Urban heat island impact on state residential energy cost and CO2 emissions in the United States

Urban heat island (UHI) is a climate effect that magnifies air temperature in cities. In the US it affects over 80% of the population and in general is considered an adverse phenomenon with externalities ranging from increased air pollution to higher energy demand and deteriorated human comfort. Therefore, UHI and its mitigation strategies have been studied extensively to focus on hot summer months and demand for cooling energy. However, current approaches fail to recognize that for regions in cold climates UHI may be a positive phenomenon with benefits from decreased heating energy demand exceeding downsides of higher cooling energy demand. Here, for the period of 12 years we analyze for 48 US states the cost that UHI imposes on the $120B residential market with CO2 emissions that exceed 550 M tons each year. While for states situated in warm climates UHI significantly increases the energy bill, due to varying heating and cooling costs and emissions associated with generation of energy, for some regions located in cold climates, UHI significantly reduces energy demand and carbon emissions. This information will help legislators and policy makers understand better energy demand of buildings and subsequently reduce their carbon footprint at city and state levels.