Addressing the Oxford Union Debating Society on Monday, theoretical physics living legend Stephen Hawking issued a dire warning: humanity will probably not survive if we don’t establish viable colonies in the next thousand years.

If you think things are looking dire right now, you might be surprised to find out that Stephen Hawking says you’re on point. It’s gotten so bad, in fact, that he says we should be on hard at working founding home-planet-B in the next 1,000 years to have any hope of survival.

“We must […] continue to go into space for the future of humanity,” Hawking said in a lecture at the University of Cambridge this week. “I don’t think we will survive another 1,000 years without escaping beyond our fragile planet.”

This isn’t the first time the professor has broached the subject of humanity’s fate. Last year, Hawking signed alongside more than 20,000 researchers and experts, including Elon Musk, Steve Wozniak, and Noam Chomsky on a letter calling for the ban of autonomous AI weapons, constructs that can use deadly force without human consent. He has also spoken out against concentration of wealth, climate change, overpopulation, and talked about the specter of pseudoscience. As Heather Saul from The Independent reports, Hawking has also estimated that viable human colonies on Mars won’t be a realistic option for another 100 years or so. In the meantime, we need to be “very careful” with the going-ons on Earth and beyond. Current troubles at home, including climate change, the rise of antibiotic-resistant plagues, and the very real threat posed by warring nations with nuclear capabilities, aren’t the full story.

Given his belief that humans seem hell-bend on repeating the mistakes of the past, Hawking says the development of “powerful autonomous weapons” is likely and will have grave consequences for humanity despite his warnings. The rise of such weapons may pit us against an enemy we don’t even understand yet, while in a precarious position. Robots are limited in what they can do today, but what happens when they equal, or even surpass us? And how can we deal with that and the effects of climate change — with shortages of land to grow crops, sinking shorelines, and spent ocean food resources — at the same time?

And then, cherry on top, an advanced alien race finds us in our desperate struggle — and decide they’re better entitled to Earth than we are.

“I am more convinced than ever that we are not alone,” Hawking says in his online film, Favourite Places.

“They will be vastly more powerful and may not see us as any more valuable than we see bacteria”.

That’s why Hawking advocates for a back-up plan. We might survive all this if there’s another place in the Solar System we can go to, a “safety planet” of sorts where we can go to lick our wounds. But the professor is still optimistic about our odds, given what we’ve accomplished so far.

“It has been a glorious time to be alive and doing research into theoretical physics”, he said. “Our picture of the universe has changed a great deal in the last 50 years and I am happy if I have made a small contribution.”

“The fact that we humans who are ourselves mere collections of fundamental particles of nature have been able to come so close to understanding the laws that are governing us and our universe is a great achievement.”

He closed his speech with a word of encouragement.

“Try to make sense of what you see, wonder about what makes the Universe exist. Be curious,” he told those attending the lecture.

“However difficult life may seem, there is always something you can do and succeed at. It matters that you don’t just give up.”

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