As the other user said, I don't believe we could get the political muster necessary to pass a law taxing meat heavily any time soon. Meat is popular! Nobody wants to give that up.

Also, you're absolutely correct that dairy milk is less efficient by a long-shot, I was just pointing to it because I know a lot of people I personally know are moving to it and away from dairy as though it's a quality alternative. It's better, but still not great.

>You don't think taxing meat by its environmental cost will work?

Economically, it would work. Politically? At least in the US, people would vote out any party that installed taxes that reduced meat consumption by an significant amount. We don't even have the political willpower to make energy slightly more expensive.