environmental debates

[miiindy]

for my environmental science class we're debating about the environmental effects of meat consumption. obviously i'm on the team that says we should lower our meat consumption. i'm trying to prepare for what the other team might say, and i assume they are going to say something about how buying organic/grass-fed meat is better than not buying meat at all.
can anyone point me in the direction of websites that will help me disprove this? thanks!