[usrusr]

Highly doubt it: vegans won't change their behavior and unrestricted meat eaters won't start eating even more meat. There's hardly anybody in between. Yes, theoretically less people might turn vegan afterwards, but how many vegans have become vegan because of methane?

[mistrial9]

a quick search shows that about ten percent of Europe are vegetarian, and about 375 million people world wide. Please note that "vegan" has a narrow, specific meaning; there are fewer vegans.

The definition of advertising is to change behavior, it is done daily for lots of reasons. Why not let people choose? Let's not prescribe outcomes, but instead enable evolution.

[usrusr]

375 million people world wide, and I'd expect not one of them to start eating meat because of some reduction of methane impact.