Cool roofs are an accepted measure to reduce air conditioning load, thus to save electric bills and CO2 emissions. But in our companion paper1 (attached) we introduce a new consideration of how cool roofs and pavements “offset” about ten times more CO2 than is avoided through reduced electric load. The new consideration is that white (or cool) surfaces increase the earth’s reflectivity to sunlight (known as its “albedo”) and hence cool the earth directly that is equivalent to reducing the greenhouse effect by removing CO2 from the atmosphere. In this note, we show that an aggressive 15‐year state‐wide campaign for cool roofs and pavements is equivalent to reducing annual California emissions by 31MtCO2, or 18% of the AB32 goal for 2020 of 175 MtCO2/yr.

Akbari H, Menon S, Rosenfeld A. Equivalent CO2 avoided by reflective roofs and pavements in California.; 2008.