Cambridge International AS and A Level Geography: Population Flashcards

NATURAL INCREASE AS A COMPONENT OF POPULATION CHANGE

Population Growth History

• Early Humankind: The first hominids appeared in Africa approximately $5 \text{ million years ago}$. For the vast majority of human history, the global population remained very low.
• 10,000 Years Ago: Global population was no more than $5 \text{ million}$.
• 3500 BC: Population reached $30 \text{ million}$.
• Time of Christ: Population rose to roughly $250 \text{ million}$.
• 1650 AD: World population reached $500 \text{ million}$.
• 1800 AD: Population grew at an increasing rate to reach its first $1 \text{ billion}$.

Table 4.1: World Population Growth by Each Billion

Recent Demographic Change

• Developing vs. Developed World: The rate of growth is significantly higher in the developing world. However, developing world growth rates only overtook developed world rates after the Second World War.
• Growth Periods: Developed countries experienced high growth in the 19th and early 20th centuries. Developing countries have seen high growth since 1950.
• Peak Growth Rate: The highest global population growth rate occurred in the early-to-mid-1960s, reaching $2.4 \% \text{ a year}$ in the developing world.
• Population Momentum: Although growth rates have fallen for three decades, the actual numbers added each year did not peak until the late 1980s.

Components of Population Change

• Natural Change: The balance between births and deaths.
• Net Migration: The difference between immigration and emigration.
• Terms of Statement:     * Absolute Terms: Actual change in numbers (e.g., $200,000$).     * Relative Terms: Expressed as a rate per thousand (e.g., $2/1000$).

MEASURING FERTILITY AND MORTALITY

Fertility Measures and Definitions

• Crude birth rate (CBR): The number of live births per $1000 \text{ population}$ in a given year. It is a broad indicator because it does not account for age or gender structure.
• Natural change: The difference between the number of births and deaths. It can be positive (natural increase) or negative (natural decrease).
• Fertility rate: The number of live births per $1000 \text{ women}$ aged $15\text{--}49 \text{ years}$ in a given year.
• Total fertility rate (TFR): The average number of children that would be born alive to a woman (or group of women) during her lifetime, if she were to pass through her child-bearing years conforming to the age-specific fertility rates of a given year.
• Replacement-level fertility: The level at which those in each generation have just enough children to replace themselves. A TFR of $2.1 \text{ children}$ is usually considered replacement level.

Global Variations in Fertility (2010 Data)

• High CBR: Niger at $52/1000$.
• Low CBR: Monaco at $7/1000$.
• High TFR: Niger at $7.4$.
• Low TFR: Macao and Hong Kong (China) at $1.0$.
• Global Average TFR: $2.5$.

Factors Affecting Levels of Fertility

• Demographic: Other population factors, especially infant mortality rates (IMR).
• Social/Cultural: Tradition demands high reproduction in some societies (e.g., parts of Africa). Religious influence is significant. Education, particularly female literacy, is the primary key to lower fertility.
• Economic: In poor countries, children are economic assets; in developed countries, the cost of child dependency years acts as a deterrent.
• Political: Governments may attempt to change growth rates for strategic or economic reasons.

Fertility Decline

• The UN predicted in 2007 that the global population would peak at $9.2 \text{ billion}$ in 2050. These peak projections have been revised downwards as fertility levels fall faster than expected.
• In 2010, $87 \text{ countries}$ had TFRs at or below $2.1$.

Mortality Measures and Definitions

• Crude death rate (CDR): The number of deaths per $1000 \text{ population}$ in a given year. Influenced heavily by age structure (e.g., the UK's CDR is $9/1000$ vs. Brazil's $6/1000$, despite the UK's higher life expectancy).
• Infant mortality rate (IMR): The number of deaths of infants under $1 \text{ year}$ of age per $1000 \text{ live births}$ in a given year.
• Life expectancy (at birth): The average number of years a person may expect to live when born, assuming past trends continue.

Mortality Variations (2010 Data)

• High CDR: Zambia at $20/1000$.
• Low CDR: Qatar at $1/1000$.
• Regional Life Expectancy: Lowest in Africa ($55 \text{ years}$); highest in North America ($78 \text{ years}$).
• Causes of Death:     * Developing World: Infectious/parasitic diseases (over $40 \%$ of deaths), tuberculosis, cholera, malaria, and measles. Linked to overcrowding, poor nutrition, and lack of healthcare.     * Rich Countries: Heart disease and cancer are the primary killers.

POPULATION STRUCTURE AND PYRAMIDS

Definitions

• Population structure: The composition of a population, primarily based on age and sex. Other studied aspects include race, religion, and occupation.
• Population pyramid: A vertical bar chart showing population distribution by age and sex.

