A Concrete World: How Cities and Urban Planning Affect the Environment

As everyone is probably aware, cities don’t appear out of thin air. People didn’t wake up one day to skyscrapers and sidewalks, buses and the constant buzz of people and activity. All elements of a city are meticulously planned and drawn out. This is the process of urban planning–the design and overseeing of a city's structure and processes. It  sets up the bus systems, the placement of parks, buildings, streets, and sidewalks, and regulates historical and green spaces.  

photo courtesy of Nancy Bourque

Unfortunately, urban planning doesn’t always have the environment's best interest at heart. For instance, many sidewalks and streets negatively impact the Earth’s water cycle and  little walkability leads to reliance on gas-guzzling vehicles. 

Streets, roads, or any other form of pavement, are “impervious” surfaces. This means that the water can’t seep through (percolate). This alters the water cycle, which is an important natural and self replenishing cycle in the Earth’s systems. In a natural water cycle, the water that precipitates should be absorbed by soil and infiltrate into underground storage called aquifers, which people and ecosystems rely on as a freshwater source 

According to Cal-NEMO (California Non-native Estuarine and Marine Organisms), 25% of rain water infiltrates deep enough for aquifer replenishment when the ground cover is all natural. This decreases as the amount of impervious cover increases, until the ground is 75%-100% covered with impervious pavement and the deep infiltration is reduced to 5% of rainfall. 

Another issue with urban planning strategies is that they often don’t prioritize walkability. The walkability of a city is how easy it is for people to walk around an area as a means of transportation. However, when grocery stores, schools, and any other everyday location is placed far away from residential spaces, walking becomes unreasonable. A lot of cities, particularly in the United States, are not built to be walkable, which causes a reliance on vehicles. One example is Pheonix, Arizona, which is a scattered city with very little pedestrian accommodations so driving is one of few transportation options. On the other hand, an example of a walkable city would be New York, because it is compact with large walkways.

photo courtesy of Josh Sorenson

According to the University of Indiana, 28% of greenhouse gas emissions in the United States come from transportation. Although the government tries to lessen this by encouraging cycling, walking, or carpooling, these modes of transport are not always accessible for people. One of the best ways to mitigate the emissions from transportation is to design cities to be walkable, so people are not forced to drive everywhere. In the end, these are just a few examples of how city planning can negatively affect the environment and speed up the process of climate change. 

In addition, poor city planning isn’t only a climate issue, but it can also worsen the effects of natural disasters. Returning to the idea of  impervious streets and water buildup, when there are heavy storms, many streets can’t accommodate the heavy amounts of rain that are occurring. This gets worse during storms when the storm drains built into the streets to prevent flooding clog with debris. This causes several feet of floodwaters, which can be very damaging to people’s homes and property, and causes people to be trapped in their homes, unable to get food, water or medication.

 However, city planning isn’t all negatives. There are many ways it can have a positive impact on the climate and communities. Although it may seem all doom and gloom, urban planners play a very important role in the upkeep of the environment. For example, green spaces- plants and vegetation within otherwise urban areas- are one of many ways to include sustainability into city planning. These spaces are so beneficial to the climate and communities. They can help mitigate pollution by providing trees that are carbon sinks. Which is important considering how much air pollution is caused by city transportation. They also allow more percolation, so less flooding and more groundwater recharging. 

One of the best positives for green spaces within cities is that they help mitigate the effects of “the urban heat island effect.” This is when urban areas get much hotter than surrounding areas because there is more absorbance of sun energy. 

The heat island effect causes a lot of problems for residents of cities, including a multitude of medical issues, revoking the ability to enjoy the outdoors, and generally just making life more difficult. However, with green spaces and an increase in trees in urban areas, there is increased shade and a cooling effect from the plants that greatly improves residents quality of life. 

Another solution that is worthwhile is permeable streets. According to the National Association of City Transportation, there are types of pavement that can be used that are porous enough to allow water to pass through. Some examples are interlocking concrete pavers, previous concrete, and more. They are mostly used on sidewalks, but even this could have a huge impact on groundwater recharge and flood control. These pavements could provide so much relief to people in frequently flooding areas, so not only is it an environmental benefit, socially and economically it is wonderful too. 

Overall, there are a lot of very hopeful solutions and things that city planners are already doing to help aid in relieving the harmful effects cities have on the environment. Learning all you can about urban planning and its effect on the environment is important in order to come up with creative solutions to its problems, and creative solutions are what make the climate movement so incredibly versatile and progressive.