Airborne lasers reveal a vast lost Amazonian civilization of millions

Airborne lidar scans across 1,737 square miles of western Brazil uncovered 400+ earthworks, roads, and geoglyphs linked to the Aquiry culture dating to about 2,500 years ago, implying a connected Amazonian civilization of 1.25–3 million people and a notable ecological footprint from maize and squash farming and forest management; published in Nature, the findings challenge the view of the Amazon as pristine and could reshape climate models, though population estimates are debated and more research is needed.