Gas-powered lawn mowers are polluting monsters. Mow for an hour or drive your car for four hours: the emissions are equal. Mowers have been largely unregulated with few emissions controls, although all that will change as of 2012, when new emissions standards for small spark-ignition engines goes into law. The rules intent is that it will provide a 35 percent reduction in hydrocarbon emissions, lower evaporative emissions, and hence less ozone and greenhouse gas formation as a result of all that grass cutting.
Goats are ruminants, and emit methane as part of the enteric fermentation that occurs in their first “stomach,” the rumen. In 2003, according to the EPA, U.S. goats emitted 0.3 Teragrams CO2 equivalent of methane emissions. By comparison, landfills emitted 131.2 Tg, termites about 20 Tg, and mobile sources 2.7 Tg. Goats are not blameless, but they are better than lawn mowers and termites. However the old fashion push mower may remain your best choice for lawns if you really want to produce NO emissions and burn some additional calories!
Traditional manicured home lawn mowing is perhaps the wrong application or wrong image to convey. Goats are best used for hillsides and or rough terrain as they not only love to eat grasses, they also love all those plants we don’t want as well. So hence we see companies, like Google and other SIlicon Valley firms, using them not on a lawn, but in weedy fields. Goats easily and happily eat a huge variety of invasive and noxious plants down to the nub. Blackberry and poison ivy are just two examples of unwanted plants that goats love to eat.
Google is not the first to prefer goats over machines: Many goat herders are renting out their goats for landscape renovation and maintenance. Goat herds are used to maintain areas alongside airplane runways, like at SeaTac in Washington state, to remove scrub in fire-prone areas, and to replace pesticides in weed eradication on ranches. They do all this and more without the impact of heavy equipment or deadly herbicides. Their byproducts provide a type of fertilizer, as their hooves stomp into ready made compost. See the video below for more insight.
