A new modelling study from the University of Oxford and collaborators has estimated how changing the reflectivity of roofs can help keep cities cooler during heatwaves and reduce heat-rated mortality rates.
A new modelling study from the University of Oxford and collaborators has estimated how changing the reflectivity of roofs can help keep cities cooler during heatwaves and reduce heat-rated mortality rates.
Cities are generally a few degrees warmer than the countryside, due to the urban heat island effect. This effect is caused partly by a lack of moisture and vegetation in cities compared with rural landscapes, and because urban building materials store up heat. During heatwaves, daytime temperatures can get dangerously high in cities, leading to serious health effects and increasing mortality risk.
The idea of ‘cool’ roofs is to make roof surfaces more reflective to sunlight (for example by painting roofs a lighter colour) thereby reducing local temperatures.
Scientists used a regional weather model to look at how temperatures changed across the study city of Birmingham and the West Midlands, depending on the extent of cool roof deployment. They looked at the hot summers of 2003 and 2006, and found that the intensity of the urban heat island (the urban-rural temperature difference) reached up to 9oC for Birmingham city.
Read more at University of Oxford
