# Population growth

Last updated

In biology or human geography, population growth is the increase in the number of individuals in a population. Many of the world's countries, including many in Sub-Saharan Africa, the Middle East, South Asia and South East Asia, have seen a sharp rise in population since the end of the Cold War. 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 has ultimately grown from 6,279,921 in 1993 to 10,329,208 in 2009, [1] further straining its resources. Niger, Pakistan, Nigeria, Egypt, Ethiopia, and the DRC are witnessing a similar growth in population.

Biology is the natural science that studies life and living organisms, including their physical structure, chemical processes, molecular interactions, physiological mechanisms, development and evolution. Despite the complexity of the science, there are certain unifying concepts that consolidate it into a single, coherent field. Biology recognizes the cell as the basic unit of life, genes as the basic unit of heredity, and evolution as the engine that propels the creation and extinction of species. Living organisms are open systems that survive by transforming energy and decreasing their local entropy to maintain a stable and vital condition defined as homeostasis.

Human geography or anthropogeography is the branch of geography that deals with the study of people and their communities, cultures, economies, and interactions with the environment by studying their relations with and across space and place. Human geography attends to human patterns of social interaction, as well as spatial level interdependencies, and how they influence or affect the earth's environment. As an intellectual discipline, geography is divided into the sub-fields of physical geography and human geography, the latter concentrating upon the study of human activities, by the application of qualitative and quantitative research methods.

In biology, a population is all the organisms of the same group or species, which live in a particular geographical area, and have the capability of interbreeding. The area of a sexual population is the area where inter-breeding is potentially possible between any pair within the area, and where the probability of interbreeding is greater than the probability of cross-breeding with individuals from other areas.

## Contents

Global human population growth amounts to around 83 million annually, [2] or 1.1% per year. The global population has grown from 1 billion in 1800 to 7.616 billion [3] in 2018. It is expected 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. [4]

In demographics, the world population is the total number of humans currently living, and was estimated to have reached 7.7 billion people as of April 2019. It took over 200,000 years of human history for the world's population to reach 1 billion; and only 200 years more to reach 7 billion.

Population [5]
Years passedYearBillion
18001
12719272
3319603
1419744
1319875
1219996
1220117
122023*8
142037*9
182055*10
332088*11
*World Population Prospects 2017
(United Nations Population Division)

## History

Population began growing rapidly in the Western world early in the industrial revolution of the late 18th century. The reasons for the "Modern Rise of Population" [6] were particularly investigated by the British health scientist Thomas McKeown (1912-1988). In his publications, McKeown challenged four theories about the population growth:

The Western world, also known as the West, refers to various nations depending on the context, most often including at least parts of Europe, Australasia, and the Americas, with the status of Latin America disputed by some. There are many accepted definitions, all closely interrelated. The Western world is also known as the Occident, in contrast to the Orient, or Eastern world.

The Industrial Revolution, now also known as the First Industrial Revolution, was the transition to new manufacturing processes in Europe and the United States, in the period from about 1760 to sometime between 1820 and 1840. This transition included going from hand production methods to machines, new chemical manufacturing and iron production processes, the increasing use of steam power and water power, the development of machine tools and the rise of the mechanized factory system. The Industrial Revolution also led to an unprecedented rise in the rate of population growth.

Thomas McKeown (1912–1988) was a British physician, epidemiologist and historian of medicine. Largely based on demographic data from England and Wales, McKeown argued that the population growth since the late eighteenth century was due to improving economic conditions, i.e. better nutrition, rather than to better hygiene, public health measures and improved medicine. This became known as the "McKeown thesis".

1. McKeown stated that the growth in Western population, particularly surging in the 19th century, was not so much caused by an increase in fertility, but largely by a decline of mortality particularly of childhood mortality followed by infant mortality, [7] [8]
2. The decline of mortality could largely be attributed to rising standards of living, whereby McKeown put most emphasis on improved nutritional status,
3. His most controversial idea, at least his most disputed idea, was that he questioned the effectiveness of public health measures, including sanitary reforms, vaccination and quarantine, [9]
4. The sometime fierce disputes that his publication provoked around the "McKeown thesis", have overshadowed his more important and largely unchallenged argument that curative medicine measures played little role in mortality decline, not only prior to the mid-20th century [7] but also until well into the 20th century. [10]

Although the McKeown thesis has been heavily disputed, recent studies have confirmed the value of his ideas. [11] 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 (2015). The latter considered McKeown as "the founder of social medicine". [12]

Robert William Fogel was an American economic historian and scientist, and winner of the 1993 Nobel Memorial Prize in Economic Sciences. As of his death, he was the Charles R. Walgreen Distinguished Service Professor of American Institutions and director of the Center for Population Economics (CPE) at the University of Chicago Booth School of Business. He is best known as an advocate of new economic history (cliometrics) – the use of quantitative methods in history.

Sir Angus Stewart Deaton is a British-American economist and academic. Deaton is currently a Senior Scholar and the Dwight D. Eisenhower Professor of Economics and International Affairs Emeritus at the Woodrow Wilson School of Public and International Affairs and the Economics Department at Princeton University. His research focuses primarily on poverty, inequality, health, wellbeing, and economic development.

The field of social medicine seeks to implement social care through

1. understanding how social and economic conditions impact health, disease and the practice of medicine and
2. fostering conditions in which this understanding can lead to a healthier society.

