If the argument is about which is better for your health vegan or omnivore, that's one thing, but this thread is about whether producing meat is good for the planet, climate-wise.
If food production produces 18% of the GG problem now - U.N.F.A.O., how much lower do you think it is possible to get it? It won't be zero.
But this is like re-arranging the deck chairs on the Titanic. You have to solve the population problem first before you worry about how many cows there are. If the population gets to 9B by 2050 as the UN says it will, the question of meat vs. veggies will seem small potatoes, if you will pardon the pun.
As for right now, reducing the number of cattle, pigs, etc. is of small concern while Nigeria and Siberia are lit up brighter than Paris or New York by gas flares you can see from space.
They flare off more natural gas each year completely wasted, than most countries and many states consume.
The GG thus produced make the cows issue trivial.
Come on now, let's focus on the correct issues..