The Effect of Overpopulation on the Environment

Ryan McKenna

Although predictions about the future of population growth vary, it is undeniable that the Earth’s population has boomed over the past two centuries. Thanks to technological advances that have allowed humans to live longer and more comfortably, the world population is currently growing at such a rate that it doubles every 35 years (Dolan 58). As the population has grown, the Earth has shown visible signs of the stress brought about by such rapid growth, mostly through changes in the environment. It seems as though the Earth can only support so many people, and that we are reaching the breaking point. The problems caused by overpopulation are numerous and serious, and if the population continues to grow at this incredible rate, the world may be in for a rude awakening.

Overpopulation is most noticeably a problem to those people living in the most densely populated places in the world, the largest cities. In these cities, people face dangers that are directly related to the fact that so many people are living in such a confined space. For one, waste management is always an issue in cities. In such tight living spaces, civil engineers often face challenges when attempted to control the removal of waste from places where people reside to places outside the confines of the city where the waste can be treated. They must be careful not to let the waste interact with the city’s water supply, and no matter how careful they are, there are always accidents when you consider that the pipes bringing water into the city are in extremely close proximity to the pipes that carry waste out of the city. This can lead to widespread disease or illness. Modern technology has allowed for better separation of the two, but before this technology was available, many people often became sickened or even fatally ill when the water supply was contaminated in early cities. Aside from the issue of sickness and cleanliness in densely populated cities, there is also the issue of increased crime. With so many people living so close to each other, cities are breeding grounds for violent acts. This type of behavior is not specific to humans; animals living in close quarters have been observed acting more aggressively than they would if they lived in larger spaces (Calhoun). Whenever living creatures live in overcrowded situations, conflicts are unavoidable, and this fact manifests itself in the increased accounts of violence in cities. This clearly negatively impacts the lives of people living in densely populated areas; not only does it affect the quality of their lives, but it also has the potential to shorten their lifespan. Those people living in cities, the most densely populated areas of the world, experience the effects of overpopulation on a daily basis.

Aside from simply impacted people living in overpopulated areas, overpopulation also has further-reaching implications, as it often creates a need for industrialization which in turn causes pollution. More people inhabiting the earth means not only an increased need for jobs, but also an increase in need for production, which combined lead to industrialization. Factories that produce various products are a major contributor to air pollution, as emissions from these factories into the air make in unclean. Pollution also comes from sewage plants that treat human waste. Other pollution comes from cars, accumulated garbage or trash collections, and the creation, use, and upkeep of roads, all of which are byproducts of industrialization. This type of pollution impacts all facets of life: the air we breath, the water we ingest and clean with, and the soil we plant in and build on; it is all-encompassing. Industrialization has also led to an increased need for energy, and increased energy use has been a main contributor to global warming, which has been a hot topic as of late. Global warming is being blamed for a host of problems in our society today, including hurricanes that are stronger than usual, various animals and plants losing their habitat and bordering on extinction, and flooding, just to name a few. The boom in population has facilitated and maintained the need for industrialization, and is cause of many types of pollution in the environment.

Other not-so-apparent effects on the environment are caused by overpopulation, including the depletion of natural resources. The world population, which is currently around 6.6 billion and growing, is putting tremendous stress on the world’s natural resources. Although no one knows just how much life the Earth can sustain, it is clear that this number is not infinite (Southwick 170). Different areas of the world are being over-farmed and much land is being left infertile, and the changing global climate is causing floods and droughts that impact growing seasons, so it is not implausible to consider that naturally produced foods may one day be scarce. Water is also in constant demand, and must be treated and recycled in order to be in sufficient supply. In addition to food and water, oil is also in high demand, and the world’s depleting oil supply has led in increased gasoline prices as well as efforts to find alternative energy sources. Aside from natural resources slowly disappearing, other aspects of the environment are being affected by overpopulation. Wildfires, a natural occurrence in the untouched environment, are usually put out with great urgency, as they threaten lives and buildings. The importance of wildfires to the environment is not widely known, but wildfires are instrumental in getting rid of old growth and allowing new growth; they are a natural and healthy part of nature (“Forest Fires”). Floods are also a result of human manipulation of the environment – as waterways and bodies of water are redirected and collected in various ways contrary to their natural state, water collects and runs off in unnatural patterns and can cause flooding. Human manipulation of the environment is a serious problem that has possibly irreversible effects on the Earth. It appears as though the only remedy for many environmental woes is for a decrease in population growth sometime in the near future.

Overpopulation is a real and serious threat to the Earth and the people who live on it. Not only does it cause immediate problems for those living in overcrowded areas, but it also creates problems that will impact future human lives. As more and more humans drain the Earth of all its available resources, problems are arising that necessitate our attention. We can not depend on the Earth to provide for more than it is meant to or capable of providing for. Unless we can find a way to stabilize population growth, we need to consider other options for harvesting resources.



Calhoun, John B. 1962.  “Population Density and Social Pathology.”  Scientific American 206:139-148.

Dolan, Edwin G., Ch. 5 from "TANSTAAFL: The Economic Strategy for Environmental Crisis" 1974, pp. 55-72.

“Forest Fires.”

Southwick, Charles H., Ch. 15 from "Global Ecology in Human Perspective" Oxford Univ. Press, 1996, pp. 159-182.

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last updated 4/9/07