Here's my way of thinking;
Humans are animals. We are part of the animal kingdom. The rules clearly state (and have from the start) "survival of the fittest". If i'm more fit than what I eat, then it just means i'm doing my correct animistic job to make the world turn.
I recently learned in my psychology class the difference between "needs" (biological factors needed to continue survival) and "wants" (objects or ideas that make living more enjoyable). We also learned that there is NOT a clear line between the two, and different people see things differently and can effectively argue for their side, there can be NO WINNER.
In general activists will always been seen as wild, non-logical people, so don't let people's comments here change anyone's mind. I'll admit I can get very activistic views on a variety of topics, and that it can block me from seeing the logical reasoning behind opponent's thoughts. Bottom-line is, people have always been concerned with keeping our home planet stable, however I personally don't see getting rid of meat as something that will be a long term positive effect on nature or the human race in general.