Human overpopulation is an issue by itself.
But, if there is one thing that is a major cause of most other sustainability issues – it’s human overpopulation.
It makes sense – more people means more consumption (of food, water, natural resources etc.), and more emissions (greenhouse gases, waste etc.)
In this guide, we discuss the causes, effects, problems and potential solutions behind overpopulation.
Summary – Human Overpopulation
- Human overpopulation is essentially the point where the number of humans in an area, region, city, country or the world, cannot be maintained
- This might occur because there is not enough resources to support that number of humans, or because the man made systems or natural environmental begin to degrade in terms of their ability to support those humans
- The number of humans in an area can increase because of increased birth rates, decrease in the mortality/death rates, and increase in immigration
- Historically, technological revolutions or advances in technologies have increased populations e.g. the tool-making revolution, the agricultural revolution, and the industrial revolution – all of which allowed humans more access to food, resulting in subsequent population explosions.
- The fertility rate is strongly influenced by cultural and social norms that are rather stable and therefore slow to adapt to changes in the social, technological, or environmental conditions.
- Population increase rates tend to be highest in areas where children die young, where there is poverty (especially extreme poverty), and where there is lack of access to education
- Religious and ideological opposition to birth control has been cited as a factor contributing to overpopulation and poverty
- Guatemala is an example of a country whose average family size halved with the decrease in extreme poverty. Cambodia and Namibia are two countries who have gone through similar trends
- Populations in some of the poorest countries in the world are expected to double and even triple by 2040-50
- Overpopulation in poorer countries is highly undesirable as economic development falls far behind a point where there is proper capital available to invest in the people and the country to support them. If you add corruption and a lack of proper social and government systems, the picture that is painted for these countries is even bleaker
- When developed countries face quicker population increases, it can place a strain on resources that were already depleting or stressed, such as a city’s water supply
- Over population means more resources are needed by a population as a whole (with freshwater and drinking water being one key example – demand increases for this crucial resource), but also more waste is produced, and there is more pollution and environmental degradation. Economically, there are more consumers and employees/skills introduced to the economy, but also more labor and more competition for jobs.
- The effects of overpopulation are compounded by overconsumption, broken or inefficient systems, ineffective technology, environmental pollution and degradation, and other factors
- Technology can play a large role in providing enough resources for a population e.g. look at the difference between agricultural sectors in developing vs developed countries, as well as the capacity to produce electricity, provide cold food storage etc.
- Perth in Western Australia is a dry city, but faces many of the same challenges as Cape Town (dry city, increasing population, prone to droughts). Perth was able to provide enough freshwater and Cape Town experienced a water shortage because of various factors like good governmental planning, investment in water treatment and recycling, investment in desalination plants and so on.
- There is an argument made that rich countries use the most resources from the planet, while poorer countries receive few of the benefits as a whole
- The US across many measures (along with other developed countries) consume far more resources per capita than many poorer countries
- The most overpopulated cities tend to be in developing countries where poverty is rampant due to this overcrowding (leading to sickness, disease, death and so on)
- Even in developed countries, cities deal with intense smog and pollution problems that exacerbate health and poverty issues. Labor prices can also start to diminish with an increase in labor
- Solutions to overpopulation tend to focus around reducing poverty, lifting education rates, increasing the quality of health care and safety (especially for children), and investing in basic living resources for the poorest countries or countries with the highest fertility and population increase rates
- Other general solutions include investing in technology to provide the most crucial resources in all countries, becoming clear on exactly how many people each city in the world can sustainably support with the technology, resources and systems they currently have, more education and access to healthcare for women in regards to pregnancy, education for men on contraception, enforcing birth laws/regulations for the most heavily populated and quickest growing cities and countries, and to examine our consumption and waste habits city by city. Cities might focus on quality of life as a measurement of how many people a city can support
- Each city has it’s own capabilities and capacity to support different populations to different extents – it’s too general to examine overpopulation at the country or state/province level
- Some people have suggested space colonization and making use of resources in space as an option in the future for further human population expansion
- The world’s population currently sits at around 7 billion in 2019, and is forecasted to reach somewhere between 9 to 13 billion between 2050 to 2100
- There is more information in this guide about whether humans and Earth might run out of resources in the future, and what might happen if we do
What Is Human Overpopulation?
