By Alan White
It is widely known that majority of the Earth’s population (+80 percent) now resides in urban areas. As the global population increases, cities are becoming increasingly congested. With this trend, come serious challenges such as increased temperatures as well as health risks due to heat, pollution, and overcrowding.
An effective way to help combat these challenges is to adapt living green landscapes into our communities which can cool urban climates, improve air quality, reduce health risks, and improve the overall well-being of people everywhere.
Concentrations of urban development produce more heat than surrounding rural areas. This phenomenon is known as the ‘urban heat island effect’ and can be managed through green development.
A plant’s life cycle inheritably cools its surrounding climate. In areas of vegetation, water can infiltrate the soil to replenish ground water and evaporate slowly, or be used by plants and transpired by them. Both of these processes create a cooling effect. When water evaporates, it takes heat energy away from the surrounding air and multiplies the cooling impact.
Heat islands can negatively affect communities by increasing summertime peak energy demand, air conditioning costs, air pollution and greenhouse gas emissions, heat-related illness and mortality, as well as water quality.
Living green landscapes also contribute to improved air quality by producing the very oxygen we need to breath, and absorbs the many contaminants we don’t want like CO2. In many ways the living urban landscape acts as the ‘Lungs of a City,’ with vegetation that traps dirt, dust, and smoke by absorbing pollutants and breaking down their components.
As water infiltrates the earth’s surface, elements in the soil help break down chemicals into harmless materials while simultaneously recharging the underground water supply. This bio-filtration system results in purified rain water which is less acidic than the alternative, run-off.
Greener communities promote physical activity, social harmony, community pride and ownership, individual expression and creativity, and improve mental health. Many community activities and youth programs take place in green areas such as schools, sports fields, and parks which provide the foundation for us to work, live, and play.
Close and connected green spaces provide cooler, cleaner air throughout the site, neighbourhood and the city. Green spaces act as protection against earth’s toughest challenges while providing significant health benefits with regards to temperature, quality of air, water and in turn our lives.
Alan White is president of Project EverGreen Canada