You can reduce your carbon footprint by orders of magnitude more by not having children, or having fewer children, but I don't see as many people advocating for voluntary sterilization (or even just abstaining from childbearing). Most people believe it's their deity-given right (and often imperative) to keep reproducing, even if our environment suffers as a result.
I point this out to suggest that at the end of the day all of this is emotional and is largely driven by how we were socialized and raised from a very young age. It's often difficult to get people to agree with rational arguments when those arguments contradict a lifetime of programming.
Having said all that, I've found that the environmental argument is the only one that gives me pause around my meat consumption.
Reducing the number of children is an aspect that rarely comes up in discussions about environmental impact (not necessarily about food), even though I find it a very compelling argument. In some countries (hint: not the US, or most of Europe), there is not even a need for much advocacy, as the concept is descriptive: fertility-rate times planetary-footprint is less than 2, so in the long run, those countries would actually be using zero resources.
I point this out to suggest that at the end of the day all of this is emotional and is largely driven by how we were socialized and raised from a very young age. It's often difficult to get people to agree with rational arguments when those arguments contradict a lifetime of programming.
Having said all that, I've found that the environmental argument is the only one that gives me pause around my meat consumption.