Global warming, mass shootings, global instability and overpopulation are all concerns humanity faces, but what is the greatest risk to all of us? Larry King asked scientific genius Stephen Hawking, who explained that there is a lot to be worried about.<br />READ MORE: http://on.rt.com/7h06<br /><br /><br />RT LIVE http://rt.com/on-air<br /><br />Subscribe to RT! http://www.youtube.com/subscription_center?add_user=RussiaToday<br /><br />Like us on Facebook http://www.facebook.com/RTnews<br />Follow us on Twitter http://twitter.com/RT_com<br />Follow us on Instagram http://instagram.com/rt<br />Follow us on Google+ http://plus.google.com/+RT<br />Listen to us on Soundcloud: https://soundcloud.com/rttv<br /><br />RT (Russia Today) is a global news network broadcasting from Moscow and Washington studios. RT is the first news channel to break the 1 billion YouTube views benchmark.