In this paper, we show that plant-based replacements for each of the major animal categories in the United States (beef, pork, dairy, poultry, and eggs) can produce twofold to 20-fold more nutritionally similar food per unit cropland. Replacing all animal-based items with plant-based replacement diets can add enough food to feed 350 million additional people, more than the expected benefits of eliminating all supply chain food loss.

https://www.pnas.org/doi/10.1073/pnas.1713820115#ref-2

This one isn’t exactly about GHGs but I is crazy to think that we could feed a whole other US population by changing what we eat.