What are Urban Heat Islands?
An urban area that is warmer than its surrounding rural areas is known as an urban heat island. The phenomenon of urban heating is more common in metropolitan areas. It was first discovered by Luke Howard, a British manufacturing chemist and meteorologist.
What Causes Urban Heat Islands?
To accommodate the growing population in urban areas, there is less space between buildings, leading to reduced air circulation. Additionally, building materials like asphalt, steel, and brick are dark in color and trap heat, which warms up the areas around the buildings.
Evapotranspiration is another significant reason behind urban heating. Heat disposed from thermal plants, industries, and appliances like air conditioners, coolers, etc., are chief contributors to urban heating.
What are the Effects of Urban Heating?
- Excessive use of cooling appliances puts extra load on power plants. Power plants produce the required energy, releasing heat and pollutants, which increase the temperature further.
- Loss of aquatic life due to runaway water from hot pavements and roads into different water bodies.
- Global warming due to large-scale cutting of trees.
- Increased temperatures cause many health hazards in humans.
How can Urban Heating be Reduced?
Urban heating can be reduced by:
- Painting rooftops white as it is a good heat reflector.
- By practicing green roofery (planting trees on the building roofs).
- Turning cities green by planting more trees. Trees absorb carbon dioxide (a warm gas) for photosynthesis and cool the surrounding air by transpiration.
- Creating awareness in society about urban heating.