human population

• Causes of exponential growth

  1. reduced environmental resistance
  2. increased carrying capacity of worlds food producing regions
  3. advancements in healthcare
  4. farming improvements (green revolution)
  5. improved sanitations (running water)
• More developed countries (MDC)

  • slow population growth
  • high standard of living - level of comfort, wealth, material goods, necessities available is high
  • Japan, USA, Australia, most of Europe
• Less Developed countries (LDC)

  • Rapid population growth - fertility rate is 5 in Africa
  • lower standard of living
  • population continues to grow due to medical improvements
• The human population puts extreme pressure on earth's resources, LDCs have a higher growth rate MDCs exert more environmental pressure. More developed countries account for 22% of the world's population but 90% of hazardous waste.
• South African population is 60.8 million (2024)
• Population Pyramids:

  • bar graph showing the composition of a nations population by age and sex at the time of a census
  • population has 3 age groups - pre-reproductive, reproductive, post-reproductive
  • age structure is determined by the proportion of the population that falls in each group
• Rapidly growing:

  • concave sides
  • high birth and death rate
  • low life expectancy
  • Rapid fall in each age group due to high death rate
  • Niger

  
• Growing:

  • straighter sides
  • still high birth rate, falling death rate
  • slightly longer life expectancy
  • more people in older age groups
  • Haiti

  
• Stable Population:

  • straight sides
  • declining birth rate, low death rate
  • long life expectancy
  • increasing proportion of people in 65+ age groups
  • Morocco

  
• Declining population:

  • convex sides
  • very low birth rate, low death rate
  • long life expectancy
  • higher dependency ratio
  • Australia

  
• Demography:

  study of populations, their size, composition and distribution across space and the process through which populations change (deaths, births, migrations) factors that stabilise or change a population.
• Purpose of population pyramids:

  • assess quickly if a population is growing or declining and the rate in which it is doing so
  • shows if it is a LDC or MDC
  • shows the number of people in each age group
  • history of nations growth and predicts future trends
  • determines number of economic dependents (under 15, over 65)
  • allows governments and countries to plan for futures in terms of financial aid and infrastructure (hospitals, schools, old age homes)
• Factors causing population change:

  • HIV and AIDs
  • young immigrants and emigrants
  • men fighting wars
  • reduced births during economic crisis
• effect of high population growth on environment:

  • Dwindling resources shared by many people causes poverty
  • poverty causes over use of natural resources, which causes environmental degradation
  • environmental degradation means more little hands are needed to help in a depleted environment
  • the little hands make a high fertility rate causing dwindling resources that many people share
• Conservation:

  protection, preservation, management or restoration of the natural environment and ecological community
• Sustainable:

  careful use of natural and human resources so that they will also be available to future generations