|Great Oxygenation Event|
(Aka GOE, Oxygen Catastrophe, Great Oxidation) The first appearance of bacteria-induced free oxygen in the Earth's atmosphere about 2,400 million years ago. It is called a catastrophe because almost every living thing on Earth died as a result of this massive climate change.
Evolution and Oxygen
1. It is the first example in Earth's history of living organisms drastically changing the atmosphere. 3,500 million years ago oxygen began to be produced by organisms that emitted it as a waste product. Initially, the oxygen they produced would have quickly been removed from the atmosphere by the weathering of minerals such as iron.
The GOE was the point when these minerals became saturated and could not capture more oxygen, hence the excess free oxygen accumulated in the atmosphere.