Overpopulation occurs when a species’ population exceeds the carrying capacity of its ecological niche.
Human overpopulation occurs when the ecological footprint of a human population in a specific geographical location exceeds the carrying capacity of the place occupied by that group.
Overpopulation can further be viewed, in a long term perspective, as existing when a population cannot be maintained given the rapid depletion of non-renewable resources or given the degradation of the capacity of the environment to give support to the population
The term human overpopulation also refers to the relationship between the entire human population and its environment: the Earth, or to smaller geographical areas such as countries.
It is possible for very sparsely populated areas to be overpopulated if the area has a meagre or non-existent capability to sustain life (e.g. a desert).
Human Overpopulation Causes
Overpopulation can result from:
- an increase in births (fertility rate),
- a decline in the mortality rate,
- an increase in immigration,
- or an unsustainable biome and depletion of resources
- The UN projects the population of the 48 poorest countries in the world will double from 850 million in 2010 to 1.7 billion in 2050.
Population Institute, via the Borgenproject.org
- The higher the death rate for children in a region, the higher the birthrate… When people know their children will survive, they have few children. Addressing global poverty and keeping children alive is crucial for reducing overpopulation.
- Poverty and the lack of access to education leads to higher birthrates and overpopulation.
– USAID, via Borgenproject.org
- “Where rapid population growth far outpaces economic development, countries will have a difficult time investing in the human capital needed to secure the well-being of its people and to stimulate further economic growth. This issue is especially acute for the least developed countries, many of which are facing a doubling, or even a tripling of their populations by 2050.”
– UN Population Fund, via Borgenproject.org
- When poverty rates drop, birthrates soon follow…
- Extreme poverty in Guatemala has decreased by nearly 40% since 1992, and with that decline in poverty, the average family size has fallen from almost 6 children to just over 3.
- In 1994, the average family in Cambodia had nearly 6 children; by 2015, extreme poverty (living on less than $1.25 per day) in Cambodia had fallen more than 40% and average family size had decreased by more than half.
- The last 20 years in Namibia have seen extreme poverty rates fall by 20% and average family size halved.
- From a historical perspective, technological revolutions have coincided with population expansion.
- There have been three major technological revolutions – the tool-making revolution, the agricultural revolution, and the industrial revolution – all of which allowed humans more access to food, resulting in subsequent population explosions.
- For example, the use of tools, such as bow and arrow, allowed primitive hunters greater access to more high energy foods (e.g. animal meat). Similarly, the transition to farming about 10,000 years ago greatly increased the overall food supply, which was used to support more people. Food production further increased with the industrial revolution as machinery, fertilizers, herbicides, and pesticides were used to increase land under cultivation as well as crop yields.
- Today, starvation is caused by economic and political forces rather than a lack of the means to produce food.
- Significant increases in human population occur whenever the birth rate exceeds the death rate for extended periods of time. Traditionally, the fertility rate is strongly influenced by cultural and social norms that are rather stable and therefore slow to adapt to changes in the social, technological, or environmental conditions.
- For example, when death rates fell during the 19th and 20th century – as a result of improved sanitation, child immunizations, and other advances in medicine – allowing more newborns to survive, the fertility rate did not adjust downward, resulting in significant population growth.
- Until the 1700s, seven out of ten children died before reaching reproductive age. Today, more than nine out of ten children born in industrialized nations reach adulthood.
- There is a strong correlation between overpopulation and poverty. In contrast, the invention of the birth control pill and other modern methods of contraception resulted in a dramatic decline in the number of children per household in all but the very poorest countries.
