Triggered by the 2015-16 El Niño, extreme drought and associated mega-wildfires caused the death of around 2.5 billion trees and plants and emitted 495 million tonnes of CO2 from an area that makes up just 1.2 per cent of the entire Brazilian Amazon rainforest, and 1 per cent of the whole biome.
The stark findings, discovered by an international team of scientists working for more than eight years on a long-term study in the Amazon before, during and after the El Niño, have significant implications for global efforts to control the atmospheric carbon balance.
In normal circumstances, because of high moisture levels, the Amazon rainforest does not burn. However, extreme drought makes the forest temporarily flammable. Fires started by farmers can escape their land and trigger forest fires.