Unit 3 Managing human population

3.1 Human population dynamics & structure

Population density: total population/land area
- # of ppl per km²
- Low density: low marriage (low birth rate), fewer jobs in rural areas (causes urbanisation), lack of available healthcare
Intrinsic growth rate: dN/N₀
- dN = (births + immigration) - (deaths + emigration)
- N₀ = original population
Doubling time: period of time required for a population to double in size
- Rule of 70: 70/percent

Environmental: natural resources, geographic & climatic factors
- Large, flat lowland plains are easier to access + better for food production than mountainous areas
- Areas w/ few extreme weather events are more appealing
- Areas w/ fertile soil like river deltas tend to have higher populations than areas with high rainfall (leached soil) & cold areas with permafrost
- A secure water supply
- Areas w/ a wealth of natural resources
Economic:
- Agriculture is a primary industry & is manufactured by a secondary industry
  - These increase job opportunities & standard of living, causing population growth
- Areas w/ good transport links are often more densely populated due to trade links
Political:
- Government policies have an impact on population density
  - Can encourage/discourage investment in an area
  - War is a ‘push’ factor & causes out migration + decrease in food production

Population change: # of people b/t the start and end of a given time period
Birth rate: # of live births per thousand ppl in a population per year
- High birth rate = increased population & vice-versa
- High infant mortality rate in LICs → high birth rates
  - Due to: spread of disease & lack of both medical care + access to clean water
Death rate: # of deaths per thousand ppl in a population per year
- Influenced by: climate, medical facilities, living standards, & social conflict + crime rates
Life expectancy increases due to: increased standards of living, access to both clean water & nutrition, & education improvements
Overall population change: annual population change of an area
- (birth rate - death rate) + net migration

Stage 1 pyramid (pre-industrial): high birth & death rate w/stable population
- Rarely found & low life expectancy
Stage 2 pyramid (transitional): declining death rate (due to medicine, better nutrition, & clean water)
Stage 3 pyramid (industrial): birth rate declines from stage 2, death is still declining/low
- Less population growth than stage 2; birth rates can typically be controlled by contraceptives
- Avg. life expectancy increases & mortality rates stabilize
Stage 4 pyramid (late-industrial): low birth & death rates
- Population size fluctuates due to economic conditions; slow growth
Stage 5 pyramid (post-industrial): birth rate is lower than death rate
- Older population reaches full life expectancy
Analyzing a population pyramid:

Dependent: ages 0 to 14 (young)& 65+ (old)
Independent: age 15-64
Total dependency ratio: [young population (0 to 14) + old population (65+)] × 100 / population aged 15 to 64
- Expressed as # of dependents per hundred ppl in the workforce
- Considered high when it’s above 62%
Decreases due to: young population reaching working age, anti-natalist policy, immigration of working age ppl, & lower birth rate

Occur when birth rates decline & life expectancy increases — typically stage 5
Average age is increasing due to: better nutrition, sanitation, standard of living, & care
Impacts of an ageing population:
- Shrinking workforce impact economy
- Pensions may be insufficient to care for older populations - higher spending
- Health care systems have more pressure since older ppl need more care
- Increased retirement age, so gov’ts can collect extra taxes

The Club of Rome: aims to alert the world about consequences of a rapidly growing population → focused on sustainable economic growth + limited population growth
UN Agenda 21: plan of action to limit human impact on the environment
Both are concerned w/ issues related to human population growth

Pro-natalist: encourage ppl to have children & increase birth rates
- Shrinking populations pressure a country’s workforce + financial stability
- Monetary incentives, childcare assistance, free schooling, & monthly grants
Anti-natalist: discourage ppl from having children & decrease birth rates
- Increasing populations that cause declining mortality rates & high rates of poverty
- e.g) China’s One Child Policy
- Other policies include:
  - encouraging marriage later in life
  - increasing access to contraceptives & family planning
  - improving education + employment opportunities for women
  - making abortions legal + safe
- Limitations as a population stabilizes: an ageing population + declining workforce