- Agriculture has sustained human population growth. This dates back to prehistoric times, when agricultural methods were first developed, and continues to the present day, with fertilizers, agrochemicals, large-scale mechanization, genetic manipulation, and other technologies.
- Humans have historically exploited the environment using the easiest, most accessible resources first. The richest farmland was plowed and the richest mineral ore mined first. Ceballos, Ehrlich A and Ehrlich P said that overpopulation is demanding the use of ever more creative, expensive and/or environmentally destructive means in order to exploit ever more difficult to access and/or poorer quality natural resources to satisfy consumers.
- An example of a country whose laws and norms are hindering the global effort to slow population growth is Afghanistan. “The approval by Afghan President Hamid Karzai of the Shia Personal Status Law in March 2009 effectively destroyed Shia women’s rights and freedoms in Afghanistan. Under this law, women have no right to deny their husbands sex unless they are ill, and can be denied food if they do.”
- Religious and ideological opposition to birth control has been cited as a factor contributing to overpopulation and poverty.
Human Overpopulation Effects & Problems
More humans means more consumption (of food, water, natural resources etc.), and more emissions (greenhouse gases, waste etc.).
It also means more production in the business and industrial sectors which are some of the biggest contributors to environmental and wildlife destruction. We are talking intensive agriculture, manufacturing, mining, textiles, construction and demolition and so on.
Some issues that are exacerbated by increase in population are:
- Waste Pollution
- Plastic Pollution
- Water Scarcity
- Climate Change and Greenhouse Gas Emissions
- Water Stress
- Water Pollution
- Outdoor Air Pollution
- Indoor Air Pollution
- + much more
- Overpopulation can mean that if there are too many people in the same habitat, people are limiting available resources to survive.
- Advocates of population moderation cite issues like quality of life, carrying capacity and risk of starvation as a basis to argue against continuing high human population growth and for population decline.
- Scientists suggest that the human impact on the environment as a result of overpopulation, profligate consumption and proliferation of technology has pushed the planet into a new geological epoch known as the Anthropocene.
- Inadequate fresh water for drinking as well as sewage treatment and effluent discharge. Some countries, like Saudi Arabia, use energy-expensive desalination to solve the problem of water shortages.
- Depletion of natural resources, especially fossil fuels.
- Increased levels of air pollution, water pollution, soil contamination and noise pollution.
- Changes in atmospheric composition and consequent global warming.
- Loss of arable land and increase in desertification. Deforestation and desertification can be reversed by adopting property rights, and this policy is successful even while the human population continues to grow.
- Mass species extinctions and contracting biodiversity from reduced habitat in tropical forests due to slash-and-burn techniques that sometimes are practiced by shifting cultivators, especially in countries with rapidly expanding rural populations; present extinction rates may be as high as 140,000 species lost per year. As of February 2011, the IUCN Red List lists a total of 801 animal species having gone extinct during recorded human history, although the vast majority of extinctions are thought to be undocumented.
- Biodiversity would continue to grow at an exponential rate if not for human influence. Sir David King, former chief scientific adviser to the UK government, told a parliamentary inquiry: “It is self-evident that the massive growth in the human population through the 20th century has had more impact on biodiversity than any other single factor.” Paul and Anne Ehrlich said population growth is one of the main drivers of the Earth’s extinction crisis.
- The Yangtze River dolphin, Atlantic gray whale, West African black rhino, Merriam’s elk, California grizzly bear, silver trout, blue pike and dusky seaside sparrow are all victims of human overpopulation.
- High infant and child mortality. High rates of infant mortality are associated with poverty. Rich countries with high population densities have low rates of infant mortality.
- Intensive factory farming to support large populations. It results in human threats including the evolution and spread of antibiotic resistant bacteria diseases, excessive air and water pollution, and new viruses that infect humans.
