A response to the paper by Mark Jacobsen and John Ten Hoeve in Climate.

The recent Journal of Climate paper by Stanford researchers Mark Jacobson and John Ten Hoeve (2011) is a useful contribution to the literature on urban heat islands and mitigation potential of reflective (or white or cool) surfaces such as roofs and pavements. However, the article’s results regarding white roofs are preliminary and uncertain. Moreover there are other published papers that address the broader benefits of white roofs. In our view, these studies taken together raise important issues that need to be considered from the policy viewpoint to fully understand the mitigation potential from more reflective (or white or cool) surfaces.
Lawrence Berkeley National Laboratory’s Heat Island Group has conducted extensive research on cool materials and their effects on regional and global climate. Due to media coverage highlighting the paper’s conclusions that speculatively suggest an overall global warming influence of converting worldwide roofs to white, the Heat Island Group would like to draw attention to a few points of the paper. We believe its conclusions need to be analyzed more carefully.

Ronnen Levinson (Lawrence Berkeley National Labs (LBNL))

Marc Fischer (Lawrence Berkeley National Labs (LBNL))

Dev Millstein (Lawrence Berkeley National Labs (LBNL))

Nancy Brown (Lawrence Berkeley National Labs (LBNL))

Francisco Salamanca (Lawrence Berkeley National Labs (LBNL))

Igor Sednev (Lawrence Berkeley National Labs (LBNL))

Art Rosenfeld (Lawrence Berkeley National Labs (LBNL))