LiDAR Data Reveals 3 Million People Once Lived in Just 3% of Amazon

New research using LiDAR remote-sensing technology suggests that up to 3 million people inhabited the Amazon rainforest before European contact, concentrated in just 3% of the surveyed forest area. A consortium of archaeological and remote-sensing teams analyzed over 20,000 square kilometers of LiDAR data spanning Brazil, Bolivia, and Ecuador to reach this estimate. The technology works by firing laser pulses from aircraft to penetrate the forest canopy and build detailed 3D terrain maps, revealing ancient causeways, plazas, terraces, and irrigation canals invisible to ground-based surveyors. Rather than scattered settlements, the data shows pre-Columbian populations clustered densely in specific zones, challenging long-held assumptions about how indigenous Amazonians organized their societies. The findings were further validated through targeted ground excavations, combining computational tools like machine learning with traditional archaeological fieldwork.