Thanks to humanity, the Brazilian Amazon is now releasing more carbon dioxide than it absorbs

Experts predicted 10 years ago that rainforests might "flip" from being carbon sinks to emitters. It's now reality

By Matthew Rozsa

Staff Writer

Published May 5, 2021 6:15AM (EDT)

Amazon rainforest, Brazil (Getty Images)
Amazon rainforest, Brazil (Getty Images)

A recent study published in the journal "Nature Climate Change" found that the Brazilian Amazon released roughly 20 percent more carbon dioxide than it absorbed during the 2010s. More specifically, the rain forest absorbed 13.9 metric tons of carbon dioxide between 2010 and 2019 — but released 16.6 billion metric tons during that same period. (To put that in context, human fossil fuel combustion is believed to produce around 35 billion metric tons of carbon dioxide.)

The authors point to poor land management policies like forest degradation as well as deforestation as causes. Notably, deforestation of the Amazon has greatly increased during the reign of Brazilian President Jair Bolsonaro. 

But forest degradation, as the authors write, is the primary culprit in terms of making the rainforest a carbon fount. Forest degradation happens when a forest's biological diversity and wealth is permanently diminished.

Indeed, forest degradation contributed 73% of the "gross biomass loss" of the Amazon, compared to deforestation, which contributed 27% of that loss. 

"Forest degradation has become the largest process driving carbon loss and should become a higher policy priority," the authors write.

Rainforests have been called the "lungs" of the Earth, and play a major role in the global carbon cycle. That the Amazon rainforest would become a net emitter of carbon was not entirely surprising given trends, however.

"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," Jean-Pierre Wigneron, a co-author of the paper, told Agence France-Presse in a statement.

Wigneron added, "We don't know at what point the changeover could become irreversible."

Rainforests are not always carbon emitters. In 2009, scientists at the Climate Congress in Copenhagen, Denmark, warned that rising temperatures and droughts could transform tropical forests into being carbon emitters — rather than carbon sinks, as they were thought to have been previously. At the time, there was some hope that the world's forests might rise to the occasion and sop up the excess carbon dioxide caused by human industrial activity. Now, that seems to not be the case, and the Climate Congress warning proved to be prophetic. 

This is the latest bit of bad news in a series of recent reports which raise red flags about how human industrial activity is changing the planet's atmosphere on a mass scale. In September the World Wildlife Fund (WWF) revealed that there has been a 68 percent decline in the population sizes of "mammals, birds, amphibians, reptiles and fish" since 1970. Scientists at McGill University revealed last year that the threshold for dangerous global warming is likely to be reached between 2027 and 2042.

Similarly, the World Health Organization (WHO) estimates that roughly 250,000 people will die annually because of factors related to climate change scientists between 2030 and 2050. Finally a study published last month revealed that human beings have not significantly reduced the amount of land we inhabit over the past 12,000 years, strongly suggesting that it is poor management of resources rather than the loss of "wild" lands which is causing climate change.

President Joe Biden has attempted to address climate change by reentering the United States into the Paris climate agreement, beefing up environmental regulations and promising to reduce America's greenhouse gas emissions by 50% to 52% below the country's 2005 levels by no later than 2030.

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By Matthew Rozsa

Matthew Rozsa is a staff writer at Salon. He received a Master's Degree in History from Rutgers-Newark in 2012 and was awarded a science journalism fellowship from the Metcalf Institute in 2022.

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