CHAPTER 8

Human population
Human population distribution and density

 Population density: population per area (figures providing an average value).

 Population distribution: how the population is spread over an area.

 Example: very few or no people live in deserts and mountains, whereas populations are very
high in coastal areas due to availability of fresh water.

Changes in population size

 Lag phase: the period of time in population growth when an organism is adapting to its new
environment and the growth is slow.

 Log/exponential phase: when the growth rate of a population increases overtime as all
requirements are in superabundance.

 Stationary phase: when the growth rate of a population has slowed down to zero as the
carrying capacity is reached.

 Carrying capacity: the maximum size of a population that an environment can support in terms
of food, water and other resources.

 History of human population: about 10000 years ago, there were about 5 million people living
as hunter-gatherers. Significant points in the growth of the human population since then are:

 About 6000 years ago, humans started growing crops and rearing animals, which provided more
food and allowed the population to begin to grow;

 By the time the modern system of counting years started, the population was about 250 million;

 It then took another 1800 years to reach 1 billion;

 After this, the growth become very rapid;

 By 1930, it was 2 billion;

 By 1975, it was 4 billion;

 By 2016, it was over 7 billion, a rise of 3 billion in just 37 years.

 Birth rate: the number of live births per thousand of population per year.

 Death rate: the number of deaths per thousand of population per year.

 Natural increase: the difference between birth rate and death rate.

 Factors effecting birth rate:

 In countries with a high death rate for the very young (high infant mortality), birth rates are also
high.

 In farming economies of many LEDCs, more people are needed for manual labour hence families
tend to be larger.

 In MEDCs, it is expensive to have children and pensions are provided by the state.

 As pensions are provided, they do not need children to take care of them in their old age.

 Many social and political factors result in low use of birth control in LEDCs, whereas in MEDCs
birth control is widely used, so both birth and death rates are lower.

 Migration: the movement of people into (immigration) or out of (emigration) a region, country
or an area.

 Most common worldwide movement is from rural to urban areas in LEDCs.

 Sometimes urban to rural migrations also occur, mostly in MEDCs.

 Population growth: (birth rate + immigration) – (death rate + emigration)

Good supplies of food whatever the

Poverty; Well-paid jobs;

Poor links with outside world; Good roads;

Poor services; Hospitals, schools, water, electricity;

Work on the land only, subsistence; Factory, shops, office work for a wage.

Desertification; No comparable pull factors

Sea-level rise;

Seasonal weather events.

Population structure

Population/age pyramid: a diagram that shows the proportion of the population that is male and
female in different age groups (usually 5-year interval).
 Expanding (young) populations (Afghanistan 2015): a typical pyramid for LEDCs with high
proportion of young people due to high birth rate.
  Stationary populations (USA 2016): population that is almost stationary, with a rectangular
shape, except at the top when old people die.

 Contracting (old) populations (Japan 2016): population is declining because of low birth rates,
and its pyramid is top-heavy because of low death rates.

 Dependant: those people in the population who are not economically active (working) i.e. the
young (<16) and old (65+) and thus rely on those who are working for their needs.

 Independent: those people in the population who are economically active (working) i.e. the
middle-aged (between 17 and 65).

 Taxes from the independent population is used for:

 Education for the youngsters and provision of school places for the children yet to reach school
age.

 Creating care-home places and hospitals for the ageing population.

Managing human population size

 Family planning: methods used by couples to decide the number of children to have and when,
which is mostly encouraged by governments

 Contraception: used to prevent pregnancy.

 Improved health and education: makes people more aware of methods to limit family size.
 Educated women may plan a career as well as having children, the former frequently limiting
how many children are born.

 Education can also lead to a tendency for later marriages and thus later child bearing.

 High infant mortality causes couples to have more children. When it is reduced by better
healthcare and sanitation, the trend is reversed.

 National population policies:

 Pronatalist policy: a national or regional policy that aims to encourage couples to have children.

 In countries like France, couples were encouraged to have more than 2 children.

 Parents are paid the equivalent of the minimum wage for a year after they have a third
child.

 They enjoy subsidised train fares, pay less tax the more children they have, and
subsidised day care.

 Antinatalist policy: a national or regional policy that aims to discourage couples to have
children.

 In LEDCs, population increases too fast, and these policies can form in weak measures
such as the provision of family planning, contraceptives and education, to laws
encouraging couples to have only one child.

 Some countries have no population policies at all and usually have high birth rates.