I never said all the oxygen would be depeleted, but there wouldn't be as much as there should be for all the animals to live.

Just going to touch on the genetically modified vegetables, fruits, etc.
I'd really like to see what type of things your eating. Bananas without seeds are technically genetically modified. I have yet to actually eat a banana with seeds in them.



http://fat-uncle.com/this-is-what-fr...o-look-like-2/

^ an article on foods

Humans have been manipulating all sorts of crops ever since we decided to start growing crops as a food source. There is nothing really wrong with GMO foods as long as the processes used to create them are proven to be safe.

Also yes, if you go from a vegetarian diet and then go and eat a fatty burger or something, you're going to feel a little sick.
In regards to animals being treated poorly. Yes, there are a lot of places where mass production of animals causes poor living conditions. There are things in place to try and prevent this from happening and create a standard. I don't personally agree with the overproduction of animals, like I've stated before about our whole idea of producing more than we can consume. Yet, there are quite a few places where animals are raised in a somewhat caring environment and are free to roam thousands of acres of land, take baths in little ponds, etc.

My great uncle who lives in Tennesee, has/had nearly 500 acres of land of which he raised black angus cows. They weren't forced to breed, they weren't forced to eat, they weren't forced to do anything but live their little cow life. Until the day they were taken to the slaughterhouse to be butchered up for food. Hell, they had a pretty nice scenery.. better than most humans get.