Interpreting Pyramids

• Broad top: High proportion of elderly living longer.
• Bulges: Indicate immigration or past baby booms.
• Indents: Higher death rates from war, famine, disease, or out-migration (emigration).
• Wide base: High birth rate.
• Narrow/Inverted base: Low birth rate.
• Height: Reflects life expectancy levels.

National Examples (2009 Data)

• Niger (Stage 2): Extremely wide base (high fertility). Marked narrowing in higher bars indicates high mortality and low life expectancy. High youth dependency.
• Bangladesh (Stage 3): Narrower base due to birth control programs. Equal width of bottom three bars shows recent fertility falls. Lengthening life expectancy in young adult bars.
• UK (Stage 4): Narrow base (low fertility). Consistent width in middle bars showing lower mortality. Significantly higher aged dependency.
• Japan (Stage 4/5 boundary): Inverted base (lowest fertility). Widest middle/upper sections due to highest global life expectancy. Lowest mortality.

Migration Effects on Pyramids

• Rural-to-Urban Migration: Age-selective. Rural areas lose young adults/parents (narrower bars in those ages). Urban areas gain these groups (bulges).
• Sex-selective: Migration may favor one gender, further distorting the pyramid profile.

Sex Ratio

• Defined as the number of males per $100 \text{ females}$.
• Biological/Social Bias: Male births consistently exceed female births.
• Mortality Bias: Female survival is usually higher as male mortality is higher at every age.
• China (2002): Recorded $116 \text{ male births}$ for every $100 \text{ female births}$ due to sex-selective abortion instances.

THE DEPENDENCY RATIO

Definitions and Formulas

• Dependants: People too young ($<15$) or too old ($>64$) to work.
• Total Dependency Ratio:$\frac{\text{number aged } 0\text{--}14 + \text{number aged over } 64}{\text{number aged } 15\text{--}64} \times 100$
• Elderly Dependency Ratio:$\frac{\text{number aged over } 64}{\text{number aged } 15\text{--}64} \times 100$
• Youth Dependency Ratio:$\frac{\text{number aged } 0\text{--}14}{\text{number aged } 15\text{--}64} \times 100$

Socio-Economic Importance

• A ratio of $60$ means every $100 \text{ workers}$ support $60 \text{ dependants}$.
• Developed Countries: Ratios between $50$ and $75$. High elderly proportion.
• Developing Countries: Ratios can reach over $100$. Primary proportion consists of young people.
• Workers contribute to the economy; dependants require funding for education, health care, and pensions.

THE DEMOGRAPHIC TRANSITION MODEL (DTM)

Definition: The historical shift of birth and death rates from high to low levels.

Stages of the Model

• Stage 1 (High Stationary): High, stable birth rates; high, fluctuating death rates (famine, war). Slow growth. No modern countries are entirely in this stage.
• Stage 2 (Early Expanding): Death rate drops steeply (nutrition, sanitation, medical advances). Birth rate remains high. Rate of natural increase peaks. Examples: Poorest developing countries.
• Stage 3 (Late Expanding): Birth rate begins to decline as social norms adjust to lower mortality. Life expectancy continues to rise. Examples: Advanced developing countries (Brazil, India, Malaysia).
• Stage 4 (Low Stationary): Both rates are low. Population growth is slow. CDR may rise slightly due to population ageing. Examples: Most developed countries (UK).
• Stage 5 (Natural Decrease): Birth rate falls below death rate. Population declines without immigration. Examples: Japan.

Criticisms of the DTM

• Eurocentric: Based on Western Europe's experience.
• Sequence Variation: Developing countries may not follow the same timeline or order.
• Migration Omission: Fails to account for population changes solely due to migration.

Differences in Developing Countries

• Higher birth rates in Stages 1 and 2 than seen in Europe historically.
• Death rates fell much more steeply.
• Larger base populations mean Stage 2 growth has a much greater impact.
• Steeper fertility fall in Stage 3.

GLOBAL AGEING AND DEVELOPMENT

Ageing Trends

• Global life expectancy: $46 \text{ years (1950)}$ to nearly $65 \text{ in 2000}$. Projected $74 \text{ years by 2050}$.
• Oldest Region: Europe ($20 \%$ aged $60+$).
• Youngest Region: Africa ($43 \%$ are children).
• 85+ Age Group: Known as the 'oldest-old'; the fastest-growing segment needing expensive residential care.

Human Development Index (HDI)

• Components: Life expectancy, education, and income.
• High HDI countries are usually in DTM Stage 4 or 5. Low HDI countries are usually in Stage 2.

England and Wales Case Study (1700–2000)

• 1798: Jenner discovered smallpox vaccination.
• 1833: Factories ban child labour.
• 1834: Poor Law Amendment Act.
• 1848/1875: Public Health Acts for pure water and drainage.
• 1876: RV Bradlaugh spread birth control propaganda.
• 1911: National Insurance against sickness.
• 1921: Local councils began treating TB.

