Paris: White or reflective paint could be more effective in colder cities and provide relief on hot summer days than covering roofs in solar panels or greenhouses, scientists say.
Two separate studies looked at the “cool roof” effect and found that white coating or reflective coating can reduce outdoor temperatures in cities by up to 2 degrees.
Scientists from University College London (UCL) used a model of Greater London to test the city’s cooling methods against the hottest day of 2018.
The findings, published Thursday in the journal Geophysical Research Letters, found that if widely accepted, cool roofs can reduce the ambient temperature by 1.2C to 2C.
Other approaches, such as planting plants at street level or installing solar panels, provided a smaller cooling effect of around 0.3C on average in London, the study found.
Covering the roof with greenery has a “negligible” effect on temperature, but can offer other benefits, such as better drainage and habitat for wildlife.
“Other methods have distinct advantages, but none reduce the heat in open cities to the same degree.”
