This I agree. It's not wether people eat animals or plants. Problem is that there are so many of us who eat so much of the Earth's resources. CO2 is rising because we cleared our forest. It does matter if we use the cleared land to feed cows or grow wheat
So problem is how to control the population. Do we choose or let nature take its course?
I think mother nature will take care of it very soon, we already seeing how the her "immune system" has started fighting off the human disease through natural disasters all around the world, if we dont sort ourselves out fast mother nature will do it for us, the world isn't going to die off because of our decisions.