A mass extinction is under way. Human activity, not natural phenomenon, is the difference between this extinction and the five previous big extinctions that have occurred in Earth's history. The current extinction is driven by habitat loss, overexploitation of species, invasive species and pollution. All of these, the result of humans.
The current extinction rate is between 1,000 and 10,000 times higher than the natural rate. (International Union for Conservation of Nature, IUCN) Current estimates put the extinction rate at roughly 30,000 species per year which is about three per hour. By the end of this century, about half of Earth's plant species could be gone. (Pitman and Jorgensen, 2002) For an assessment of global biodiversity, refer to the IUCN Red List.
Protected Area
Protected areas are efforts to conserve ecosystems and species. They offer some hope in preventing habitat loss, one of the main causes of extinction. Application of protected area status varies country by country. The IUCN defines a protected area as "an area of land and/or sea especially dedicated to the protection and maintenance of biological diversity, and of natural and associated cultural resources, and managed through legal or other effective means." The use of these areas for sustainable natural resource extraction and other livelihood activities also differs among classification of the protected area. Figure 1 shows the comprehensive list of protected areas around the world.
Note: Red denotes national sites. Yellow denotes international sites.
Biodiversity Hotspots
The concept of a biodiversity hotspot allows for an efficient focus on protecting important areas of biodiversity. There are 34 biodiversity hotspots as defined by Conservation International. These areas have high numbers of endemic species, but they only cover 2.3 percent of the land surface. A hotspot is defined as containing at least 1,500 species of vascular plants as endemics and having lost at least 70 percent of its original habitat. The 34 hotspots comprise over 50 percent of the world's plant species and 42 percent of all terrestrial vertebrate species.
EarthTrends
Biodiversity and Protected Areas
Related Links
The World Database on Protected Areas
Conservation International
International Union for Conservation of Nature
United Nations Environment Programmes World Conservation Monitoring Centre (UNEP-WCMC)
