To add on to this, the title should really end with, “than being vegetarian”, or else the title should be " Consuming animal products creates four time more greenhouse gases than being vegan,…"
It’s not really a 1 to 1 comparison if you’re comparing a meat eater with someone who doesn’t consume milk, meat, eggs, or any other animal products. You can also have meat eaters that don’t consume milk due to allergies and such.
Plus, technically speaking (with cultured meat on the rise), there could be vegans that aren’t vegetarian, as vegans could still eat cultured meat.