Amazon rainforest turned carbon source during 2023 drought

Tuesday 17 - 16:50

By: Dakir Madiha

Amazon rainforest turned carbon source during 2023 drought

The Amazon rainforest shifted from absorbing carbon to releasing it during the extreme drought of 2023, emitting millions of tonnes of carbon into the atmosphere instead of storing it, according to new research from the Max Planck Institute for Biogeochemistry.

The study, published in AGU Advances, estimates that the Amazon released between 10 million and 170 million tonnes of carbon in 2023, accounting for roughly 30 percent of net carbon emissions from all tropical land areas that year. The findings add to concerns that climate change and deforestation are pushing the world’s largest tropical forest closer to a potential tipping point.

Researchers led by Santiago Botia combined measurements from the Amazon Tall Tower Observatory, satellite observations and vegetation models to track carbon flows across the basin. They found that unusually high temperatures in 2023, averaging 1,5 degrees Celsius above the 1991 to 2020 baseline, along with severe atmospheric drought between September and November, sharply reduced the forest’s ability to absorb carbon.

Susan Trumbore, who coordinates the German contribution to the ATTO project at the University of California, Irvine, said the abnormal carbon release was mainly driven by weakened carbon uptake by vegetation rather than an increase in fire related emissions. Fire activity remained within the range observed over the past two decades, the researchers reported.

The shift began in May, with carbon emissions peaking in October as persistent heat and low humidity caused plants to limit photosynthesis. Although the forest absorbed more carbon than usual between January and April, that gain did not offset losses during the driest months.

Separate research published in Communications Earth & Environment in November examined how deforestation is reshaping the Amazon’s regional climate. Scientists from Brazil’s National Institute for Space Research found that heavily deforested areas experienced surface temperatures up to 3 degrees Celsius higher during the dry season compared with regions retaining more than 80 percent forest cover.

The study also showed that areas with less than 60 percent forest cover now display climate characteristics similar to savanna transition zones, including 25 percent less rainfall and an average of 11 fewer rainy days per year. Luiz Aragão, a researcher at the institute who presented the findings at COP30 in Belém, said tropical forests exert a significant influence on climate with consequences for multiple sectors of society.

Since 1985, the Brazilian Amazon has lost about 520,000 square kilometers of native vegetation, an area larger than Spain. While deforestation rates have declined in recent years, more than 6,300 square kilometers were cleared in 2024 alone.

Trumbore said the future of the forest is closely tied to global carbon dynamics. As tropical forests degrade and lose trees, they release stored carbon and become less capable of absorbing carbon dioxide, intensifying climate change.