The biggest problem with this world?

Seems pretty obvious to me...

There are humans on it. Lots of humans.

Deport the lot of us, send us away, let the planet heal itself...

Hopefully the next time it comes up with an intelligent species it won't be quite so destructive...

Deport to where though?

Oh, I'm sure there much be some other dimension or habitable planet... Just create a wormhole or something, use your imagination...

:)