Parts of the Amazon Emit More Carbon Than They Absorb
The Amazon River Basin is home to our planet's largest rainforest -- roughly the size of the 48 contiguous US states and covering about 40% of the South American continent. The Amazon Basin also contains 10% of all known species, 20% of the world's fresh water, and is home to 30 million people. This vast forest has traditionally been a carbon sink, but for years scientists have feared that the Amazon could instead turn into a carbon source. A new study in Nature has now confirmed that parts of Southeastern Amazonia are indeed emitting more carbon dioxide than they are absorbing.
Why This Matters
If global warming prevents the Amazon from removing atmospheric carbon, the forest could be trapped in a positive feedback loop, meaning the negative effects of climate change will only accelerate and intensify. In addition to carbon sequestration, rainforests release moisture into the air, a process that comprises as much as 35% of the region's rainfall.
This new study suggests that the areas with the greatest changes are those that have been heavily deforested or burned to clear land for industrial uses. The Amazon is facing compounding threats, making an even more urgent case for the world to protect 30% of nature by 2030.
NASA: Tracking Amazon Deforestation, April 19, 2021.
Seeing the Forest For the Trees
The Amazon has been losing its ability to absorb carbon for decades. In 2015, Nature published a 30-year study that showed "a long-term decreasing trend of carbon accumulation" due to climate change and earlier deaths of trees.
In 2018, an essay in Science Advances suggested that the Amazon was on the edge of turning into a savanna: "The precious Amazon is teetering on the edge of functional destruction and, with it, so are we … We stand exactly in a moment of destiny: The tipping point is here, it is now."
This new study is the first large-scale measurement of this trend, encompassing different altitudes across thousands of square kilometers, and showing how the changes have affected atmospheric carbon.
That said, the Brazilian government hasn't shown signs of curbing deforestation in the Amazon. Brazil's president, Jair Bolsonaro, has leveled thousands of square kilometers of the rainforest. The government, under increasing pressure, has recently announced plans to counter the trend, but spikes in deforestation have continued.
However, some think there is still some hope to save the Amazon, even if some changes have been irreversible. Thomas Lovejoy of George Mason University, the co-author of the "Amazon tipping point: Last chance for action" op-ed, told the New York Times: "I don't think you'll ever get it back to what it was, but you can certainly improve it."
BBC: Is the Amazon rainforest beyond saving?, Feburary 11, 2020.
DW: Who is responsible for the Amazon deforestation fires in Brazil?, October 1, 2020.