## Population growth rate

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:

${\displaystyle Population\ growth\ rate={\frac {P(t_{2})-P(t_{1})}{P(t_{1})(t_{2}-t_{1})}}}$

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 rates, death rates, immigration rates, and age distribution between the two times. [13]

The birth rate is the total number of live births per 1,000 in a population in a year or period. The rate of births in a population is calculated in several ways: live births from a universal registration system for births, deaths, and marriages; population counts from a census, and estimation through specialized demographic techniques. The birth rate are used to calculate population growth.

A related measure is the net reproduction rate. 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) indicates that the population of females is decreasing.

The net reproduction rate (NRR) is the average number of daughters that would be born to a female if she passed through her lifetime conforming to the age-specific fertility and mortality rates of a given year. This rate is similar to the gross reproduction rate but takes into account that some females will die before completing their childbearing years. An NRR of one means that each generation of mothers is having exactly enough daughters to replace themselves in the population. If the NRR is less than one, the reproductive performance of the population is below replacement level.

Sub-replacement fertility is a total fertility rate (TFR) that leads to each new generation being less populous than the older is any rate below approximately 2.1 children born per woman, but the threshold can be as high as 3.4 in some developing countries because of higher mortality rates. Taken globally, the total fertility rate at replacement was 2.33 children per woman in 2003. This can be "translated" as 2 children per woman to replace the parents, plus a "third of a child" to make up for the higher probability of boys born and mortality prior to the end of their fertile life.

Most populations do not grow exponentially, rather they follow a logistic model. Once the population has reached its carrying capacity, 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 resources. [14]

### Logistic equation

The growth of a population can often be modelled by the logistic equation [15]

${\displaystyle {\frac {dP}{dt}}=rP\left(1-{\frac {P}{K}}\right),}$

where

• ${\displaystyle P(t)}$ = the population after time t;
• ${\displaystyle t}$ = time a population grows;
• ${\displaystyle r}$ = the relative growth rate coefficient;
• ${\displaystyle K}$ = the carrying capacity of the population; defined by ecologists as the maximum population size that a particular environment can sustain. [14]

As it is a separable differential equation, the population may be solved explicitly, producing a logistic function:

${\displaystyle P(t)={\frac {K}{1+Ae^{-rt}}}}$,

where ${\displaystyle A={\frac {K-P_{0}}{P_{0}}}}$ and ${\displaystyle P_{0}}$ is the initial population at time 0.

## Human population growth rate

In 2017, the estimated annual growth rate was 1.1%. [16] The CIA World Factbook gives the world annual birthrate, mortality rate, and growth rate as 1.86%, 0.78%, and 1.08% respectively. [17] 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 [18] made possible by the Green Revolution.

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. [16] Generally, developed nations have seen a decline in their growth rates in recent decades, though annual growth rates remain above 2% in poverty-stricken countries of the Middle East and Sub-Saharan Africa, and also in South Asia, Southeast Asia, and Latin America. [19]

In some countries the population is declining, especially in Eastern Europe, mainly due to low fertility rates, high death rates and emigration. In Southern Africa, growth is slowing due to the high number of AIDS-related deaths. Some Western Europe countries might also experience population decline. [20] Japan's population began decreasing in 2005. [21]

The United Nations Population Division projects world population to reach 11.2 billion by the end of the 21st century, but Sanjeev Sanyal has argued that global fertility will fall below the replacement rate in the 2020s and that world population will peak below 9 billion by 2050, followed by a long decline. [22] A 2014 study in Science concludes that the global population will reach 11 billion by 2100, with a 70% chance of continued growth into the 22nd century. [23]

## Growth by country

According to United Nations population statistics, the world population grew by 30%, or 1.6 billion humans, between 1990 and 2010. [24] In number of people the increase was highest in India (350 million) and China (196 million). Population growth was among highest in the United Arab Emirates (315%) and Qatar (271%). [24]

Growth rates of the world's most populous countries
RankCountryPopulation
1990
Population
2010
Estimated population

2018 [25]

Growth (%)
1990–2010
Growth (%) 2010–2018
World 5,306,425,0006,895,889,0007,503,828,18030.0%
1  China 1,139,060,0001,341,335,0001,384,688,98617.1%3.23%
2  India 873,785,0001,224,614,0001,296,834,04240.2%5.90%
3  United States 253,339,000310,384,000329,256,46522.5%6.08%
4  Indonesia 184,346,000239,871,000262,787,40330.1%9.55%
5  Brazil 149,650,000194,946,000208,846,89230.3%7.13%
6  Pakistan 111,845,000173,593,000207,862,51855.3%19.74%
7  Nigeria 97,552,000158,423,000203,452,50562.4%28.42%
9  Russia 148,244,000142,958,000142,122,776-3.6%-0.58%
10  Japan 122,251,000128,057,000126,168,1564.7%-1.48%

Many of the world's countries, including many in Sub-Saharan Africa, the Middle East, South Asia and South East Asia, have seen a sharp rise in population since the end of the Cold War. 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 has ultimately grown from 6,279,921 in 1993 to 10,329,208 in 2009, [1] further straining its resources. Vietnam, Mexico, Nigeria, Egypt, Ethiopia, and the DRC are witnessing a similar growth in population.

