Three-dimensional simulation for urban warming in Tokyo and proposal of an environmental index for urban outdoor comfort

According to a computer simulation for urban warming in the Tokyo metro area in 2031, the maximum ambient temperature in the evening (18:00) at Otemachi will exceed 42°C. In contrast to the interior thermal comfort in residential and office buildings, the urban outdoor comfort is strongly affected by intense thermal radiation coming from the surface of the structures, as well as solar radiation. Motivated by the above facts, we propose a new standard effective temperature index (USET*), which is applicable to evaluate urban thermal comfort. By using this thermal comfort index, assessment of the urban environment can be made for both present Tokyo and Tokyo around 2030. Furthermore, it is suggested that a comprehensive urban environmental index (UEI), which includes pollutants and ultraviolet rays, might be adopted for the future urban environment