Human Geography: World Population Notes for UPSC

Human geography studies how people are distributed on the Earth, how they move, where they live and how they use the land. It connects physical geography with society and the economy, and it helps to understand the present problems of the world, such as the rapid growth of population in some countries, the ageing of others, large-scale migration and the growth of mega-cities. In the UPSC Prelims, questions come on the distribution of population, demographic terms, types of settlements and urban concepts. In the Mains, you may be asked about migration, urbanisation and population issues in the world and in India. This note explains these topics in simple language, with tables and a Mains structure.

World Population: Size and Distribution

The world population crossed 8 billion in November 2022, as estimated by the United Nations, and about three-fifths of the people live in Asia. India and China are the two most populous countries, with India now estimated to have overtaken China as the largest in 2023. Other large countries are the USA, Indonesia and Pakistan. The population is unevenly distributed: some areas are very crowded and some are almost empty.

Factors Affecting Distribution

• Physical: Relief (plains support more people than mountains), climate (moderate climates are preferred), soil (fertile alluvial soil) and the availability of fresh water.
• Economic: Minerals, industries, trade and urban jobs attract people.
• Social and cultural: Religious centres, political stability and government policy.

Population Terms You Should Know

Population Pyramids and Demographic Transition

A population pyramid shows the age and sex structure of a country. A pyramid with a wide base, as in Nigeria, shows high birth rates and a young population (expanding). A pyramid with a straight, narrow shape, as in many European countries, shows a stable population (constant). A pyramid with a narrow base, as in Japan, shows a falling birth rate and an ageing population (declining). The demographic transition theory explains how a country moves from high birth and death rates to low birth and death rates in stages: the first stage is stable with high rates; the second has falling death rates but high birth rates, so the population grows fast; the third has falling birth rates and slower growth; and the fourth has low rates and a stable or declining population. Most developing countries are in the second or third stage, while the developed countries are in the fourth stage. Some countries, like China, introduced a one-child policy (1980-2015) to control growth, but later faced an ageing population and a shortage of workers.

Theories of Population

• Malthusian theory (1798): Thomas Malthus said that the population increases in a geometric progression, while food grows in an arithmetic progression, so famine, disease and war will check the population. It was proven wrong in part because of technology and the green revolution.
• Boserup's view: Ester Boserup said that population pressure leads to the invention of better farming methods.

Migration

Migration is the movement of people from one place to another to live. Emigration is leaving a place, and immigration is entering a new place. The causes are divided into push factors (unemployment, poverty, war, natural disasters and persecution) and pull factors (jobs, higher wages, education, safety and better services). Migration can be internal (within a country) or international. People move as workers, students, families or refugees. The effects are remittances and skills for the home country, but also the brain drain (loss of skilled people). The destination gains labour and talent but may face pressure on housing, jobs and culture. India is one of the top receivers of remittances in the world, mainly from the Gulf countries and the developed economies.

A refugee is a person who flees from his or her country because of a fear of persecution. The United Nations High Commissioner for Refugees (UNHCR), set up in 1950 with its headquarters at Geneva, protects the refugees. The 1951 Refugee Convention sets the legal base, and India is not a party to it, though it has hosted large refugee populations over time.

Human Races and Cultures

The old classification divides humankind into three major races: Caucasoid (in Europe, West Asia and North Africa), Mongoloid (in East Asia and the Americas) and Negroid (in Sub-Saharan Africa). Modern science says that races are social and not biological categories, since all humans belong to one species, Homo sapiens. Languages, religions and customs decide the cultural regions of the world.

Settlements

A settlement is a place where people live permanently. Rural settlements depend mainly on agriculture and are of different patterns: compact or nucleated (houses close together, as in fertile plains), dispersed (scattered houses in the hilly or forest areas), linear (along a road, river or canal) and circular (around a lake or a central place). Urban settlements depend on secondary and tertiary activities. A hamlet is the smallest, followed by the village, town and city. The towns are classified by function as administrative, commercial, industrial, mining, port, cultural or religious towns.

