Examine the view that population change is responsible for water scarcity.

There are many possible approaches to this question.

Responses should understand the term water scarcity, both economic and physical. In terms of population change it can be broadly interpreted and could refer to a growth/decline and/or a change in structure.

Population growth is expected to be the change that is most commonly discussed. Population growth causes increased demand for water. In areas where water resources are under pressure this is likely to be a significant factor increasing water stress. Population growth causes increased demand for agricultural production and an associated demand for water. Population growth may be associated with increased industrial and domestic water demand. Areas that are resource poor are less likely to be able to support larger populations and are more susceptible to overconsumption of the limited resource (for example, Australia).

Responses could argue that demographic change alone has little impact on water scarcity and that other factors are more important such as the growing affluence of a population, as this determines levels of consumption. Affluent societies are likely to have a higher per capita water consumption and are thus more likely to lead to physical water scarcity. Affluence increases demand because of lifestyle (dishwashers, washing machines, showers/baths) and diet (water used in meat production). The relationship between supply and demand should be addressed. Another factor (other than population change) that could be addressed could be changes in supply, for example, drought.

The strongest answers, accessing bands E and F, will need to make effective use of a relevant example or examples and reach a conclusion regarding the statement.

Marks should be allocated according to the markbands.

The best answers had rigorous knowledge and understanding of water scarcity, both economic and physical and could relate this to population change (although often only growth). Only the best candidates disagreed with the statement explaining that population growth is just one of a complex number of factors that impact on water scarcity. Some of these responses were excellent, looking at political and economic factors such as privatization of water and increased affluence. Case studies tended to be generalized but there were some instances of precise examples, particularly from Australia.