A phenomenon that scientists have called “underground climate change” is deforming the ground beneath cities, a study conducted in Chicago has found.
This shifting of land under urban areas could pose a problem for buildings and infrastructure, threatening long-term performance and durability, according to the research.
Technically known as “subsurface heat islands,” underground climate change is the warming of the ground under our feet, caused by heat released by buildings and subterranean transportation such as subway systems.
“The denser the city, the more intense is underground climate change,” said lead study author Alessandro Rotta Loria, an assistant professor of civil and environmental engineering at Northwestern University in Evanston, Illinois.
Soil, rocks and construction materials deform when subjected to temperature variations. For example, the ground underneath buildings can contract when heated, causing unwanted settlement, Rotta Loria said.
But underground climate change is not the same as what we think of as climate change in the atmosphere, which is largely driven by greenhouse gases and has far-reaching effects, said David Archer, a professor of geophysical sciences at the University of Chicago.
“Calling it climate change seems like a bit of a coattail thing,” Archer, who was not involved with the study, said.
The term “underground climate change,” however, was not coined for this study — it has been in use, and the phenomenon a subject of research, for some time.