Given the implications from expanding human populations in the previous article, it is of interest to assess the related question of extinction rates thanks to us.

The International Union for Conservation of Nature (IUCN) Red List has 908 extinctions since 1500, but this is considered to be extremely conservative and biased toward known birds and mammals.

Other estimates vary between 100-1,000 times the pre-human levels of 1 Extinction per Million Species per Year (E/MSY) (e.g. Jurriaan et al 2014). Cowie et al (2022) found that 100 E/MSY was a reasonable value and that it could easily be as high as 250.

Four of these animals have become extinct on the Peninsula.

Applying 100 E/MSY to the ~2 million documented species, we arrive at an estimate of ~125,000 species having gone extinct due to humans since 1500. Expanding to the presumed 8.7 million species on earth (Mora et al 2011), we arrive at over 500,000 species having become extinct.

In summary: when it comes to how many extinctions can be attributed to us, the simple answer is we can at best make educated guesses. But even the most conservative assessment arrives at us driving species to extinction at a staggering 100 times the natural background rate.

– Article by Greg Holland.