Underground Climate Change: A Silent Hazard Threatening Urban Infrastructure
What is Underground Climate Change?
Underground climate change, also known as “subsurface heat islands,” occurs when heat from human-made structures, such as buildings and underground transportation systems, radiates into the earth. This phenomenon is distinct from climate change in the atmosphere, which is caused by greenhouse gas emissions.
How Does Underground Climate Change Affect Chicago?
Researchers have discovered that underground climate change is causing the ground beneath downtown Chicago to slowly sink. As the ground temperature rises, Chicago’s clay soil contracts, leading to potential cracks in building foundations and even distortion or tilting of structures.
Measuring the Impact
To assess the impact of underground climate change, researchers installed a network of temperature sensors above and below ground in the Chicago Loop. They also used a model to simulate temperature changes since 1951 and predict future temperatures through 2051.
Their findings showed that ground temperatures below the city are rising by about 0.25 degrees Fahrenheit every year. Some underground locations have reached temperatures up to 27 degrees warmer than undisturbed ground, and beneath buildings in the Loop, temperatures are often 18 degrees hotter than below Grant Park.
Consequences for Infrastructure
The rising temperatures due to underground climate change pose significant challenges for urban infrastructure. Warmer temperatures can cause the ground to expand or contract, leading to:
- Cracks in building foundations
- Distortion or tilting of structures
- Overheating of subway rails, slowing down or halting train services
- Thermal pollution of groundwaters
Health Implications
Increased underground temperatures can also have adverse health effects, including:
- Dehydration
- Asthma
- Hypertension
Mitigation Strategies
To mitigate the effects of underground climate change, cities can implement strategies such as:
- Applying thermal insulation to underground building enclosures to reduce heat loss into the earth
- Capturing excess underground heat and using it as geothermal energy to warm and cool buildings
Long-Term Monitoring and Planning
Understanding the impacts of underground climate change is crucial for long-term urban planning and infrastructure management.
- Continuous monitoring of ground temperatures is essential to track changes over time.
- Cities need to evaluate the vulnerability of their ground conditions to subsurface heat islands.
- Regulations and policies should be developed to address the challenges posed by underground climate change.
Conclusion:
Underground climate change is a silent hazard that poses threats to urban infrastructure and human health. By understanding its impacts and implementing mitigation strategies, cities can ensure the sustainability and resilience of their built environments.
