What is the great oxygen catastrophe?

The Great Oxygen Catastrophe, also known as the Great Oxidation Event, occurred around 2.4 billion years ago when cyanobacteria began producing significant amounts of oxygen through photosynthesis. This dramatic increase in atmospheric oxygen led to the extinction of many anaerobic organisms that thrived in low-oxygen environments. The rise of oxygen also paved the way for the evolution of aerobic life forms, fundamentally transforming Earth's atmosphere and ecosystems. This event marked a crucial turning point in the planet's biological and geochemical history.