Child and Maternal Mortality

• Child Mortality: Death before 5th birthday. Fell below $10 \text{ million}$ for the first time in 2006 (down from $13 \text{ million in 1990}$). Reasons: measles vaccinations, mosquito nets, breastfeeding.
• Maternal Mortality: Death during or after pregnancy. Risk is $1 \text{ in 92}$ globally, but $1 \text{ in 22}$ in sub-Saharan Africa compared to $1 \text{ in 6000}$ in developed nations.

POPULATION-RESOURCE RELATIONSHIPS

Carrying Capacity and Biocapacity

• Carrying Capacity: The largest population the resources of an environment can support. It is dynamic, changing with technology.
• Biocapacity: Capacity of an ecosystem to generate resource supply and absorb waste.

Ecological Footprint

• Measured in global hectares (average productive hectare).
• Components (6): Built-up land, fishing ground, forest, grazing land, cropland, carbon footprint.
• Overshoot: Humanity has been in ecological overshoot since the mid-1980s. Global footprint exceeds regenerative capacity by $30 \%$.

Food Shortages

• Approximately $800 \text{ million people}$ suffer from hunger.
• Natural Causes: Soil exhaustion, drought, floods, tropical cyclones, pests, disease.
• Economic/Political Causes: Low capital investment, rising population, transport difficulties, conflict.
• Health Impacts: Malnutrition causes diseases like Beri-beri (Vitamin $B_1$ deficiency) and Kwashiorkor (protein deficiency).

Green Revolution

• Introduction of High-Yielding Variety (HYV) seeds (wheat, rice, maize, sorghum, millet) and modern techniques. India started the HVP in $1966\text{--}67$.
• Advantages: Yields $2\text{--}4 \times$ greater, extra crops due to shorter seasons, higher farming incomes.
• Disadvantages: High fertiliser/pesticide costs, salinisation from irrigation, rural unemployment from mechanisation, minerals/vitamins deficiency in some HYVs.

THEORIES OF POPULATION CHANGE

Optimium Population

• Economic Optimum: The population level providing the highest average standard of living.
• Underpopulated: Too few people to use resources efficiently.
• Overpopulated: Too many people relative to resources and technology.

Thomas Malthus (1798)

• Arithmetical Progression: Food supply increases ($1-2-3-4-5-6…$).
• Geometrical Progression: Population increases ($1-2-4-8-16-32…$).
• Limiting Factors (Checks): Famine, disease, and war.

Neo-Malthusians vs. Resource Optimists

• Neo-Malthusians: Point to declining farmland per person, rising food costs, and fish scarcity.
• Resource Optimists (e.g., Esther Boserup): Believe humans are the "ultimate resource." Innovation, intensification, and green technology will conquer resource problems.

Population Curves

• S-curve: Exponential growth that slows to a stable equilibrium at carrying capacity.
• J-curve: Exponential growth followed by a sudden collapse ("dieback") after overshooting carrying capacity.

CASE STUDY: MANAGING NATURAL INCREASE IN CHINA

Context and Implementation

• Policy: "One-child policy" introduced in $1979$.
• Incentives/Deterrents: Rural households obeying rules get priority loans/assistance. Slogan: "shao sheng kuai fu" (fewer births, quickly richer).
• Impact: Prevented at least $300 \text{ million births}$. CBR fell from $43.8/1000 (1950)$ to $13.6/1000 (2005)$.

Adverse Consequences

• Unbalanced Sex Ratio: Currently $119 \text{ boys to 100 girls}$ at birth (natural rate is $106:100$) due to selective abortion.
• Demographic Ageing: The "four-two-one" problem (one child supporting two parents and four grandparents).
• Social Issues: Generation of "spoiled" children; wealthy couples "buying their way round" the policy.

QUESTIONS AND DISCUSSION

Now Test Yourself: Review Questions

1. Define Crude Birth Rate and Crude Death Rate: CBR is live births per 1000 people/year; CDR is deaths per 1000 people/year.
2. Rate of Natural Increase Calculation: (Birth Rate - Death Rate) / 10.
3. Why is Fertility Rate better than CBR? It focuses on women in reproductive age ($15\text{--}49$) rather than the whole population.
4. List four factors affecting fertility: Demographic, Social/Cultural, Economic, Political.
5. Define Infant Mortality Rate: Deaths of infants under 1 year per 1000 live births per year.
6. Contrast causes of death (MEDC vs LEDC): MEDCs die mostly of heart disease/cancer; LEDCs die mostly of infectious/parasitic diseases ($40 \% +$).
7. Dependency ratio of 80 meaning: For every 100 economically active people, there are 80 dependants.
8. Define Carrying Capacity: The largest population the resources of an environment can support.
9. Malthus's limiting factors: Famine, disease, and war.