Stephen Hawking is giving humanity a tall order: Colonize Mars in the next century or watch as life on Earth fizzles out. After last year claiming that humans have 1,000 years left on Earth, Hawking says in a new documentary that we instead have about 100 years until we'll need to jump ship as Earth is overwhelmed by overpopulation, climate change, disease, and artificial intelligence.

It might be a bit premature to start packing, but the BBC's Expedition New Earth will explore technological and scientific advances that will enable life in space or a colony on another planet, reports the Telegraph.

It will show "Hawking's ambition isn't as fantastical as it sounds—that science fact is closer to science fiction than we ever thought," the BBC says, per Newsweek.

Elon Musk of SpaceX is already planning to send humans to Mars in the next decade. But while a Mars colony is a good idea, bringing new scientific discoveries, columnist Eric Mack says Hawking needs to give his head a shake if he honestly believes Mars, the moon, or anywhere else in our solar system will be more hospitable than Earth even after a host of disasters.

"Just cleaning up our own mess and starting over by rising from the rubble seems more practical" and more affordable than figuring out how to grow food or survive radiation poisoning on Mars, he writes at Forbes.

The solution to all of our problems is here on Earth, he adds. "Yet somehow, the grass is always greener for some people, even when it's on a dead Red Planet." (For some much funnier Hawking news, check out this skit.)

This article originally appeared on Newser: Hawking: Actually, We Have 100 Years to Escape Earth