The Amazon rainforest now emits more carbon than it absorbs

A major and unprecedented transformation. The Brazilian Amazon rainforest, a victim of human activity, has since 2010 rejected more carbon than it absorbs, a historic setting for this important ecosystem in curbing global warming, according to a new study published on Thursday April 29th. The Nature of Climate Change (In English).

Between 2010 and 2019, the Brazilian Amazon rainforest, which accounts for 60% of the planet’s primary forest, lost part of its biomass. Thus, the forest released about 18% more carbon than it absorbed, with 4.45 billion tons discarded, versus 3.78 billion stored tons.

Right now, a priori, “Other countries are compensating for the losses of the Brazilian Amazon” And so on The Amazon region hasn’t changed completely yet, but it may soon.One of the study’s authors, Jean-Pierre Winner, a researcher at the French Research Institute for Agriculture, Food and the Environment (INRAe), told AFP.

Without forests, which are one of the planet’s “lungs” that absorb between 25% and 30% of the greenhouse gases emitted by humans, climate change would be much worse.

But for several years, scientists have been concerned about the loss of steam in tropical forests, and feared that they would play their role as less and less carbon sinks. Of particular concern comes from the Amazon rainforest, which accounts for half of the planet’s tropical forests.

“So far, forests, especially tropical forests, are protecting us by helping to reduce global warming. But our last fortress, the Amazon, is in the process of being tipped over.”

Jean-Pierre Winner is a researcher at INRAE

To Agence France-Presse

With melting ice caps, melting permafrost or disappearing coral reefs, the decline of the Amazon rainforest is one of the “breaking points” or “turning points” that scientists have identified as key elements including a fundamental modification. The climate system is undergoing a radical change that cannot be cured.

The study also highlights the unrecognized but primary responsibility for forest degradation. Unlike deforestation, which causes a forested area to disappear, degradation includes everything that can damage it, without completely destroying it: weak trees at the edge of deforested areas, selective cutting, small fires, and tree deaths associated with drought. Attacks that can be detected are less easily detected than large flattened areas.

Using a vegetation index from microwave observations, which makes it possible to examine the entire vegetation layer and not just the top of the canopy, the study concluded that forest degradation contributed to 73% of carbon loss, versus 27% for deforestation, but at a large scale. .

The study also shows an explosion of deforestation in the Brazilian Amazon in 2019, the year in which far-right President Jair Bolsonaro took power, but also a major drought: 3.9 million hectares were lost, a 30% increase from 2015, and nearly four times more than 2017 and 2018.