I can see this happening: A woman standing/sitting in a business when her rustles from a breeze. the person standing/sitting next her says: that was just my contribution to global warming. :)
I live in L.A. - people are all about their RAW diet and RAW vegan green smoothies and whole-grain, gluten-free this or that yada yada...but hello...
And now the new thing is the fake meat burgers, which also apparently cause...issues.
In a nutshell: vegans contribute to global warming a plenty.