The following table gives some example countries:

Example nation1967 population1990 population1994 population2002 population2008 populationLife expectancy in years (2008)Total population growth from 1960s to 2007- 2011
Eritrea*N/A*N/A*3,437,000 [26] 4,298,2695,673,520 [27] 61 [28] [28] 2,236,520
Ethiopia*23,457,000* [29] 50,974,000* [30] 54,939,000 [26] 67,673,031(2003)79,221,000 [31] 55 [28] 55,764,000
Sudan 14,355,000† [29] 25,204,000† [30] 27,361,000† [26] 38,114,160 (2003)†42,272,000† [27] 50† [28] 27,917,000
Chad 3,410,000 [29] 5,679,000 [30] 6,183,000 [26] 9,253,493(2003)10,329,208 (2009) [1] 47 [28] 6,919,205
Niger 3,546,000 [29] 7,732,000 [30] 8,846,000 [26] 10,790,352 (2001)15,306,252 (2009) [32] 44 [28] 11,760,252
Nigeria 61,450,000 [29] 88,500,000 [30] 108,467,000 [26] 129,934,911158,259,000 [27] 47 [28] 96,809,000
Mali 4,745,000 [29] 8,156,000 [30] 10,462,000 [26] 11,340,48014,517,176(2010) [33] 50 [28] 9,772,176
Mauritania 1,050,000 [29] 2,025,000 [30] 2,211,000 [26] 2,667,859 (2003)3,291,000 (2009) [1] 54 [28] 2,241,000
Senegal 3,607,000 [29] 7,327,000 [30] 8,102,000 [26] 9,967,21513,711,597 (2009) [34] 57 [28] 10,104,597
Gambia 343,000 [29] 861,000 [30] 1,081,000 [26] 1,367,124 (2000)1,705,000 [27] 55 [28] 1,362,000
Algeria 11,833,126 (1966) [29] 25,012,000 [30] 27,325,000 [26] 32,818,500 (2003)34,895,000 [31] [35] 74 [28] 23,061,874
The DRC/Zaire 16,353,000 [29] 35,562,000 [30] 42,552,000 [26] 55,225,478 (2003)70,916,439 [31] [36] 54 [28] 54,563,439
Egypt 30,083,419 (1966) [29] 53,153,000 [30] 58,326,000 [26] 70,712,345 (2003)79,089,650 [31] [37] [37] 72 [28] 49,006,231
Réunion (overseas region of France)418,000 [29] N/A [30] N/A [26] 720,934 (2003)827,000 (2009) [27] N/A [28] 409,000
The Falkland Islands (British Overseas Territory)2,500 [29] N/A [30] N/A [26] 2,967 (2003)3,140(2010) [38] N/A [28] 640
Chile 8,935,500 [29] 13,173,000 [30] 13,994,000 [26] 15,116,43517,224,200 (2011)77 [28] 8,288,700
Colombia 19,191,000 [29] 32,987,000 [30] 34,520,000 [26] 41,088,22745,925,397 (2010) [39] 73 [28] 26,734,397
Brazil 85,655,000 [29] 150,368,000 [30] 153,725,000 [26] 174,468,575 (2000)190,732,694 (2010) [40] 72 [28] 105,077,694
Mexico45,671,000 [29] 86,154,000 [30] 93,008,000 [26] 103,400,165 (2000)112,322,757 (2010) [41] 76 [28] 66,651,757
Fiji 476,727 (1966) [29] 765,000 [30] 771,000 [26] 844,330 (2001)849,000 [35] (2010)70 [28] 372,273
Nauru 6,050 (1966) [29] 10,000 [30] N/A [26] 12,3299,322 (2011) [42] N/A [28] 3,272
Jamaica 1,876,000 [29] 2,420,000 [30] 2,429,000 [26] 2,695,867 (2003)2,847,232 [43] (2010)74 [28] 971,232
Australia 11,540,764 (1964) [29] 17,086,000 [30] 17,843,000 [26] 19,546,792 (2003)25,236,683 [44] (2010)82 [28] 10,066,508
Albania 1,965,500 (1964) [29] 3,250,000 [30] 3,414,000 [26] 3,510,4842,986,952 (July 2010 est.) [1] [45] 78 [28] 1,021,452
Poland 31,944,000 [29] 38,180,000 [30] 38,554,000 [26] 38,626,349 (2001)38,192,000 (2010) [46] 75 [28] 6,248,000
Hungary10,212,000 [29] 10,553,000 [30] 10,261,000 [26] 10,106,0179,979,000 (2010) [47] 73 [28] -142,000
Bulgaria 8,226,564 (1965) [29] 8,980,000 [30] 8,443,000 [26] 7,707,495(2000)7,351,234 (2011) [48] 73 [28] -875,330
United Kingdom 55,068,000 (1966) [29] 57,411,000 [30] 58,091,000 [26] 58,789,19462,008,048 (2010) [49] 79 [28] 7,020,048
Ireland 2,884,002 (1966) [29] 3,503,000 [30] 3,571,000 [26] 3,840,838 (2000)4,470,700 [50] (2010)78 [28] 1,586,698
People's Republic of China 720,000,000 [29] 1,139,060,000 [30] 1,208,841,000 [26] 1,286,975,468 (2004)1,339,724,852 (2010) [51] 73 [28] 619,724,852
Japan‡98,274,961 (1965) [29] 123,537,000 [30] 124,961,000 [26] 127,333,002127,420,000 (2010) [52] 82 [28] 28,123,865
Ryukyu Islands (Once occupied by the United States)‡934,176 (1965) [29] N/AN/AN/AN/AN/AN/A
India#511,115,000 [29] 843,931,000 [30] 918,570,000 [26] 1,028,610,328 (2001)1,210,193,422 (2011) [53] 69 [28] 699,078,422
Singapore 1,956,000 (1967) [29] 3,003,000 (1990) [30] 2,930,000 (1994) [26] 4,452,732 (2002)5,076,700 (2010) [54] 82 (2008) [28] 3,120,700
Sikkim#183,000 (1967) [29] N/AN/AN/AN/AN/AN/A
Monaco 24,000 (1967) [29] 29,000 (1990) [30] N/A (1994) [26] 31,842 (2000)35,586 [55] (2010)(2008) [28] 11,586
Greece 8,716,000 (1967) [29] 10,123,000 (1990) [30] 10,426,000 (1994) [26] 10,964,020 (2001) [56] 11,305,118 (2011) [57] N/A (2008) [28] 2,589,118
Faroe Islands (Danish dependency)38,000 (1967) [29] N/A (1990) [30] N/A (1994) [26] 46,345 (2000)48,917 (2010) [58] N/A (2008) [28] 18,917
Liechtenstein 20,000 (1967) [29] 29,000 (1990) [30] N/A (1994) [26] 33,307 (2000)35,789 (2009) [59] (2008) [28] 15,789
South Korea 29,207,856 (1966) [29] 42,793,000 (1990) [30] 44,453,000 (1994) [26] 48,324,000 (2003)48,875,000 (2010) [60] (2008) [28] 19,667,144
North Korea 12,700,000 (1967) [29] 21,773,000 (1990) [30] 23,483,000 (1994) [26] 22,224,195 (2002)24,051,218 (2010) [61] (2008) [28] 11,351,218
Brunei 107,200 (1967) [29] 266,000 (1990) [30] 280,000 (1994) [26] 332,844 (2001)401,890 (2011) [62] 76 (2008) [28] 306,609
