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
The point is that you can grow a plant based diet for a human for much less resource cost than you could for a cow.
Multiplied by the amount our current meat industry runs at and you get decimation of large swaths of lands, much higher emission of greenhouse gasses, etc…