Humans will not be able to survive another 1,000 years unless they escape Earth and colonize some other planet, according to eminent physicist Stephen Hawking.

Delivering a lecture at the Oxford Union, Hawking issued a call for humans to keep on going into space to ensure a future for humans, and stressed that he didn’t think that humans would be able to survive another one thousand years without escaping beyond our fragile planet.

He stressed that 1,000 years seem to be quite a long period of time for humans to repair things, or mess them up quickly. However, the celebrated physicist also offered optimistic tones and praised humans for what they achieved.

Delivering a lecture on the universe and the origins of humans, he said, “The fact that we humans, who are ourselves mere fundamental particles of nature, have been able to come this close to understanding the laws that govern us and the universe is certainly a triumph.”

He also argued that in order for humans to survive the serious challenges ahead, such as population explosion, climate change and overtaxed food production, they need to oppose the individualism and isolationism that have given birth to political movements like Brexit (Britain’s exit from EU).

In the recent past, Hawking has used his stature in the sciences to make criticize and attack the controversial political as well as moral dilemmas being faced by modern societies.