You can live on a vegan diet, but it is easier to live on an omnivore diet. And since for most people easier is preferable, and when talking about the population of the world as a whole, you'll still find that a large percentage of the world's population will eat meat if it is easily available.
So seguing into climate change issues, this took politics too. It started with grassroots taking hold in the 60's counter culture, then the start of political pressure in the 70's. The first big political move was Reagan coming on board during the 80's; and also some lucky technology hook ups like solar powered calculators (never underestimate the power of logistical growth from a low end but widely used product).
The 90's brought us government sponsored research and industry backed development and product roll outs; this led to massive improvements in cost mainly though scale. The last 15 years have led to product refinements, financing options, and a greater society wide understanding of just how bad climate change could be.
And now we are at a situation of solar becoming cheaper than coal for producing electricity. 50 years!
So if you want to achieve the same with meat vs vegetables there is an enormous amount to achieve, above all you'll need to convince people at least as well as climate change issues, get government backing, make it as enjoyable as eating meat, and drive down the cost of Lysine and Methionine extraction.
In fact Canola (low erucic acid rapeseed) meal (what's left over after oil extraction) is currently used as livestock feed, this could be used for human consumption but would require further post-processing and possibly protein profile adjustment.
To accept it you must either be against democracy as a concept of equal rights to vote, or for an almost equal distribution of income. Neither of which is particular mainstream ideologies today.
We could demand that farms had zero carbon footprint, zero water usage/drainage, a new tree for every cut one, and no pesticides. It is expensive, and food labeled under a mission which try to cover some of those aspects do demand a much higher price. At best it can be said is that its has a lower environmental impact that cows, even through my government (Sweden) explicitly says that if we don't get more farmers, most of the open field and bio diversity that comes from open fields will be lost.
Personally, I would go with a omnivore diet that pay a little extra (ie about double vs the cheapest) for products under environmental focused labels, and then just eat less of it. Even better, skip that car and you will end up having a much lower carbon footprint than any car owner has, regardless of diet.