I heard something to do with Nitrogen and …cow farts(?) I am really unsure of this and would like to learn more.
Answer -
4 Parts
- Ethical reason for consuming animals
- Methane produced by cows are a harmful greenhouse gas which is contributing to our current climate crisis
- Health Reasons - there is convincing evidence that processed meats cause cancer
- it takes a lot more calories of plant food to produce the calories we would consume from the meat.
Details about the answers are in the comments
Because the amount of resources required to raise the livestock required to support the free market of meat is unsustainable. Also the impact of all that livestock is a huge contributor to climate change. So besides the moral argument of it being wrong to eat another living beings there is a very real danger to ourselves in the future.