While methane is a potent greenhouse gas; the main issue is CO²-equivalent per produced calorie.
Growing edible plant is orders of magnitude more efficient than growing them + converting it to meat, before consumption.
There is just a lot of lost energy in the meat production chain. Therefore we have to produce so much more plants to feed the meat. And any production has a greenhouse cost to it.
Countries should ban import of meat and stop any subsidies for their own meat production. Then prices would influence customer choices appropriately; with dramatic drops in CO²-equivalent emissions.
this requires political will and less corruption.