Malaysia 10,671,000 (1967) [29] 17,861,000 (1990) [30] 19,489,000 (1994) [26] 21,793,293 (2002)27,565,821 (2010) [63] (2008) [28] 16,894,821
Thailand 32,680,000 (1967) [29] 57,196,000 (1990) [30] 59,396,000 (1994) [26] 60,606,947 (2000) [64] 63,878,267 (2011) [65] (2008) [28] 31,198,267
Lebanon 2,520,000 (1967) [29] 2,701,000 (1990) [30] 2,915,000 (1994) [26] 3,727,703 [66] (2003)4,224,000 [27] (2009)- (2008) [28]
Syria 5,600,000 (1967) [29] 12,116,000 (1990) [30] 13,844,000 (1994) [26] 17,585,540 (2003)22,457,763 (2011) [67] -(2008) [28]
Bahrain 182,00 (1967) [29] 503,000 (1990) [30] 549,000 (1994) [26] 667,238 (2003)1,234,596 [68] (2010)75 (2008) [28]
Sri Lanka 11,741,000 (1967) [29] 16,993,000 (1990) [30] 17,685,000 (1994) [26] 19,607,519 (2002)20,238,000 [35] (2009)- (2008) [28]
Switzerland 6,050,000 (1967) [29] 6.712,000 (1990) [30] 6,994,000 (1994) [26] 7,261,200 (2002)7,866,500 [69] (2010)- (2008) [28]
Luxembourg 335,000 (1967) [29] 381,000 (1990) [30] 401,000 (1994) [26] 439,539 (2001)511,840 (2011) [70] - (2008) [28]
Romania 19,105,056 (1966) [29] 23,200,000 (1990) [30] 22,736,000 (1994) [26] 21,680,974 (2002)21,466,174 [71] (2011)- (2008) [28]
Niue (associated state of New Zealand)1,900 (1966) [29] N/A (1990) [30] N/A (1994) [26] 2,134 (2002)1,398 (2009) [72] N/A (2008) [28] -502
Tokelau (New Zealand territory)5,194 (1966) [29] N/A (1990) [30] N/A (1994) [26] 1,445 (2001)1,416 (2009)N/A (2008) [28] -3,778
Jamaica 1,876,000 (1967) [29] 2,420,000 (1990) [30] 2,429,000 (1994) [26] 2,695,867 (2003)2,847,232 [43] (2010)74 (2008) [28] 971,232
Argentina 32,031,000 (1967) [29] 32,322,000 (1990) [30] 34,180,000 (1994) [26] 37,812,817 (2002)40,091,359 (2010)74 (2008) [28] 8,060,359
France49,890,660 (1967) [29] 56,440,000 (1990) [30] 57,747,000 (1994) [26] 59,551,000 (2001)63,136,180 (2011) [73] 81 (2008) [28]
Italy52,334,000 (1967) [29] 57,662,000 (1990) [30] 57,193,000 (1994) [26] 56,995,744 (2002)60,605,053 [74] (2011)80 (2008) [28]
Mauritius 774,000 (1967) [29] 1,075,000 (1990) [30] 1,104,000 (1994) [26] 1,179,137 (2000)1,288,000 (2009) [35] 75 (2008) [28] 514,000
Guatemala 4,717,000 (1967) [29] 9,197,000 (1990) [30] 10,322,000 (1994) [26] 12,974,361 (2000)13,276,517 (2009)70 (2008) [28] 8,559,517
Cuba 8,033,000 (1967) [29] 10,609,000 (1990) [30] 10,960,000 (1994) [26] 11,177,743 (2002)11,239,363 (2009) [75] 77 (2008) [28]
Barbados 246,000 (1967) [29] 255,000 (1990) [30] 261,000 (1994) [26] 250,012 (2001)284,589 (2010) [1] 73 (2008) [28] 18,589
Samoa 131,377 (1967) [29] 164,000 (1990) [30] 164,000 (1994) [26] 178,173 (2003)179,000 (2009) [27] N/A (2008) [28]
Sweden 7,765,981 (1967) [29] 8,559,000 (1990) [30] 8,794,000 (1994) [26] 8,920,705 (2002)9,354,462 (2009)81 (2008) [28]
Finland 4,664,000 (1967) [29] 4,986,000 (1990) [30] 5,095,000 (1994) [26] 5,175,783 (2002)5,374,781 (2010)N/A (2008) [28]
Portugal 9,440,000 (1967) [29] 10,525,000 (1990) [30] 9,830,000 (1994) [26] 10,355,824 (2001)10,647,763 [76] (2011)N/A (2008) [28]
Austria 7,323,981 (1967) [29] 7,712,000 (1990) [30] 8,031,000 (1994) [26] 8,032,926 (2001)8,404,252 (2011)N/A (2008) [28]
Libya 1,738,000 (1967) [29] 4,545,000 (1990) [30] 5,225,000(1994) [26] 5,499,074 (2002)6,420,000 (2009) [27] 77 (2008) [28]
Peru 12,385,000 (1967) [29] 21,550,000 (1990) [30] 23,080,000(1994) [26] 27,949,639 (2002)29,496,000 (2010)70 (2008) [28]
Guinea Bissau 528,000 (1967) [29] 965,000 (1990) [30] 1,050,000 (1994) [26] 1,345,479 (2002)1,647,000 [27] (2009)48 (2008) [28]
Angola 5,203,066 (1967) [29] 10,020,000 (1990) [30] 10,674,000 (1994) [26] 10,766,500 (2003)18,498,000 [35] [77] (2009)38 (2008) [28]
Equatorial Guinea 277,000 (1967) [29] 348,000 (1990) [30] 389,000 (1994) [26] 474,214 (2000)676,000 (2009) [35] 61 (2008) [28]
Benin 2,505,000 (1967) [29] 4,736,000 (1990) [30] 5,246,000 (1994) [26] 8,500,500 (2002)8,791,832 (2009)59 (2008) [28]
Laos 2,770,000 (1967) [29] 4,139,000 (1990) [30] 4,742,000 (1994) [26] 5,635,967 (2002)6,800,000 [78] (2011)56 (2008) [28]
Nepal 10,500,000 (1967) [29] 18,961,000 (1990) [30] 21,360,000 (1994) [26] 25,284,463 (2002)29,331,000 [35] (2009)- (2008) [28]
Iran 25,781,090 (1966) [29] 54,608,000 (1990) [30] 59,778,000 (1994) [26] 66,622,704 (2002)75,330,000 (2010) [79] 71 (2008) [28]
Canada 20,014,880 (1966) [29] 26,603,000 (1990) [30] 29,248,000(1994) [26] 31,081,900 (2001)32,623,490 (2011) [80] 81 (2008) [28]
United States 199,118,000 (1967) [29] 249,995,000 (1990) [30] 260,650,00(1994) [26] 281,421,906 (2000)308,745,538 (2010) [81] 78 (2008) [28]
Uganda 7,931,000 (1967) [29] 18,795,000 (1990) [30] 20,621,000 (1994) [26] 24,227,297 (2002)32,369,558 (2009)52 (2008) [28]
Notes
* Eritrea left Ethiopia in 1991.
Split into the nations of Sudan and South Sudan during 2011.
Japan and the Ryukyu Islands merged in 1972.
# India and Sikkim merged in 1975.
Population growth 1990–2012 (%) [82]
Africa 73.3%
Middle East 68.2%
Asia (excl. China)42.8%
China19.0%
OECD Americas 27.9%
Non-OECD Americas36.6%
OECD Europe 11.5%
OECD Asia Oceania 11.1%
Non-OECD Europe and Eurasia -0.8%

