Without meaning to offend, you're talking out of your backside.
We eat meat because it's full of protein etc.. which, when scrubbing around in prehistoric Britain (or anywhere else for that matter) was a rare and wonderful thing, which we all need to survive.
Also, we continue to eat meat because a) it tastes nice, and b) it's still a bloody good source of protein. The reason a vegetarian diet is proven to make people live longer is because meat-eaters tend to indulge themseleves in other areas aswell whereas veges tend to look after themselves more. Yes, red meat is a little bad for you, but eaten in proportion, like anything else, it is OK. and white meat is even better.
One more thing for you to think about - if everyone stopped eating meat, what would we do with all the cows and sheep etc..? turn them loose in the wild? kill them all? either way it would mean practical extinction of hundreds of breeds that would otherwise have survived quite happily.
I'm not saying you don't mean well, you probably do, but perhaps you should think a little more of the full implications of what you preach before you go spouting off.