According to the research done in North-western University in Illinois in the US, Underground Climate Change is a silent hazard that threatens major cities across the world.
The heat from buildings in underground transportation system diffuses below the surface.
Over time the ground warms and then expansions and contractions caused by this heat creates rocks.
This impairs the long-term durability and operational performance of structures.
They also claim that such rising temperatures may have contributed to previous building deterioration.