![Absolute increase in global population per year, OWID](https://upload.wikimedia.org/wikipedia/commons/e/eb/Absolute_increase_in_global_population_per_year%2C_OWID.svg)
Population growth is the increase in the number of people in a
population
Population typically refers to the number of people in a single area, whether it be a city or town, region, country, continent, or the world. Governments typically quantify the size of the resident population within their jurisdiction using a ...
or dispersed group. Actual global human population growth amounts to around 83 million annually, or 1.1% per year. The
global population
In demographics, the world population is the total number of humans currently living. It was estimated by the United Nations to have exceeded 8 billion in November 2022. It took over 200,000 years of human prehistory and history for the ...
has grown from 1 billion in 1800 to 7.9 billion in 2020. The UN projected population to keep growing, and estimates have put the total population at 8.6 billion by mid-2030, 9.8 billion by mid-2050 and 11.2 billion by 2100. However, some academics outside the UN have increasingly
developed human population models that account for additional downward pressures on population growth; in such a scenario population would peak before 2100.
World human population has been growing since the end of the
Black Death
The Black Death (also known as the Pestilence, the Great Mortality or the Plague) was a bubonic plague pandemic occurring in Western Eurasia and North Africa from 1346 to 1353. It is the most fatal pandemic recorded in human history, causi ...
, around the year 1350.
A mix of technological advancement that improved
agricultural productivity
Agricultural productivity is measured as the ratio of agricultural outputs to inputs. While individual products are usually measured by weight, which is known as crop yield, varying products make measuring overall agricultural output difficu ...
and sanitation and medical advancement that reduced mortality increased population growth. In some geographies, this has slowed through the process called the
demographic transition
In demography, demographic transition is a phenomenon and theory which refers to the historical shift from high birth rates and high death rates in societies with minimal technology, education (especially of women) and economic development, to l ...
, where many nations with high standards of living have seen a significant slowing of population growth. This is in direct contrast with less developed contexts, where population growth is still happening. Globally, the rate of population growth has declined from a peak of 2.2% per year in 1963.
The global
human population is projected to peak during the mid-21st century and decline by 2100.
Population growth alongside
increased consumption is a driver of
environmental concerns
Environmental issues are effects of human activity on the biophysical environment, most often of which are harmful effects that cause environmental degradation. Environmental protection is the practice of protecting the natural environment on t ...
, such as
biodiversity loss
Biodiversity loss includes the worldwide extinction of different species, as well as the local reduction or loss of species in a certain habitat, resulting in a loss of biological diversity. The latter phenomenon can be temporary or permanent, de ...
and
climate change
In common usage, climate change describes global warming—the ongoing increase in global average temperature—and its effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes to E ...
, due to resources utilised in
human development Human development may refer to:
* Development of the human body
* Developmental psychology
* Human development (economics)
* Human Development Index, an index used to rank countries by level of human development
* Human evolution, the prehistoric ...
. International policy focused on mitigating the impact of human population growth is concentrated in the
Sustainable Development Goals
The Sustainable Development Goals (SDGs) or Global Goals are a collection of 17 interlinked objectives designed to serve as a "shared blueprint for peace and prosperity for people and the planet, now and into the future".United Nations (2017) R ...
which seek to improve the standard of living globally while reducing the impact of society on the environment.
History
World population
In demographics, the world population is the total number of humans currently living. It was estimated by the United Nations to have exceeded 8 billion in November 2022. It took over 200,000 years of human prehistory and history for the ...
has been rising continuously since the end of the
Black Death
The Black Death (also known as the Pestilence, the Great Mortality or the Plague) was a bubonic plague pandemic occurring in Western Eurasia and North Africa from 1346 to 1353. It is the most fatal pandemic recorded in human history, causi ...
, around the year 1350.
Population began growing rapidly in the
Western world
The Western world, also known as the West, primarily refers to the various nations and state (polity), states in the regions of Europe, North America, and Oceania. during the
industrial revolution
The Industrial Revolution was the transition to new manufacturing processes in Great Britain, continental Europe, and the United States, that occurred during the period from around 1760 to about 1820–1840. This transition included going f ...
