“Cool Pavements” Could Reduce Urban Heat Islands in Nation’s Hottest Cities

Image: Sgt. Christopher Ruano, Public domain, via Wikimedia Commons

By Amy Lupica, ODP Staff Writer

Pavement covers about 40% of America’s cities, absorbing solar radiation and creating urban heat islands. These heat islands can lead to health and environmental risks, and as seemingly unending heatwaves and drought sweep the Western U.S., they may become exceedingly dangerous. Researchers at the MIT Concrete Sustainability Hub (MIT CSHub) are paving the way to cooler cities and have developed strategies that could cool some of the nation’s hottest towns while cutting emissions in the process.

Why This Matters: Heat is increasingly becoming a threat to human health. In the Pacific Northwest, a summer heat dome led to hundreds of heat-related deaths. Like most impacts of climate change, heat risks are highly inequitable, and urban heat islands impact communities of color at much higher rates than their white neighbors.

  • One study found that neighborhoods with more people of color in Baltimore, Dallas, Denver, Miami, Portland, and New York, were 5 to 20 degrees Fahrenheit hotter than wealthier, whiter parts of town.

The MIT team found that cooling pavement (which reflects more solar radiation and emits less heat than conventional paving surfaces) could help quell this inequitable and increasing heat, saving lives, jobs, and even children’s educations in the process.

Paving the Way: A recent study published by MIT CSHub researchers in the journal of Environmental Science and Technology outlines implementing “cool pavements” to decrease temperatures in even the hottest cities. These types of pavements reflect up to three times more solar radiation than asphalt and emit less heat. There are also many ways to create cool pavements, making them more practical for cities with different climate and infrastructure needs. “Brighter materials like concrete and lighter-colored aggregates offer higher albedo while existing asphalt pavements can be made ‘cool’ through reflective coatings,” said Randolph Kirchain, a researcher in the Materials Science Laboratory and co-director of the CSHub. Asphalt currently makes up 95% of the world’s pavement.

The researchers studied several of these options in Boston and Phoenix and found that implementing cool pavements decreased air temperatures by up to 3 and 3.7 degrees Fahrenheit, respectively. The pavements could also cut total greenhouse gas emissions by 3 percent in Boston and 6 percent in Phoenix. However, the researchers found that the best approach varied by neighborhood and that different areas may need different cool pavement approaches. “Though the climate change impacts we studied have proven numerous and often at odds with each other, our conclusions are unambiguous: Cool pavements could offer immense climate change mitigation benefits for both cities,” said Kirchain.

Up Next

California Bill Aims to Clarify Recycling Symbols

California Bill Aims to Clarify Recycling Symbols

By Ashira Morris, ODP Staff Writer Those three arrows in a triangle are an easy shorthand for recyclables, but there’s one problem:  just because the symbol is printed on a product, doesn’t necessarily mean the item is recyclable. It simply informs consumers of the type of plastic used based on the number within the arrows. […]

Continue Reading 391 words
One Cool Thing: Think Outside the Sauce

One Cool Thing: Think Outside the Sauce

“Recycling just got saucy.” Taco Bell has announced that it’s teaming up with recycling firm TerraCycle to keep its iconic sauce packets out of landfills. The company says that more than 8 billion of their spicy sauce packets end up in landfills each year, but with this new partnership, those friendly packets can become something […]

Continue Reading 139 words
One Cool Thing: Net-Zero Sports

One Cool Thing: Net-Zero Sports

Sky Sports, Tottenham Hotspur Football Club, the Premier League, and COP26 have teamed up to put on the world’s first major net-zero football game (or Soccer game as it’s called in the US). #GameZero, featuring Tottenham vs. Chelsea, will be a showcase of how fans, teams, and broadcasters can move toward a net-zero future. The […]

Continue Reading 131 words

Want the planet in your inbox?

Subscribe to the email that top lawmakers, renowned scientists, and thousands of concerned citizens turn to each morning for the latest environmental news and analysis.