A list of doomsday scenarios that could wipe out humanity has been released by scientists.
Asteroid impact, extreme weather, war, nuclear apocalypse and a fast-spreading pandemic are among the "doomsday risks".
Cyberattacks on infrastructure, computers becoming self-aware, a man-made supervirus or a food supply sabotage complete the list.
The "existential risks" to Earth will be investigated by a group of scientists, which includes physicist Professor Stephen Hawking and Astronomer Royal Lord Rees.
Experts from Cambridge University say they now plan to work with colleagues at Oxford to come up with a more complete list of doomsday risks, and to "assess how to enhance resilience against the more credible ones".