In this summer's blockbuster hit Transformers, "Decepticons" from an alien species, wreak havoc on Earth – things look bad, humanity seems doomed. But just in the nick of time, against all odds, our young heroes save the planet.

It’s an enduring Cliché: From Superman and Wonder Woman to Batman and Spiderman, we love to watch our celluloid heroes save us from whatever creatures are threatening our world.

In Leonardo DiCaprio's new documentary, The 11th Hour, the creatures are us. And the ways in which we are wreaking havoc on planet Earth are far more frightening than anything dreamed up by Hollywood: