Population change
- The world's population passed 8 billion in 2022.
- The birth rate is the number of live births per 1000 people per year; the death rate is the number of deaths per 1000 people per year. Natural increase = birth rate − death rate.
- As countries develop, death rates fall first (better healthcare and food), then birth rates fall (contraception, education and careers for women), so growth slows.
Population structure and density
- A population pyramid shows the numbers of males and females in each age group.
- A wide base shows a high birth rate, common in lower-income countries. A narrow base and wide top show an ageing population, common in high-income countries.
- Population density is the number of people per square kilometre. Places are densely populated where there are jobs, flat land, a good climate and resources, and sparsely populated where it is mountainous, very hot or very cold.
Migration
- Migration is the movement of people from one place to another. Internal migration is within a country; international migration is between countries.
- Push factors make people want to leave (war, persecution, unemployment, natural disasters). Pull factors attract them (jobs, higher wages, safety, family, education).
- Economic migrants move for work. Refugees are forced to flee war or persecution.
- Migration can fill job shortages and add to a country's culture, but can also put pressure on housing and services. The places people leave may lose young workers but receive money sent home.
Key terms
- Birth rate
- The number of live births per 1000 people per year.
- Death rate
- The number of deaths per 1000 people per year.
- Natural increase
- The birth rate minus the death rate.
- Population pyramid
- A graph showing the age and sex structure of a population.
- Ageing population
- A population with a large proportion of older people.
- Population density
- The number of people per square kilometre.
- Migration
- The movement of people from one place to another.
- Push factor
- Something that makes people want to leave a place.
- Pull factor
- Something that attracts people to a place.
- Refugee
- Someone forced to leave their country because of war or persecution.
- Economic migrant
- Someone who moves to find work or earn more.