Existential risk, as defined by Nate Hagens, is a risk that could result in the extinction of humanity, or the permanent and drastic destruction of the capability for people to live in a meaningful way. It may be the result of technological disasters, extreme climate shifts, pandemics, natural disasters, or any combination of these factors. In many cases, the consequences of such events are hard to predict and even harder to mitigate, making existential risks particularly perilous.
See also: exponential growth, nuclear weapon, population growth, nuclear exchange, mass extinction