The other issue regarding excessive need for A/C is that we have for a long time built buildings that don't do anything to reduce unnecessary heat load. For example the memorial classroom building at the University of Miami was built back in the late 40's without a/c. But it was designed accordingly. It's just a long, straight, 3 story building that runs from east to west. Open air "hallways" are on the south side, with doors to the classrooms. The north wall is entirely windows that could be opened wide from 3 feet off the floor to the ceiling. The south hallways prevent the sun from hitting the south walls of the building and there are transoms over the classroom doors. Open up the north side windows and the transom and you could get a nice breeze. By the time I went to school there in the late 80's the building had been retrofitted with A/C because by then everything in Florida had A/C since people like me from cooler climates would probably have opted to go to school elsewhere if they didn't have A/C everywhere. The newer campus buildings, though, didn't even attempt to manage heat load or provide for good ventilation. Housing all over the country has similarly lost the commonsense heat reduction strategies, making A/C far more urgent than it would be with appropriate shading and ventilation.