Here is yet more proof of the obvious:
White Roofs May Successfully Cool Cities
I am surprised that we are still studying and debating this concept. It is self-evident and has been suggested for decades, alongside other concepts such as white roads and green-garden/grass rooftops. These seem to be no-brainers and I am still flabbergasted that they aren’t already standard.
What is the downside? Color is irrelevant and if one is much cooler than another, then use it. We know cities are super hotspots, so change the construction parameters and voila you might solve the whole problem or at least positively impact it.
If you have doubts, check it out, white roofs look nice — perhaps even nicer than traditional black roofs. I think the trend in black roofs came about in a two-fold way: 1) tar to seal from leaks was black, so make it all black; 2) soot from wood- and coal-burning chimneys used to make for clack-roofed cities. This no longer applies.
Why are we still studying this? Simply start designing and building smarter. If you want to see which is best, simply build half the buildings with white roofs and half with green garden/grass roofs and see which surpasses the other. Done.
In closing, it is instructive to look back in history and learn. Throughout the Middle East, North Africa, and Mediterranean regions, where there is much sunshine and heat, cities have been mitigating the effects of overheating for millennia by whitewashing their roofs and walls. It just works.