. The most significant increase in the world's population has been since the 1950s, mainly due to
medical advancements and increases in
agricultural productivity
Agricultural productivity is measured as the ratio of agricultural outputs to inputs. While individual products are usually measured by weight, which is known as crop yield, varying products make measuring overall agricultural output difficu ...
.
Haber process
Due to its dramatic impact on the human ability to grow food, the
Haber process
The Haber process, also called the Haber–Bosch process, is an artificial nitrogen fixation process and is the main industrial procedure for the production of ammonia today. It is named after its inventors, the German chemists Fritz Haber and C ...
, named after one of its inventors, the German chemist
Fritz Haber
Fritz Haber (; 9 December 186829 January 1934) was a German chemist who received the Nobel Prize in Chemistry in 1918 for his invention of the Haber–Bosch process, a method used in industry to synthesize ammonia from nitrogen gas and hydrogen ...
, served as the "detonator of the
population explosion
Overpopulation or overabundance is a phenomenon in which a species' population becomes larger than the carrying capacity of its environment. This may be caused by increased birth rates, lowered mortality rates, reduced predation or large scale m ...
", enabling the
global population
In demographics, the world population is the total number of humans currently living. It was estimated by the United Nations to have exceeded 8 billion in November 2022. It took over 200,000 years of human prehistory and history for the ...
to increase from 1.6 billion in 1900 to 7.7 billion by November 2019.
Thomas McKeown hypotheses
Some of the reasons for the "Modern Rise of Population"
were particularly investigated by the British health scientist
Thomas McKeown (1912-1988). In his publications, McKeown challenged four theories about the population growth:
# McKeown stated that the growth in Western population, particularly surging in the 19th century, was not so much caused by an increase in
fertility
Fertility is the capability to produce offspring through reproduction following the onset of sexual maturity. The fertility rate is the average number of children born by a female during her lifetime and is quantified demographically. Fertili ...
, but largely by a decline of
mortality
Mortality is the state of being mortal, or susceptible to death; the opposite of immortality.
Mortality may also refer to:
* Fish mortality, a parameter used in fisheries population dynamics to account for the loss of fish in a fish stock throug ...
particularly of childhood mortality followed by
infant mortality
Infant mortality is the death of young children under the age of 1. This death toll is measured by the infant mortality rate (IMR), which is the probability of deaths of children under one year of age per 1000 live births. The under-five morta ...
,
# The decline of mortality could largely be attributed to rising standards of living, whereby McKeown put most emphasis on improved nutritional status,
# His most controversial idea, or at least his most disputed idea, was that he questioned the effectiveness of public health measures, including sanitary reforms, vaccination and quarantine,
# The sometimes fierce disputes that his publication provoked around the "McKeown thesis" have overshadowed his more important and largely unchallenged argument that
curative medicine
Curative care or curative medicine is the health care given for medical conditions where a cure is considered achievable, or even possibly so, and directed to this end. Curative care differs from preventive care, which aims at preventing the appear ...
measures played little role in mortality decline, not only prior to the mid-20th century
but also until well into the 20th century.
Although the McKeown thesis has been heavily disputed, recent studies have confirmed the value of his ideas. His work is pivotal for present day thinking about population growth, birth control, public health and medical care. McKeown had a major influence on many population researchers, such as health economists and Nobel prize winners
Robert W. Fogel (1993) and
Angus Deaton
Sir Angus Stewart Deaton (born 19 October 1945) is a British economist and academic. Deaton is currently a Senior Scholar and the Dwight D. Eisenhower Professor of Economics and International Affairs Emeritus at the Princeton School of Public ...
(2015). The latter considered McKeown as "the founder of
social medicine
The field of social medicine seeks to implement social care through
# understanding how social and economic conditions impact health, disease and the practice of medicine and
# fostering conditions in which this understanding can lead to a health ...
".
