But its not a falsehood to call the Amazon "lungs of the Earth" - its an illustration of the fact that the Amazon, until perhaps recently has been the "largest residual terrestrial carbon sink on the planet"[1]

The article opens with this headline which is false: "Humans could burn every living thing on the planet and still not dent its oxygen supply."

If every living thing was burnt, the planet would cease to resupply oxygen and most of the free oxygen reserves in the atmosphere and oceans would be consumed through geological processes. It would take millennia to complete but its not an outcome which is valid to describe in an educational or truth straightening context as "not a dent".

[1]https://www.nature.com/articles/nature14283 "Long-term decline of the Amazon carbon sink"