Most of Our Oxygen Doesn’t Come From Where You Think

Forget rainforests. Here’s the real source of our air — and why it’s in danger

This “Rainforest” stock photo is beautiful, luscious, and probably full of invisible oxygen — but it’s not the main source of our breathable air. Photo by Hidayat Abisena.

As a child, when I learned about how plants produce the oxygen that we breathe, I imagined that I could see that oxygen in the air. In my mind’s eye, I saw vast waves of oxygen rising from a lush tropical rainforest.

The image makes sense — if plants produce oxygen, it stands to reason that bigger plants produce more, and areas of dense vegetation produce more oxygen than areas with only sparse plants. A rainforest, with its multiple levels of vegetation, surely produces the majority of our oxygen, right?

Not quite.

Consider the Amazon, the world’s largest rainforest. By one estimate, this entire area is only responsible for a piddling 6 percent of the world’s oxygen production.

So if lush rainforests, filled with many different plant species all living in somewhat tenuous and competitive harmony, aren’t responsible for the creation of most of the air we need to breathe… where’s it coming from?

And are we in danger of accidentally destroying our own air supply in a climate catastrophe?

The Earth is a Blue Marble