THINK PIECE / WILL WE RUN OUT OF BREATHABLE AIR SOON?

THE MIRACLE OF A CONSTANT OXYGEN SUPPLY

Tourists to Stonehenge feeling the breeze 

By F. Stop Fitzgerald, PillartoPost.org Photo and Science Editor--It’s a question that floats in and out of our collective minds—especially when standing on a breezy coastal bluff, watching waves roll in under a crisp, oxygen-rich sky: Why doesn’t Earth ever run out of air? 

Why, despite our factories, traffic jams, and burning forests, can we still breathe? 

The short answer? Earth's atmosphere is a brilliantly balanced, self-renewing system—at least, so far. The breathable air we rely on—roughly 78% nitrogen, 21% oxygen, and a dash of carbon dioxide and other gases—doesn’t sit still. It circulates constantly, stirred by winds, weather systems, and the rotation of the planet. 

But the deeper reason we don’t run out lies in Earth’s biosphere: the partnership between plants, oceans, and atmospheric chemistry. 

Photosynthesis 

Is the Planet’s Life Support Plants, algae, and oceanic phytoplankton continuously convert carbon dioxide into oxygen through photosynthesis. They act as Earth’s lungs, exhaling oxygen as a byproduct of capturing sunlight. While old-growth forests help, it’s the oceans—those vast blue mirrors you see from the coast—that do the heavy lifting. 

Around 50 to 80 percent of all atmospheric oxygen is generated by microscopic plankton drifting just below the surface. 

A Stable Mix Through Natural Feedback Earth's atmosphere has stayed remarkably stable for millions of years thanks to built-in feedback loops. 

Too much carbon dioxide? Photosynthetic life ramps up. 

Volcanic eruption? The ash and sulfur might temporarily cool the planet, but the atmosphere adjusts. 

The natural carbon and oxygen cycles, although delicate, are robust on a planetary scale. 

What About the Smog in Cities? 

Urban air pollution is real, but it's local. In cities, air becomes temporarily fouled due to vehicle emissions and industrial output, but prevailing winds and weather patterns usually disperse it. 

That’s why standing on a coastal cliff feels so different—there, the ocean acts not just as a source of oxygen, but also as a stabilizer and purifier. 

The scale and motion of the atmosphere smooth out much of the damage we do, at least for now. 

Still, This Balance Isn’t Guaranteed Forever Earth’s atmosphere is vast, but not infinite. 

Human activity—especially deforestation, fossil fuel burning, and unchecked carbon emissions—is testing the limits of this balance. 

Climate change, acidifying oceans, and mass species die-offs are warning signs. We haven’t run out of air—but we’re learning that even resilient systems can be pushed too far. For now, when you stand on that cliff, take a deep breath. You're inhaling part of a miracle—a living, circulating sky that’s been running the same oxygen relay for over two billion years. 

*Why?  Is a series exclusive to PillartoPost.org online magazine style blog.