Apologies for the very long delay in my response:

1) Thanks

2a) Fewer babies would indeed solve the problem. I would bet a hefty sum that convincing people to stop having unprotected sex would be more difficult than convincing people to go vegan.

2b) It is not economics that will force people to eat more meat. The price increase is a derivative of the scarcity arable land, fresh water and waste disposal for meat production.

3) Ah, now I get you. I concede that I was too bombastic, but there is a lot of meat on that bone to chew. (sorry, couldn't help it ;) ). I'll table that one for a chance meeting over a beer.

4) Agreed, but massive depopulation is not a feasible solution to the problem that we have right now, and veganism for the rich in the western world IS a solution.

That last is similar to a lot of current issues. 70% of global emissions are created by (IIRC) 100 mega corporations. The richest 1% of humans (mostly in the west) have a massively disproportionate carbon footprint.

Bang for the buck logic says getting a significant portion of the richest 20% of North Americans and EU residents to eat more vegan would be the best bang for the buck solution to the problems of big ag.