- Increased chance of the emergence of new epidemics and pandemics. For many environmental and social reasons, including overcrowded living conditions, malnutrition and inadequate, inaccessible, or non-existent health care, the poor are more likely to be exposed to infectious diseases.
- Starvation, malnutrition or poor diet with ill health and diet-deficiency diseases (e.g. rickets). However, rich countries with high population densities do not have famine.
- Poverty coupled with inflation in some regions and a resulting low level of capital formation. Poverty and inflation are aggravated by bad government and bad economic policies. Many countries with high population densities have eliminated absolute poverty and keep their inflation rates very low.
- Low life expectancy in countries with fastest growing populations.
- Unhygienic living conditions for many based upon water resource depletion, discharge of raw sewage and solid waste disposal. However, this problem can be reduced with the adoption of sewers. For example, after Karachi, Pakistan installed sewers, its infant mortality rate fell substantially.
- Elevated crime rate due to drug cartels and increased theft by people stealing resources to survive.
- Conflict over scarce resources and crowding, leading to increased levels of warfare.
- Less personal freedom and more restrictive laws. Laws regulate and shape politics, economics, history and society and serve as a mediator of relations and interactions between people. The higher the population density, the more frequent such interactions become, and thus there develops a need for more laws and/or more restrictive laws to regulate these interactions and relations. It was even speculated by Aldous Huxley in 1958 that democracy is threatened due to overpopulation, and could give rise to totalitarian style governments.
The effects of overpopulation are compounded by overconsumption. According to Paul R. Ehrlich:
Rich western countries are now siphoning up the planet’s resources and destroying its ecosystems at an unprecedented rate. We want to build highways across the Serengeti to get more rare earth minerals for our cellphones. We grab all the fish from the sea, wreck the coral reefs and put carbon dioxide into the atmosphere. We have triggered a major extinction event … A world population of around a billion would have an overall pro-life effect. This could be supported for many millennia and sustain many more human lives in the long term compared with our current uncontrolled growth and prospect of sudden collapse … If everyone consumed resources at the US level – which is what the world aspires to – you will need another four or five Earths. We are wrecking our planet’s life support systems.
- poverty and environmental degradation are some of the main effects
- the world’s resources shrink
- resources can be unevenly distributed (less resources means the available resources will go to those who can most afford it)
- there is a declining ratio of food producers to food consumers
- There are not enough resources or available land for many struggling individuals to survive
- there are too many people trying to fill a limited number of jobs within an area (labor price is diminished)
- The most overpopulated cities tend to be in developing countries where poverty is rampant due to this overcrowding.
- Even in developed countries, the cities listed deal with intense smog and pollution problems that exacerbate health and poverty issues.
- In less developed regions, there is a higher death rate for children and adolescents. Unsanitary living conditions threaten survival rates. This is especially evident in urban areas where crowding is so common that slums have grown rapidly.
Potential Human Overpopulation Solutions & Strategies
It appears some of the major solutions are:
- Improve overall quality of life
- Reduce poverty
- Increase availability of jobs
- Increase the level and availability of education
- Increase access to quality healthcare and contraception
- Give the option for safe abortions
- Focus on countries in particular with high fertility rates (above the replacement level)
Note that overpopulation is a slightly different issue to overconsumption.
One of the big alternatives to controlling population levels, is to change the way we consume i.e. consume less, consume more efficiently.
Inventing new technology to cater for increased population levels is another option.
Even if human quality of life is maintained with increasing population growth – there are still sub issues like social issues, environmental issues and wildlife issues that must be addressed.
All these issues and sub issues bridge and work in together.
- Changes in lifestyle could reverse overpopulated status without a large population reduction.
- The key thing you can do to reduce population growth is actually improve health.
– Bill Gates, via Borgenproject.org
- In order to combat poverty in the most overpopulated cities, education and economic growth are critical.
- By engaging the government to work with its community, the government will better understand which challenges should be addressed first.
