Vegetation such as trees, flowers, and moss use a process called photosynthesis in which they convert carbon dioxide into oxygen, reducing the amount of carbon dioxide going into the atmosphere. Green roofs use a soil substrate as a growing medium for the plants which serve a few purposes such as removing airborne particles, heavy metals, and evaporative organic compounds (European Federation of Green Roof Associations). Since they are assimilated into the growing medium, these pollutants do not enter the water system through stormwater runoff which in turn improves the quality of water and lowers the risk of sewers overflowing (Klinkenborg 2009). Green roofs also have a positive impact on the urban heat island effect, which is the main cause of ozone production (US Environmental Protection Agency). The vegetation which grows on the roof absorbs some of the light from the Sun which would otherwise be turned into heat energy (Green Roofs). This in turn aids in the cooling of the overall temperature of urban areas such as cities. Green roofs are readily available to be implemented and with continual innovation, they can become a regular, eco-friendly method of modern roof …show more content…
In the summer season, insufficient insulation of roofs can cause overheating of areas below them which lead to an increased use of air conditioning. A green roof serves as not only an insulation barrier, but uses the combination of the plant and soil processes such as evapotranspiration and evapo-transmission to aid in the reduction of solar energy being absorbed by the green roof itself (Green Roofs). This causes temperatures beneath the roof to become cooler which requires less use of the air conditioning. In the winter season, green roofs can reduce heat loss with the combination of root activity of the plants, air layers in-between the growing medium and plants, and the amount of water that is held by the system, which create heat and provide a good insulation barrier (European Federation of Green Roof Associations). Sound is produced by sound waves which travel through air as a medium and vary at different frequencies. With the combination of plants, soil substrate, and pockets of air trapped in the system, a green roof can provide good sound insulation. The plants block the higher frequencies of sound waves while the soil substrate blocks the lower frequencies (European Federation of Green Roof Associations). A study by Kalzip, an international roofing company compared a conventional roof versus a dry green roof to see how much sound reduction