As cities are expanding at unprecedented rate, the environmental impact of such concentrated living is evident in increased pollution levels, Water demand , and high consumption of electricity. However, the most significant issue is that millions of people who live close to one another are affected by the urban heat island.
In this article, we’ll talk about 10 solutions to Combat Urban Heat Island Effect.
What is Urban Heat Island Effect?
Heat islands are generally created when natural land cover is replaced by artificial structures, buildings, and other infrastructure. These buildings are packed closely together and the narrow spaces between them trap heat and block airflow, which is making the city even warmer.
In addition, concrete, asphalt and black roof tops absorb and store more heat which raises temperatures even more compared to natural ground cover. This heat, combined with air trapped between tall and closely placed buildings, has nowhere to escape as it is like a dome over a city.
This is called “urban heat island,” . This effect becomes more deadly as cities grow. In certain places, cities can differ in temperature by as much as 5.5 degrees Celsius from nearby rural areas.
Top 10 ways to Combat Urban Heat Island
Numerous cities around the world are now taking these steps to reduce their temperatures and develop a more sustainable urban environment.
- Cool Pavements
By looking at these urban heat maps, it is clear that traditional asphalt and concrete pavements absorb and retain heat, which greatly contributes to the urban heat island effect. Citis like Singapore, Los Angeles, and Chicago are using Cool pavements to Combat Urban Heat Island. These materials in comparison to traditional paving materials, absorb less heat and reflect more sunshine. Surface temperatures can be lowered by ten to fifteen degrees Celsius by swapping out conventional pavements for cool alternatives.
Cool pavements operate by enhancing the surface’s reflectivity. High-albedo materials reflect more of the sun’s light and hence absorb less heat. This not only cools the streets and pavements, but also serves to reduce the total temperature of the surrounding area. As a result, cool pavements can reduce the need for air conditioning, which lowers energy consumption and greenhouse gas emissions.
In addition to cooling benefits, cool pavements can improve road safety by lowering the danger of heat-related damage and increasing the life of road surfaces. They are also more comfortable for walkers and bicycles, promoting active transportation and minimising reliance on automobiles.
- Cool Roofs
“Cool roofs” are a very similar method to cool pavement which are utilised in many cities to Combat Urban Heat Island effect. These roofs are coated with materials that reflect more sunlight and absorb less heat, which results in dramatically lower temperatures within buildings.
This not only reduces the demand for air conditioning, which saves energy and reduces greenhouse gas emissions, but it also helps to chill the urban area. Cool roofs can lower roof surface temperatures by up to 50°C, resulting in a significant reduction in internal temperatures. This cooling effect reduces air conditioning expenses by up to 15%, resulting in significant energy savings. Furthermore, cool roofs can assist offset the urban heat island effect, which lowers ambient temperatures in densely populated areas.
- Green Roofs and Walls
Green roofs and walls are one of the most effective solutions for cooling metropolitan areas. Cities such as Chicago and Singapore have embraced this strategy, covering rooftops and building facades with plants. These green surfaces absorb sunlight and provide natural insulation, minimising heat retention in buildings. They not only lower temperatures but also improve air quality, reduce stormwater runoff, and create habitats for urban wildlife.
These roofs can reduce the surface temperature of a roof by up to 30-40°C, resulting in much lower internal temperatures. Similarly, green walls or vertical gardens can cool the surrounding air and have a significant impact in densely populated regions, generating pockets of cooler microclimates within the metropolis. In Singapore, for example, the “Garden City” programme aims to incorporate greenery into all aspects of urban life, increasing sustainability and improving the quality of life for people.
- Urban Forests.
And studies have shown that cool roofs and pavements have a smaller cooling effect than plants. So this brings us to our fourth approach to combat Urban Heat Island that is urban forests.
Trees are nature’s air conditioners, and urban forests are an effective tool for cooling cities. Tokyo, for example, has made significant investments in tree planting and the creation of green spaces. Trees produce shade, which reduces heat absorption by buildings and pavements. Trees also release moisture into the air through transpiration, which cools the environment even more. If we compare a thermal image of a metropolis to a map of vegetation, you’ll notice that where there’s foliage, the temperature decreases.
Urban forests may significantly decrease the urban heat island effect. According to studies, regions with dense tree cover might be up to 5-7 degrees Celsius cooler than surrounding areas. This cooling impact not only enhances city dwellers’ comfort levels, but it also reduces the need for air conditioning, resulting in energy savings and decreased greenhouse gas emissions. Numerous cities, including New York, Shanghai, and London, have started programmes like the Million Trees programme, which aims to plant and care for one million new trees, improving the city’s green infrastructure and providing a cooler, healthier urban environment.
- Urban Planning
Innovative urban planning has the potential to significantly improve city cooling. Curitiba in Brazil, is a notable example, emphasising the creation of green spaces and their integration into urban landscapes. Since the 1970s, Curitiba has planted 1.5 million trees and created 28 public parks. Thoughtful planning include constructing streets and buildings to maximise airflow, including plenty of foliage, and ensuring that new projects do not worsen the heat island effect.
Smart urban planning entails constructing cities in a way that encourages natural cooling while reducing heat absorption. Orienting buildings to maximise airflow, establishing shady paths and green spaces, and utilising light-colored materials in construction are all successful tactics for cooling urban environments.
- Light-colored materials
Dark materials absorb more heat, whilst light colours reflect it. Cities such as Athens have adopted building standards that promote the use of light-colored materials in construction.
- Green Corridors
Green corridors are areas of greenery that connect parks and other green spaces throughout a city. Melbourne was a pioneer in developing green corridors, which help to cool the city by offering continuous stretches of shade and greenery.
Green corridors can help to lessen the urban heat island effect by providing cool, shaded routes that limit heat absorption.
In China’s capital, Beijing, authorities have proposed a similar urban strategy, connecting parks and waterways to improve ventilation and combat smog.
- Water Features
Incorporating water elements such as fountains and ponds may significantly cool metropolitan areas. Tokyo and Paris are excellent examples of cities that use water features to combat heat. Water evaporates and cools the air, resulting in natural air conditioning for the surrounding region.
Water features can reduce ambient temperatures through evaporative cooling. Water evaporates and absorbs heat from the surrounding air, producing a cooling effect. This can lower temperatures by a few degrees, making public spaces more comfortable for both inhabitants and tourists.
Avoid using air conditioning
The widespread usage of air conditioning heats up the streets. So, a long-term solution to combat heat island effect is to avoid using air conditioning when you don’t need it because it uses electricity. When we generate power using coal or natural gas, we emit more carbon dioxide into the atmosphere, warming the globe and making cities even hotter.
- Public Awareness
Awareness campaigns can encourage people and businesses to adopt techniques that help to cool urban areas.
So, from green roofs and cool pavements to urban trees and smart design, these solutions not only lower temperatures but also improve the quality of life for residents of cities. As climate change continues to raise issues, it is critical that metropolitan regions embrace and execute these policies. By doing so, we can make cities cooler, greener, and more sustainable for future generations.
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