Leonardo DiCaprioLeonardo DiCaprioWe've known for a while that Leonardo DiCaprio is a big greeny.

Of the environmental sort, that is...

But now the celeb eco-warrior is putting his money where his mouth his.

True to the cause, he has produced a film, The 11th Hour, all about the impact human life has on the earth's ecosystems, and what we can do to change what's currently happening.

It's a cause close to Leo's heart - he also co-wrote the script and he narrates the action.

Check out the celebs who rocked up to see how green our future could be...