- Therefore, education, paired with improved living conditions in cities, will help ensure children are surviving into adulthood.
- These are the key ingredients to overcoming poverty and environmental pollution in overpopulated urban areas.
Proposed solutions and ways to mitigate overpopulation related issues according to Wikipedia.org are:
- Several solutions and mitigation measures have the potential to reduce overpopulation.
- Some solutions are to be applied on a global planetary level (e.g., via UN resolutions), while some on a country or state government organization level, and some on a family or an individual level
- Some of the proposed mitigations aim to help implement new social, cultural, behavioral and political norms to replace or significantly modify current norms.
- For example, in societies like China, the government has put policies in place that regulate the number of children allowed to a couple.
- Other societies have implemented social marketing strategies in order to educate the public on overpopulation effects. “The intervention can be widespread and done at a low cost. A variety of print materials (flyers, brochures, fact sheets, stickers) needs to be produced and distributed throughout the communities such as at local places of worship, sporting events, local food markets, schools and at car parks (taxis / bus stands).”
- Such prompts work to introduce the problem so that new or modified social norms are easier to implement. Certain government policies are making it easier and more socially acceptable to use contraception and abortion methods.
- Scientists and technologists including e.g. Huesemann, Huesemann, Ehrlich and Ehrlich caution that science and technology, as currently practiced, cannot solve the serious problems global human society faces, and that a cultural-social-political shift is needed to reorient science and technology in a more socially responsible and environmentally sustainable direction.
- Education and Empowerment…
- One option is to focus on education about overpopulation, family planning, and birth control methods, and to make birth-control devices like male and female condoms, contraceptive pills and intrauterine devices easily available.
- Worldwide, nearly 40% of pregnancies are unintended (some 80 million unintended pregnancies each year).
- An estimated 350 million women in the poorest countries of the world either did not want their last child, do not want another child or want to space their pregnancies, but they lack access to information, affordable means and services to determine the size and spacing of their families.
- In the United States, in 2001, almost half of pregnancies were unintended.
- In the developing world, some 514,000 women die annually of complications from pregnancy and abortion, with 86% of these deaths occurring in the sub-Saharan Africa region and South Asia.
- Additionally, 8 million infants die, many because of malnutrition or preventable diseases, especially from lack of access to clean drinking water.
- Women’s rights and their reproductive rights in particular are issues regarded to have vital importance in the debate….wherever women are put in control of their lives, both politically and socially, where medical facilities allow them to deal with birth control and where their husbands allow them to make those decisions, birth rate falls. Women don’t want to have 12 kids of whom nine will die.
- Egypt announced a program to reduce its overpopulation by family planning education and putting women in the workforce.
- It was announced in June 2008 by the Minister of Health and Population, and the government has set aside 480 million Egyptian pounds (about $90 million US) for the program.
- Several scientists (including e.g. Paul and Anne Ehrlich and Gretchen Daily) proposed that humanity should work at stabilizing its absolute numbers, as a starting point towards beginning the process of reducing the total numbers.
- They suggested the following solutions and policies: following a small-family-size socio-cultural-behavioral norm worldwide (especially one-child-per-family ethos), and providing contraception to all along with proper education on its use and benefits (while providing access to safe, legal abortion as a backup to contraception), combined with a significantly more equitable distribution of resources globally.
- Business magnate Ted Turner proposed a “voluntary, non-imposed” one-child-per-family cultural norm. A “pledge two or fewer” campaign is run by Population Matters (a UK population concern organisation), in which people are encouraged to limit themselves to small family size.
- Greater and better access to contraception
- Reducing infant mortality so that parents do not need to have many children to ensure at least some survive to adulthood.
- Improving the status of women in order to facilitate a departure from traditional sexual division of labour.
- One-Child and Two-Child policies, and other policies restricting or discouraging births directly.