## Growth by region

Population growth rates vary by world region, with the highest growth rates in Sub-Saharan Africa and the lowest in Europe. For example, from 1950 to 2010, Sub-Saharan Africa grew over three and a half times, from about 186 million to 856 million. On the other hand, Europe only increased by 35%, from 547 million in 1950 to 738 million in 2010. As a result of these varying population growths, Sub-Saharan Africa changed from 7.4% of world population in 1950 to 12.4% in 2010, while Europe declined from 22% to 11% in the same time period. [83]

## Into the future

According to the UN's 2017 revision to its population projections, world population is projected to reach 11.2 billion by 2100 compared to 7.6 billion in 2017. [84] [85] In 2011, Indian economist Sanjeev Sanyal disputed the UN's figures and argued that birth rates will fall below replacement rates in the 2020s. According to his projections, population growth will be only sustained till the 2040s by rising longevity, but will peak below 9 bn by 2050. [22] Conversely, a 2014 paper by demographers from several universities and the United Nations Population Division projected that the world's population would reach about 10.9 billion in 2100 and continue growing thereafter. [86] One of its authors, Adrian Raftery, a University of Washington professor of statistics and of sociology, says "The consensus over the past 20 years or so was that world population, which is currently around 7 billion, would go up to 9 billion and level off or probably decline. We found there’s a 70 percent probability the world population will not stabilize this century. Population, which had sort of fallen off the world’s agenda, remains a very important issue." [87]

## Related Research Articles

India is the second most populated country in the world with nearly a fifth of the world's population. According to the 2017 revision of the World Population Prospects, the population stood at 1,324,171,354.

