Why I don't eat meat, in typically verbose fashion:
I stopped eating meat in between Thanksgiving and Christmas in 2001. At the time, I really liked eating meat; in fact, I cooked my steak very rare, and poked fun at friends who were vegetarian. Growing up, I had imagined the cattle, poultry and swine I ate probably lived like the stock on the farms surrounding my grandpa's home in upstate New York. The conditions there weren't palatial, but they were fine; the animals were treated well and always had a quick death.
At a certain point, however, I learned that almost all of the meat consumed in the US comes from factory farms. I was surprised to discover that factory farms treat the animals raised there very inhumanely, and kill them in very grisly ways. Not to be crazy eco-guy, but if you've ever been in a room with 20 cows hanging from hooks in their legs, and watched them spasm for hours while they choke on their own blood as it pours from their throats into a big drain, you get the sense of what I'm talking about. If you look for it, you can find an endless supply of information regarding how cattle and other animals are treated in these facilities online.
I also learned about the surprising (to me, at least) environmental impact of our culture's meat consumption. You always hear those statistics about how a chunk of rainforest the size of whatever is cut down every day, and who knows if we just killed a species of frog that could cure cancer etc. What I never wondered was why all that forest is being chopped down -- it turns out it is mainly to create temporary grazing land for cattle, and temporary cropland to feed cattle and other livestock. I also learned that the meat industry contributes significantly to carbon and methane emissions, and the overuse of water and oil. Additionally, it struck me that, with so many hungry people in the world, it is ironic that most of the world's grain goes to feed livestock for first-world consumption.
With all this being said, I acknowledge that me not eating meat will have very little impact in most of these areas. The loss of revenue from one individual is not substantial to a large agribusiness. Also, if all the people in the world stopped eating meat tomorrow, it is unlikely that world hunger would come to a halt – hunger is, at its core, a solvable economic issue largely unrelated to first-world meat consumption. Additionally, because I am not strictly vegan (for example, I buy bread made from eggs and milk, and I eat omelets when I go out for breakfast) there is more that I could be doing; the line I've drawn is indeed somewhat arbitrary.
However, and this is the intellectual rub, I like the fact that my money does not go to the livestock industry, in the same way that I don’t buy diamonds, cigarettes, Disney merchandise, etc. so as not to support those things. In the same way that I recognize that not buying conflict diamonds will not singlehandedly bring DeBeers to its knees, I understand that vegetarianism is unlikely to hurt agribusiness or reverse climate change. But at least I know that my paycheck isn’t going to support those things, which is a good first step. Also, in the same way that it would be somewhat hypocritical to drive an Expedition to an anti-oil rally, not eating meat maybe makes me a little less hypocritical climate change activist.
Also, maybe surprisingly, as time has gone on, I have developed a less intellectual, more emotional investment in not eating meat. For example, when I first started out, if someone had offered me a burger from a cow that was raised totally sustainably, and killed entirely painlessly, 'cause ole Bessie got on in years, and we had to put her down, I probably would have chowed down. Now, though, the thought frankly grosses me out a little. Even here in Alaska, home of some of the most sustainably caught and delicious fish in the history of the world, I have absolutely no desire to try a bite, no matter how much my friends try and goad me. I don't have a good explanation for this feeling, but there it is. With that in mind, in answer to your question, I'm probably not going to be eating any people - no matter how sustainably they are raised (which, in reality, would probably be pretty difficult to do anyway).
Finally, I guess I'd just like to say that, while not choosing to eat any meat is a pretty good choice for me, I really don't care that pretty much everybody else around me eats meat. I always hate it when people feel so insecure that they are going to get in other people's faces -- and doubly so at the dinner table; so you'll never hear me cracking wise when someone else orders a veal steak with bacon. I don't care if the food I eat is cooked on a grill used to cook meat; I don't care if the gang is going out to dinner and everyone wants to go to FatBurger, or a steakhouse, or Applebees (well, maybe Applebees; come on); I don't care if someone wants to talk to me for an hour about moose hunting (this happens almost every day). I'm not trying to convert anyone over to my way of thinking; not eating meat is just something I do -- or, more accurately from my perspective, I eat what I want; and I understand that most people do it a different way.
So, yeah, that was not concise! Hope I answered your question and then some.