A lot of new technology could potentially solve this problem.
There are certain types of roofs being installed called cool roofs that reflect heat and don’t absorb it that keeps the inside of building a little cooler.
Radiative cooling roofs, like those from sky cool systems actually cool your house during the day. I'm not sure how cost effective those are but the technology seems to be very promising.
Yep! Looks like the authors of the first paper I read on it (glass microspheres in silver-backed clear plastic film) are finally starting to commercialize it too... http://radi-cool.com/technologies/