World population

We explain the concept of world population, and describe its main characteristics. In addition, we discuss world population distribution, population growth, and main problems.

The world population

The world population is the number of people living on the planet at a given time. This figure results from the difference between the number of births and deaths: if the number of births exceeds that of deaths, the population grows; conversely, if deaths outnumber births, the population declines.

Throughout history, the world population has experienced periods of growth and decline; yet the general trend shows that the number of people living on the planet increases with time.

The past 200 years have seen profound changes in the world population: rapid acceleration in population growth, a rise in the median age (population aging), and a significant increase in urban population.

• See also: Environment

Characteristics of the world population

• The current world population stands at 8 billion.
• Major population indicators include birth rate, death rate, life expectancy, and rate of urbanization.
• Population distribution in the world is uneven.
• Population has experienced sustained growth for centuries, accelerating particularly during the last century.
• Over the past 200 years, the world population has grown and aged (meaning the median age has risen). The urban population has increased, with migration flows between countries intensifying due to globalization.

Population growth in the past 200 years

In the year 0, the world population was about 200 million people, taking 1,000 years to double to 400 million. By 1800, the population on the planet was over 1 billion.

Since then, the global population growth rate has accelerated. By 1900, the population had reached 1.5 billion, and in the year 2000, it surpassed 6 billion. By November 2022, the global population was over 8 billion inhabitants.

While the world population is on the rise, the growth rate has slowed down, with experts suggesting that in the 21st century the number of people on the planet will continue to grow at a steadily slower rate. It is projected that by 2040 the population will reach 9 billion, and only by the end of the century will it peak at 10 billion people.

Year	Population
0	200 million
1000	400 million
1500	500 million
1800	1 billion
1930	2 billion
1960	3 billion
1975	4 billion
1990	5 billion
2000	6 billion
2011	7 billion
2023	8 billion

Major demographic indicators

The main demographic indicators used to analyze and study the growth, distribution, and quality of life of the world population include:

• Birth rate. It measures the number of births in a year per 1,000 inhabitants. Niger and Somalia have the highest birth rates in the world, at 45 ‰ and 42 ‰ respectively. 
• Mortality rate. It measures the number of deaths in a year per 1,000 inhabitants. Bulgaria and Ukraine have the highest mortality rates in the world, at 18 and 17 respectively. 
• Infant mortality rate. It measures the number of infants dying before the age of one per 1,000 live births. Afghanistan, at 104, has the highest infant mortality rate on the planet, meaning that for every 1,000 children born, 104 die before reaching their first year of age.
• Life expectancy. It is the average number of years that a person is expected to live. Japan at 86.2 years and Switzerland at 84.5 have the highest life expectancy on the planet.
• Fertility rate. It measures the number of children born to a woman on average. Niger and Angola have the world’s highest fertility rates, at 6.91 and 5.9 children per woman respectively.
• Rate of natural increase. It is the difference between the number of births and deaths in a year.
• Migration rate. It is the difference between the number of people who come to live in a given area (immigrants) and the number of people who leave the same area (emigrants).
• Population growth rate. It is the combined rates of natural increase and migration.
• Population density. It is the number of people living in a given area measured in inhabitants per square kilometer. The most densely populated areas in the world may reach 15,000 inhabitants per square kilometer, while the world's great deserts have a population density of less than 0.1 inhabitants per square kilometer.
• Rate of urbanization. It is the percentage of the population living in urban areas.

World population aging

In recent decades, the world has seen a rising growth in population aging. A demographic indicator used for measuring population aging is the percentage of the world population over 65 years of age, which has risen from 6% in 1960 to 10% today.

Another indicator used for measuring world population aging is life expectancy, which has steadily risen in recent decades from 51 years in 1960 to 71 years today.

Life expectancy reached its maximum level at 73 years in 2019, before dropping due to the COVID-19 pandemic, which has affected the world population since 2020. Life expectancy has declined to 71 years in the past three years.

The steady rise in world population aging poses a series of challenges and problems at the economic, social, health, and political levels.

• Pressure on health systems. As the population ages, the demand for health services increases. This may overburden hospitals, clinics, and health centers, affecting the availability of medical and professional resources to care for an ever-growing population.
• Rise in the number of retirees. The proportion of economically inactive people rises, posing funding problems for states across the globe, which must guarantee the payment of pensions to an increasing number of people.
• Skilled labor shortage. The decline in the working-age population may result in skilled labor shortage in certain industries, professions, and trades.

World population distribution

The world population is unevenly distributed over the Earth's surface. In some areas, the population density is extremely high, with major cities having over 10 million inhabitants. In other regions of the planet, in contrast, the concentration is extremely low, giving rise to the so-called "demographic voids" where the population density is less than 1 inhabitant per square kilometer.

