Introduction (AQA A Level Geography)

Environmental Context

• The environmental context refers to aspects of physical geography that affect the size, distribution and growth rate of an area’s population. It includes
  • Climate 
  • Soils
• Availability of resources including water supply

Physical factors affecting population size and density

Key population parameters

• Distribution
  • Describes the pattern of how population is spread over an area
  • The world has an uneven population distribution

• Density
  • The number of people living in a certain area
  • Usually measured in population per km2

•  Numbers
  • The total amount of people living in an area

• Change
  • How  population increases or decreases over time
  • Population is never static; the distribution, density and number is constantly evolving due to various processes

Key role of development processes

• Population parameters are affected by human factors as well as physical factors
• Development processes describe how human societies advance over time due to technological change
• Each advance in development changes the population size, density and distribution

Major Global Advances in Development

• Development processes can also reduce population totals

• Countries reaching an advanced stage with highly developed social systems mean life expectancy can be very high
• increasing proportion of the population is elderly so that death rates increase
• Population growth rate slows and in some cases total population falls
• Japan’s population is falling (2020 growth rate was -0.30%)

Global patterns of population numbers, densities and change rates

• World population grew very slowly until 18th century
• From 10,000 BCE to 1700 CE the average growth rate was just 0.04% per year
• Exponential growth in population since the mid 18th century
• World population reached 8 billion in November 2022
• Despite the growth rate falling, world population is projected to continue to grow until approximately 2100 when it could reach more than 11 billion

World population total and growth rate, 1750-2015 (with projections until 2100)

• Population density varies across space and changes over time
• Approximately 55% of the world now lives in cities but this figure is projected to reach 65% by 2050 as urbanisation increases
• The densest populations are in areas that have the most favourable environmental conditions or where human development processes have occurred

Global pattern of population density (2018)

• Population change rates vary with time
  • Global average growth rate has declined since around 1970 (see ‘World population total and growth rate’ graph above)

• Population change rates vary over space
• Countries that went through Industrial Revolutions in the 18th and 19th centuries experienced rapid population growth. Today those countries are developed and their growth rates have fallen. In some cases they have fallen so much that their total populations are in decline (e.g. Japan)
• The fastest population growth today occurs in developing countries that are rapidly industrialising 

Global pattern of population growth rate (2021)