Understanding Population Growth

• Population is increasing

Essential Questions

• A key question is whether there is a limit to the number of living things Earth can sustain
• Another key question is what causes population of a place to grow or decrease

Population Growth

• Population growth = (Birth Rate - Death Rate) + Effect of Migration
• Natural increase/decrease is also known as natural population change
• Birth Rate (BR), Death Rate (DR), Natural Increase (NI), and Natural Decrease (ND) all have specific definitions
• It is important to understand the reasons for high and low population growth

Birth Rate

• Birth rate is defined as the number of live births for every 1000 people in a year
• Birth rate is usually expressed as a number per 1000 people; for example, 30 live births per 1000 people

Highest Birth Rates Globally (2024 estimates)

• Niger has the highest birth rate at 46.6 per 1000
• Angola's birth rate is 41.1 per 1000
• Benin's birth rate is 40.3 per 1000
• Mali's birth rate is 40 per 1000
• Uganda's birth rate is 39.6 per 1000
• Niger, Angola, Benin Mali and Uganda are all located in Africa

Lowest Birth Rates Globally (2024 estimates)

• Ukraine has the lowest birth rate at 6 per 1000
• Saint Pierre and Miquelon has a birth rate of 6.4 per 1000
• Monaco has a birth rate of 6.5 per 1000
• Japan has a birth rate of 6.9 per 1000
• Andorra has a birth rate of 6.9 per 1000
• Singapore has a birth rate of 8.8 per 1000

Death Rate

• Death rate is defined as the number of deaths for every 1000 people per year
• Death rate is usually expressed as a number per 1000 people, for example, 30 deaths per 1000 people

Highest Death Rates Globally (2024)

• Ukraine has the highest death rate at 18.6 per 1000
• Lithuania has a death rate of 15.2 per 1000
• Serbia has a death rate of 14.9 per 1000
• Latvia has a death rate of 14.7 per 1000
• Romania has a death rate of 14.6 per 1000

Natural Increase

• If the birth rate is higher than the death rate, there is natural increase in the country
• For example, Singapore (2023) is a developed country with a birth rate of 7.4 live births per 1000 people, a death rate of 6.2 deaths per 1000 people, and a natural increase of 1.2 per 1000 people which is considered low
• Niger (2024) is a less developed country with a birth rate of 46.6 live births per 1000 people, a death rate of 9.5 deaths per 1000 people, and a natural increase of 37.1 per 1000 people

Definition of Life Expectancy

• Life expectancy is the number of years a person can expect to live
• In 2023, the life expectancy in less developed countries is about 67 for females and 63 for males
• In 2023, the life expectancy in developed countries is about 81 for females and 75 for males
• In 2023, the life expectancy in Singapore is about 85.2 for females and 80.7 for males

Natural Decrease

• If the birth rate is less than the death rate, there is natural decrease in the country
• For example, Russia (2024) has a birth rate of 8.4 live births per 1000 people, a death rate of 14 deaths per 1000 people, and a natural decrease of 5.6 per 1000 people

Population Trends

• Population trends can be examined over time (temporal) and space (spatial)
• Global population distribution is a component of spatial population trends

Population Explosion

• Population explosion is defined as the rapid growth of world population, with 30 people added every 10 seconds
• A steeper gradient on a population graph indicates a faster rate of growth

Population Growth by Region

• It is important to understand which region experiences the fastest rate of population growth, and which follows behind

Population Growth (General)

• Population growth refers to a change in population size, which can be positive or negative
• Zero population growth occurs when there is no change in population numbers
• Population growth is uneven across the world
• Some parts of the world have a faster rate of population growth than others, for example, Asia, Africa, and Latin America

Natural and Overall Population Change

• To calculate natural and overall population change, need to understand the birth reate, death rate, and net migration

Infant Mortality Rate

• Infant mortality rate is defined as the number of deaths of children less than one year of age per 1000 live births

Population Density

• Population density is defined as the number of people living on a unit area of land

Population density = (Number of people) / (Area)

• Calculating population density helps to understand the concentration of people in a given area
• Population density can be described as high, low, or moderate
• High population density is 200-1000+ persons/km²
• Moderate population density is 10-199 persons/km²
• Low population density is 0-9 persons/km²
• Singapore 2024 population density: 8,384.5 persons per km2
• USA 2024 population density: 34.8 persons per km2
• Singapore's population density is significantly higher than the USA's

Singapore's High Population Density

• 85% of Singaporeans live in HDB flats

Factors Affecting Population Distribution

• Physical environment: Climate, Relief, Soils, Resources
• Climate is defined as rainfall and temperature of a place over a long period of time, which determines living conditions and affects cultivation; places that are too hot (e.g., Kalahari Desert) or too cold (e.g., the Arctic) attract fewer people
• Relief: Refers to the height and gradient of ground and affects drainage cultivation.
• Steep slopes unsuitable for cultivation, unless terracing is practiced which may lower population density.
• Mountainous regions are inaccessible and make it difficult for habitation which lowers population density.
• Places on higher relief may be safer than lower relief may have higher population density
• Soils of Ganges - Brahmaputra Delta, Mekong River Delta are fertile ⇒ high population density whereas poor soils, affect agricultutal cultivation, and thus cause low population density
• Resources (water, materials for shelter, food, minerals) are man's basic needs for survival
• Without resources, expect population density to be lower, unless technology is used to overcome the shortage
• Electricity, power and water that people use to meet their needs

