From using lighter asphalt on roads to painting roofs white, a senior lecturer at the Malta Campus of London’s Queen Mary University has proposed several solutions to prepare the island against extreme heat.
After nearly two weeks of power cuts amid a sweltering heatwave, climate change and health expert John Paul Cauchi explained that painting surfaces with lighter colours can help bounce heat back towards the sky.
Light grey tarmac would absorb less heat – and more trees are also needed. Photo: Shutterstock.com“A no-brainer is to have white roofs when solar panels aren’t there to reflect heat,” Cauchi said.
Known as the albedo effect, surfaces painted with lighter colours can reflect a lot of the sun’s heat back into the atmosphere, while darker surfaces absorb the light and its warmth.
Last Monday, the heat rose to 42.7°C, equalling the highest-ever temperature registered in July.
Another solution, Cauchi continued, is using lighter asphalt on roads so the tarmac does not absorb as much heat.
Utilising the albedo effect, the lighter asphalt would mean that the intense heat is able to bounce off the ground instead of being absorbed.
“Depending on where you are, if you put your hand on the asphalt right now at noon, it will be 50 to 70 degrees,” he said.
Last Tuesday, Enemalta’s distribution engineer John Zammit told Times of Malta that the widespread power outages were primarily due to the sudden spike in temperature that hit the underground electricity cables.
Although those temperatures have not been measured, Zammit explained that once
the heat is absorbed into the ground, the stone surrounding the power cables can retain the heat into the night.
Lighter roads are not a new concept – California painted some of its streets white in 2018, according to CBS News.
Proposing to use light grey tarmac rather than using paint, the shift in colour would contribute to combatting what is known as the “urban heat island effect”, Cauchi said.
Thanks to the concentrated number of buildings and concrete surfaces that tend to absorb and retain heat, the phenomenon amplifies a city’s temperature levels.
However, this should be combined with another solution, Cauchi proposed: planting more canopy trees to cast more shade onto roads and urban areas.
“Malta is putting indigenous trees on our roads which is biologically good,” he said, because invasive species can cause harm to the surrounding environment. Yet Cauchi emphasised that they offer no shade and that, on a practical level, there are better solutions.
“Our island needs better urban planning,” Cauchi said, adding the future was only going to get worse.
“This is just the start of it, so we better be prepared.”
Responding to questions from Times of Malta, Infrastructure Malta CEO Ivan Falzon said the black tarmac used across the island is more durable and sees more use globally.
Noting that their research and development team is consistently monitoring developments in the field, Falzon said there were no plans to introduce coloured asphalt in the immediate future.