The following is an overview of the demographics of Myanmar, including statistics such as population, ethnicity, language, education level and religious affiliation.

In the 2011 census, Nepal's population was approximately 26 million people with a population growth rate of 1.35% and a median age of 21.6 years. In 2016, the female median age was approximately 25 years old and the male median age was approximately 22 years old. Only 4.4% of the population is estimated to be more than 65 years old, comprising 681,252 females and 597,628 males. 61% of the population is between 15 and 64 years old, and 34.6% is younger than 14 years. In 2011, the Birth rate is estimated to be 22.17 births per 1,000 people with an infant mortality rate of 46 deaths per 1,000 live births. Compared to the infant mortality rate in 2006 of 48 deaths per 1000 live births, the 2011 IMR is a slight decrease within that 5-year period. Infant mortality rate in Nepal is higher in rural regions at 44 deaths per 1000 live births, whereas in urban regions the IMR is lower at 40 deaths per 1000 live births. This difference is due to a lack of delivery assistance services in rural communities compared to their urban counterparts who have better access to hospitals and neonatal clinics. Life expectancy at birth is estimated to be 67.44 years for females and 64.94 years for males. The mortality rate is estimated to be 681 deaths per 100,000 people. Net migration rate is estimated to be 61 migrants per 100,000 people. According to the 2011 census, 65.9% of the total population is literate.

The economy of Sierra Leone is that of a least developed country with a GDP of approximately 1.9 billion USD in 2009. Since the end of the civil war in 2002 the economy is gradually recovering with a GDP growth rate between 4 and 7%. In 2008 its GDP in PPP ranked between 147th and 153rd (CIA) largest in the world.

Bangladesh is largely ethnically homogeneous, and its name derives from the Bengali ethno-linguistic group which comprises 98% of the population. The Chittagong Hill Tracts, Sylhet, Mymensingh and North Bengal divisions are home to diverse indigenous peoples. There are many dialects of Bengali spoken throughout the region. The dialect spoken by those in Chittagong and Sylhet are particularly distinctive. The population is estimated at 163 million (2016). About 86% of Bangladeshis are Muslims, followed by Hindus (12%), Buddhists (1%) and Christians (0.5%) and others (0.5%).

Mortality rate, or death rate, is a measure of the number of deaths in a particular population, scaled to the size of that population, per unit of time. Mortality rate is typically expressed in units of deaths per 1,000 individuals per year; thus, a mortality rate of 9.5 in a population of 1,000 would mean 9.5 deaths per year in that entire population, or 0.95% out of the total. It is distinct from "morbidity", which is either the prevalence or incidence of a disease, and also from the incidence rate.

The population of Africa has grown rapidly over the past century and consequently shows a large youth bulge, further reinforced by a low life expectancy of below 50 years in some African countries. Total population as of 2017 is estimated at more than 1.25 billion, with a growth rate of more than 2.5% p.a. The most populous African country is Nigeria with 191 million inhabitants as of 2017 and a growth rate of 2.6% p.a.

Demographics of the world include population density, ethnicity, education level, health measures, economic status, religious affiliations and other aspects of the human population of the planet Earth.

Projections of population growth established in 2017 predict that the human population is likely to keep growing until 2100, reaching an estimated 8.6 billion in 2030, 9.8 billion in 2050 and 11.2 billion by 2100, while the 7 billion milestone was reached in 2011. As the demographic transition follows its course worldwide, the population will age significantly, with most countries outside Africa trending towards a rectangular age pyramid.

The African country of Zambia faces a number of ongoing health challenges.

Adherents of Islam constitute the world's second largest religious group. According to a study in 2015, Islam has 1.8 billion adherents, making up about 24.1% of the world population. Most Muslims are either of two denominations: Sunni or Shia. Islam is the dominant religion in Central Asia, Indonesia, Middle East, North Africa, the Sahel and some other parts of Asia. The diverse Asia-Pacific region contains the highest number of Muslims in the world, easily surpassing the Middle East and North Africa.