- Family planning
- Creating small family “role models”
- Tighter immigration restrictionsPopulation planning that is intended to reduce population size or growth rate may promote or enforce one or more of the following practices, although there are other methods as well:
- The method(s) chosen can be strongly influenced by the cultural and religious beliefs of community members.
- Birth Regulations…
- Overpopulation can be mitigated by birth control; some nations, like the People’s Republic of China, use strict measures to reduce birth rates.
- Sanjay Gandhi, son of late Prime Minister of India Indira Gandhi, implemented a forced sterilization programme between 1975 and 1977. Officially, men with two children or more had to submit to sterilization, but there was a greater focus on sterilizing women than sterilizing men. Some unmarried young men and political opponents may also have been sterilized. This program is still remembered and criticized in India, and is blamed for creating a public aversion to family planning, which hampered government programs for decades.
- Urban designer Michael E. Arth has proposed a “choice-based, marketable birth license plan” he calls “birth credits”. Birth credits would allow any woman to have as many children as she wants, as long as she buys a license for any children beyond an average allotment that would result in zero population growth. If that allotment was determined to be one child, for example, then the first child would be free, and the market would determine what the license fee for each additional child would cost. Extra credits would expire after a certain time, so these credits could not be hoarded by speculators. The actual cost of the credits would only be a fraction of the actual cost of having and raising a child, so the credits would serve more as a wake-up call to women who might otherwise produce children without seriously considering the long term consequences to themselves or society.
- Another choice-based approach, similar to Arth’s birth credits, is financial compensation or other benefits (free goods and/or services) by the state (or state-owned companies) offered to people who voluntarily undergo sterilization. Such compensation has been offered in the past by the government of India.
- In 2014 the United Nations estimated there is an 80% likelihood that the world’s population will be between 9.6 billion and 12.3 billion by 2100. Most of the world’s expected population increase will be in Africa and southern Asia. Africa’s population is expected to rise from the current one billion to four billion by 2100, and Asia could add another billion in the same period.
- Because the median age of Africans is relatively low (e.g. in Uganda it is 15 years old) birth credits would have to limit fertility to one child per two women to reach the levels of developed countries immediately.
- For countries with a wide base in their population pyramid it will take a generation for the people who are of child bearing age to have their families.
- An example of demographic momentum is China, which added perhaps 400,000 more people after its one-child policy was enacted. Arth has suggested that the focus should be on the developed countries and that some combination of birth credits and additional compensation supplied by the developed countries could rapidly lead to zero population growth while also quickly raising the standard of living in developing countries.
Extraterrestrial Settlement & Space Colonisation
- Various scientists and science fiction authors have contemplated that overpopulation on Earth may be remedied in the future by the use of extraterrestrial settlements.
- In the 1970s, Gerard K. O’Neill suggested building space habitats that could support 30,000 times the carrying capacity of Earth using just the asteroid belt, and that the Solar System as a whole could sustain current population growth rates for a thousand years. Marshall Savage (1992, 1994) has projected a human population of five quintillion (5 x 1018) throughout the Solar System by 3000, with the majority in the asteroid belt.
- Freeman Dyson (1999) favours the Kuiper belt as the future home of humanity, suggesting this could happen within a few centuries. In Mining the Sky, John S. Lewis suggests that the resources of the solar system could support 10 quadrillion (1016) people.
- In an interview, Stephen Hawking claimed that overpopulation is a threat to human existence and “our only chance of long-term survival is not to remain inward looking on planet Earth but to spread out into space.”
- K. Eric Drexler, famous inventor of the futuristic concept of molecular nanotechnology, has suggested in Engines of Creation that colonizing space will mean breaking the Malthusian limits to growth for the human species.
- It may be possible for other parts of the Solar System to be inhabited by humanity at some point in the future.
