Causes of Overpopulation (and Effects on the Planet)

There are almost Eight billion people on the planet and this number is growing rapidly.

Issues like pollution, climate change, and water shortages all seem to take precedence, but population growth is one of the main contributors to many other environmental issues.

Overpopulation will place great demands on resources and land, leading to widespread environmental issues in addition to impacting global economies and standards of living.

The issue is compounded by the difficulty in providing solutions for this problem and the misunderstanding of the causes and effects of overpopulation.

Here we will cover causes and effects of overpopulation to give you a more informed view of the risks that come with it.

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Overpopulation Definition

Hong Kong streets are full of people buying, selling, and commuting.
Some cities, like Hong Kong, are crammed with people but they have the resources they need to thrive so it isn’t overpopulated.

Overpopulation occurs when there are more people than can be sustained by resources in a given area.

It leads to poverty, high mortality rates, lack of resources, environmental degradation, habitat loss, and ecosystem loss.

While it is a global issue, overpopulation is a serious problem in developing countries with fewer natural resources.

Causes of Overpopulation

With population growth comes a decrease in resources and an increase in mortality rates and poverty. There are a number of factors that contribute to overpopulation.

These are the leading causes:

Read our related article on the Cause of Overpopulation in South Africa for a bird’s eye view of African overpopulation.


Syrian child standing in the mud of an impoverished refugee camp
This refugee camp in Syria is full of people in extreme poverty due to war. Poverty often leads to a high birth rate because people don’t have the resources to avoid it.

Poverty is one cause for overpopulation. Lack of education and contraceptive resources makes it inevitable that sexual activity will bring new babies on the scene in the poorest countries.

Couple this with the uncertainty of survival and many couples aim to produce many offspring because they expect to lose a significant number of children before they can reach adulthood.

The effect is so extensive that the UN has predicted that the forty-eight poorest countries in the world are also likely to be the biggest contributors to population growth.

Their estimates state that the combined population of these countries is likely to balloon to 1.7 billion in 2050, from 850 million in 2010.

Poor Contraceptive Use

Though the availability of contraceptives is widespread in developed countries, poor planning on both partners’ parts can lead to unexpected pregnancies.

Statistics have shown that in Great Britain 76% of women aged between 16 and 49 used at least one form of contraceptive.

It is assumed that the other 25% are desirous to build a family or face an unplanned pregnancy.

A study by the World Health Organization (WHO) shows that contraceptive usage drops to 43% in countries that are blighted by issues like poverty, which leads to higher birth rates.

Though couples may want to use some form of contraceptive, it is not available to them.

Child Labor

As distressing as it may be to hear, child labor is still used extensively in many parts of the world.

UNICEF estimates that approximately 150 million children are currently working, primarily in countries that have few child labor laws.

This means that children are often seen as a source of income by impoverished families.

Furthermore, children who begin work too young also lose the educational opportunities they should be granted, perpetuating a destructive cycle of poverty.

Reduced Mortality Rates

Two men running to stay fit and live longer
A global focus on fitness helps people to live longer, healthier lives than ever before. This helps people stay out of the medical system, but it also reduces morbidity and aids overpopulation.

Improvement in medical technology has led to lower mortality rates for many serious diseases.

Particularly dangerous viruses and ailments such as polio, smallpox, and measles have been practically eradicated by such advances.

While this is positive news in many ways, it also means that people are living longer than ever before.

This “delay” in the cycle of life and death has led to birth rates outstripping death rates by over two to one.

However, in developing countries where the infant mortality rate is high, statistics show that people have more babies to counteract the probability of infant mortality.

Fertility Treatments

Though it only plays a minor role in comparison to the other causes of overpopulation, improved fertility treatments have made it possible for more people to have children.

The number of women using various fertility treatments has been on the rise since their inception.

Now, most women have the option of conceiving children, even if they may not have been able to do so without fertility treatments.

This is a blessing to those who greatly desire children, but it often results in a woman having multiple babies at once.


Unchecked immigration into countries may lead to overpopulation to the point where those countries no longer have the required resources for their population.

In this case, overpopulation refers to the local inability to provide for the number of residents rather than the overarching problem of taxing global resources.

This is particularly problematic in countries where immigration numbers far exceed emigration numbers.

