3 – Combat the urban heat island effect
The urban heat island effect is what happens as urban areas develop and changes occur in the landscape. As open land and vegetation are replaced with buildings and roads, surfaces become hot and dry, absorbing and retaining the heat of the sun. Therefore, urban regions become much warmer than surrounding rural areas. This excess heat causes increased energy consumption for cooling, resulting in higher levels of pollution. Hot streets also heat storm water as it runs over the surfaces, impacting waterways when the water is released back into them.
By covering up black rooftops – some of the hottest surfaces in cities – with vegetation, a huge reduction in the heat island effect is achievable. Much of the light that would otherwise become heat energy is absorbed by plants. Also through the daily evaporation cycle of vegetation, living roofs and walls can cool cities significantly during hot summer months.
4 – Improve quality of life
In addition to providing a cooler urban atmosphere, green roofs provide a pleasing, natural aesthetic value to homes and buildings. They also create a habitat for birds and other wildlife in areas that were otherwise wiped clean of greenery. In addition, since plants act as natural air filters, they remove many air pollutants and reduce greenhouse gas emissions.
So how do you “go green” on your own roof? There are organizations sprouting up across the US supporting the green roof movement. Many urban areas are promoting living roofs on new construction and often provide education on the topic. There are a huge variety of planting methods available, from rolling sod right onto the rooftop to complex, layered systems with a variety of plants. The method you choose will vary depending on the size and type of roof you want to plant. You can do a search for information and contractors in your area, or build one yourself. If greening your whole roof seems daunting, try a smaller project first, like the roof of a shed or chicken coop.