Wednesday, August 27, 2014

Urban heat Islands

Big cities rule the world in this day in age, but they are also the culprit to a very dangerous phenomenon known as the urban heat island effect.  The “heat island” effect refers to built up areas, usually within large cities, that are warmer than nearby rural areas.  Urban area development causes the landscape to change with construction of roads, buildings, and other infrastructures.  The open, moist land is then replaced by dry and impermeable structures, causing an increase in temperatures in the developed areas.  According to the Environmental Protection Agency (EPA), the annual mean air temperature of a city with 1 million people or more can be 1.8–5.4°F (1–3°C) warmer than its surroundings.  The EPA also reports that during the evening hours, the difference can get as high as 22 °F (12 °C).

By the year 2025, two-thirds of the world will be living in urban settings.  This means that a raised awareness is essential in preventing this harmful effect.  While there are very few positives as a result of heat islands, such as a longer plant-growing season, most impacts are severally negative that include: increased energy consumption, elevated emissions of air pollutants and greenhouse gases, compromised human health and comfort, impaired water quality.  This also has a strong impact on our local and global economies.  The Heat Island Group says that the urban heat island around Los Angeles, California, costs the city $100 million a year in energy.

According to the Environmental Protection Agency, communities can take a number of steps to diminish the heat island effect, using four main strategies: increasing tree and vegetative cover; creating green roofs (also called “rooftop gardens” or “eco-roofs”); installing cool—mainly reflective—roofs; and using cool pavements.  These strategies will not only have a positive effect on the local communities, but will create a safer environment for the surrounding rural areas and our global climate. 

-Adam Gruszcynski, Legal Intern