If you want to go down that route, you must include the CO2 emitted by the manufacture of the lawn mowers and their transport from China (we can assume) to Moun

If you want to go down that route, you must include the CO2 emitted by the manufacture of the lawn mowers and their transport from China (we can assume) to Mountain View. Regardless of whether trucking a load of goats around uses more gas than running the lawn mowers (a hypothesis I seriously suspect is incorrect), goats manufacture themselves whereas making steel and aluminum uses a lot of energy. And if you want to argue that demand for goats breeds more goats which increases their methane emission, shouldn't you also include the fact that demand for more lawnmowers makes the lawnmower factory hire more people, which then have a salary to do things like buy cars that they wouldn't if they were unemployed? It's effects like that that people appeal to when they say corn ethanol leads to a net increase in CO2 compared to running gasoline directly. Somehow assuming a baseline that implies that people would be homeless bums living at 3rd world level unless they are employed by the ethanol industry seems like a dubious calculation to me.