How and why has the world's population grown, and why is it so unevenly distributed?
World population growth, the factors affecting birth and death rates, and the physical and human factors affecting population distribution and density (AO1, AO2).
A focused CCEA GCSE Geography guide to population growth and distribution. Covers natural change, the factors affecting birth and death rates, why world population has grown rapidly, and the physical and human factors that make population distribution and density so uneven.
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What this dot point is asking
CCEA wants you to explain how the world's population has grown, the factors that drive birth and death rates (and so natural change), and why population is so unevenly distributed across the globe. You need to separate natural change (births and deaths) from migration, and to explain distribution using both physical factors (climate, relief, water) and human factors (jobs, transport, resources). This is the foundation for the demographic transition model that follows.
Population growth and natural change
World population grew slowly for most of history, then rapidly from the 1800s onwards. The main reason is that death rates fell (better medicine, vaccination, clean water, sanitation and food supply) while birth rates stayed high, so the gap, and the rate of growth, widened.
Factors affecting birth and death rates
The course expects you to explain why these rates rise or fall.
- Birth rate is high when: contraception and family planning are limited; children are needed to work or support parents; infant mortality is high; people marry young; and culture or religion favours large families.
- Birth rate is low when: contraception is available; women are educated and work; children are costly; and families choose to have fewer children.
- Death rate is high when: healthcare, food, clean water and sanitation are poor, or there is war, famine or disease.
- Death rate is low when: medicine, diet, water and sanitation improve.
Population distribution and density
Worked example: explaining uneven distribution
Common mistakes
Examples in context
Example 1. Why river valleys are crowded. The Ganges valley in India and the Nile valley in Egypt are among the most densely populated rural areas on Earth, because their flat land, fertile soil and reliable river water make intensive farming possible and have done for thousands of years. This shows how several physical factors combine to draw people in, the kind of joined-up reasoning examiners reward over a single point.
Example 2. Falling death rates and the population surge. When clean water, vaccination and better food spread through a country, far fewer babies and adults die, yet families keep having many children out of habit and need. For a generation, births greatly exceed deaths and the population surges. This lag between falling death rates and falling birth rates is exactly what the demographic transition model captures in its next stage.
Try this
Q1. Define natural increase. [2 marks]
- Cue. When the birth rate is higher than the death rate, so the population grows naturally.
Q2. Give two physical factors that lead to a low population density. [2 marks]
- Cue. Any two: too cold, too dry, too high (mountains), or dense forest.
Q3. Give one reason birth rates are often high in poorer countries. [1 mark]
- Cue. Limited contraception, children needed for work or support, high infant mortality, or cultural preference for large families.
Exam-style practice questions
Practice questions written in the style of CCEA exam questions on this dot point, with worked answer explainers. The year tag is the paper they imitate, not the source.
CCEA Unit 2 (style)4 marksExplain two factors that can lead to a high birth rate.Show worked answer →
Four marks, two for each factor explained.
Limited access to contraception and family planning means people cannot easily control family size, so more children are born.
In poorer, rural societies children are needed to work on the land and to care for parents in old age, so families choose to have many children.
Other accepted factors include high infant mortality (parents have more children expecting some to die), early marriage, and religious or cultural traditions that favour large families.
Markers reward a named factor plus a clear explanation of how it raises the birth rate, not just a list.
CCEA Unit 2 (style)6 marksExplain why population is unevenly distributed across the world.Show worked answer →
Six marks for physical and human factors explained.
Physical factors: people avoid areas that are too cold (polar regions), too dry (deserts), too high (mountains) or covered in dense forest, and cluster where the climate is temperate, the land is flat and fertile, and there is a water supply.
Human factors: people gather where there are jobs, good transport, services and resources, so cities and industrial and mining areas are densely populated, while remote areas with few opportunities are sparsely populated.
A good answer gives examples: sparse population in the Sahara or the Himalayas, dense population in river valleys, deltas and major cities.
Markers reward both physical and human factors, each explained and ideally supported with an example.
Related dot points
- The five stages of the demographic transition model, the birth, death and population trends in each, and its uses and limitations (AO1, AO2).
A focused CCEA GCSE Geography guide to the demographic transition model. Covers the five stages, the birth rate, death rate and total population in each, example countries, and the strengths and limitations of the model.
- How to read a population pyramid, the dependency ratio, and the challenges of youthful and ageing population structures (AO1, AO2, AO3).
A focused CCEA GCSE Geography guide to population structure. Covers how to read a population pyramid, the meaning of the dependency ratio, the contrast between youthful and ageing populations, and the challenges and responses each brings.
- The push and pull factors behind migration, the difference between economic migrants and refugees, and the effects on source and host areas (AO1, AO2).
A focused CCEA GCSE Geography guide to migration. Covers push and pull factors, the difference between economic migrants and refugees, and the positive and negative effects on both the source country and the host country.
- The causes of urbanisation and the pattern of urban land use, including the functions of the main zones of a city (AO1, AO2).
A focused CCEA GCSE Geography guide to urbanisation and urban land use. Covers what urbanisation is and why it happens, the difference between richer and poorer countries, and the functions and pattern of the main land-use zones from the central business district to the suburbs.
- The meaning of development and the development gap, and the economic and social indicators used to measure it (AO1, AO3).
A focused CCEA GCSE Geography guide to the development gap and how development is measured. Covers what development means, the gap between richer and poorer countries, the economic and social indicators used, and why a combined index such as the HDI is more reliable than any single measure.
Sources & how we know this
- CCEA GCSE Geography specification — CCEA (2017)
- CCEA GCSE Geography (2017) Unit 2 past papers and mark schemes — CCEA (2024)