Growth rate models
The "population growth rate" is the rate at which the number of individuals in a population increases in a given time period, expressed as a fraction of the initial population. Specifically, population growth rate refers to the change in population over a unit time period, often expressed as a percentage of the number of individuals in the population at the beginning of that period. This can be written as the formula, valid for a sufficiently small time interval:
:
A positive growth rate indicates that the population is increasing, while a negative growth rate indicates that the population is decreasing. A growth ratio of zero indicates that there were the same number of individuals at the beginning and end of the period—a growth rate may be zero even when there are significant changes in the
birth rate
The birth rate for a given period is the total number of live human births per 1,000 population divided by the length of the period in years. The number of live births is normally taken from a universal registration system for births; populati ...
s,
death rate
Mortality rate, or death rate, is a measure of the number of deaths (in general, or due to a specific cause) in a particular population, scaled to the size of that population, per unit of time. Mortality rate is typically expressed in units of de ...
s,
immigration rates, and age distribution between the two times.
A related measure is the
net reproduction rate
In population ecology and demography, the net reproduction rate, ''R''0, is the average number of offspring (often specifically daughters) that would be born to a female if she passed through her lifetime conforming to the age-specific fertility ...
. In the absence of migration, a net reproduction rate of more than 1 indicates that the population of females is increasing, while a net reproduction rate less than one (
sub-replacement fertility
Sub-replacement fertility is a total fertility rate (TFR) that (if sustained) leads to each new generation being less populous than the older, previous one in a given area. The United Nations Population Division defines sub-replacement fertilit ...
) indicates that the population of females is decreasing.
Most populations do not grow exponentially, rather they follow a
logistic model. Once the population has reached its
carrying capacity
The carrying capacity of an environment is the maximum population size of a biological species that can be sustained by that specific environment, given the food, habitat, water, and other resources available. The carrying capacity is defined as t ...
, it will stabilize and the exponential curve will level off towards the carrying capacity, which is usually when a population has depleted most its
natural resource
Natural resources are resources that are drawn from nature and used with few modifications. This includes the sources of valued characteristics such as commercial and industrial use, aesthetic value, scientific interest and cultural value. O ...
s.
In the world human population, growth has been following a
linear trend throughout the last few decades.
Logistic equation
The growth of a population can often be modelled by the
logistic equation
A logistic function or logistic curve is a common S-shaped curve (sigmoid curve) with equation
f(x) = \frac,
where
For values of x in the domain of real numbers from -\infty to +\infty, the S-curve shown on the right is obtained, with the ...
:
where
*
= the population after time t;
*
= time a population grows;
*
= the relative growth rate coefficient;
*
= the carrying capacity of the population; defined by ecologists as the maximum population size that a particular environment can sustain.
As it is a separable differential equation, the population may be solved explicitly, producing a
logistic function
A logistic function or logistic curve is a common S-shaped curve (sigmoid curve) with equation
f(x) = \frac,
where
For values of x in the domain of real numbers from -\infty to +\infty, the S-curve shown on the right is obtained, with the ...
:
:
,
where
and
is the initial population at time 0.
Population growth rate
![World population (UN)](https://upload.wikimedia.org/wikipedia/commons/1/11/World_population_%28UN%29.svg)
The world population growth rate peaked in 1963 at 2.2% per year and subsequently declined.
In 2017, the estimated annual growth rate was 1.1%.
The
CIA World Factbook
''The World Factbook'', also known as the ''CIA World Factbook'', is a reference resource produced by the Central Intelligence Agency (CIA) with almanac-style information about the countries of the world. The official print version is available ...
gives the world annual birthrate, mortality rate, and growth rate as 1.86%, 0.78%, and 1.08% respectively. The last 100 years have seen a massive fourfold increase in the population, due to
medical advances, lower mortality rates, and an increase in agricultural productivity made possible by the
Green Revolution
The Green Revolution, also known as the Third Agricultural Revolution, was a period of technology transfer initiatives that saw greatly increased crop yields and agricultural production. These changes in agriculture began in developed countrie ...
