My first point already explained why it benefits your class, but I will also add that a vegan diet is the single most impactful thing someone can do to reduce their carbon footprint. So, if your class will suffer from climte change (it will) then going vegan is a necessity.

the idea of the personal carbon footprint is propaganda created by BP to distract from real environmental issues, much like the idea of the litterbug was corporate propaganda created to distract from actually meaningful pollution by industry.