Some environmental trade-offs with reflective pavement technologies by UC Science Today

One way to fight what’s called ‘urban heat islands’ – a phenomenon in which dark-colored roads and buildings bring cities’ air temperature up – is to change the color of the pavement. That’s according to Ronnen Levinson, a scientist at Lawrence Berkeley National Laboratory.

“You can choose a more reflective pavement surface instead of a darker less reflective pavement surface. The more reflective pavement surface will stay cooler in the sun. It also won’t heat the air of the city as much as the darker, hotter pavement will.”

But there are trade-offs; Levinson was part of a team that found that the energy spent on manufacturing light-colored pavements can lead to increased carbon emissions.

“We found that in many cases switching to a more reflective pavement technology, for example, a light grey cement concrete pavement in place of a black asphalt concrete pavement, requires much more energy and carbon.”

So Levinson says city officials need to keep this in mind when they choose pavements.