First: Cows do emit a lot of methane and it does have a terrible effect the level of greenhouse gases.
Second: Humans have no inherent need to eat beef, especially in the quantity that we do. Until this past century no people in the entire world could expect to have a meat entree every night. Why? Because ridiculous unsustainable factory farms are necessary to produce that amount of cattle.
Third: Cattle farming on the current scale will not last unless there is some huge breakthrough that no one has even an inkling of yet.
Fourth: Wouldn't you rather get to choose between chickens, pigs, and lamb rather than just eating cows?