.
The annual increase in the number of living humans peaked at 88.0 million in 1989, then slowly declined to 73.9 million in 2003, after which it rose again to 75.2 million in 2006. In 2017, the human population increased by 83 million.
Generally, developed nations have seen a decline in their growth rates in recent decades, though annual growth rates remain above 2% in some countries of the
Middle East
The Middle East ( ar, الشرق الأوسط, ISO 233: ) is a geopolitical region commonly encompassing Arabian Peninsula, Arabia (including the Arabian Peninsula and Bahrain), Anatolia, Asia Minor (Asian part of Turkey except Hatay Pro ...
and
Sub-Saharan Africa
Sub-Saharan Africa is, geographically, the area and regions of the continent of Africa that lies south of the Sahara. These include West Africa, East Africa, Central Africa, and Southern Africa. Geopolitically, in addition to the List of sov ...
, and also in
South Asia
South Asia is the southern subregion of Asia, which is defined in both geographical and ethno-cultural terms. The region consists of the countries of Afghanistan, Bangladesh, Bhutan, India, Maldives, Nepal, Pakistan, and Sri Lanka.;;;;;;;; ...
,
Southeast Asia
Southeast Asia, also spelled South East Asia and South-East Asia, and also known as Southeastern Asia, South-eastern Asia or SEA, is the geographical United Nations geoscheme for Asia#South-eastern Asia, south-eastern region of Asia, consistin ...
, and
Latin America
Latin America or
* french: Amérique Latine, link=no
* ht, Amerik Latin, link=no
* pt, América Latina, link=no, name=a, sometimes referred to as LatAm is a large cultural region in the Americas where Romance languages — languages derived f ...
.
In some countries the
population is declining, especially in
Eastern Europe
Eastern Europe is a subregion of the Europe, European continent. As a largely ambiguous term, it has a wide range of geopolitical, geographical, ethnic, cultural, and socio-economic connotations. The vast majority of the region is covered by Russ ...
, mainly due to low
fertility rate
The total fertility rate (TFR) of a population is the average number of children that would be born to a woman over her lifetime if:
# she were to experience the exact current age-specific fertility rates (ASFRs) through her lifetime
# she were t ...
s, high death rates and
emigration
Emigration is the act of leaving a resident country or place of residence with the intent to settle elsewhere (to permanently leave a country). Conversely, immigration describes the movement of people into one country from another (to permanentl ...
. In
Southern Africa
Southern Africa is the southernmost subregion of the African continent, south of the Congo and Tanzania. The physical location is the large part of Africa to the south of the extensive Congo River basin. Southern Africa is home to a number of ...
, growth is slowing due to the high number of AIDS-related deaths. Some
Western Europe
Western Europe is the western region of Europe. The region's countries and territories vary depending on context.
The concept of "the West" appeared in Europe in juxtaposition to "the East" and originally applied to the ancient Mediterranean ...
countries might also experience population decline. Japan's population began decreasing in 2005.
The
United Nations Population Division
The United Nations Department of Economic and Social Affairs (UN DESA) is part of the United Nations Secretariat and is responsible for the follow-up to major United Nations Summits and Conferences, as well as services to the United Nations Ec ...
projects world population to reach 11.2 billion by the end of the 21st century.
The
Institute for Health Metrics and Evaluation
The Institute for Health Metrics and Evaluation (IHME) is a research institute working in the area of global health statistics and impact evaluation at the University of Washington in Seattle. The Institute is headed by Christopher J.L. Murray ...
projects that the global population will peak in 2064 at 9.73 billion and decline to 8.89 billion in 2100.
[
] A 2014 study in ''
Science
Science is a systematic endeavor that builds and organizes knowledge in the form of testable explanations and predictions about the universe.
Science may be as old as the human species, and some of the earliest archeological evidence for ...
