THE Amazon rainforest stores the equivalent of almost two years of global carbon emissions, but its role as a carbon sink is under threat, according to a new study.

Following an analysis of satellite data provided by the Planet company, the US-based Amazon Conservation Association has concluded that, with deforestation, the rainforest could start contributing more carbon than it absorbs from the atmosphere.

Researchers found Amazon trees held 56.8 billion metric tons of carbon above ground in 2022. That is 64.7 million metric tons more than in 2013, they said, making the Amazon a carbon sink over the last decade.

But it´s now a “very small buffer,” according to an analysis by Planet. “There’s reason to worry that the biome could flip from sink to source with ongoing deforestation.”

Clearing vegetation eliminates trees that absorb carbon. Cutting and burning them puts more carbon into the atmosphere. And cleared land is often used for farming and livestock grazing, which produce greenhouse gases.

State University of Campinas ecologist Professor David Lapola, who was not part of the study, told the Associated Press news agency that the findings were consistent with other studies.

While overall carbon absorption in the Amazon basin remains positive when considering only intact areas, the inclusion of forest degradation changes the picture, Prof Lapola said.

However, he added that deforestation, which has destroyed roughly 20 per cent of the Amazon, is an easier problem to solve than the impact of climate change on the rainforest, which is struggling with a severe drought for the second year in a row.

“It is crucial to turn our attention to how climate change and extreme weather events could alter the carbon sink in untouched forests," Prof Lapola said.

“This is considerably more difficult to address as it involves a concerted effort to reduce greenhouse emission.”