A global vegetarian diet, the same study showed, would be the most effective of all diets (not including vegan) in achieving a reduction in greenhouse gas emissions, as well as a decrease in agricultural land demand and land clearing. [google.com]
It follows that the vegan diet, by eliminating dairy and egg, would reduce emissions the most,
[google.com]
Fwiw, the comment I'd make on this is that if it's the case that global raising of meat is as massively damaging as is claimed, then the pathway to fix this (in my view) is not moralizing, but in pricing and policies. Raise the price of the damaging aspects, and much more will be accomplished toward the end goal of environmental improvement (if that's is actually what is wanted). So, for example, if it is damaging to a massive amount of private and public property, then, as a control measure, raise taxes in various parts of the meat-raising value chain and let consumers see the price signals that will help them make different decisions.
cutting down population drastically is the only thing that will save most creatures including humans imminent extinction.
@Noemi
We are an overpopulated, over consuming over polluting species. We are a plague, a totally feral pest.
@Rugglesby yes we are and we don't help anything by being here either like say bees and flowers.