Causes of Overpopulation: Growth Rates, Resource Depletion, and More

Causes of Overpopulation: Growth Rates, Resource Depletion, and More
Page content


Overpopulation refers to when an animal species reaches over a carry capacity in a particular environment. When animal species rise above this carrying capacity, large numbers of species can die due to lack of resources or competition with other species. Even though few animal species actually reach this limit, humankind is the exception.

Until recently, humankind has never even posed a problem in breaking its carry capacity. This is because its death and birth rates were remarkably high and would balance each other out while maintaining a low population. This all changed with the advancements such as medicine which has drastically reduced the birth and death rates.

According to Carolyn Kinder, the human population reached one billion in 1810, two billion in 1930, four billion in 1975, and around six billion in 2000. Experts predict that by 2025, the population will reach 10 billion after only 25 years. What are some causes of overpopulation that are allowing human populations to explode?

Causes of Overpopulation

There are three main causes to overpopulation. The first and second are linked to the advancement of medicine and public health, while the third is related to food distribution. Even though these are the main causes today, more causes can come about in the future.

First is the understanding of diseases and the use of medicine. Before the realization of the germ theory, many individuals did not know that diseases were spread through germs such as bacteria and viruses. With the adoption of these practices, humans were able to understand that germs caused these diseases and could be countered through practices such as medicine and vaccinations. With this new knowledge, death rates plummeted and new health practices relating to child birth helped improve birth rates.

Second is the vast improvement of public health. Public health refers to the acquisition of three basic needs humans need: food, shelter and water. For example, since the creation of plumbing, individuals have had the opportunity of accessing water. Another is the improvement of shelters which also allow humans to survive for longer periods. The last point brings us to our third cause.

Third is the improvement of food distribution. It is amazing to think that food can be transported all over the world and combined with preservation services, such as canned food, certain food can last forever. The improvement of food distribution had ended the worries of starvation in many regions of the world; however, certain regions (such as parts of Africa) still exhibit famines from the lack of food.


There are many consequences associated with human overpopulation. The most damaging is the impact overpopulation has on other


animal species, the environment, and other humans. For example, Dr. Robert E. Wigley states, “By the year 2050…it is anticipated that the burgeoning human population will level off between 11 and 15 billion, driving over 25% of the Earth’s remaining wildlife into extinction.” In other words, humans have exceeded the carrying capacity and will influence drive off other animal species by encroaching on their territory.

The environment is also affected with humans needing more space to live. In underdeveloped countries, many populations, such as India, are starting to reach levels that the environment cannot support. When this happens, populations may be affected by lack of food which can allow famines to start taking place. Although technology (such as the Green Revolution) can temporarily increase carrying capacities of certain environments, it is only a matter of time before humans reach this breaking point.

Possible Solutions

Protecting Earth

There are only a few solutions that can fix overpopulation. The first is education. By educating families on the importance of overpopulation, families can limit how many children they wish to conceive. Another solution is to try to conserve the resources and space that humans have access to and perhaps allow future generations to enjoy the Earth’s resources.

In conclusion, the causes of overpopulation are staggering. With numbers approaching 14 billion by the end of the century, humankind needs to learn the dangers of overpopulation. By limiting conceived children and protecting resources, humans can hope to prevent the consequences of overpopulation and protect the Earth as well.




This post is part of the series: All About Overpopulation

Need information on human overpopulation in the world today? Read Bright Hub’s overpopulation series to get a gist of the problems today as well as some theories that help explain this phenomenon.

  1. Causes of Overpopulation: Growth, Land, and More
  2. The Demographic Transition Theory and Overpopulation