National security threat

How likely is an existential catastrophe?

To underline the urgency of existential risks, let’s compare these estimates to the probability of an average American dying in an “air and space transport accident”—which is 1 in 9,737 over the course of a roughly 80-year lifetime. As mentioned above, the Future of Humanity Institute survey participants assigned a 19 percent chance of human extinction by the year 2100, which would mean that the average American is at least 1,500 times more likely to die in a human extinction catastrophe than in a plane crash.

Rees’ estimate concerns civilizational collapse, which is more probable than human extinction. His estimate of a 50 percent chance of collapse this century suggests a 42 percent chance within the average American’s life span. This means that the average US citizen is nearly 4,000 times more likely to encounter the ruination of modern civilization than to perish in an aviation disaster. Even relative to dying in a motor vehicle crash, which has a probability of about 1 in 113, Rees’ figure implies that the average individual is almost 50 times more likely to see civilization collapse than to die in a vehicular accident.