[citation][nom]falchard[/nom]I don't think Google did a google search about the effects livestock have on CO2 and methane emissions. If they did they would realize they are a far greater cause then a lawn mower. Although a lawnmower in use can produce alot of exahaust, it can be turned off. An animal on the other hand cannot be turned off on the fly. Its not like you can instantly grow 200 goats to eat the grass for you.Also I don't think Google is familar with farm life. Out of all the animals you could pick to eat the grass, the goat is one that is not only noisy but creates a really annoying sound.[/citation]
Methane production is moot. Since the animals were rented rather than being raised specifically for this purpose, they'd be producing the same gas elsewhere.
I'd be more inclined to question the choice of goats over, say, sheep. Goats are browsers rather than grazing animals, and prefer to eat shrubbery and other woody material rather than grass.