Urban Concepts

• Conurbation: The merging of several cities into a continuous urban area, a term given by Patrick Geddes in 1915 (for example, Greater London and Greater Mumbai).
• Megalopolis: A chain of connected cities, as in the north-eastern USA from Boston to Washington (called Boswash), a term made popular by Jean Gottmann.
• Megacity: A city with a population of more than 10 million, such as Tokyo, Delhi, Shanghai, Sao Paulo and Mexico City.
• Primate city: A city that is much larger than the next city in the country, such as Paris in France.
• Central place theory: Walter Christaller's theory that towns provide services to the surrounding areas, and so are arranged in a hierarchy.

More than half of the world's people now live in cities, and the fastest urban growth is in Asia and Africa. The problems of rapid urban growth include slums, traffic, air and water pollution, poor sanitation and the urban heat island effect. Solutions include planned housing, good public transport, waste management and the development of small and medium towns to reduce the pressure on the big cities.

Mains Angle: Ageing Population vs Young Population

You can compare the countries. Japan, Italy and Germany face ageing and a shrinking workforce, rising health and pension costs and a need for immigrants or automation. Many African countries and India have a young population, which can give a demographic dividend if there are jobs, skills and good health and education, but can become a burden if these are missing. Conclude that population policy must match the stage of the country: encouraging births and active ageing in the first group, and investment in human capital in the second.

Human Development and Population Quality

The quality of the population matters as much as its number. The Human Development Index of the UNDP measures three things: a long and healthy life (life expectancy), knowledge (years of schooling) and a decent standard of living (income per person). Countries like Norway, Switzerland and Iceland rank at the top, while many countries of Sub-Saharan Africa are at the bottom. High literacy, good health care and the empowerment of women lead to a fall in the birth rate and to better human development, as Kerala in India and Sri Lanka show. This is why the modern population policy stresses education and health and not only family planning.

Practice Questions

• Q1. Who gave the term conurbation? Answer: Patrick Geddes.
• Q2. Which pyramid shape shows an ageing population? Answer: A narrow base (declining).
• Q3. Which body protects the refugees of the world? Answer: UNHCR.
• Q4. Who proposed the central place theory? Answer: Walter Christaller.

Read it with our notes on Indian population and urbanisation and world resources and industries.

Quick Revision

• World population: 8 billion (2022); about 60 per cent in Asia.
• Pyramids: expanding (Nigeria), constant, declining (Japan).
• Push and pull factors; brain drain; refugees and UNHCR.
• Settlements: nucleated, dispersed, linear, circular; conurbation, megalopolis, megacity.

Frequently Asked Questions (FAQ)

How many people are there in the world?

The world population crossed 8 billion in November 2022, according to the United Nations.

Which continent has the most people?

Asia has about three-fifths of the world's population.

What is a population pyramid?

It is a graph that shows the age and sex structure of a country's population.

What does a narrow base of the pyramid indicate?

A narrow base shows a falling birth rate and an ageing population, as in Japan.

What is the demographic transition theory?

It explains how a country moves from high birth and death rates to low birth and death rates in stages.

What is the Malthusian theory?

Malthus said that population grows geometrically and food arithmetically, so checks like famine and disease will limit population.

What are push and pull factors of migration?

Push factors like poverty and war make people leave a place, while pull factors like jobs and safety attract them to another place.

What is brain drain?

It is the migration of skilled and educated people from one country to another.

What is a conurbation?

It is a continuous urban area formed by the merging of several cities, a term given by Patrick Geddes.

What is a megalopolis?

It is a chain of connected cities, such as Boswash in the north-eastern USA.

What is a megacity?

A megacity is a city with more than 10 million people.

What is the central place theory?

It is Walter Christaller's theory that towns provide services to their surroundings in a hierarchy.