Hawking: move to space or face extinction

From The Huffington Post:

Is the future of the human race in outer space? Theoretical physicist Stephen Hawking, in an interview with Big Think, warns that if humans can't find another planet to inhabit, they will face extinction.

"We are entering an increasingly dangerous period in our history," Hawking says. "There have been a number of times in the past when survival has been a question of touch and go," like the Cuban Missile Crisis of 1963, and the frequency of such occasions "is likely to increase in the future."

Because we are rapidly depleting the finite natural resources that Earth provides, and because our genetic code "carries selfish and aggressive instincts," our "only chance for longterm survival" may be to "spread out into space."

But how do we get there? Scientists estimate that it would take roughly 50,000 years to make it to the nearest star, if we traveled using chemical-fuel rockets. To arrive within our life span, humans would need the technology to travel at near the speed of light and to remain shielded from cosmic radiation for the duration of the journey.