Eat Chicken and Turkey instead, when you choose which meat to eat.
from Eco & Beyond article on the subject:
"What Is the Most Environmentally Friendly Meat?
#1 TURKEY AND CHICKEN
These birds do not produce methane and need less food and water than sheep and cows. If you want to minimize your carbon footprint without giving up meat, chicken is your best option.
Chicken produces only 2.33 kg of C02 per kg of meat before transport and processing."