stop global warming - promote the end of humanity. =D
I don't go only veggie, but I mix my meals. There will be days where I eat vegan meals, veggie meals, and then carnivorous meals. I generally eat chicken or fish, with red meat rarely. I don't do this for environmental reasons, I do it for health/weight loss reasons. Meat, especially beef, can take up to a month before it fully passes through your body. Most people eat 12-20 oz of meat a day. Recommended portions are 6-8 ounces per day.
If you're so worried about the environment, start elsewhere though. Do you know that only about 30% of the US is mandated to recycle? It amazes me that most cities and states either do not offer a recycling program at all, or don't mandate their residents to recycle. Schools are horrible at recycling, businesses too. If the US was at even 80% recycling, the amount of waste and deforestation would dramatically increase.
SO, if you want to fight a battle for mother earth, start petitions and get your senator/leader to start enforcing recycling in your state, province, nation, whatever. It'll do a lot more good than simply eating differently.