Predicting Population Growth (AQA A Level Geography)
Revision Note
Population, Resources & Pollution Model
Population, Resources and Pollution Model
The population, resources and pollution model conveys the relationship between humans and their environment
The model describes a systems approach so that a change in one part has knock on effects for other parts of the model
The model is useful when planning for sustainable development
There are various positive and negative feedback loops in the model
Positive feedback examples:
Population increase → increase demand for resources → more resources acquired → resources enhance survival and support further increase in population
Population increase → more fossil fuel extraction → more fuel for transporting food more easily around the world → diets improve reducing death rates → population increases further
If these positive feedback loops continue unchecked they may cause resource depletion and environmental damage as population overshoots the earth’s carrying capacity
Negative feedback examples:
Population increase → increase demand for resources → more resources acquired → pollution and environmental damage increases → decline in population as death rates rise
Population increase → more food resources required and acquired → increased environmental degradation of soils (soil erosion) → crop yields and agricultural productivity falls → less food, so population declines
These negative feedback loops can be devastating to local populations in vulnerable areas
E.g. famine in Sahel countries
They work to bring populations back to equilibrium and level with carrying capacity
Examiner Tip
Feedback loops are often associated with physical geography, such as in the water and carbon cycles, but be sure to look for them in the human geography topics too. They often help to make links between the human and physical worlds, and identifying these links will score you marks for assessment objective two (AO2).
Perspectives on Population Growth
Perspectives on Population Growth
Social and economic theorists have had contrasting views on how human’s use of resources will impact future population change
Some show optimistic implications
Others are more pessimistic
Examiner Tip
You could get asked to outline any one of these theories in a 4 mark question, so make sure you could make four or five separate points about each. Alternatively, in a higher tariff question you might get asked for some sort of assessment or evaluation of these theories. Be sure to think about how useful each model is in the real world, and what its limitations are.
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