This is something said by people who have nothing to say. You can also say this to brake the silence. Just do not say it randomly while having sex, or it might get awkward.
example 1
guy 1:You want to rob a bank joe?
guy 2:uh, the world is green!
guy 1:what?
example 2
girl: oh baby
guy:the world is green
girl:we are through
on 9th june of every year, we celebrate the world green day to honor our beloved pal ravu