Mr Musk spoke about the importance of building a self-sustaining city on Mars and how it is one of the most important things we can do to ensure "the long-term existence of consciousness".

He said: "I think there's arguably a great filter that we face with, you know, will we become a multi-planet species or not.

"You know, we'll be surprised if out there in our galaxy and others, there are a whole bunch of dead one-planet civilisations that prospered for a while - they might have prospered for millions of years - but then gradually the civilisation collapsed for reasons externals or internal and that was that.

"All civilisations go through an arc where they build, they grow up in technology complexity but then they don't keep going up, they, over time they decline and they fall.

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End of the world: Elon Musk warns of 'civilisation collapse' if we don't leave Earth soon - Daily Express