I wonder what the global temperature rise would be right now if everyone in Europe had air conditioning since it was invented. Probably about half a degree hotter - so about two degrees total warming?
That said F-gases would have been an issue, EU only recently banned them.
Also most of Europe truly didn't need AC for a long time, growing up temperature above 30C was exceptional and I didn't even know the term tropical night (nighttime temperature above 20C).
(Now that places are getting 10+ consecutive days above 30 with peaks close or above 40)