Arizona State University Research Debunked by Global Cool Cities Alliance

For decades scientists and green building advocates have agreed that the most effective method of reducing urban heat islands is to use light colored pavements and cladding such as concrete. Recently, however, the Asphalt Pavement Alliance has been challenging the science behind urban heat island effect with new research from Arizona State University (ASU). "Unintended Consequences: A Research Synthesis Examining the Use of Reflective Pavements to Mitigate the Urban Heat Island Effect," calls into question many common assumptions about the ability of reflective pavements to mitigate urban heat island effect. 

Given the large body of scientific evidence associated with reflective pavements, it is no wonder the flawed ASU paper has been called into question. The Global Cool Cities Alliance has issued a letter to the director of ASU Global Institute of Sustainability characterizing the research as "biased, misleading, and error-riddled industry white paper" and urged a retraction of the paper, citing its "institutional reputation" at risk.

Green building standards have widely adopted reflective material as UHI reduction strategy: The International Green Construction Code mandates heat island mitigation with hardscape materials that are light colored with a Solar Reflectance Index (SRI) of at least 29. LEED 2009 credit SSc7.1 Heat Island Effect and LEED v4 SSc5 Heat Island Reduction contains substantially the same requirement; And Green Globes offers 1 credit for at least 25% of a site hardscape having an SRI of 25.