Unfortunately, it seems that the best choices for which animals to eat are opposite depending on whether your goal is killing fewer animals or minimizing your carbon footprint.
The obvious solution is to stop eating all those kinds of animal/animal products. That would satisfy CO2 concerns and killing concerns.
Of course, it might not satisfy things like fun of eating meat, ease of eating meat, health etc.
Unfortunately, it seems that the best choices for which animals to eat are opposite depending on whether your goal is killing fewer animals or minimizing your carbon footprint.
The obvious solution is to stop eating all those kinds of animal/animal products. That would satisfy CO2 concerns and killing concerns.
Of course, it might not satisfy things like fun of eating meat, ease of eating meat, health etc.