I had a similar exchange with one of ours. Butted in and asked if I had a conscience about destroying the world we live in or some other over exaggerated claptrap.
I then pointed out that I barely drive my car and even then its mostly for fun and not only to get somewhere, therefore I get more from driving my car than he ever would.
Then called him a hypocrite for driving a Camper van with a 30 year old petrol engine that I doubt offers him any better economy, yet isn't anywhere nearly as quick or the fact I do less than 5000 miles a year.
Then told him that I trust he'd be pointing the same concerns at the CEO who was driving the GT3 RS.
On another occasion with a different one who was a female staff member, who was far ruder and I wasn't in the mood for it - I told her I wasn't happy that my car was "only" a band G for emissions, so I removed the cat and had it further tuned to make it even worse to annoy people like her.
I then told her I loved driving down country roads purely to watch the trees spontaneously die as I drove past them.
I don't think I ever spoke to her again.