The Heat Island Effect

Are you guys familiar with the heat island effect? What is it exactly? How does it affect us and what can we do to prevent it? This is probably the time to start thinking about the environment, considering we may be the ones who can either destroy it or save it.

The term heat island or urban heat island describes built up areas that are hotter than nearby rural areas. Heat islands can affect communities by increasing summertime peak energy demand, air conditioning costs, air pollution and greenhouse gas emissionsand water quality.

What causes it?  Replacement of natural surfaces by built surfaces such as houses and buildings, through urbanization, is currently the main cause of heat island or urban heat island formation. Natural surfaces are often composed of grass and trees, as well as soil which utilize a relatively large proportion of the absorbed radiation from the sun and release water vapor that contributes to cool the air in their vicinity. The decrease in number of vegetated areas such as parks and gardens not only reduces the benefits of natural surfaces, but it also inhibits atmospheric cooling due to horizontal air circulation generated by the temperature difference between vegetated and urbanized areas. Instead of cooling down the atmosphere, the cool air just circulates over its area, thereby producing little effect on the temperature. This is known as the park cool island effect.

In contrast, houses and buildings are composed of a high percentage of non-reflective and water-resistant construction materials. As consequence, they tend to absorb a significant proportion of the incident radiation, which is released as heat. The radiation is also scattered and emitted from atmospheric pollutants to the urban area.  Other factors that increase heat emission include air conditioning and refrigeration systems, as well industrial processes and motorized vehicular traffic.

So, we have concluded that urbanization really does impact the environment mainly by the production of pollution, the modification of the physical and chemical properties of the atmosphere, and the covering of the soil surface. What can we do now? Choosing green options is a start. If you’re planning to build a home, do make sure to use green materials. Green roofing is also a great way to help. These types of roofs absorb the radiation instead of emitting it back to the atmosphere. Visit our News and Information page to find out more!