This simple solution was suggested long ago. It'll help keep the building cooler and the roof will last longer. I'm so bored with these dead simple suggestions and no action.
I'm not an expert on the matter, but my understanding is that rooftop greenery is a cheaper and more effective way to reduce cooling in the summer and heating in the winter.
Someone correct me if I'm wrong, but isn't there more energy used to heat buildings than cool them? Of course it depends on many factors, including location; so a blanket statement of "white roofs everywhere" seems wrong.
I've thought about this a while back when a co-worker and I were discussing the aesthetics of light colored shingles. Dark ones look better was his opinion, and probably in the opinion of many others.<p>If one were to develop a process by which titanium-dioxide (or whatever, white) paint could be applied to the "top" face of the shingles on a sloped roof (asphalt shingles are covered with small 3-dimensional granules), while leaving the lower faces dark, you would have the best of both worlds: Reflectivity from the summer sun which is high in sky and also heat capture from a sun in the winter when it is low in the sky, plus the aesthetic of a darker roof when viewed from ground level.<p>Just another half-baked idea of mine...
How much energy would be spent on the production of white paint? How much energy would be saved by painting the roofs white? Unless a detailed quantitative analysis is provided, this is pretty much nonsensical...