New Oxygen research. (Introduction)

by David Turell , Tuesday, October 21, 2014, 23:10 (3685 days ago)

Oxygen can be freed from CO2 in the upper atmosphere. Some O2 may have been around from the beginning of the Earth:-http://www.sciencedaily.com/releases/2014/10/141003092259.htm-"About one fifth of Earth's atmosphere is oxygen, pumped out by green plants as a result of photosynthesis and used by most living things on the planet to keep our metabolisms running. But before the first photosynthesizing organisms appeared about 2.4 billion years ago, the atmosphere likely contained mostly carbon dioxide, as is the case today on Mars and Venus.- 
"Over the past 40 years, researchers have thought that there must have been a small amount of oxygen in the early atmosphere. Where did this abiotic ("non-life") oxygen come from? Oxygen reacts quite aggressively with other compounds, so it would not persist for long without some continuous source." (my bold)