M. Novacek (2001) reports that Earth is suffering the fastest mass extinction in its history, which is clearly a direct result of human activity, ‘yet the public remains unaware of the crisis in sustaining biodiversity’. E. O. Wilson (1992) calculates that if the annual extinction rate is 0.27%, and tropical forests contain 50% of all species, then about 0.14% of all species are committed to extinction each year. Unless immediate action is taken to restrain the rate of tropical habitat loss, the twenty-first century will see another major extinction catastrophe. See Pimm et al. (1995) Science 269, 5222, and Gaston and Fuller (2007) PPG 31, 2.

http://www.iucn.org Website of International Union for Conservation of Nature.