During the first half of the University of New Mexico’s fall semester, our Community and Regional Planning (CRP165) class covered a long span of history as it relates to how urban planning developed from ancient practices into today’s cities. Our class structure is formed by a quick check-in from the professor with an engaging question to the class, a power-point lead lecture, followed by an active-learning group project.

 

A few weeks ago, we were making our own city plan by organizing existing neighborhoods in the best design we decided on as a class. We added different components like a community center, a sports complex, hospitals, gas stations, schools, lower-income apartments and housing, public green spaces, and nature trails while eliminating excess parking, additional long-term developments that tax dollars couldn’t cover, and large, single-use parking lots. During this particular class, the term “heat-island effect” was mentioned. I decided to do further research on the topic outside of class, which led me to discover that my major and future career path would directly affect it- in a good way!

 

Heat-island effect refers to land that used to be open, natural, and permeable is now trapped and transformed into a concrete-heavy city.  Asphalt, tar, concrete, brick, and other building materials absorb heat rather than reflecting it, creating a hotspot or “heat-island” compared to the cooler, rural land surrounding it. The Environmental Protection Agency (EPA) says that a city containing one million people is considered a heat-island if it is 1.8 °F warmer than the land around it. This difference can spike as high as a 22 °F difference during summer evenings!

 

Due to these warmer temperatures, coupled with a higher density of people, the use of air conditioners noticeably increases.  Power plants need to produce more energy to cater to these higher A/C demands which lead to greater consumption of non-renewable resources, a larger contribution of greenhouse gas emissions, and more expensive electric bills for households. See how this is a vicious cycle? Heat-island effect can generate air and water pollution too.  The good news is, the EPA says that cities are finding ways to cope with this effect by implementing some cooling strategies like increasing tree and vegetative cover, installing green or reflective roofs, using permeable or reflective pavements, and using smart growth designs.

 

An example of designing with cool pavements and reflective roofs can be seen in Mykonos, Greece. Those city planners went a step further by covering all the buildings with an almost heavenly, bright white hue. It is as beautiful as it is effective- made from a hardened lime plaster (no paint at all). This particular plaster absorbs carbon dioxide from the air and uses it to harden back into limestone. As limestone, it is now waterproof, won’t disintegrate quickly like an adobe plaster, happens to be a natural insect repellent and most importantly, withstands the troublesome heat-island effect. The white walls have high albedo, meaning it’s a very reflective surface which keeps the city cool by bouncing the sun’s rays (heat) away. I loved learning about this cooling strategy, and as I continue my studies, I am learning of other strategies that also pique my interest.

 

The reason the topic of heat-islands had such an impact on me is that I realized that I could personally help combat the heat-island effect with my passion for the environment by installing green roofs and increasing vegetative cover! For those of you that don’t know, a green roof replaces a barren, unattractive, heat-absorbing rooftop and adorns it with bountiful garden beds or perhaps every square foot is freely covered with soil, grass, and shallow-rooting plants. Green roofs help lower carbon emissions by plants’ natural process of photosynthesis, function as a natural, cooling shade for the building and are aesthetically pleasing. Green roofs can invoke a stronger sense of community by bringing tenants together to tend to their building’s urban garden while enjoying amazing rooftop views. Personally, I would LOVE to see this trend come back. Can you imagine the air quality in a city if all the rooftops were covered in plants?

 

I also want to increase vegetative cover by designing additional public green spaces, protecting and embellishing our existing city parks, while using stormwater as a means to irrigate it all. This is the direction that I hope to devote my energy, education, skills, and passion to after graduation. I want to work in cites, to complement our ever-growing population with my love for nature and my degree in Landscape Architecture. It just so happened that my curiosity and research led me to discover that I will be one of the designers amending this heat-island effect we see all over the world. How cool is that? (Pun… maybe intended).

 

1. “Heat Island Effect.” EPA, Environmental Protection Agency, 27 Aug. 2019, https://www.epa.gov/heat-islands.

2. “Heat Island Cooling Strategies.” Heat Island Cooling Strategies, Environmental Protection Agency, 6 Sept. 2019, https://www.epa.gov/heat-islands/heat-island-cooling-strategies.