Population (Cambridge (CIE) IGCSE Geography)

Population Increase

• Nearly 80 million people are added to the world's population each year

• Population growth was steady and low until 1804, when the world population reached 1 billion 

• After 1804, it took just over 100 years for the population to double to 2 billion

• The rate of increase after 1930 was more rapid and led to a population explosion

• The fastest increase in population happened during the 1980s and 1990s

• Population growth rate is the average annual change of the population size during a set period of time, usually a year  

  • The population is still increasing but at a slower rate

  • In 1970, the growth rate was 2% 

  • In 2022, the growth rate is under 1%

• It is predicted by the UN that the population will stabilise at around 11 billion in 2100 

Overpopulation & Underpopulation

• Every area has a carrying capacity this is the number of people that an area can support

  • Overpopulation occurs when there are more people in an area than can be supported by its resources and technology

  • Underpopulation occurs when there are more resources available than the population can use effectively

• Overpopulation can lead to increased:

  • levels of pollution

  • crime rates

  • unemployment or underemployment

  • levels of food and water shortages 

  • pressure on services such as hospitals and schools

• Underpopulation also has consequences, including:

  • fewer people pay taxes, which can lead to higher taxes

  • underused resources, which can lead to waste

  • a shortage of workers

  • lower levels of exports and production, which affects the wealth of an area

  • fewer customers for goods and services

• The optimum population occurs when there is a balance between the number of people and the resources and technology available

• It is the optimum population that results in the highest standard of living because:

  • there are not so many people or so few resources that the standard of living falls

  • there are enough people to develop the resources of the country 

Case Study: Nigeria

• Nigeria's population is over 227 million (2024)

• It is forecast to reach 400 million by 2050 and 1 billion by 2100

  • Lagos is predicted to become the world's largest city by 2100 

• Over 30% of the population live in poverty, earning less than $515 a year

• The urban population has increased from 18% in 1960 to almost 53% in 2021

• Nigeria is experiencing rapid population growth at 2.5%

• Nigeria's population density is 226 people per km²

  • In Lagos, the population density reaches 6871 people per km²

Resources

• Nigeria has many resources, including oil, gas, iron ore, coal, zinc and arable land

• The resources do not provide wealth to the whole population due to:

  • poor management

  • ownership by foreign companies

  • corruption

• The top 5 richest Nigerians own and control more resources than the remaining 95% combined

• When combined with rapid population growth, this means that currently, resources are not supporting the population

Causes of over-population

• The high birth and fertility rates are the main cause of the rapidly increasing population

• The age of marriage in some areas can be as low as 13 and 45% of women are married before they reach 18

  • This increases the number of children each woman has due to being married and of childbearing age for longer

  • The fertility rate is 5.32 births per woman (2019)

• Larger families are traditionally associated with higher social status

• In the past, infant mortality rates have been high 125 per 1000 (1990); this decreased to 72 per 1000

  • High infant mortality rates are associated with high fertility rates as women have more children to ensure that some survive to adulthood. It takes time for this to adjust to lower infant mortality rates

• Other factors affecting the population growth rate include:

  • Religious beliefs lead to larger family size

  • Lack of education about family planning and contraception

  • The decreasing death rate

  • Life expectancy is increasing

  • The death rate has fallen from 19 per 1000 (1990) to 11 per 1000 (2020)

Impacts of overpopulation

• Lack of fresh water, which leads to the spread of disease 

  • 29% of children in Nigeria do not have enough water to meet their daily needs

• Increased levels of water, air and land pollution

  • Lagos has one of the highest levels of air pollution of any city in the world

• Increased cultivation of land for food, which leads to soil erosion and desertification

  • Approximately 40 million people in northern Nigeria are at risk of losing their livelihoods due to desertification

  • Over 19.5 million people face acute food insecurity

• Increased pressure on already poor services such as health and education

• Higher crime rates

• High youth unemployment has led to increased gang activity and militant groups 

• Development of informal settlements around cities, particularly Lagos

  • An estimated 70% of the population of Lagos lives in informal settlements

  • 66% live on less than $1 US a day

Case Study: Canada

• Canada is the second-largest country in the world

  • Population of 38.5 million

  • Population density of 4 people per km²

• The rate of natural increase for Canada is 2.42 per 1000

• The net population increase is mostly the result of immigration

Resources 

• Canada has vast resources:

  • fishing—it has the longest coastline in the world

  • largest producer of zinc and uranium

  • timber

  • gas, coal and oil 

  • gold, nickel, lead and aluminium

  • major exporter of wheat

Causes of under-population

• The main cause of underpopulation in Canada is the low birth and fertility rates. It has:

  • a low birth rate of 9 births per 1000

  • a fertility rate of 1.47 children per woman, which is below the fertility replacement rate of 2.1

• The reasons for these low rates include: 

  • the average age for a woman to have her first child is 31 years, which means that her childbearing years are reduced 

  • increased levels of family planning and access to contraceptives

  • higher levels of education mean that women have careers and delay having children

• It has many areas which are remote and difficult to access; building infrastructure for settlements and industry would be costly

Impacts of under-population

• There are many impacts of underpopulation, including:

  • Low rates of unemployment

  • Shortage of workers in several areas, including:

    • Construction

    • Engineering

    • Food services

    • Health care

  • An ageing population means more people of retirement age

  • Fewer workers to pay taxes

  • Healthcare and other social costs increase as the population ages

  • Resources are not exploited, fully reducing potential

  • Lack of services due to low demand, particularly in rural areas