If you think veganism will save the world, you should probably look at a graph of greenhouse gas sources.
I don't drive. I've already done more than vegans ever will. Got an electric car? Good for you, but in the US that will still be powered by 60-70% coal and gas.
The only thing vegans have is the moral superiority on animal cruelty.
The only thing that will save the world is to stop burning fossil fuels. The only people that can force that change are governments. Once again those in charge have turned the people on each other. "Look at him, he's eating meat! Doesn't he know he's killing the planet?", while they're authorising another gas powerplant being built, or pushing back the banning of petrol cars by five years.