Bends in the Amazon River, aerial view, Peru.
Image: DeAgostini/Getty Images
Hundreds of high-altitude air samples collected over the last decade showed that southeastern Amazon, in particular, has shifted from a "sink" to a source of carbon dioxide, the main greenhouse gas, they reported in the journal Nature.
Terrestrial ecosystems worldwide are crucial as the world struggles to curb CO2 emissions, which topped 40 billion tonnes in 2019.