There would likely be unintended consequences to raising the price of meat through a carbon tax. It creates a market for cheaper meat that there will be no shortage of producers or consumers for. How that meat is made cheaper is an open question. It could be through carbon offsets but it could just as well be through worse conditions for the animals or importing the meat from countries where production is cheaper.
The same argument is made against raising the taxes on tobacco products, that "people will smuggle in cigarettes from countries without the tax", but it never seems to actually happen to any significant degree.
People are lazy, and if the only source of cheap meat is the black market of illegally-imported products, only a very small segment of people will bother.
I live somewhere with high taxes on tobacco products and illegal cigarettes are a big problem. It's not a small segment of the smoking population either but it is disproportionately those who are more economically disadvantaged. People are lazy but they are also motivated by economic pressures. It's easy for something like that to become an 'invisible' problem to people who aren't in those economic or social groups while still having severe negative effects on a large number of people.
