The Brazilian Amazon, where dense rainforest was long believed to be absorbing human-caused pollution, has emitted close to one-fifth more carbon dioxide (CO2) into the atmosphere than it has stored.
An alarming new study found that between 2010 and 2019, the Amazon released 16.6billion tonnes of CO2, while sucking up 13.9bn tonnes.
“We half-expected it, but it is the first time that we have figures showing that the Brazilian Amazon has flipped, and is now a net emitter,” the study’s co-author Jean-Pierre Wigneron, a scientist at France’s National Institute for Agronomic Research (INRA), told AFP. “We don’t know at what point the changeover could become irreversible.”
The research was published on Thursday in the journal Nature Climate Change.
Researchers compared the volume of CO2 sunk into the forest to the volumes released by fires or cutting down trees.
Trees, especially the old growth forests which have been standing for millennia, store carbon and have had an impact on slowing the climate crisis being driven by man-made pollutants like the burning of fossil fuels.
However the reverse is also true: when forests burn, tree carbon matter is pumped into the air as CO2, adding to emissions levels.
The Amazon, one of the planet’s richest regions of biodiversity and home to thousands of indigenous peoples, suffered the worst blazes in a decade last year.
The destruction of the rainforest has proliferated under right-wing President Jair Bolsonaro, whose government has weakened environmental protections and pushed development of mining, cattle-ranching and logging.
Mr Bolsonaro has frequently played down the Amazon fires, calling evidence produced by his own government showing thousands of blazes a “lie”.
The study also found that deforestation increased by four times in 2019 compared with 2017 and 2018, leaping from around 2.5million acres to 9.6million acres – an area more than twice the size of Connecticut.