Switching from an omnivorous to vegetarian diet could reduce a person's carbon footprint by about 30 percent, says Martin Heller, an engineer at the Center for Sustainable Systems at the University of Michigan.
https://www.popsci.com/vegetarian-environment-health (I've picked this as the first hit on google, but if you want to find other sources go for it).
The point about vegetarianism is that eating meat is SOOOOOOOOOOOOOOOOOOOO inefficient that climate change won't be solved until we ALL stop eating meat (or at least the majority of the planet).
Yes, there are corporate plutocrats that are destroying the planet. No, that does not let you off the hook. If you see a collective action problem and decide that, since it's hard, and other people suck, you don't have to participate, then you're just as much a part of the problem as the sucky people.