Around 2.4 billion years ago, tiny microbes helped trigger Earth’s biggest environmental revolution by filling the atmosphere with oxygen

Years before plants covered continents or animals roamed the surface of the planet, Earth’s atmosphere was almost entirely ...
Ars Technica

Want an oxygen-rich atmosphere? Stuff oxygen’s friends in the mantle.

Planet Earth has some pretty great qualities going for it. (Negative reviews mostly revolve around the staff and clientele.) Pretty high on the list of positives is a richly oxygenated atmosphere. But ...