Level of Technology

• Improvements in technology allow environments previously unsuitable for living to become habitable
• With technology, people can live in the desert if water can be channelled from a source to their living environment, such as Las Vegas in the USA, where technology enables water to be transported to the city through pipes and canals

High Population Growth

Causes of High Birth Rate

• Early marriages
• Preference for sons (to carry family name)
• Need for farm labour (subsistence farming)
• Lack of family planning

Factors Leading to High Birth Rate: Early Marriages

• Early marriages: Leads to frequent pregnancies
• Customary for women to wed early
• World Bank and ICRW in 2017 estimated that women who married at age thirteen have on average 26.4% more live births than if they had married at eighteen or later

Factors Leading to High Birth Rate: Preference for Sons

• Preference for sons as they can carry the family name
• Contribute to working on farms
• In Indian funeral customs, the eldest son carries out the funeral rites

Factors Leading to High Birth Rate: Need for Farm Labour

• People in LDCs depend on agricultural activities to earn a living
• Subsistence farming is the practice of producing enough for families with little to sell for profit
• Farmers are unable to afford machinery therefore rely on family members

Factors Leading to High Birth Rate: Lack of Family Planning

• Due to population being less educated
• Religious and traditional beliefs
• Limited access to family planning via advice e.g. clinics

Factors That Lead to a Declining Death Rate

• Improvements in medical and health care
• Better hygiene

Factors That Lead to Declining Death Rate: Health Care

• Medical care refers to availability to hospitals, clinics, doctors, etc.
• Health care refers immunization, nutritional knowledge, and availability of other measures aimed at improving quality of life
• Health care enables babies to survive beyond their first year thus lower infant mortality rates
• Under the National Childhood Immunisation Programmes in Singapore, vaccination for measles and rubella was made compulsory in 1976
• Elderly live longer thus increasing life expectancy

Factors That Lead to Declining Death Rate: Better Hygiene

• Less prone to falling sick and contracting diseases
• Lower death rates due to availability of the supply of clean water and sanitation

Consequences of High Population Growth

• Higher demand for resources
• Higher demand for housing
• Higher demand for education
• Higher demand for jobs
• Environmental problems

Consequences of High Population Growth: Pressure on Resources

• Need for increased food supplies
• Using technology to improve food production, such as irrigation and chemical fertilisers
• Can LDCs afford such technology? What happens when supply cannot meet demand?

Consequences of High Population Growth: Housing

• Higher demand for housing
• Competition leads to insufficient housing
• Particularly in cities due to migration in the country
• Insufficient land for building homes, causing shanty towns or squatter settlements
• Informal, poor quality housing with no/limited basic services (e.g., water, waste disposal, electricity) built illegally on available land

Consequences of High Population Growth: Education

• Higher demand for education requires ensuring sufficient schools and teachers
• LDCs may lack the funds to build more schools → not everyone will be able to attend school and obtain a good education

Consequences of High Population Growth: Jobs

• Higher demand for jobs
• Estimated 30 million new jobs must be created in the world every year to provide employment for new entrants to the workforce

Consequences of High Population Growth: Environmental Problems

• Larger population creates more waste

Low Population Growth: Causes and Consequences

Factors That Lead to Low Birth Rate

• Later marriages
• Fewer marriages
• Preference for small families

Factors That Lead to Low Birth Rate: Later Marriages

• Women have higher academic qualifications, pursuing careers before settling down
• Fertility declines after age 50
• A 2016 report showed the median age at first marriage for brides in Singapore rose from 26.9 years in 2005 to 28.2 years in 2015

Factors That Lead to Low Birth Rate: Fewer Marriages

• People choose to remain single
• Fewer births result in the number of young people decreasing
• According to the 2017 Marriage and Parenthood Survey, 17% of singles aged 21 to 35 years old indicated they do not intend to marry

Factors That Lead to Low Birth Rate: Preference for Small Families

• Especially so in developed countries
• Due to the number of working women who find it difficult to balance family and work
• Feel that the cost of raising children has increased
• 58% of adults feel that having no more than two children is ideal for a family

Factors That Lead to Low Death Rate

• Better medical care and healthcare
• Better nutrition
• High standards of hygiene

Factors That Lead to Low Death Rate: Healthcare

• Healthier lives with vaccinations available
• In Singapore, all children are given vaccinations to protect them from diseases
• World-class hospitals and well-trained doctors are enablers

Factors That Lead to Low Death Rate: Nutrition

• High levels of income, the ability to buy sufficient food and water makes food shortages rare

Factors That Lead to Low Death Rate: Hygiene

• High standards of hygiene, there being clean food, water and air
• Cleaner populations are less prone to contracting diseases

Consequences of Low Population Growth

• Ageing population results when population growth is low
• Higher taxes results from shrinking population, meaning each working person will have to pay more taxes to fund public projects
• Smaller talent pool causes fewer people to lead and serve the country