17000 species are at risk of extinction on earth. Birds, mammals, conifers and amphibians are all particularly at risk (in ascending order) Climate change alone might commit an additional fifteen to thirty seven percent of extant species to premature extinction. Overexploitation of species, including logging: grizzly bears are vulnerable to overhunting (population grows at a very slow rate, mortality for young bears is high) Introduction of exotic species into ecosystems where they aren"t native: american bullfrog is outcompeting the oregon spotted frog (only in the. Fraser valley in b. c) stronger, aggressive, and eating adult oregon spotted frogs. Humanity in the long-term is dependent on the maintenance of the world"s biodiversity. Ecosystem services are currently being degraded or used unsustainably. Provisioning services such as food, fuels and fibers. Regulating services that affect the climate, disease outbreaks, wastes and pollination. Cultural services that provide aesthetic, recreational and spiritual value. Supporting services such as nutrient cycling and water purification and storage.