- Geoffrey Landis of NASA’s Glenn Research Center in particular has pointed out that “[at] cloud-top level, Venus is the paradise planet”, as one could construct aerostat habitats and floating cities there easily, based on the concept that breathable air is a lifting gas in the dense Venusian atmosphere. Venus would, like also Saturn, Uranus, and Neptune, in the upper layers of their atmospheres, even afford a gravitation almost exactly as strong as that on Earth (see colonization of Venus).
- Many science fiction authors, including Carl Sagan, Arthur C. Clarke, and Isaac Asimov, have argued that shipping any excess population into space is not a viable solution to human overpopulation. According to Clarke, “the population battle must be fought or won here on Earth”. The problem for these authors is not the lack of resources in space (as shown in books such as Mining the Sky), but the physical impracticality of shipping vast numbers of people into space to “solve” overpopulation on Earth. However, Gerard K. O’Neill’s calculations show that Earth could offload all new population growth with a launch services industry about the same size as the current airline industry.
- The StarTram concept, by James R. Powell (the co-inventor of maglev transport) and others, envisions a capability to send up to 4 million people a decade to space per facility.
- A hypothetical extraterrestrial colony could potentially grow by reproduction only (i.e., without any immigration), with all of the inhabitants being the direct descendants of the original colonists.
- Despite the increase in population density within cities (and the emergence of megacities), UN Habitat states in its reports that urbanization may be the best compromise in the face of global population growth. Cities concentrate human activity within limited areas, limiting the breadth of environmental damage. But this mitigating influence can only be achieved if urban planning is significantly improved and city services are properly maintained.
- More than 200 million women in developing countries are sexually active without effective modern contraception even though they do not want to be pregnant anytime soon, according to the Guttmacher Institute, a reproductive health research group. By the best estimates, some 80 million pregnancies around the world are unintended. Although the numbers aren’t strictly comparable—many unplanned pregnancies end in abortion—the unintended pregnancies exceed the 78 million by which world population grows every year.
- In the U.S., which is well informed and spends nearly 20 cents per dollar of economic activity on health care, nearly one out of every two pregnancies is unintended. That proportion has not changed much for decades. In every nation, rich and poor, in which a choice of contraceptives is available and is backed up by reasonably accessible safe abortion for when contraception fails, women have two or fewer children.
- Educating girls reduces birthrates.
- Worldwide, according to a calculation provided for this article by demographers at the International Institute for Applied Systems Analysis in Austria, women with no schooling have an average of 4.5 children, whereas those with a few years of primary school have just three.
- Women who complete one or two years of secondary school have an average of 1.9 children apiece—a figure that over time leads to a decreasing population.
- With one or two years of college, the average childbearing rate falls even further, to 1.7.
- And when women enter the workforce, start businesses, inherit assets and otherwise interact with men on an equal footing, their desire for more than a couple of children fades even more dramatically.
- Most of the drop in Chinese fertility occurred … as the government brought women by the millions into farm and industry collectives and provided them with the family planning they needed to stay on the job. Many developing countries—from Thailand and Colombia to Iran—have experienced comparable declines in family size by getting better family-planning services and educational opportunities to more women and girls in more places.
Top 20 Countries With Largest Populations In Total People
As of September 2018, these are the top 20 largest population countries:
- China – 1,416,221,148
- India – 1,357,226,853
- USA – 327,258,161
- Indonesia – 267,393,413
- Brazil – 211,204,519
- Pakistan – 201,628,675
- Nigeria – 196,949,995
- Bangladesh – 166,730,612
- Russia – 143,959,398
- Mexico – 131,100,059
- Japan – 127,121,981
- Ethiopia – 108,089,628
- Phillipines – 106,853,251
- Egypt – 99,766,661
- Vietnam – 96,693,923
- Democratic Republic Of The Congo – 84,581,357
- Germany – 82,331,523
- Iran – 82,192,940
- Turkey – 82,167,606
- Thailand – 69,214,108
Past, Current & Future World Population Stats & Forecasts/Projections, Including Population Growth
You can see past, current and future world population stats and forecasts here:
- https://www.weforum.org/agenda/2016/09/the-countries-with-the-biggest-populations-from-1950-to-2060/ – countries with biggest population by 2060
- https://www.businessinsider.com/worlds-most-populous-cities-2100-2017-6?IR=T – most populous cities by 2100
The world’s population will rise from just over 7 billion in 2012 to nearly 9.6 billion by 2050
- The world population is currently growing by approximately 74 million people per year. Current United Nations predictions estimate that the world population will reach 9.0 billion around 2050, assuming a decrease in average fertility rate from 2.5 down to 2.0.
