We know it isn't. Immense amounts of crops like alfalfa are grown, with extensive fertilizing via petroleum products, to feed inefficiently to cattle.
> The point being it is something that can be modified and addressed.
It's enough of a fight over clearly-better extant solutions like solar. The near-term fix to climate change isn't gonna be evolving cows to burp less.
> Recycle carbon, rather than dredge up and release fossil carbon might be a better framing for any wanting to get to the root of the issue.
This describes a tiny percentage of cattle raising practices.
> Shooting and eating kangaroos, feral camels, goats, donkeys, clean skin bulls, etc. somehow adds in a significant manner to AGW ?
This describes a tiny percentage of meat production. You're not going to feed Australia off the kangaroo population, let alone the world.