Volcanic activity billions of years ago set the stage for Earth's oxygen-rich atmosphere, research suggests

It is widely believed that Earth's atmosphere has been rich in oxygen for about 2.5 billion years due to a relatively rapid increase in microorganisms capable of performing photosynthesis. Researchers, including those from the University of Tokyo, provide a mechanism to explain precursor oxygenation events, or "whiffs," which may have opened the door for this to occur.