It's a problem.

Solution: Perpetual motion machines!

Yeah, no.

Unless my idea would work, and I doubt it. Though I can't find any flaws in it right now. 

It's a little depressing. I don't think it can be fully reversed at this point, even if there was an apocalypse and all the humans died or stopped pollution by whatever means. We'll probably all either die or move to space. It's interesting to think about what life will come after, though, if any. They would probably breathe in everything that we're pouring into the atmosphere, but what would they exhale? Would trees survive unchanged? Would intelligent life rise again? Would dragons become possible?