Wildfire Ozone Pollution Cuts Amazon Carbon Uptake by 24% of Fire Emissions

New research from James Cook University, the University of Exeter, and ETH Zurich finds that ozone pollution from wildfires cuts the Amazon's carbon uptake by an amount equal to about 24% of the carbon the fires release. The damage is worse during major droughts tied to El Nino, and the 2023-24 drought nearly doubled ozone damage compared with the previous decade. The authors call this a hidden loss because trees keep losing some capacity to absorb CO2 after the fires end. The study covers nearly three decades of observations from 1997 to 2024. Since almost all fires in the Amazon are started by people, either for land clearing or when agricultural burns spread, the extra ozone damage is largely preventable. The researchers say policies that cut deforestation and degradation address both direct fire emissions and the ozone pollution that weakens the remaining forest.