Growing meat (it’s hard to use the word “raising” when applied to animals in factory farms) uses so many resources that it’s a challenge to enumerate them all. But consider: an estimated 30 percent of the earth’s ice-free land is directly or indirectly involved in livestock production, according to the United Nation’s Food and Agriculture Organization, which also estimates that livestock production generates nearly a fifth of the world’s greenhouse gases — more than transportation.
and this one, which I already was aware of qualitatively but didn't know the difference was so substantial:
Though some 800 million people on the planet now suffer from hunger or malnutrition, the majority of corn and soy grown in the world feeds cattle, pigs and chickens. This despite the inherent inefficiencies: about two to five times more grain is required to produce the same amount of calories through livestock as through direct grain consumption, according to Rosamond Naylor, an associate professor of economics at Stanford University. It is as much as 10 times more in the case of grain-fed beef in the United States.
My fiancee and I currently are not vegetarians, but we do try to limit our meat intake for both health and economic reasons (we have a lot of fresh, cheap vegetables available out here in California). Sometimes I joke that we're "vegetillusullarians", i.e., that we "usually eat vegetables". I believe the information will further factor into my mind when I'm looking through our recipes deciding what I should make for dinner.