As I said, the issues are a lot more complicated. I'm supplying the basic gists of the arguments with the intention that people who aren't familiar with them should go find some professional literature to get themselves familiar with them. I'm not educated enough to defend it that well myself (at least, not tonight). Someone who is better equipped can probably beat me in an argument about how precisely it impacts the environment. But beating me is irrelevant - winning arguments doesn't make you right. If you HAVEN'T looked at the environmental issues, there's a good chance you're missing out on important considerations. The cow pollution > automobile pollution statement might be more hyperbolic or complicated than I made it out to be, but the bottom line is that cow pollution IS a real concern, however it compares to automobile pollution.

There are ways to eat meat that doesn't impact the environment, doesn't impact human health standards, and causes minimal suffering to the animals in question. But my general heuristic is that unless you know exactly where your meat is coming from, chances are it comes from a food industry that is harmful in all three categories.