- Almost all growth will take place in the less developed regions, where today’s 5.3 billion population of underdeveloped countries is expected to increase to 7.8 billion in 2050. By contrast, the population of the more developed regions will remain mostly unchanged, at 1.2 billion. An exception is the United States population, which is expected to increase by 44% from 2008 to 2050.
Fertility Rates, & Replacement Level Rates
“Replacement level fertility” is the total fertility rate—the average number of children born per woman—at which a population exactly replaces itself from one generation to the next, without migration.
This rate is roughly 2.1 children per woman for most countries, although it may modestly vary with mortality rates.
Sub-Saharan Africa is the exception to this fertility trend. Its total fertility rate was 5.4 during the 2005–10 period― double that of any other region―and is projected to decline only to 3.2 by 2050. These expected reductions in fertility rates reflect expectations of increasing urbanization, expected declines in child mortality, and increases in income, among other factors.
The birth rates by country development level are:
- World – 2.5
- More Developed – 1.7
- Less Developed – 2.6
- Least Developed – 4.3
– UNFPA, via borgenproject.org
Carrying capacity refers to the number of individuals who can be supported in a given area within natural resource limits, and without degrading the natural social, cultural and economic environment for present and future generations. The carrying capacity for any given area is not fixed.
It can be altered by improved technology, but mostly it is changed for the worse by pressures which accompany a population increase. As the environment is degraded, carrying capacity actually shrinks, leaving the environment no longer able to support even the number of people who could formerly have lived in the area on a sustainable basis.
No population can live beyond the environment’s carrying capacity for very long.
We must think in terms of “carrying capacity” not land area. The effects of unfettered population growth drastically reduce the carrying capacity in the United States.
Countries With The Worst Human, Wildlife & Environmental Issues
Rather than looking at overall population numbers – instead, look at whether the population has enough resources to meet demand, look at quality of life indicators, and look at population effect on humans, wildlife and the environment.
Also look at human density (also called overcrowding) – number of people per square mile in that city.
10 of the most overcrowded cities in the world in 2017 based on number of people per square mile are:
- 1. Dhaka, Bangladesh – 16,235,000 total people, and 114,300 per square mile
- 2. Hyderabad, Pakistan – 2,990,000 total people, and 106,800 per square mile
- 3. Vijayawada, India – 1,775,000 total people, and 80,700 per square mile
- 4. Chittagong, Bangladesh – 3,250,000 total people, and 75,600 per square mile
- 5. Mumbai, India – 22,885,000 total people, and 67,300 per square mile
- 6. Hong Kong, – 7,280,000 total people, and 66,200 per square mile
- 7. Aligarh, India – 1,050,000 total people, and 65,600 per square mile
- 8. Macau – 655,000 total people, and 65,500 per square mile
- 9. Hama, Syria – 1,300,000 total people, and 65,000 per square mile
- 10. Mogadishu, Somalia – 2,265,000 total people, and 64,700 per square mile
There is also a list of the fastest growing cities in the world – https://www.telegraph.co.uk/travel/lists/fastest-growing-cities-in-the-world/
Overpopulation In Developing vs Developed Countries
It’s quite clear from the above information that overpopulation occurs at different rates, and has different results in developing vs developed countries.
10. https://www.businessinsider.com/worlds-most-populous-cities-2100-2017-6?IR=T – most populous cities by 2100