Not going to enter into a vegan/veggie/omnivore debate but as we're talking numbers it's worth noting that the CO2 figures for meat use a global average that includes very poor feedlot practices ... UK beef production methods, being pasture based, only emit a third of the global average per Kg ... so if you eat British beef then the saving for going Vegan would only be 5%
According to
these stats global emissions for Livestock farming is 6.8%, and the passenger transport accounts for 7.1% (60% of the 11.9% from Road Transport). It would be far cheaper and easier for the entire population to go vegan, than to replace the millions of ICE cars with EV's (not withstanding all the emissions from manufacture).
Of course, I'm not advocating we all go vegan - each to their own, I can fully understand why people enjoy a succulent rare steak or a bacon sarnie as much as the next man - but if people are genuinely interested in saving the planet, then it makes sense to go vegan first before forking out tens of thousands on solar panels and EV's.