(Our store is mostly outdoors, but it has a small greenhouse where cafe customers often sit and have coffee.)

Customer: “Excuse me, I would like to sit in the greenhouse. Could you open a vent for me?”

Me: “Actually, when it’s windy like today it rattles a lot when the doors are open, so you might be more comfortable with them closed.”

Customer: “But we can’t sit in there without ventilation. What about the greenhouse gas?!”

Me: “Sorry?”

Customer: “Greenhouse gas! Like global warming! You can’t let people sit in there if you’re letting the greenhouse gas build up!”