White-painted roofs could have saved lives in London’s hottest summer, as per a recent study conducted by researchers. The study, led by experts from University College London (UCL) and the University of Exeter, looked at the impact of ‘cool roofs’ and solar panels on urban heat during the scorching summer of 2018.
The researchers found that painting London’s roofs white or in reflective colours could potentially save hundreds of lives in increasingly hot summers. Additionally, covering the city’s rooftops with solar panels could also have a positive impact in reducing heat-related deaths, while simultaneously generating significant amounts of clean energy.
Cool roofs, which are typically painted in white or reflective colours, absorb less radiant energy from the sun compared to traditional dark roofs. This helps to mitigate the ‘urban heat island’ effect, where cities tend to absorb and retain more heat than surrounding areas, leading to increased temperatures.
During the summer of 2018, when London experienced record-breaking temperatures, it was estimated that 786 deaths in Greater London in June, July, and August were linked to the heat. The researchers projected that if all of London’s rooftops were cool roofs, it could lower average outside air temperatures by 0.8°C. If all rooftops were covered in solar photovoltaic (PV) panels, temperatures would decrease by 0.3°C.
The study suggested that with full coverage of cool roofs, approximately 249 deaths could have been prevented, representing a significant reduction in heat-related fatalities. Moreover, if all roofs were equipped with solar panels, around 96 deaths could have been avoided, and the solar PV systems could have generated up to 20 terawatt hours of electricity.
According to the researchers, implementing these measures could have saved the city millions in economic costs associated with heat-related deaths. Lead author Dr. Charles Simpson from UCL emphasised the significant cooling effects of cool roofs, underscoring their potential to save lives and enhance the quality of life for urban residents.
Co-author Professor Tim Taylor from the University of Exeter highlighted the urgent need for cities to adapt to climate change. Taylor stressed the importance of initiatives like implementing cool roofs and solar panels, not only to reduce the impact of excess heat on urban populations but also to harness additional benefits such as energy generation.
In conclusion, the study’s findings underscore the potential of simple interventions like white-painted roofs and solar panels to mitigate the effects of rising temperatures in urban areas, offering a sustainable solution to combat the challenges posed by climate change.