The Earth is a sinking ship, and we all have to get on spaceship lifeboat and go to another planet if we want to survive, according to physicist Stephen Hawking.

Speaking via Skype in the science and art festival Starmus in Norway this week — a weeklong event about life and the universe that also included Apollo 11 astronaut Buzz Aldrin and astrophysicist Neil deGrasse Tyson among its speakers — Hawking reiterated his stance that humans need to colonize Mars and set up shop on other planets within the next 100 years or we will all be doomed, according to Vox.

Read: Would A Colony on Mars Be an Awful Idea? The ESA Chief Thinks So

It’s just the latest in extreme predictions Hawking has made about the future of Earth and humanity. Last month it was reported that he was working on a documentary for the BBC about how the human species will have to leave Earth and colonize other worlds if we are going to make it.

It could be climate change, a disease epidemic, nuclear war, an enormous asteroid strike or some other catastrophic series of events that could lead to our downfall, but Hawking doesn’t see much hope for our future on this planet. One of his recent predictions is that scientists will genetically engineer a virus — making or modifying it on a genetic level — that, while perhaps designed and created with noble medical intentions, will end up accidentally spreading and wiping us all out.

hawking1 Physicist and doomsayer Stephen Hawking says humans will go extinct on Earth if we don’t start branching farther out into space and build a Mars colony within the next 100 years. Photo: REUTERS/Neil Hall

The physicist has long called for colonizing Mars or exploring other locations in space for habitation as a way to escape the dreadful demise of life on Earth as he foresees it.

His assertions this week about the fate of humans on Earth tie into his upcoming BBC documentary called Expedition New Earth, part of the series Tomorrow’s World, in which he explores how humans can go about breaking away from the planet and making a life elsewhere.

“I am arguing for the future of humanity and a long-term strategy to achieve this,” Hawking said, according to Vox. On Earth “there is no new world, no utopia around the corner. … We are running out of space, and the only places to go to are other worlds.”

Vox reported that Hawking’s plan includes make cheaper, better tech for traveling through space and put our efforts into finding habitable planets, as well as finding ways to survive on planets like Mars that are less hospitable.

According to the BBC, Hawking has hope that a goal of sending humans off Earth in the interest of defying extinction will unite nations to work together.

“Whenever we make a great new leap, such as the Moon landings, we bring people and nations together, usher in new discoveries, and new technologies,” he said. “To leave Earth demands a concerted global approach, everyone should join in. We need to rekindle the excitement of the early days of space travel in the ‘60s.”

Read: Mars Colonists Would Evolve Into a New Race

Although there are many people who would be excited about the prospect of a human community on Mars — such as SpaceX CEO Elon Musk — not everyone agrees with Hawking about sending large groups of people into the universe on a spaceship that is a more high-tech version of Noah’s ark. The head of the European Space Agency was recently said Mars and the moon would be unpleasant places to live, and in fact no place would be as good as Earth.

“Colonization — that always sounds to me as though we should leave the Earth,” Jan Wörner said at the recent U.K. Space Conference in Manchester, England. “And I hope that we will not leave the Earth in the next 3 billion years, but that humans will find a way to secure life on Earth.”