In some cases, immigrants may be attempting to escape population growth in their own countries, only to contribute to the same issues in the countries they move to.

However, data also exists to show that immigration can bolster economies, with the effect in the UK being particularly pronounced.

Effects of Overpopulation

There is a long list of environmental issues surrounding humanity’s use and abuse of the planet.

Overpopulation effects mainly involve the number of resources required to support a large population.

When resources are overtaxed, it leads to a great deal of pollution, natural resource depletion, soil degradation, and other detriments to the environment.

In many countries, the resources are used faster than they can replenish. This leads to an overall degradation in the quality of life for the people that live there.

Lack of Water

Girl washing dishes outside in a trickle of running water with mud and dirty water all around.
In many areas of the world, there are people clustered around water sources that provide barely enough fresh water to keep them alive.

Overpopulation creates greater demand for freshwater supplies. As only roughly 1% of the world’s water is fresh and accessible, this creates a major issue.

In areas where fresh water is in short supply or heavily polluted, this demand creates dire suffering for residents.

Some estimates state that human demand for fresh water will stand at approximately 70% of what is available on the planet by 2025.

This will place those living in impoverished areas that already have limited access to fresh water at great risk.

Lower Life Expectancy

While higher life expectancy is leading to increases in population in developed countries, lower life expectancy may be caused by the same booms in population.

A large proportion of global population growth occurs in less developed countries.

This stretches the scant resources these countries have resulting in less access to medical care, fresh water, food, and jobs, all resulting in a drop in life expectancy.


The effect of overpopulation on the world’s wildlife is also a major issue. As demand for land grows, so too does the destruction of natural habitats, such as forests.

Some scientists warn that if present trends continue, as many as 50% of the world’s wildlife species will be at risk of extinction.

Data has also been collected to show that there is a direct link between increases in human population and decreases in the number of species on the planet.

Natural Resource Depletion

As the global population grows, so too does the number of resources needed to keep so many people alive.

Food, water, and fossil fuels are all being consumed at record rates, placing greater demands on producers and the planet itself. This causes depletion of non-renewable natural resources.

This is exacerbated by urban sprawl. What is urban sprawl? It is the ever-expanding cities marked by burgeoning suburbia that seems to never end. It is high water consumption and an hour-long commute.

All of this is fueled by a burgeoning global population.

Ironically, it is the discovery of many of these natural resources – particularly fossil fuels – that have contributed to conditions that are favorable to population growth.

A study has shown that the world’s ecosystem changed more rapidly in the latter half of the twentieth century than at any other point in history because of the use of these resources.

This is why it’s vital that we explore these natural resources examples to see which ones we can use now to curb the negative effects of the energy needs of our global population.

Increased Intensive Farming

Intensive farming practices in Brazil bring wealth to the area and help to feed the population.
Intensive farming helps to ensure that everyone has something to eat, but it tends to have a negative impact on the environment because of fertilizer use.

As the population has grown over the years, farming practices have evolved to produce enough food to feed larger numbers of people.

However, intensive farming methods is one of the most prevalent types of environmental degradation.

Environmental degradation refers to the damage to local ecosystems and the land, which may pose problems in the future.

Furthermore, intensive farming is also considered a major contributor to climate change due to the machinery required.

This effect will likely increase as the global population continues to grow.

Faster Climate Change

Overpopulation directly correlates to climate change, particularly as larger nations, like China and India, continue to develop their industrial capacities.

They now rank as two of the three largest contributors to emissions in the world, alongside the United States.

China’s recent investments in the advantages of nuclear energy will help to clean up the environmental impact of its massive population.

However, this type of clean energy is too expensive for developing countries where it is needed the most to supply electricity for development without contributing to climate change.

Overpopulation Solutions

Overpopulation solutions are necessary to mitigate the impacts of overpopulation.

Education, access to contraceptives, and policy will help control the population in developing countries.

Better Sex Education

A lack of sex education – or poorly-implemented education – has led to overpopulation issues in many countries.

It has also led to rapidly spreading sexually transmitted diseases and AIDS. The more people know, the better decisions they can make for themselves and others.

Better education will also do away with many of the myths that surround sex and contraceptive methods.

Access to Contraceptives

Access to contraceptives must go hand-in-hand with better sex education.

