Smoke rises during a fire in an area of ​​the Amazon rainforest near Porto Velho, Rondonia state, Brazil, September 10, 2019.

Bruno Kelly | Reuters

According to a new study, the Amazon rainforest emits more carbon than it can absorb.

The rainforest was once a carbon sink – that is, it absorbed more carbon than it released – but it now emits more than 1 billion tons of emissions each year, mainly due to forest fires and deforestation.

The nine-year research project, published on Wednesday, was led by the Brazilian National Institute for Space Research in collaboration with scientists from several countries, including the United States, the Netherlands and New Zealand.

Drones collected samples to measure carbon levels in four locations in the Amazon, with the long time frame of the study allowing researchers to account for the annual variation in forest carbon levels.

The Amazon’s carbon footprint – the final balance between emissions and carbon uptake – showed that 1.06 billion tons of CO2 were released into the atmosphere annually between 2010 and 2018. According to the study, 0.87 billion tons of emissions came from the Brazilian Amazon.

Incineration was the largest source of CO2 emissions from the Amazon, accounting for 1.5 billion tons of CO2 emissions, according to the study. If there were no fires or deforestation, the agency said, the Amazon would remove nearly 0.5 billion tons of carbon from the atmosphere.

Researchers found that regions of the rainforest where deforestation was above 30% had 10 times more carbon emissions than areas with 20% or less deforestation.

The most heavily deforested areas of the Amazon had drier, warmer, and longer dry seasons, the study found. In dry months, the temperature in these parts of the Amazon rose by 2 degrees Celsius, which increased the forest’s flammability and reduced its ability to absorb carbon dioxide.

Emanuel Gloor, one of the researchers at the University of Leeds in the UK, told CNBC that the study showed immediate need for action.

“The data shows that forests in much of the Amazon region that are increasingly exposed to the heat are suffering,” he said in an email. “It is another wake-up call that the attack on the Amazon forests should be stopped urgently.”

Although the Amazon stretches across nine countries, about 60% of the forest is in Brazil. According to Greenpeace, the Brazilian Amazon has lost more than 18% of its rainforest in the past 40 years.

In 2019, Brazil’s President Jair Bolsonaro was criticized for telling a UN assembly that the Amazon was “untouched and virtually untouched” after the rainforest was found to burn at record speed.

After increasing international pressure, he later authorized the Brazilian military to fight the fires. Last month, Reuters reported that Bolsonaro put a 120-day ban on unauthorized outdoor fires and switched the military to contain forest fires in the Amazon.