The world population by continent is distributed as follows:

Continent	Total population	% of total
Asia	4,561,000,000 inhabitants	57%
Africa	1,320,000,000 inhabitants	16.5%
America	1,000,000,000 inhabitants	12.5%
Europe	746,000,000 inhabitants	9.2%
Oceania	42,000,000 inhabitants	0.5%
Antarctica	4,000 inhabitants (temporary)	-

The areas with the highest population concentration on the planet are major cities. Among them are:

• Tokyo (Japan), with 37 million inhabitants.
• New Delhi (India), with 32 million.
• Shanghai (China), with 23 million.

Conversely, the largest demographic voids on the planet are found in great desert areas such as the Sahara or Tibet deserts, some areas of the Amazon rainforest, regions in the Arctic Ocean, and Antarctica.

Urbanization of the world population

Urbanization is a demographic phenomenon that has characterized the world population throughout the 20th century and continues to be a trend into the 21st century. During this period, there has been a significant rise in the proportion of the population living in urban areas worldwide.

In the early 20th century, the majority of the world population lived in rural areas. By 1950, the proportion of the urban population had increased, accounting for 30 % of the total. As the century progressed, the trend became more pronounced, with over half of the global population living in urban centers by the year 2000.

According to recent estimates, about 55% of the current world population is urban, and this figure is expected to rise in the coming decades.

Several factors contribute to the urbanization process. Some of them include:

• The process of industrialization. During the 19th century, the Industrial Revolution attracted people to cities in search of employment in factories and industry. Throughout the 20th century this trend continued and deepened.
• Improvements in agricultural technology. Advances in technology resulted in agricultural machinery replacing human labor, which led to the migration of unemployed populations from rural areas to cities.
• Increased supply and quality of services. The wider variety of health, education, transportation, and communications services in cities has attracted people to urban centers in recent decades.
• Employment opportunities. Job opportunities in commerce, service companies, and government agencies is an important draw for living in cities.

Globalization and international migration

Globalization has led to increasing international labor mobility, that is, a rise in workers’ migration between countries. People who migrate are generally of working age, moving from middle- or low-income countries to more developed countries.

Over the past few decades, Europe and the United States have become important destinations for major demographic flows from various parts of the world. However, this was not always the case throughout the 20th century.

Between 1914, the start of World War I, and 1945, the end of World War II, migration flows came from Europe to other countries, especially in the Americas.

In the United States, foreign immigrants account for nearly 15 % of the current population, while in Europe, the figure approaches 9%. In the United States, the main migratory flows come from countries in the Americas, particularly from Mexico and Central America. Western European countries, on the other hand, receive immigrants mainly from Africa.

Globalization in transportation and communications has favored the growing international migration of the world population. Better connections between countries, regional agreements and blocs allowing the free movement of goods and people, increased access to information, and improvements in the quality and speed of communications are some of the factors that have contributed to the rise in migratory flows in recent decades.

The world in 2100

Projections estimate that the world population will reach 8.5 billion by 2030, 9.7 billion by 2050, and 10.4 billion by 2100. These estimates are based on the progression of the fertility rate, which anticipates a decline in the number of children women have, particularly in countries where large families are still common. These projections take into account the increase in life expectancy and the progressive aging of the global population.

The poorest countries in Africa are expected to contribute the most to demographic growth. This continent has the highest population growth rate in the world; therefore it is estimated that a rapid population increase will occur. Some of the poorest countries in the Americas and Asia are also expected to contribute to population growth during this century.

Conversely, the population of most European countries is expected to decline during the 21st century. The fertility rate in European countries has been very low for several decades, and it is believed that this trend will intensify in the coming years.

In Asia, countries like China and Japan have also seen a sharp decline in population growth rates, and it is believed that this trend will continue over the next decades. In 1979, China adopted a birth control demographic policy known as the "one-child policy", which contributed to a sharp decline in its birth rate. Although the one-child policy has been relaxed in recent years, China's population growth rate remains very low. 

Japan, in turn, is one of the few countries to experience a significant population reduction in the past few years, with an estimated decline of about 600,000 inhabitants every year. 

Explore next:

• Continents
• Latin America
• South America

References

• Azun, L. y Zori del Almo, J. (2022). Las diez ciudades más pobladas del mundo en 2023. https://viajes.nationalgeographic.com.es/
• Kenk, J. (s.f) 29 de octubre de 2015. China pone fin a la política del hijo único. https://elordenmundial.com/
• Melo, M. (2022) ¿Cuántas personas habrá en el mundo en 2100? https://es.statista.com/
• Organización de Naciones Unidas (s.f) Población. Desafíos globales. https://www.un.org/