In this modern world, urbanization is an undeniable transformation, creating concrete jungles where buildings and pavements absorb and radiate heat, affecting what is known as urban heat islands (UHIs). As our cities expand, it’s becoming increasingly vital to explore innovative ways to tackle the issue with UHIs, which is the significant temperature increase – potentially putting a risk to our environment and health. This is primarily due to human activities industrial processes, transportation, and air conditioning discharge heat and the extensive use of concrete and asphalt, absorbing and re-emitting heat. The vast areas of concrete, asphalt, and dark surfaces in urban environments absorb and re-radiate this heat, raising temperatures. Not only that, lack of vegetation and green spaces also results in reduced shade and evapotranspiration – the process by which plants release water into the atmosphere, cooling their surroundings. Based on these effects alone, UHIs have real and tangible effects: increased energy consumption for cooling, higher greenhouse gas emissions, reduced air quality, and adverse health outcomes.
This is where green infrastructure plays a crucial role in mitigating these effects. Green infrastructure emerges as a promising solution to mitigate the impact of urban heat islands. It involves integrating nature-based elements into urban planning. This will enable cities to harness the ecological benefits of vegetation, open spaces, and water bodies. By implementing green infrastructure, it will allow cities to cool down, improve air quality, and promote public well-being. Some examples of green infrastructures are urban green roofs, green spaces, urban parks, street trees, permeable pavements, riverbanks, and including canal systems to cool down the surrounding environment.
Green infrastructure is not just a solution to UHIs, it also offers numerous other advantages as follows:
-
Energy Efficiency
Green infrastructure, such as green roofs and walls, can help cool buildings and outdoor spaces by providing shade and reducing the heat absorbed by buildings. This can lead to a decrease in the use of air conditioning systems, which in turn reduces energy consumption leading to cost savings in the long run.
-
Improved Air Quality
Plants are natural air purifiers. They absorb harmful pollutants from the air, such as carbon dioxide, and release oxygen through photosynthesis. By increasing vegetation in urban areas through green infrastructure, the air quality can be significantly improved.
-
Biodiversity
Urban green spaces like parks and gardens can serve as habitats for various species of birds, insects, and other wildlife. This promotes biodiversity in urban areas, which is crucial for a healthy ecosystem.
-
Health and Well-being
Green spaces provide a respite from urban stressors and offer opportunities for physical activity, which is beneficial for mental and physical health. They also contribute to cooler and cleaner urban environments, which can reduce heat-related illnesses and improve overall well-being.
-
Economic Benefits
Green infrastructure can increase property values as they make the surroundings more attractive. This can attract more businesses, residents, and tourists to the city, boosting the local economy. Additionally, the cost savings from reduced energy consumption can also have economic benefits.
Successful Examples
Numerous cities worldwide have embraced green infrastructure to combat UHIs effectively. For example, in Singapore, the “Garden City” project has integrated green infrastructure into its urban planning. This includes green roofs, vertical gardens, and verdant walls like Supertree Grove – iconic tree-like structures are planted with ferns, orchids, and other climbers, providing shade, and reducing local temperatures. According to National Geographic 2017, green building has been mandatory since 2008. Singapore’s approach to green infrastructure extends to its public housing, emphasizing community-centric towns and amenities.
Urban heat islands pose a growing challenge to cities worldwide, with implications for public health, energy consumption, and the environment. However, green infrastructure offers a sustainable solution by harnessing the power of nature within urban environments. By creating cooler, more vibrant, and healthier cities, green infrastructure is a crucial step toward combating UHIs. As cities expand and populations grow, integrating green infrastructure becomes an essential element of urban planning, fostering a more sustainable and habitable future for all.
- Balany, F., Ng, A. W. M., Muttil, N., Muthukumaran, S., & Wong, M. S. (n.d.). Green Infrastructure as an Urban Heat Island Mitigation Strategy—A Review.
- Filho, W. L., et al. (n.d.). Addressing the Urban Heat Islands Effect: A Cross-Country Assessment of the Role of Green Infrastructure.
- U.S. Environmental Protection Agency (n.d.). Reduce Urban Heat Island Effect.
- Shoaib, A. (n.d.). Multiple Benefits of Green Infrastructure.
- Benfield, K. (n.d.). Distressed city neighborhoods need green investment for community, environment. Smart Cities Dive
- U.S. Environmental Protection Agency (n.d.). Healthy Benefits of Green Infrastructure in Communities2