'' concludes that the global population will reach 11 billion by 2100, with a 70% chance of continued growth into the 22nd century.
The
German Foundation for World Population
DSW (german: Deutsche Stiftung Weltbevölkerung) is an international non-governmental organisation addressing Sexual & Reproductive Health (SRH) and population dynamics. DSW funds its project and advocacy work from private donations and the finan ...
reported in December 2019 that the global human population grows by 2.6 people every second, and could reach 8 billion by 2023.
Growth by country
According to
United Nations
The United Nations (UN) is an intergovernmental organization whose stated purposes are to maintain international peace and international security, security, develop friendly relations among nations, achieve international cooperation, and be ...
population statistics, the world population grew by 30%, or 1.6 billion humans, between 1990 and 2010.
In number of people the increase was highest in India (350 million) and China (196 million). Population growth rate was among highest in the
United Arab Emirates
The United Arab Emirates (UAE; ar, اَلْإِمَارَات الْعَرَبِيَة الْمُتَحِدَة ), or simply the Emirates ( ar, الِْإمَارَات ), is a country in Western Asia (The Middle East). It is located at th ...
(315%) and
Qatar
Qatar (, ; ar, قطر, Qaṭar ; local vernacular pronunciation: ), officially the State of Qatar,) is a country in Western Asia. It occupies the Qatar Peninsula on the northeastern coast of the Arabian Peninsula in the Middle East; it sh ...
(271%).
Many of the world's countries, including many in
Sub-Saharan Africa
Sub-Saharan Africa is, geographically, the area and regions of the continent of Africa that lies south of the Sahara. These include West Africa, East Africa, Central Africa, and Southern Africa. Geopolitically, in addition to the List of sov ...
, the
Middle East
The Middle East ( ar, الشرق الأوسط, ISO 233: ) is a geopolitical region commonly encompassing Arabian Peninsula, Arabia (including the Arabian Peninsula and Bahrain), Anatolia, Asia Minor (Asian part of Turkey except Hatay Pro ...
,
South Asia
South Asia is the southern subregion of Asia, which is defined in both geographical and ethno-cultural terms. The region consists of the countries of Afghanistan, Bangladesh, Bhutan, India, Maldives, Nepal, Pakistan, and Sri Lanka.;;;;;;;; ...
and
South East Asia
Southeast Asia, also spelled South East Asia and South-East Asia, and also known as Southeastern Asia, South-eastern Asia or SEA, is the geographical south-eastern region of Asia, consisting of the regions that are situated south of mainland ...
, have seen a sharp rise in population since the end of the
Cold War
The Cold War is a term commonly used to refer to a period of geopolitical tension between the United States and the Soviet Union and their respective allies, the Western Bloc and the Eastern Bloc. The term '' cold war'' is used because the ...
. The fear is that high population numbers are putting further strain on natural resources, food supplies, fuel supplies, employment, housing, etc. in some of the less fortunate countries. For example, the population of
Chad
Chad (; ar, تشاد , ; french: Tchad, ), officially the Republic of Chad, '; ) is a landlocked country at the crossroads of North and Central Africa. It is bordered by Libya to the north, Sudan to the east, the Central African Republic ...
has ultimately grown from 6,279,921 in 1993 to 10,329,208 in 2009,
further straining its resources.
Vietnam
Vietnam or Viet Nam ( vi, Việt Nam, ), officially the Socialist Republic of Vietnam,., group="n" is a country in Southeast Asia, at the eastern edge of mainland Southeast Asia, with an area of and population of 96 million, making i ...
,
Mexico
Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...
,
Nigeria
Nigeria ( ), , ig, Naìjíríyà, yo, Nàìjíríà, pcm, Naijá , ff, Naajeeriya, kcg, Naijeriya officially the Federal Republic of Nigeria, is a country in West Africa. It is situated between the Sahel to the north and the Gulf o ...
