It seems to me like people are confusing eating meat with our modern agricultural processes. And if that's the case then the solution should be to improve said processes, not to stop eating meat.
The thing is - how is the average person going to improve the processes? People can eat less meat and urge the governments in different areas to force better farming practices through regulation, financial support for upgrades, investment in technology (for example, something that composts manure and spreads it better than the liquid manure we keep in vats or somehow breeding cows that produce less methane), and other such things.
Some countries will be able to pull this off. Others... well, will fail. And some of those are either major contributors or consumers.
I've found that substituting meat is an almost impossible task, I certainly haven't found anything that is as satisfying as a good steak. But replacing it with something I find enjoyable in a different way works really well, as long as you have an open mind and accept that it's not going to be an identical experience. (Personally, I prefer the black bean burgers for this reason. I absolutely adore spicy foods, I've been topping burgers with pepper jack and jalapenos since I was 13, having the patty itself with a good texture and a nice kick out of the box is wonderful)