WATCH: David Letterman 'Years Of Living Dangerously' Trailer.

What is David Letterman doing in his television return? more below.

‘The King Of Late Night’ is back. National Geographic has brought David Letterman back into the world of television to host ‘Years Of Living Dangerously’. A show that allows Dave to explore his ‘love affair’ with global climate and solar power. Watch the trailer below. More info HERE.