Parking lots are a fundamental part of urban life as we know it. Unless you are car-free, you need parking lots to accomplish daily tasks. They are where you park when you go to the supermarket. They are where you pull up to pick your kids up from school. Because of the public perception about parking availability, planners often create more parking space at shopping malls and public buildings than is actually required. However, nobody can deny that in a society based on cars as the dominant form of transportation, parking lots are as crucial as roads.
And yet, parking lots pose a myriad of environmental problems. In fact, the environmental costs of parking infrastructure can equal or exceed the environmental cost of the cars themselves[sc:1]. Think about it. Vehicles spend most of their lives parked. Most Americans, for example, choose to use cars as their dominant, and often sole, means of transportation. Because of this, there is a huge demand for parking infrastructure, and it is worth examining the environmental implications of this.
Most urban planners and environmental scientists consider urban sprawl to be a massive environmental problem[sc:2]. Urban sprawl is only enabled by the provision of roads and parking infrastructure – without those, it would not be feasible.
The most common environmental problems of parking lots
The main environmental implication of parking infrastructure is the total amount of energy consumed, and emissions produced, in creating and maintaining these spaces[sc:3]. A huge amount of resources is used to create a parking lot – mostly concrete, which has its own environmental implications.
Another severe environmental problem caused by parking lots is water pollution. Because parking lots accumulate a lot of pollutants (such as oil, grease, heavy metals and sediment), a major environmental issue is the runoff of these into waterways[sc:4].
What’s more, there’s the problem of parking lots contributing the “urban heat island” effect, which can raise temperatures by 2 to 3 degrees Celcius[sc:4]. An urban heat island is where common construction materials (such as those used in roofs and parking lots) absorb and retain more of the sun’s heat than natural minerals in less developed rural areas[sc:5]. These surfaces reach much higher temperatures than surfaces covered with soil or vegetation do. As such, urban heat islands contribute to higher temperatures in cities. This in turn puts a further demand on non-renewable resources by, for example, leading to a greater demand for air conditioning in unnaturally hot cities.
Furthermore, the more parking lots there are, the less green spaces there are. The demand for huge amounts of land to be taken up by parking lots means that there is less room for trees, green wedges and public spaces that are good for human health and for the environment.
An uneasy task for urban planners
The solution to the problem of parking lots and the environment is for our cities and towns to be planned in such a way that transportation by car is discouraged. We need to be encouraging walking, cycling and public transport. Doing so will drastically reduce the need for parking lots, and as such would allow our cities to be cleaner and greener.