Read the full story at EnvironmmentalResearchWeb.
Several cities in the US are encouraging the use of green or cool roofs on buildings in an attempt to reduce the urban heat island effect. But assessing the effectiveness of this policy has been challenging. Most models look at the effect of a green or cool roof on one building but up-scaling this to a city or metropolitan area is difficult due to different urban landscapes and their effect on atmosphere exchanges.
Now researchers from Princeton University in the US have developed a new urban canopy model (UCM) that they claim is ideal for city-scale investigations into the mitigation of urban heat island effects. Dan Li and his colleagues tested their model on the Baltimore-Washington metropolitan area during a four-day heatwave and found that a reduction of surface temperature of 1 °C could be achieved if 30% of all roofs in the area were green or cool roofs.