Why? For environmental or ethical reasons?

Arguably not all farming is unethical and not all meat production is bad for the environment.

I no longer eat mammals for ethical reasons, and to a lesser degree, some concern over the environmental sustainability of the production of meats like beef. I'd love to see very tight environmental and ethical regulations introduced for the meat industry which I accept would effectively make meats like Beef a luxury, but I see no reason to ban it entirely so long as no significant level of harm is being done.

The problem with animal meat isn't the meat itself, but the factory farming process which produces the vast majority of it. This is what we should limit or ban if anything.

Short answer: No.

In general banning anything is a brutal and also a clumsy measure, often causing more harm than good. It should only be used as the very last resort in intolerably extreme cases.

I find the idea of growing animals just to kill them unbearably horrible, nevertheless I believe this should be addressed gradually by adjusting cultures to decrease meat consumption with time and to always eat what you bought rather than eating a part and throwing the rest away.

Maybe.

Can we also ban war, murder, narcotics, alcohol, global warming, long queues, uncomfortable silences and idiots who don't know what they are talking about at meetings?

PS: who is going to tell the carnivores...

PSS: not sure which faith you mean?

No, I'm not convinced you would achieve much at all. Unless you are trying to prevent animals being eaten for ethical reasons. In that case you would dramatically reduce the numbers of some farmed Animals.

Your question is a bit vague, but what are the alternatives? do we have sustainable and affordable alternatives assuming spoiled first world people?

This could be rephrased by replacing meat with fish! Intensive food production process tend to be unsustainable, see overfishing (https://en.wikipedia.org/wiki/Overfishing)

Learn to cook tastier veg food instead. If the veg options are boring cant blame anyone.

Banning meat would effectively ban animal farming, which would make most land based food production unviable - animals essential to farm sustainably; fertilizer, seedbed preparation, weed control, seed spreading...and many others.