>Farmer owns cows. People eat his products. Cows fart. People tax cow farts and burps. Farmer can't afford to pay taxes per head of cattle so...

I'm with you this far, but then you go off the rails a bit. Here's what actually happens:

... Farmer raises prices to keep up with higher production cost. Animal products are now more expensive to buy. People change their diets to more plant and less animal based. Plant based food is now more in demand so framer expands production into areas previously used to produce animal feed crops. Emissions decrease. Land use decreases. Nobody starves.

Also, footnote: Yes, humans fart too. But humans have a different diets and are considerably smaller then cows. Thus human fart emissions are negligible in comparison.