There have been 5 mass extinction events in Earth's history. In the worst one, 250 million years ago, 96 percent of marine species and 70 percent of land species died off.

In 2019, the past 5 years were the 5 warmest years on record, with the 20 warmest years occurring over the past 22 years. Since 2016, the average concentration of CO2 in the atmosphere has been above 400PPM (and is continuing to rise rapidly) compared to 275 PPM for past 400,000 years.