So what would happen? Animals would break free and start Animal Farms, of course.
The oceans, lakes and rivers would self-clean.
Roads and cities would become forests and jungles.

But what else would happen?

And what the heck happened to all the humans?
Plague?
Nuclear holocaust {bombs, power plant explosions [Japan 2011]}
Zombies?

{I got this idea direct from a reply I just read by Cruiser}?