,
Egypt
Egypt ( ar, مصر , ), officially the Arab Republic of Egypt, is a transcontinental country spanning the northeast corner of Africa and southwest corner of Asia via a land bridge formed by the Sinai Peninsula. It is bordered by the Mediter ...
,
Ethiopia
Ethiopia, , om, Itiyoophiyaa, so, Itoobiya, ti, ኢትዮጵያ, Ítiyop'iya, aa, Itiyoppiya officially the Federal Democratic Republic of Ethiopia, is a landlocked country in the Horn of Africa. It shares borders with Eritrea to the ...
, and the
DRC
The Democratic Republic of the Congo (french: République démocratique du Congo (RDC), colloquially "La RDC" ), informally Congo-Kinshasa, DR Congo, the DRC, the DROC, or the Congo, and formerly and also colloquially Zaire, is a country in ...
are witnessing a similar growth in population.
The following table gives some example countries or territories:
;Notes
:
* Eritrea left Ethiopia in 1991.
:
† Split into the nations of Sudan and
South Sudan
South Sudan (; din, Paguot Thudän), officially the Republic of South Sudan ( din, Paankɔc Cuëny Thudän), is a landlocked country in East Africa. It is bordered by Ethiopia, Sudan, Central African Republic, Democratic Republic of the C ...
during 2011.
:
‡ Japan and the Ryukyu Islands merged in 1972.
:
# India and Sikkim merged in 1975.
Future population
See also
*
List of countries by population growth rate
This article includes a table of countries and subnational areas by annual population growth
Population growth is the increase in the number of people in a population or dispersed group. Actual global human population growth amounts to around 8 ...
*
Demographic history Demographic history is the reconstructed record of human population in the past. Given the lack of population records prior to the 1950s, there are many gaps in our record of demographic history. Historical demographers must make do with estimates, ...
*
Demographic transition
In demography, demographic transition is a phenomenon and theory which refers to the historical shift from high birth rates and high death rates in societies with minimal technology, education (especially of women) and economic development, to l ...
*
Density dependence
*
Ecological overshoot
Ecological overshoot is the phenomenon which occurs when the demands made on a natural ecosystem exceed its regenerative capacity. Global ecological overshoot occurs when the demands made by humanity exceed what the biosphere of Earth can provide ...
*
Epidemiological transition
In demography and medical geography, epidemiological transition is a theory which "describes changing population patterns in terms of fertility, life expectancy, mortality, and leading causes of death." For example, a phase of development marked ...
*
Human population planning
Human population planning is the practice of intentionally controlling the growth rate of a human population. The practice, traditionally referred to as population control, had historically been implemented mainly with the goal of increasing po ...
*
Irruptive growth
Irruptive growth is a growth pattern over time, defined by a sudden rapid growth in the population of an organism. Irruptive growth is studied in population ecology. Population cycles often display irruptive growth, but with a predictable pattern s ...
*
Overshoot (population)
In environmental science, the concept of overshoot means demand in excess of regeneration. It can apply to animal populations and people. Environmental science studies to what extent human populations through their resource consumption have risen ...
*
Population decline
A population decline (also sometimes called underpopulation, depopulation, or population collapse) in humans is a reduction in a human population size. Over the long term, stretching from prehistory to the present, Earth's total human population ...
*
Population density
Population density (in agriculture: standing stock or plant density) is a measurement of population per unit land area. It is mostly applied to humans, but sometimes to other living organisms too. It is a key geographical term.Matt RosenberPopul ...
*
World population
In demographics, the world population is the total number of humans currently living. It was estimated by the United Nations to have exceeded 8 billion in November 2022. It took over 200,000 years of human prehistory and history for the ...
*
Estimates of historical world population
This article lists current estimates of the world population in history. In summary, estimates for the progression of world population since the Late Middle Ages are in the following ranges:
Estimates for pre-modern times are necessarily fraugh ...
References
External links
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* Published in Issue No. 125, page 39 to 40 - (5802) characters
{{Authority control
Ecological metrics
Population ecology
Human overpopulation
Environmental controversies