Human activity in the 19th through 22nd centuries led to the catastrophic decline and wholesale collapse of the natural world. Of the approximately 30 million known species of flora and fauna, more than 90% were lost as a result of pollution, climate change, deforestation, mining, agriculture, urban sprawl, overfishing and hunting. Extinctions on this scale had occurred only five times previously in the whole of Earth's 3 billion year natural history.