A new report by the Lawrence Berkeley National Laboratory says white roofs are the optimal choice, both economically and for cooling the globe.

Compared to traditional dark-colored roofs and green or “vegetated” roofs, white roofs offer greater ability to lower temperatures that lead to the urban heat island effect, and they do it at less cost. The report, Economic Comparison of White, Green, and Black Flat Roofs In the United States, states flatly…