimate the true extentof road networks and future predictions of road-related impacts rely on incomplete andoutdated data, undermining development planning and conservation decision-making.Here, we develop a multivariate “road expansion risk” index to identify areas prone toroad building and therefore vulnerable to road-related environmental impacts. Using amassive road dataset—137 million 1-ha raster cells drawn from three different sourcesarrayed across the Amazon and Congo basins and insular Asia-Pacific region—we predictroad-prone locations via a statistical model that integrates a range of biophysical, socio-economic, and administrative data. This highly integrative, large-scale approach allowedus to identify areas likely to experience future road building and regions that may containunmapped roads. Importantly, our road expansion risk index is a strong predictor offorest loss and degradation and can hence identify future road building and deforestationhotspots, even for the many tropical forest locales with grossly deficient road data.