Why The Amazon Rainforest is No Longer a Carbon Sink

This article explains a recent study that has concluded the Amazon rainforest is now emitting more CO2 than it absorbs. Read more to find out about the study and how the largest forest in the world has deteriorated to the point where it can no longer keep up with the world’s carbon production.

Written by: Thomas Tinmouth

The Amazon Rainforest is world renowned for being the largest forest in the world and containing some of the most unique and plentiful wildlife on the planet. The forest covers parts of 9 different countries taking up approximately 40% of the entire Southern American Continent. The forest is 6,000,000 square km and shrinking by the day. With a combination of wildfires, increasing temperatures, and land being cleared for agriculture, this once beast of a forest and climate change combatant is slowly but surely losing its dominant presence. Arguably the greatest thing about the Amazon is its ability to capture CO2, at least, that was the greatest thing. An alarming study has revealed the Amazon Rainforest now emits more CO2 than it captures, and that is horrifying. Since 1960 trees and plants have sucked up a quarter of all fossil fuel emissions with the Amazon leading the charge as the world’s largest forest, but we have not exhausted this valuable resource. We asked it to work too hard, now, the need to cut our fossil fuel emissions is direr than ever. If the largest carbon sink we have on the planet has switched from a sink to an emitter, we are going to have to change the way we live on this planet a lot faster than we previously thought. 

The Science Points in One Direction

_{Figure 1 – The Amazon Rainforest being devastated by forest fires.}

The tests that revealed parts of the Amazon emitting CO2 were groundbreaking. Previously, there was knowledge that the sink was deteriorating and areas were most likely emitting CO2, but these tests were done by satellite in which results can be skewed due to cloud cover and ground measurements of trees over a smaller area. This study was so amazing because it used direct atmospheric measurements spanning a wide region. How they completed these tests was by using small planes to measure CO2 levels up to 4,500m above the forest over the last decade, giving researchers the ability to see how the forest makeup has been changing.

One of the more worrying discoveries from this study was the fact that the Amazon emits CO2 without forest fires being present. As deforestation from agriculture and fires is rampant in the Amazon, forests adjacent to these affected areas become more susceptible the following year to fires. As more trees are ripped and burned down, there is less rain as trees produce much of the area’s precipitation. This means more droughts and heatwaves, circling back to more fires and more trees being burnt down. It is an amplifying feedback loop that does not seem to show any trace of slowing down. Research from the journal Nature found that fires in the Brazilian Amazon released about 1.5bn tonnes of CO2 a year. The growth of new trees in the forest would remove about 0.5bn tonnes of this CO2, leaving 1bn tonnes left in the atmosphere. This is the same amount of annual emissions as Japan.

Why Is This Happening?

_{Figure 2 – Thick Amazon rainforest is cut down to make room for agriculture.}

So what exactly is causing the Amazon to go from a carbon sink to a carbon emitter? There are three main culprits, forest fires, increasing temperatures, and agriculture. Forest fires and increased heat feed off of each other, as previously mentioned they are big parts of the amplifying feedback that is ruining this forest. The worst part is (or one of the many “worst parts”) that many of these fires are actually set deliberately to clear land for beef and soy production. So, there are the emissions from the fire, the emissions of cattle and their harsh impact on the land, and fewer trees to suck up this CO2. “The worst part is we don’t use science to make decisions,” said Luciana Gatti, at the National Institute for Space Research in Brazil. “People think that converting more land to agriculture will mean more productivity, but in fact, we lose productivity because of the negative impact on rain.” The fewer trees in the Amazon, the less rain, the less rain, the worse it is for crops and cattle. Most of the time the practices in these cleared areas are very intense agriculture for 3-5 years, and then repeat the process elsewhere in the forest, once again clearing more land. The area left behind by the intensive agriculture is so damaged that a once lush forest turns to savannah, with no hope of returning to the forest it once was. 

Role of The Brazilian Government

_{Figure 3 – Map of Amazon primary forest loss in 2020.}

So what is Brazil doing to protect their invaluable forest? The answer is quite devastating. They have continually ignored science and have actually increased deforestation. This is in large part due to their president Jair Bolsonaro, a right-wing leader with direct ties to agribusiness. Under his leadership deforestation has surged to a 12-year high and forest fires are at their highest levels since 2007. It is widely regarded within the scientific community that if Bolsonaro remains president, the Amazon rainforest will end in an ultimate collapse. This would devastate Brazil’s economy and the world’s chances of beating climate change. It is estimated that Brazil’s soy industry loses $3.5bn a year from increasing temperatures and forest destruction. 

Luciana Gatti, at the National Institute for Space Research in Brazil, says that a “global agreement to save the Amazon” is needed. Some European nations have mentioned a potential trade block with Brazil and partnering countries if the Brazilian government does not do more to solve the issues the Amazon is facing.

The studies explained in this article are not the only ones that reveal alarming evidence of the Amazon deteriorating to the point where it is actually emitting CO2. Prof Scott Denning, at Colorado State University, says “There are complementary studies with radically different methods that come to very similar conclusions.” This shows the overwhelming amount of scientific evidence that points to the same conclusion. This is not solely a Brazil problem, it is a worldwide problem. Action must be taken to stop deforestation in the Amazon if there is any chance of achieving the Paris Climate Accord and defeating climate change. Governments around the world must take a stand, our future depends on it.