Need a breather with more oxygen? Put the oxygen friends in the dresser.

The origin of the matter, they say, could be the meeting of the first “supercontinent” (think Pangaea) is called. Columbia. Because of the amount of land on the surface of the ocean, erosion can bring enough nutrients to the oceans to support photosynthetic cyanobacteria. We can see evidence of this in the sedimentary rocks of the ocean floor that contain carbon.

The end of Columbia coincides with the first signs of a warming trend. This would have caused much of this organic carbon—as well as the carbonate that accumulates in the shallow waters around the Columbia—to be pumped into the mantle.

Then comes the Boring Billion, where even the movement of mantle and tectonic plates seems to have slowed down. But after this, the formation and breakup of the large landmasses of Gondwana and Pangea lead us to the map of the tectonic plate boundaries that appear as our modern world, with a significant drop in temperature.

The “Ring of Fire” around the Pacific Ocean today, for example, shows a large subduction zone that continues to transport carbon and sulfur compounds into the mantle. When such reductions were common, the planet’s atmosphere could become more inclined towards the atmosphere.

There is much more to the story, in terms of biology and geology. Our oxygen-rich air comes from many sources. But, the researchers write, “All of these mechanisms work above what is defined by the emission of carbon (and sulfur) between the Earth and the atmosphere, which we argue was driven by the evolution of the cooling of the cold Earth.”

PNAS, 2026. 10.1073/pnas.2534056123 (About DOIs).