Human extinction is the end of the human species. Various scenarios have been discussed in science, popular culture and religion (see End time). The scope of this article is existential risks. Humans are very widespread on the Earth, and live in communities that (while interconnected) are capable of some level of basic survival in isolation. Therefore, pandemics and deliberate killing aside, to achieve human extinction the entire planet would have to be rendered uninhabitable by humans, with no opportunity provided or possibility for humans to establish a foothold beyond Earth. This would typically be during a mass extinction event, a precedent of which exists in the Permian–Triassic extinction event among other examples.