Due to the materials used commonly in cities, urban environments often experience temperatures that are warmer than their surrounding suburban and rural environments. These common materials include concrete, bricks, and asphalt. These materials are known to trap heat; they have a high capacity for thermal storage. Overall, this is to blame for higher temperatures within cities compared to surrounding rural areas. The materials used to build the infrastructure traps the heat and makes the city warmer than suburban and rural areas that surround it. This impacts public health and the amount of energy used in cities. Since it is so much hotter, cities tend to use more energy and consequently spend more money in order to cool the urban environment. One current solution to the urban heat island effect is to increase the vegetation within the city itself. “urban vegetation has been widely adopted, common practices including urban lawns, green roofs (also known as “Eco roofs”), shade trees, and urban agriculture [17–19]. Urban vegetation, supplied with adequate soil water availability, is capable of reducing environmental temperature through the cooling effect of evapotranspiration.”
20
During evapotranspiration, water is transferred to the atmosphere by evaporation from the soil and transpiration from plants. The process produces a cooling effect associated with the change of state (latent heat of evaporation) of water from liquid to gas. This has led many cities all around the world to take a closer look at the benefits or urban farming.
In places such as Singapore they have constructed what are known as “supertrees”. These structures were constructed in order to create vertical gardens within the city. These vertical gardens provide shade and habitats for many different specifies. They also collect rainwater and support plant life. Structures such as these supertrees in Singapore greatly help to cool off cities and reduce the effects of the Urban Heat Island. Urban farming is a great potential solution to help cool down these hot urban environments.