The Discovery Channel website has an article explaining how America's consumption of meat could eventually turn the Gulf of Mexico into a "dead" sea. Here's a clip from the post:
Gidon Eshel of Bard College at Simon's Rock in Massachusetts and Pamela Martin of the University of Chicago calculate that if Americans kicked their meat habit, it would prevent seven million tons of nitrogen from spilling into the gulf -- a reduction of nearly 90 percent.
"When we did the calculations, it was astonishing," Eshel said. "The main reason is we're feeding so much corn to livestock. It takes 4.5 times more cropland to do that than if you feed people a plant diet, and corn is so nitrogen-intensive."
There are many great reasons to go Veg (or to reducing meat in one's diet)--one being the positive effects on the environment.