A comprehensive revision for Cambridge AS Geography, chapter 4 Population, subchapter 4.3 Population Relationship.

1. ASGEOGRAPHYREVISION
POPULATION
4.3 POPULATIONRELATIONSHIP

2. KEYTERMSANDDEFINITIONS
Carrying capacity is the largest population that the resources of a given
environment can support.
Population ceiling is the theoretical maximum number of people who
can be supported by the available resources and level of technology in
a geographical area.
Ecological footprint is a sustainability indicator, which expresses the
relationship between population and the natural environment. It
accounts for the use of natural resources by a country’s population.
Bio capacity is the capacity of an area or ecosystem to generate an
ongoing supply of resources and to absorb its wastes.
Global hectare: one global hectare is equivalent to one hectare of
biologically productive space with world average productivity.

4. KEYTERMSANDDEFINITIONS
Carbon footprint is ‘the total set of GHG (greenhouse gas) emissions
caused directly and indirectly by an individual, organisation, event or
product’ (UK Carbon Trust, 2008).
Overshoot occurs when humanity’s demand on nature exceeds the
biosphere’s supply, or regenerative capacity.
Green revolution is the introduction of high yielding seeds and modern
agricultural techniques in developing countries.
Perennial crops are crops that do not die off once harvested (annual
crops), existing for years before reseeding may be required.
Optimum population is the one that achieves a given aim in the most
satisfactory way.

6. KEYTERMSANDDEFINITIONS
Economic optimum is the level of population that, through the
production of goods and services, provides the highest average
standard of living.
Underpopulated is when there are too few people in an area to use the
resources available efficiently.
Overpopulated is when there are too many people in an area relative
to the resources and the level of technology available.
Optimum rhythm of growth is the level of population growth that best
utilises the resources and technology available.
Improvements in the resource situation and/or technology are
paralleled by more rapid population growth.

8. Population pressure is when population per unit area exceeds the
carrying capacity.
Neo-Malthusians are the pessimistic lobby who fear that population
growth will outstrip resources, leading to the consequences predicted
by Thomas Malthus.
Anti-Malthusians are the optimists who argue that either population
growth will slow well before the limits of resources are reached or that
the ingenuity of humankind will solve resource problems when they
arise.
TOPICSUMMARY

9. TOPICSUMMARY
Carrying capacity is the largest population that the resources of a given
environment can support. Carrying capacity is not a fixed concept as
advances in technology can significantly increase the carrying capacity
of individual regions and the world as a whole.
The enormous growth of the global economy in recent decades has had
a phenomenal impact on the planet’s resources and natural
environment.
The ecological footprint has arguably become the world’s foremost
measure of humanity’s demands on the natural environment.

10. TOPICSUMMARY
The ecological footprint is measured in global hectares. A global
hectare is a hectare with world-average ability to produce resources
and absorb wastes.
Human demand on the Earth has more than doubled over the past 45
years due to a combination of population growth and rising living
standards that have involved greater individual consumption.
About 800 million people in the world suffer from hunger.
The problem is mainly concentrated in Africa but also impacts on a
number of Asian and Latin American countries. Food shortages can
occur because of both natural and human problems.

11. TOPICSUMMARY
The effects of food shortages are both short and longer term. The
global usage of resources has changed dramatically over time.
As society has changed, attitudes to certain resources and their use
have also changed.
Innovation in food production has been essential to feeding a rising
global population. The package of agricultural improvements generally
known as the Green Revolution was seen as the answer to the food
problem in many parts of the developing world.
The answer to many of the world’s current agricultural problems may
lie in the development of perennial crops. There are a significant
number of potential constraints in developing resources to sustain
changing populations.

12. TOPICSUMMARY
The idea of optimum population has been mainly understood in an
economic sense. At first, an increasing population allows for a fuller
exploitation of a country’s resource base, causing living standards to
rise. However, beyond a certain level, rising numbers place increasing
pressure on resources, and living standards begin to decline.
The most obvious examples of population pressure are in the
developing world, but the question here is: Are these cases of absolute
overpopulation or the results of underdevelopment that can be
rectified by adopting remedial strategies over time?

14. TOPICSUMMARY
The neo-Malthusians (resource pessimists) see the world entering a
new phase of intense population-resource pressures which may result
in serious consequences.
The anti-Malthusians (resource optimists) argue that human ingenuity
will overcome resource problems as it has done so many times in the
past.
Studies of the growth of animal and fungus populations show that
population numbers may either crash after reaching a high level or
reach an equilibrium around the carrying capacity. These contrasting
scenarios are represented by Sand J-growth curves.

16. ADDITIONALWORK
1. Visit www.footprint.wwf.org.uk to calculate your own ecological
footprint. What do you think you could reasonably do to reduce this figure?
How does your ecological footprint differ from other people’s in your class?
2. What is your view on the relationship between population and resources?
3. Set up a class debate to discuss what will happen to the human population
in the future. How relevant are the S- and J-shaped growth curves?

17. SUGGESTEDWEBSITES
www.earthtrends.wri.org – Earth Trends
www.footprint.wwf.org.uk
www.prb.org – Population Reference Bureau
www.statistics.gov.uk – National Statistics (UK)
www.fao.org/WorldFoodSummit
www.oxfam.org
www.newscientist.com
www.greeneconomics.ca
www.overpopulation.org
www.optimumpopulation.org