Global Warming more dangerous than nuclear hollocaust?

I was watching this thing on national geographic channel awile ago and it said the number one threat to human survival is global warming. Above a number 2 ranked supervirus and a number 2 ranked nulear hollocoust. I know global warming can be a bad thing. Stronger Storms, bad droughts, and costal cities flooded. But I highly doubt global warming will be the end of mankind. I think a supervirus or a nulear hollocaust will do a much better job at that. I think that episode was some sort of political statement. What do you think?