The World Health Organization (WHO) states that 270 million women in developing countries would prefer to postpone giving birth but have no access to contraceptives.

Many organizations, such as the American Congress of Obstetricians and Gynecologists (ACOG), also support improving access to contraceptives.

This is the safest, most humane way to promote family planning around the world.

Changes in Policy

Babies are needed to ensure the economy doesn't collapse in the future but too many can be hard to support.
Babies are a form of economic capital for most countries. A low birth rate brings economic stagnation and possibly collapse in the future.

Many nations offer rewards, whether in the form of financial incentives or increased benefits, to those who have more children.

This helps to ensure that the country will have enough population to maintain GDP and wartime security. It also helps to offset the cost of caring for the elderly and maintaining retiree pensions.

However, when the benefits are too good it encourages women to have children for the sake of the financial benefits they will receive.

Family planning shouldn’t be financially incentivized.

Education on Overpopulation

While a number of organizations exist to provide schools with curricula and teaching materials to cover the subject of global population, it is still a subject that is not covered in schools as well as it should be.

This education should extend beyond talking about sex and into the global consequences of overpopulation and family planning.

Dialog about the subject needs to be more open, with sites like offering useful resources that allow the issue to be confronted rationally.

The key is to discuss the issue without abandoning human dignity.

Overpopulation Effects

The effects of overpopulation look different depending on where you find it. In some areas there is no problem with overpopulation.

There are vast areas in the world where there are 0-50 people per square mile. The problem is that there also hasn’t been a development of natural resources so people don’t congregate there.

People flock to areas where there is access to water. This can be a river, spring, lake, ocean, or reservoir. If there is drinkable water, there is where you’ll find heavy population density.

These areas have expanded due to our ability to drill deep wells for water.

In the developed world, overpopulated areas suffer from traffic congestion, air pollution, high crime, obesity, high rents, high housing prices, and expensive commodities.

Typically wages rise to meet the need and people stay because they enjoy the metro lifestyle and the convenience of shopping, schools, work, etc.

In the developing world, overpopulation has dire consequences.

People often don’t have any shelter, they live on just a little water that’s not always clean, they never have enough to eat, and work is hard to find.

Medical care can be nearly impossible to get. In some areas, people wait for hours or even days to be seen by a doctor.

In these areas, sexual education and access to contraceptives are seen as a lesser need than basic medical care because people suffer so deeply and lack basic things like clothing and shelter.

What is the Overpopulation Myth?

Man in a wide open space in England with not another person for miles challenging the idea that the planet is overpopulated.
Because there are so many wide-open spaces on the planet and so many people live in opulence, many argue that the overpopulation scare is a myth to exert excessive control over the lives of humans.

Many people, including the Population Research Institute, believe that the overpopulation theory put forth by Malthus is a myth based on bogus science.

They put forth the following tenets to disprove the overpopulation myth.

  • The earth has plenty of resources to support global population growth. The problem is distribution, not availability.
  • Forced abortions in nations like China and India are used to exterminate girls in favor of culturally valued boys.
  • Concentrations of abortion centers in areas that are majority black are used to control specifically the black population – the racist agenda of Planned Parenthood founder, Margaret Sanger.
  • The birth rate and death rate will naturally balance out when left alone.
  • Statistics show that we are currently living in the largest human population that ever will be.
  • A sharp decline in the human population is about to occur – the natural effect of abortion, contraceptives, and mortality in overpopulated areas.
  • Depopulation is a bigger risk than overpopulation – causing an economic catastrophe and cultural stagnation in countries with declining populations.

The overpopulation myth proponents seek to maintain individual human dignity and propose different solutions to natural resource depletion that don’t involve harm to humanity.

Jordan Peterson worked on the UN Secretary General’s Report on Sustainable Economic Development and argues that the world is heading toward a precipitous drop in the birth rate.

Final Thoughts

Education and medical care are the keys to helping women make the decisions they need to have the families they want when the time is right.

Overpopulation in any area taxes the natural resources and makes medical care, food, housing, and water harder to get than they should be.

The fact is that not every place on the planet can be developed to sustain large numbers of humans. That leads to overpopulation in areas where there are limited resources and many people.

What are your thoughts about global overpopulation? Let us know in the comments below!