What If We Humans Left the Earth?

I love science-fiction films, books, and my obsession began with Tom Cruise’s Minority Report. I enjoy watching all post-apocalypse films too. In recent times, Interstellar and Oblivion are films I have watched over and over again.
That said, I love nature. I am aware of the many ghastly possibilities we face as we continue to erode and defile nature on a daily basis. This very thought got me intrigued – I know that colonies on Mars are still far-fetched. No, we have not discovered any wormhole (not to my knowledge) nor any habitable planet yet. But what I do know is that we are soon not going to have a home to live in! So what if humans left the earth like in Wall-E? What would happen?
I came across this video on YouTube and must say, I was hooked. Do watch what would happen when humans left the Earth! 
Another theory is that Humans are the so-called aliens, that we don't belong! More on this later...
Also, I wrote more on this here: What would happen if human beings left the earth!