global cooling, reflectivity, walls, roofs
Lawrence Berkeley Laboratory scientists hold that if the world’s urban areas were highly reflective, global warming would be delayed by eleven years. However, America’s building energy codes do not cite reflective surfaces as key paths to reducing solar heat gain in buildings. This paper introduces a new methodology for combining roof and wall reflectance values with climate data, solar insolation incidence, energy costs and payback times, using modeled buildings as examples, with the same buildings using conventional insulation technologies. The results are side-by-side comparisons of performance, initial and energy costs and payback times in a variety of locations worldwide. The paper also includes analyses of widely differing life spans of various reflective surfaces and stresses the importance of extended reflectivity due to resistance to organism growth. Suggested language for inserting reflective technologies into energy codes is included, as is a case for adopting such codes in hot areas worldwide as a key path to global cooling.