'http://en.wikipedia.org/wiki/Human_extinctionHuman extinction would be the extinction of the human species, Homo sapiens, whether on Earth or from the entire universe, provided the species colonizes on other planets.There have been countless prophesies of extinction throughout history; in most cases the predicted date of doom has passed without much notice, making future warnings less frightening. However, a survivor bias would undercut the credibility of accurate extinction warnings. John von Neumann was probably wrong in having “a certainty” that nuclear war would occur; but our survival is not proof that the chance of a fatal nuclear exchange was low.Nick Bostrom suggests that extinction-analysis may be an overlooked field simply because it is too depressing a subject area to attract researchers.There are thousands of public safety jobs dedicated to analyzing and reducing the risks of individual death. There are no full-time existential safety commissioners partly because there is no way to tell if they are doing a good job, and no way to punish them for failure. The inability to judge performance might also explain the comparative governmental apathy on preventing human extinction (as compared to panda extinction, say).
Various scenarios for the extinction of the human species have originated from science, popular culture, science fiction, and religion (see apocalypse and eschatology). The expression existential risk has been coined to refer to risks of total and irreversible destruction of human life, or of some lesser, but universal and permanent detriment to it.
The following are among the extinction scenarios that have been envisaged by various authors: