GEO 3/4 Unit 4 AOS 1 population dynamics

what is the present day global population distribution?

The present-day global population is unevenly distributed, with dense clusters in South and East Asia, Southeast Asia, Europe, and Eastern North America, mostly in fertile, low-lying, and coastal areas.

Large regions such as deserts, polar areas, high mountains, and dense rainforests remain sparsely populated due to harsh environmental conditions.

what are the changes in population growth since the 1700s?

- Early 1700s pop growth was slow as CDR was high and CBR was also high.

The first billion was reached in 1804, and took another 120 years to reach the next billion in 1927, then a reduced 35 years for the third billion.

Experienced exponential growth/ population explosion.

Since 1950:

2.1-2.2% increase in mid 60s fastest growth

1975 4 billion

7 billion in 2011

Slower rate since 1970s, but population momentum means it's still growing.

Changes to BR and DR= less natural increase

china and india contribute to 1/3 of the pop

what is the projected changes in the 21st century?

The UN projects a population of 9.7 billion by 2050 and 11.2 by 2100.

Africa is projected to contribute most to the growth, whereas Asia and Europe's share will decrease.

Nigeria by 2100 is projected to be the 3rds largest country in the world.

What are the 3 classic pyramid shapes and its presence?

1 - EXPANSIVE GROWING POP

- wide base, narrow top, high BR and mortality, typically developing countries e.g. Kenya, Niger.

2- CONSTRICTIVE DECLINING POP

- narrow base, wider middle, low BR, ageing pop, seen in developing countries with shrinking pop e.g. Italy and Germany

3 - STATIONARY, STABLE POP

- rectangular shape, low BR and DR, stable pop growth. E.g. USA and AUS

what do population pyramids tell us about population characteristics?

Age Dependency Ratio

- Reveals the proportion of young and elderly dependents relative to working-age adults. Higher ratios indicate greater economic pressure on the working population.

Life Expectancy Insights

- Wider top bars indicate longer lifespans. Often more females than males in older age groups due to biological factors and lifestyle differences.

Fertility Trends

- Base width reflects birth rates and future population growth potential. Narrowing bases suggest declining birth rates and vice versa.

Historical Events

- Indentations or bulges reveal wars, baby booms, famines, and migration flows. These anomalies move up the pyramid over time.

what is the dependency ratio?

dependency ratio = no. of independents/no. of people in working age (15-64) x 100%

DTM stage 1

BR - high

DR - high

Pop growth - slow gradual

pyramid shape - wide base, narrow top, concaved sides.

countries - none, only some tribal areas in Amazon

Factors - poor medication, no vaccination, high IFR, famine

DTM stage 2

BR - high

DR - high but falling

pop growth - rapid growth

pyramid shape - more triangular

countries - niger

factors - better hygiene, medication, more vaccinations.

DTM stage 3

BR - falling

DR - steady decrease

population growth - growing, not as rapidly

pyramid shape - wide base, medium middle and narrow top

countries - BRICS (Brazil, Russia, India, China, south Africa)

DTM stage 4

BR - low

DR - low

pop - growing

pyramid shape - wide base, middle and narrow top

countries - USA, Canada and Aus

factors - family planning, food security, better medication and healthcare.

DTM stage 5

BR - low and decreasing

DR - low, not as low as BR

declining

pyramid - narrow base, wide top/middle and narrow top

countries - Japan, Italy, Germany.

Factors - later marriages, accessible health, longer life expectancy.

What is Malthusian theory?

Proposed by Thomas Malthus in 1798, the theory suggests that population grows exponentially whilst resources grow arithmetically, leading to shortages and societal challenges.

Exponential: 2-4-8-16-32 (doubles each generation)

arithmetic: 2-4-6-8-10 (grows by same amount each time)

what are the positive and negative checks?

POSITIVE/NATURAL CHECKS - linked to food production that increase the CDR:

- disease

- disaster

- war

- famine

NEGATIVE/PREVENTATIVE CHECKS - for society to reduce CBR

- couples practicing abstinence, late marriages or celibacy.

