There is a difference, as I just explained. To add on to the difference, their is ethical concerns to eating beyond pollution, which you also ignored to make your false analogy. The UN has projected we will cap out on humans about 12 billion. Figured I would give you a number because you didnt have one. If you take everything required for meat to hit the shelf, from the animal being raised, transportation, and all other emmisions along the way, studies have found that animal agriculture accounts for 51% of greenhouse emmisions. However, it is important to note that if everyone switched to veganism it wouldnt cut this number down to 0% but it would exponentianlly reduce it.