## References

1. Barbados: People. World Factbook of CIA
2. "World Population Prospects 2017" . Retrieved 2017-11-21.
3. [worldometers.info/world-population/title=World Population 2017 worldometers.info/world-population/title=World Population 2017] Check |url= value (help). Retrieved 2018-04-18.Missing or empty |title= (help)
4. "World Population Prospects: The 2017 Revision: Key Findings and Advance Tables" (PDF). United Nations Department of Economic and Social Affairs, Population Division. p. 2. Retrieved 2019-01-05.
5. McKeown, Thomas (1976). The Modern Rise of Population. London, UK: Edward Arnold. ISBN   9780713159868.
6. McKeown T, Brown RG (1955). "Medical evidence related to English population changes in the eighteenth century". Population Studies. 9 (2): 119–141. doi:10.1080/00324728.1955.10404688. JSTOR   2172162.
7. McKeown T, Brown RG, Record RG (1972). "An interpretation of the modern rise of population in Europe". Population Studies. 26 (3): 345–382. doi:10.1080/00324728.1972.10405908. JSTOR   2173815.
8. McKeown T, Record RG (1962). "Reasons for the Decline of Mortality in England and Wales during the Nineteenth Century". Population Studies. 16 (2): 94–122. doi:10.2307/2173119. JSTOR   2173119.
9. McKeown T, Record RG, Turner RD (1975). "An Interpretation of the Decline of Mortality in England and Wales during the Twentieth Century". Population Studies. 29 (3): 391–422. doi:10.1080/00324728.1975.10412707. JSTOR   2173935. PMID   11630508.
10. Korotayev, A. V.; Malkov, A. S. (2016). "Compact Mathematical Model of the World System Economic and Demographic Growth, 1 CE–1973 CE". International Journal of Mathematical Models and Methods in Applied Sciences. 10: 200–209.
11. Deaton, Angus (2013). The Great Escape. Health, wealth, and the origins of inequality. Princeton and Oxford: Princeton University Press. pp. 91–93. ISBN   978 0 691 15354 4. McKeown's views, updated to modern circumstances, are still important today in debates between those who think that health is primarily determined by medical discoveries and medical treatment and those who look to the background social conditions of life.
12. Reece, Jane; Urry, Lisa; Cain, Michael; Wasserman, Steven; Minorsky, Peter; Jackson, Robert (2014). Campbell Biology. Pearson.
13. Stewart, James; Clegg, Daniel (2012). Brief Applied Calculus. Brooks/Cole Cengage Learning.
14. "World Population Prospects 2017". Archived from the original on 2017-07-11.
15. "The World Factbook". 20 November 2015. Retrieved 4 January 2016.
16. "International Programs". Archived from the original on 2009-07-01.
17. UN population projections Archived 2010-10-28 at WebCite
18. "Japan sees biggest population fall". the Guardian. Associated Press. 2009-01-02.
19. Sanjeev Sanyal (2011-10-30). "Sanjeev Sanyal on The End of Population Growth - Project Syndicate". Project Syndicate.
20. Carrington, Damien (September 18, 2014). "World population to hit 11bn in 2100 – with 70% chance of continuous rise". The Guardian. Retrieved December 19, 2016.
21. "East Asia/Southeast Asia :: China — The World Factbook - Central Intelligence Agency". www.cia.gov. Retrieved 2019-05-15.
22. The British Collins Longman Student Atlas, the 1996 and in 1998 publications, ISBN   978-0-00-448879-0 for the 1998 edition, ISBN   0-00-448365-0 for the 1996 edition
23. Department of Economic and Social Affairs Population Division (2009). "World Population Prospects, Table A.1" (PDF). 2008 revision. United Nations. Retrieved 2009-03-12. NB: The preliminary results of the National population census in Guinea-Bissau put the figure at 1,449,230, according to email information by the Instituto Nacional de Estudos e Pesquisa, Bissau.
24. 'Modern School Atlas (96th edition)', ISBN   978-1-84907-013-3.
25. The British Oxford economic atlas of the World 4th edition, ISBN   0-19-894107-2
26. The British Collins Atlas of the World, the 1993 edition, ISBN   0-00-448038-4
27. Central Intelligence Agency (2009). "Niger". The World Factbook . Retrieved January 10, 2010.
28. "Mali preliminary 2009 census". Institut National de la Statistique. Archived from the original on April 18, 2010. Retrieved January 12, 2010.
29. Central Intelligence Agency (2009). "Senegal". The World Factbook . Retrieved January 10, 2010.
30. Department of Economic and Social Affairs Population Division (2010). "World Population Prospects, Table A.1" (PDF). 2008 revision. United Nations. Retrieved 2009-03-12.
31. The World Factbook- Congo, Democratic Republic of the. Central Intelligence Agency.
32. "Central Agency for Population Mobilisation and Statistics — Population Clock (July 2008)". Msrintranet.capmas.gov.eg. Archived from the original on 2010-09-08. Retrieved 2010-08-25.
33. "Falkland Islands (Islas Malvinas)". The World Factbook. CIA. Retrieved 5 March 2010.
34. "Departamento Administrativo Nacional de Estadística". Dane.gov.co. Archived from the original on 2015-09-05. Retrieved 2010-08-22.
35. "INEGI 2010 Census Statistics". inegi.org.mx. Retrieved 2010-11-25.
