This article popped up in my Facebook feed:
Chew On This For Earth Day: How Our Diets Impact The Planet

My own two cents:
I'm not a vegetarian.  I believe humans need meat to be healthy.
But, we don't need to eat meat 3 times a day.  Once a day should be good.
And you could probably even make the argument that we don't need meat every day.  After all, our caveman ancestors would go for a week sometimes without tracking down and killing something.
It's probably not realistic to expect people to give up meat entirely, but we can definitely cut back. I've been trying to be conscientious about only eating meat once a day myself.