Famed British naturalist Sir David Attenborough told the UN climate conference in Poland that the "collapse of our civilizations and the extinction of much of the natural world is on the horizons" if no urgent action is taken against global warming. He was joined by the likes of Arnold Schwarzenegger in calling for change at the COP 24 United Nations climate change conference. Welcome to The National, the flagship nightly newscast of CBC News »»» Subscribe to The National to watch more videos here: www.youtube.com/user/CBCTheNational?sub_confirmation=1 Voice Your Opinion & Connect With Us Online: The National Updates on Facebook: www.facebook.com/thenational The National Updates on Twitter: twitter.com/CBCTheNational »»» »»» »»» »»» »»» The National is CBC Television's flagship news program. Airing six days a week, the show delivers news, feature documentaries and analysis from some of Canada's leading journalists.