36. Central Intelligence Agency (2011). "Nauru". The World Factbook . Retrieved 12 February 2011.
37. "Population clock". Australian Bureau of Statistics website. Commonwealth of Australia. Retrieved 12 April 2011. The population estimate shown is automatically calculated daily at 00:00 UTC and is based on data obtained from the population clock on the date shown in the citation.
38. "Wzrasta liczba ludności Polski - Wiadomości - WP.PL". Wiadomosci.wp.pl. 2010-07-23. Archived from the original on 2013-10-05. Retrieved 2010-07-27.
39. Hungarian Central Statistical Office. Retrieved 25 July 2010.
40. "Total population at 1 January". Eurostat. 11 March 2011. Retrieved 29 April 2011.
41. "CSO – Population and Migration Estimates April 2010" (PDF). September 2010. Retrieved 21 September 2010.
42. "Provisional Population Totals - Census 2011". Indian Census Bureau 2011. Retrieved 2011-03-29.
43. "Time Series on Population (Mid-Year Estimates)". 31 Aug 2010. Statistics Singapore. 2010. Archived from the original on 2009-02-21.
44. Monaco, The World Factbook, Central Intelligence Agency. Retrieved 7 June 2010.
45. "Πίνακας 1. Πληθυσμός κατά φύλο και ηλικία" (PDF). National Statistical Service of Greece: Population census of 18 March 2001. Archived from the original (PDF) on March 25, 2009.
46. "Total population". Eurostat. 1 January 2010. Retrieved 8 January 2010.
47. "Archived copy". Archived from the original on 2013-12-10. Retrieved 2015-12-10.CS1 maint: Archived copy as title (link) (Faroese)
48. Bevölkerungsstatistik 30. Juni 2009 Archived 2013-11-14 at the Wayback Machine , Landesverwaltung Liechtenstein.
49. "총인구, 인구성장률 : 지표상세화면". Index.go.kr. Retrieved 2010-10-29.
50. UNFPA (2009-10-01). 한반도 인구 7천400만명 시대 임박 (in Korean). United Nations. Archived from the original on 2010-04-17. Retrieved 2010-04-14.
51. "Brunei". CIA World Factbook. 2011. Retrieved 2011-01-13.
52. "Laporan Kiraan Permulaan 2010". Jabatan Perangkaan Malaysia. p. iii. Archived from the original on July 8, 2011. Retrieved 31 January 2011.
53. "Population and Housing Census 2000, National Statistical Office". Web.nso.go.th. 2000-04-01. Retrieved 2010-04-25.
54. "Archived copy" (PDF). Archived from the original (PDF) on 2011-07-16. Retrieved 2011-07-16.CS1 maint: Archived copy as title (link)
55. "Central Intelligence Agency. March 2011 est". Cia.gov. Retrieved 2011-04-23.
56. "Central Intelligence Agency. March 2011 est". Cia.gov. Retrieved 2011-04-23.
57. "REMARKABLE GROWTH EXPATS OUTNUMBER BAHRAINIS IN 2010 CENSUS". Bahraini Census 2010. 2010-11-28. Archived from the original on February 19, 2011. Retrieved 14 February 2011.
58. "Population size and population composition". Swiss Federal Statistical Office. Swiss Federal Statistical Office, Neuchâtel. 2010. Archived from the original on 2016-06-28. Retrieved 2011-04-29.
59. "Population: 511 840 habitants au 1er janvier 2011", Le Portail des statistiques: Grand-Duché de Luxembourg, 3 May 2011. (in French) Retrieved 4 May 2011.
60. "Romania - Population". epp.eurostat.ec.europa.eu. Retrieved 26 May 2011.
61. "Niue". The World Factbook. Central Intelligence Agency . Retrieved 2009-07-20.
62. INSEE, Government of France. "Population totale par sexe et âge au 1er janvier 2011, France métropolitaine" (in French). Retrieved 20 January 2011.
63. "Monthly demographic balance: January–November 2010" (PDF) (in Italian). Istat. 28 March 2011. Retrieved 2 April 2011.
64. Anuario Estadístico de Cuba 2009. Edición 2010 Archived 2010-07-16 at the Wayback Machine , Oficina Nacional de Estadísticas, República de Cuba. Accessed on November 6, 2010. Note: An exchange rate of 1 CUC to 1.08 USD was used to convert GDP.
65. Pordata, "Base de Dados Portugal Contemporâneo". Accessed on March 7, 2011.
66. "Population Forecast to 2060 by International Futures hosted by Google Public Data Explorer" . Retrieved 2011-07-13.
67. "Background notes - Laos". US Dept. of State. Retrieved 2011-01-20.
68. "Official Iranian Population clock". Amar.org.ir. Archived from the original on 2011-07-22. Retrieved 2011-07-13.
69. "Estimated population of Canada, 1605 to present". Statistics Canada. 6 July 2009. Retrieved 2011-04-17.
70. "Resident Population Data – 2010". U.S. Census Bureau. 2010. Archived from the original on 2011-10-28. Retrieved 2010-12-22.
71. CO2 Emissions from Fuel Combustion Population 1971–2014 IEA (PDF Page 74, marked page 72)
72. Shackman, Gene; Xun, Wang; Liu, Ya-Lin (2012-06-10). "Brief Review of World Demographic Trends Summary". Elsevier. SSRN  .
73. Gerland, P.; Raftery, A. E.; Ev Ikova, H.; Li, N.; Gu, D.; Spoorenberg, T.; Alkema, L.; Fosdick, B. K.; Chunn, J.; Lalic, N.; Bay, G.; Buettner, T.; Heilig, G. K.; Wilmoth, J. (September 14, 2014). "World population stabilization unlikely this century". Science. 346 (6206): 234–7. Bibcode:2014Sci...346..234G. doi:10.1126/science.1257469. ISSN   1095-9203. PMC  . PMID   25301627 . Retrieved September 21, 2014.
74. World population to keep growing this century, hit 11 billion by 2100. UWToday. September 18, 2014