Historically, an estimated 0.1 percent of all species go extinct each year. That may not sound like a lot, but considering that there are 1.7 million species that have been scientifically identified so far, that means an annual extinction rate of 1,700 species, or more than four per day.
This is known as the background extinction rate, which is the number of species that can be expected to go extinct over a period of time, based on non-human factors. Today, the rate of extinction is an unprecedented 1,000 times higher than natural background rates, with recent reports indicating the risk of losing 1 million species in the near future.
