“The Amazon rainforest produces 20% of the world's oxygen”

The idea that the Amazon rainforest supplies 20% of the world's oxygen is a widespread misconception, often fueled by its evocative nickname, "the lungs of the Earth." This figure likely originated from a misunderstanding of the Amazon's significant role in photosynthesis on land. While the Amazon does indeed produce a substantial amount of oxygen through its vast plant life, it's crucial to consider the entire ecosystem's oxygen balance, not just production.

Scientifically, mature forests like the Amazon are in a state of near equilibrium when it comes to oxygen. The immense amount of oxygen generated by plants through photosynthesis is almost entirely consumed within the rainforest itself through respiration by the plants, animals, and, significantly, by microbes decomposing dead organic matter. This means the net release of oxygen into the atmosphere from the Amazon is effectively zero. The vast majority of the oxygen we breathe, estimated to be between 50% and 80%, actually comes from microscopic marine organisms, primarily phytoplankton, in the world's oceans.

People commonly embrace this myth due to the Amazon's sheer scale and visible lushness, making it seem like an obvious source of breathable air. The "lungs of the Earth" metaphor, while powerful for emphasizing the rainforest's ecological importance, inadvertently reinforces this inaccurate oxygen claim. While the Amazon is not a net oxygen producer for the planet's atmosphere, its critical roles as a carbon sink, a biodiversity hotspot, and a regulator of regional and global climate remain undeniable and vital for the health of our planet.