The rate is a calculation of the number of extinctions per million species per year. In Earth’s geological and biological history (excluding major extinction events like the dinosaurs), the normal extinction rate—what is called the “background extinction rate”—is estimated to be about one species per million per year. The planetary boundary for extinctions set by the Stockholm Resilience Center <10 E/MSY. Many estimates of the current extinction rate vary between 10 and 100+ times greater than the pre-human background rate, while others (the IUCN Red List) affirm the rate is between 1000 and 10,000.
Extinction rate
