Underground climate change: How heat is trapped under the surface, threatening buildings

On a recent tour underneath Chicago’s iconic skyline, Alessandro Rotta Loria, an assistant professor of civil and environmental engineering at Northwestern University, pointed out one of the sensors he and his team have installed across the city to track underground temperatures.

CHICAGO — On a recent tour underneath Chicago’s iconic skyline, Alessandro Rotta Loria, an assistant professor of civil and environmental engineering at Northwestern University, pointed out one of the sensors he and his team have installed across the city to track underground temperatures. 

Not much bigger than a credit card,  more than 100 of the sensors have been placed in parking garages, basement boiler rooms and subway tunnels all around the downtown Loop of Chicago in an effort to track what Rotta Loria describes as a “silent hazard.”

According to his research, air temperatures in underground human-made structures can be up to 77 degrees Fahrenheit (25 degrees Celsius) higher than “undisturbed” ground temperature. It’s a threat distinct from global warming but one that comes with similar threats of wreaking havoc on public health and crucial infrastructure.

“There’s already a significant amount of heat beneath our feet,” Rotta Loria said. “And this heat has caused the ground to deform already.”