What Are Urban Heat Islands?
Urban heat islands (UHIs) are a phenomenon in which cities reach higher temperatures than their rural neighbors. This is caused by human activities, infrastructure, and certain materials in urban settings that retain more heat than natural landscapes – and it’s a point of concern in the fight against climate change.
The urban heat island effect was first observed by British scientist Luke Howard in the early 1800s. Today, it’s a critical topic when it comes to public policy, urban sustainability, and improving urban quality of life. Cities around the world are incorporating strategies to mitigate heat islands in their urban planning initiatives and environmental policies – and greenroofs are an important part of the solution.
Dangers of Heat Islands
The urban heat island effect is harmful to both urban residents and the environment itself.
Higher Energy Consumption
Higher temperatures in urban areas lead to increased use of air conditioning and other forms of energy consumption. This surge in energy demand can strain power grids and increase greenhouse gas emission.
Health Risks
Prolonged exposure to heat can pose serious health risks, particularly for vulnerable populations such as the elderly, children, and those with preexisting health conditions. Heat islands can increase the risk of heat-related illnesses, including heat exhaustion, heatstroke, and cardiovascular problems. Even when not posing a health risk, the increased heat can simply make outdoor activities less comfortable, which reduces quality of life for city dwellers and limits the use of public spaces.
Deterioration of Air and Water Quality
Higher temperatures in urban areas can lead to the formation of ground-level ozone, an unhealthy air pollutant. Heat islands can also affect water quality by increasing the temperature of stormwater runoff.
Urban Heat Island Solutions
Several strategies can help ease the effects of heat islands and create more sustainable urban environments.
Urban Green Spaces
Creating and maintaining parks, gardens, and other green spaces in urban areas can help combat the heat island effect. Trees and vegetation offer shade, cool the air, and absorb carbon dioxide which improves air quality.
Cool Roofs and Pavements
Cool roofs are designed with materials that reflect more sunlight and absorb less heat than standard roofing materials. They can reduce surface temperatures and lower indoor cooling demands. Much like cool roofs, cool pavements are made from materials that reflect more sunlight and retain less heat than traditional paving materials. Implementing cool pavements in urban areas can help reduce surface and air temperatures.
Urban Forests
Expanding urban forests by planting more trees along streets, in parks, and around buildings can provide shade and reduce temperatures. Trees also improve air quality and enhance the aesthetic appeal of urban areas.
Green Walls
Green walls, or living walls, are vertical gardens installed on building facades. These walls provide insulation, reduce heat absorption, and contribute to cooling the surrounding air.
Reflective Building Materials
Using reflective building materials for roads, sidewalks, and buildings can reduce the amount of heat absorbed and lower surface temperatures.
Greenroofs
Greenroofs are particularly important tools in managing the heat island effect. They provide buildings with natural insulation, reducing the amount of heat transferred to the building and keeping temperatures lower indoors. They reduce heat absorption and promote evapotranspiration, cooling the surrounding air via the plants’ water vapor. This cooling effect can extend beyond the surface of the greenroof itself. Greenroofs also absorb rainwater and help reduce runoff. The plants on greenroofs can help improve air quality and release oxygen while increasing the city’s biodiversity. This can create a more resilient and adaptable urban ecosystem, capable of withstanding environmental stressors.
If you have a roof, you can be part of the solution. Start building your greenroof today to save on energy and improve your city. Shop now for FTM greenroof bags to make the setup process easier than ever.