Meat Is the Answer

There's been plenty written about the effects of meat on the environment as well as on individual human bodies. The antibiotics and hormones pumped into the animals to get them to grow faster on diets they don't eat in nature; the amount of water required to raise a cow or a pig; their methane gas emissions (see: diet); the amount of petroleum used to transport the grain to feed the animals and then transport the meat to the place where it's eaten; the use of grain to feed animals in countries where people are starving.... The list goes on.

And there's actually something you can do about it. In the last paragraph of his article, "Think Before You Eat: The Widespread Effects of Factory-Farmed Meat," Brian Colleran quotes Paul Shapiro of the Humane Society’s Factory Farming Campaign:

“The silver lining is that this is one of the easiest ways for individuals to reduce their environmental footprint. Whereas switching to a hybrid car or worrying about coal stacks may be beyond our daily means, choosing more plant-based meals is something where we can stand up for animals and the environment every time we sit down to eat."

And a can of beans--or, if you're so inclined, a whole bag to be soaked and boiled--is a whole lot cheaper than a slab of meat.