Elon Musk, co-founder and chief executive officer of Tesla Motors Inc., speaks during a news conference at the Nevada State Capitol building in Carson City, Nevada, U.S., on Thursday, Sept. 4, 2014. Tesla will build the worlds largest lithium-ion battery plant in Nevada, bringing a $100 billion boost to the states economy over two decades, Governor Brian Sandoval said. Photographer: David Calvert/Bloomberg via Getty Images

No one has been to Mars yet, and Elon Musk wants to change that in a big way. The SpaceX CEO says we need to put a million people on the Red Planet to make sure human civilization survives.

"I think there is a strong humanitarian argument for making life multi-planetary... in order to safeguard the existence of humanity in the event that something catastrophic were to happen," Musk said in a recent interview with the digital magazine Aeon.

Musk's comment sounds ominous but may not be off the mark, given the threats that scientists see in climate change and space rocks.

Just what would it take to move so many people to Mars?

"Excluding organic growth, if you could take 100 people at a time, you would need 10,000 trips to get to a million people," Musk told Aeon. "But you would also need a lot of cargo to support those people. In fact, your cargo to person ratio is going to be quite high. It would probably be 10 cargo trips for every human trip, so more like 100,000 trips. And we’re talking 100,000 trips of a giant spaceship."

This isn't the first time Musk has made a pitch for colonizing Mars. At the AllThingsD's 2013 conference last year, Musk said, "Either we spread Earth to other planets, or we risk going extinct... An extinction event is inevitable and we’re increasingly doing ourselves in."

Got it.