- policies to reduce CBR

- restricting marriage between couples of extreme poverty or 'social defects'

Malthus theory links to social sustainability

SUPPORTING

- overpopulation puts pressure on resources, causing unrest and social instability.

E.g. Niger: Bokom Haram and civil unrest

AGAINST:

- High income countries still maintain high standards of living and social stability despite pop pressure.

E.g. - Bangladesh experiencing improved education and healthcare leading to greater LE.

Malthus theory links to economic sustainability

SUPPORTING

- overpopulation can hinder economic development.

E.g. Niger, Nigeria show pop. growth putting strain on resources and maintaining poverty levels

AGAINST

- China and developed nations demonstrate that economic growth, technology and policy can offset population pressures.

Malthus theory links to environmental sustainability

SUPPORTING

- Overpopulation leads to degradation and pollution

e.g. Amazon - deforestation from pop demands, Niger - desertification from overuse of land.

AGAINST

- Germany and other HIC's investing in green energy and conservation despite population pressures.

what is Malthus theory's main critics and modern perspectives?

TECH INNOVATION - Green revolution proved food production could keep pace with population growth through agricultural advances.

DEMOGRAPHIC TRANSITION - many developed countries now face population decline (Germany, Japan), directly contradicting malthusian predictions

HUMAN ADAPTIBILITY - fails to account for human ingenuity, policy interventions, and economic adaptations.

what is carrying capacity, overpopulation, overconsumption and sustainability? (use in malthus qs)

CARRYING CAPACITY - The max number of people that can be supported by the number of resources available in a place. If surpassed, tipping point is reached, pop will have abrupt change.

OVERPOPULATION - pop exceeds the carrying capacity of the area.

OVERCONSUMPTION - consuming to excess> environmental degradation/resource loss.

SUSTAINABILITY - The ability to meet the needs of the present without compromising those of the future.

what are the 4 key insights into population growth?

1. the world population has increased rapidly over the last few centuries.

2. the population growth is no longer exponential - it peaked decades ago

3. the world has passed 'peak child;

4. the UN expects the global population to peak by the end of the century.

Population change to remember since 1950s (peak annual growth, doubling time, TFR, pop milestone, projection to equilibrium)

PEAK ANNUAL GROWTH - 2.2% in 1962-63 - growth rate has since halved

DOUBLING TIME - before 1900, it took centuries to double, between 1950 and 1987, the population doubled in just 37 years.

TFR - global TFR has fallen from around 5 in late 1960s to approximately half than that today.

POP MILESTONE - world reached 8 billion people on 15 November 2022, just 11 years after 7 billion in 2011.

PROJECTION TO EQUILIBRIUM - UN data suggests global population will peak around 10.4 billion before stabilizing or declining.

What are the types of migration and their definitions?

VOLUNTARY - people choose to move for reasons such as employment, education or lifestyle.

FORCED - people are compelled to move due to conflict, persecution or environmental disasters.

INTERNAL - movement with a country e.g rural to urban

EXTERNAL - movement across international borders.

SHORT TERM - movement for less that 12 months

LONG TERM - movement for more than 12 months.

what are the causes of movement (push and pull factors)

PUSH

- conflict or war (Ukraine or Afghanistan)

- natural disasters (drought in the horn of Africa)

- economic hardship (unemployment in Venezuela)

-political instability or persecution (Rohingya in Myanmar)

PULL

- job opportunities (UAE attracting south Asian workers)

- higher living standards (migration to US or EU)

- access to education and healthcare

- family reunification

what are these factors contribution of population movements to population change?

Migration significantly impacts pop size, structure and distribution:

POP GROWTH - countries like Aus rely on migration for growth. in 2022-23, net overseas migration contributed 518,000 people to pop.

DEMOGRAPHIC CHANGES - migration often involves younger people, affecting structure and dependency ratios e.g Germany or Japan

URBANISATION - internal migration contributes to the growth of urban areas. Over 56% of worlds pop lives in urban areas according to UN 2023.

REDISTRIBUTION - migration can lead to regional pop decline and growth