Over the past century, overpopulation has emerged as one of the greatest threats to the sustainability of our planet. It is the thread that connects all environmental issues – pollution, biodiversity and habitat loss, food and water scarcity, climate change, even disease outbreaks – all of these can be linked in one way or another to overpopulation. Earth has a finite amount of space and natural resources, and with an ever-growing human population (according to Census.gov, net population gain is about 1 person every 16 seconds), we are putting immense pressure on the planet and stripping it of its ability to provide clean air, food, and water.
Understanding the magnitude of human population growth is the first step towards comprehending the overpopulation issue. Human population can be measured through a census, which is the process of counting everyone in a country or territory. The U.S. conducted the first official census in 1970, and it has conducted one every 10 years since, including in 2020. National census data is combined with estimates of birth and death rates to provide an approximation of global population. This information is collected every 10 years by the United Nations World Population and Housing Census Programme (How Stuff Works).
The current world population is approximately 7.7 billion people (Census.gov). According to Our World in Data, almost all of this growth happened recently. Historical demographers estimate that the population grew very slowly from 10,000 BCE to 1700. The world population was around 1 billion in the year 1800 and increased 7-fold since then. Today’s population size makes up 6.5% of the total number of people ever born (Our World in Data).
Population growth is influenced by many factors, including fertility and mortality rates, both of which are influenced by income, education, and access to contraception (Pew Research Center). The most populous countries are China (1.42 billion), India (1.37 billion), and the U.S. (329 million). It is worth noting that population size doesn’t always equate to environmental footprint. Some wealthy countries like Canada, Australia, and the UK have relatively low total populations but high per capita emissions (World Population Review). The relationship between population size and environmental impact is incredibly complex. Factors such as life expectancy and age structure, consumption, wealth, political and religious history, and education are all inextricably linked when it comes to measuring a country’s overall environmental footprint.
At its core, the issue of overpopulation relates to exceeding the earth’s carrying capacity, which is the maximum population that can be supported by the environment indefinitely. In the book Overshoot (1982), author William R. Catton, Jr. explores the predicament of mankind as earth’s ecological processes can no longer withstand the strain of the human population, leading to an inevitable crash. The author argues that we are essentially stealing resources from future generations by rapidly destroying our own habitat.
Discussion of overpopulation is controversial, and can lead to overwhelming feelings of impuissance. But there are still reasons for hope. For one, the earth has an impressive ability to heal itself through natural ecological processes such as carbon sequestration and water filtration. There are also indications that the global population growth rate is slowing, having peaked in 1962 and 1963 with an annual growth rate of 2.2% (Our World in Data). The UN estimates that the annual increase will decline by around 1 million people per year. The growth rate may be slowing, however the total population is still increasing. The most promising approach to solving the overpopulation dilemma while maintaining social integrity is through education, particularly for women. According to the World Economic Forum, increasing women’s access to reproductive healthcare, raising the legal age of marriage, and enabling women’s active participation in the workforce are sustainable ways to slow population growth. Access to education should also include environmental education. This will help ensure that people around the world acquire the knowledge for appropriate family planning as well as the environmental consciousness needed to protect our planet.
