The Brazilian Amazon has been a net carbon emitter since 2016

Rapid deforestation outweighs carbon capture by remaining trees

IF tropical forests were Earth’s respiratory system, the Amazon would be a full lung. The region is home to half of the undisturbed forests of the tropics. Its flora absorbs 1.5 billion tons of carbon dioxide (CO2) per year, equivalent to 4% of emissions from fossil fuels.

This lung is being deforested at a cancerous rate. A chunk nearly the size of Kuwait is felled or burned every year. This removes both CO2-absorbs trees and releases their stored carbon into the air.











The Brazilian Amazon is vast – 5.37 million square kilometers in 2005. Here you can see a five-year average of carbon flux from the forest. Most of its area (in green) CO absorbed2 and put it away.

In the early 2000s, land-hungry soybean farmers and cattle ranchers cleared 20,500 km2 a year. Where deforestation has taken place, the carbon stored by the Amazon has been emitted (zones of purple).

Towards the end of the decade, CO2 production fell when the central bank cut credit to companies facing fines for deforestation, and more forest areas gained legal protection. The Brazilian Amazon has once again become a net carbon sink.

But in 2012 the government granted an amnesty for past deforestation, and in 2014 a recession began, which may have prompted farmers to seek new land.

In 2016, emissions jumped: 32,600 km² were felled in that year alone, and the destruction has continued apace ever since.

Over the past 20 years, the Brazilian Amazon has lost 350,000 km2 and emitted 13% more CO2 which he did not absorb. The trend shows few signs of reversing anytime soon.

The worst-case scenarios involve a tipping point in tree loss, beyond which the forest could no longer produce enough moisture to sustain its ecosystem. But even if this catastrophe can be avoided, serious damage has already been done. Each year of continued logging reduces the forest’s ability to retain carbon: since 2001, the Brazilian Amazon’s absorption rate has decreased by 1.2% per year.

Two analyzes from 2021 identified chunks of the Amazon as net emitters. One, in Nature, found this pattern in atmospheric samples from the southeastern Amazon. The other builds on a paper in Natural climate change, which combined satellite images of tree losses with data on soil types; tree densities and ages; and the impact of land use change on emissions. Based on the resulting estimates of CO2 streams, authors at MAAPa conservation group, calculated that between 2001 and 2020 net emissions from the Brazilian Amazon exceeded those of Argentina or Pakistan, although the entire Amazon, including parts of the forest of the neighboring countries, has remained a net carbon sink.

Both of these studies measured emissions over long periods of time. Neither indicated whether recent trends across the region were positive or negative. To find out, we compared the latest data on CO2 flow with annual tree cover maps to generate the above maps.

Greenhouse gas fluxes, average for 2001-21

Tons of CO₂ equivalent per km²

Some regions with vertices

emissions outweigh greater

modest absorption zone

Brazil has pledged to end illegal deforestation by 2028. However, Jair Bolsonaro, the president, has relaxed enforcement of environmental safeguards. Satellite images suggest that twice as much forest has been lost in 2022 as the January-April average in 2010-21. The future trajectory of global warming depends in part on Mr. Bolsonaro being re-elected this year.

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