So here's what I'm getting:
Google is trying to be enviromently friendly, ignoring the fact that their computers are "not the best thing for the enviroment."
One (or more) lawn mower(s) apparently leaves (leave) such a carbon footprint, that all the man power of brining in the goats, picking up waste, feeding them, and keeping them from being a distraction from employees is easier than it is to minimize other carbon footprints.
I'm no lawn expert, but how would eating the grass keep it as neat looking as a lawn mower designed to cut the grass just how you want it? Last time I checked, the land under barn yard animals is no fairway.