Climate Change

Amazon River

The Amazon rainforest is sometimes referred to as the “lungs of the earth.” Many believe this is because the Amazon supplies the world with oxygen, but actually forests consume about as much oxygen as they produce.1 In fact, the carbon dioxide the Amazon breathes in is more crucial for our climate than the oxygen it breathes out. During photosynthesis, plants absorb carbon dioxide and store the carbon in their leaves, stems, and roots. With an estimated 390 billion trees, the Amazon is estimated to contain about 123 billion tons of carbon above and below ground, making it one of the biggest carbon reserves in the world.2, 3

When plants and other organisms decompose, they gradually release some of their stored carbon dioxide back into the atmosphere. While this is a natural part of the carbon cycle, destruction of forests accelerates this process, so much so that deforestation is the second leading source of greenhouse emissions behind fossil fuel burning.4 A study published in July 2021 found that in recent decades the eastern portion of the Amazon for the first time emitted more carbon dioxide than it absorbed, flipping it from a carbon sink to a carbon source. Due to a combination of fires, climate change, and land-use activities, particularly agriculture and cattle ranching, this area of the Amazon has now lost 30% of its forests.5

The Amazon is crucial in the fight against climate change, but it is also uniquely vulnerable to the impacts of climate change. While temperate organisms are accustomed to seasonal variations, tropical organisms like those in the Amazon tend to be more sensitive to temperature changes.6 The Amazon rainforest is also home to a huge portion of the world’s reptiles, amphibians, fish and insects, all of whom more vulnerable because they are unable to control their body temperature. In addition, while some global species can adapt to rising temperatures by migrating upslope or away from the equator, species in much of the Amazon basin are more locked in due to climate and geography.7

Perhaps most concerning is the way climate change interacts with other anthropogenic factors to create a negative feedback loop that is drying out the rainforest. Deforestation, fires, and warmer temperatures disrupt the Amazon’s hydrological cycle, leading to even more droughts, wildfires, and lengthier dry seasons, and so on. Some scientists fear this negative feedback loop could trigger an ecosystem shift from rainforest to savannah, a threshold called the tipping point.

Keeping the Amazon green protects the world from the negative effects of climate change. By the same token, fighting climate change protects the Amazon and its ability to store carbon. Whichever way you look at it, the relationship between the Amazon and climate change should inspire us to act now.

Works Cited

  1. Denning, Scott. (2019, August 24). Amazon fires are destructive, but they aren’t depleting Earth’s oxygen supply. The Conversation. https://theconversation.com/amazon-fires-are-destructive-but-they-arent-depleting-earths-oxygen-supply-122369?utm_source=twitter&utm_medium=twitterbutton
  2. Pitman, Nigel. (2013, October 30). How many trees are there in the Amazon? Field Museum. https://www.fieldmuseum.org/blog/how-many-trees-are-there-amazon
  3. Stein, Theo. (2021, July 14). Deforestation, warming flip part of Amazon forest from carbon sink to source. NOAA Research News. https://research.noaa.gov/article/ArtMID/587/ArticleID/2778/Deforestation-warming-flip-part-of-Amazon-forest-from-carbon-sink-to-source
  4. Plotkin, Mark. (2020). The Amazon: What Everyone Needs to Know. Oxford University Press. 10.1093/wentk/9780190668297.001.0001
  5. Gatti, L.V., Basso, L.S., Miller, J.B. et al. (2021). Amazonia as a carbon source linked to deforestation and climate change. Nature 595, 388–393. https://doi.org/10.1038/s41586-21-03629-6
  6. Freeman, B.G., Song, Y., Feeley, K.J. and Zhu, K. (2021), Montane species track rising temperatures better in the tropics than in the temperate zone. Ecology Letters, 24: 1697-1708. https://doi.org/10.1111/ele.13762
  7. Plotkin, Mark. (2020). The Amazon: What Everyone Needs to Know. Oxford University Press. 10.1093/wentk/9780190668297.001.0001