| Date | November 2016 | Marks available | 1 | Reference code | 16N.1.SL.TZ0.1 |
| Level | Standard Level | Paper | Paper 1 | Time zone | Time zone 0 |
| Command term | Calculate | Question number | 1 | Adapted from | N/A |
Question
Figure 1: Three projections for world population from the present day to 2100. The three lines indicate the high, medium and low projections for population size.
[Source: From World Population Prospects: the 2015 Revision, by UN Department of Economic and Social Affairs, Population Division, ©2015 United Nations. Reprinted with the permission of the United Nations.]
Calculate the range between the highest and lowest projected population size for 2100.
Identify two factors that could explain the variation in the projected population growth for the world.
Outline one economic implication of the highest projection for world population being realised.
Outline one environmental implication of the highest projection for world population being realised.
Outline one advantage of modelling future human population sizes.
Outline one disadvantage of modelling future human population sizes.
Markscheme
(16.3 billion − 6.6 billion =) 9.7 billion;
Accept 9.5 billion to 10 billion.
[1 max]
strict anti-natal policies;
higher level of education for women (reduces number of births/leads to lower population);
disease (can reduce population growth);
war (can reduce population growth);
natural disasters (can reduce population growth);
availability / lack of sufficient resources/water/food (can curtail population growth);
pro-natal policies;
lack of access to contraception/birth control/family planning;
increase access to healthcare;
technology / technological development (that allows sufficient resources/food to meet demand of growing population);
varied basic assumptions;
different modelling methods.
[2 max]
lack of sufficient jobs (for increasing number of people) leading to under employment / unemployment;
unemployment leading to greater demand for unemployment insurance/social assistance;
unemployment leading to growth in crime requiring more investment in police force/greater insurance costs;
increase in the number of people in poverty;
increase in workforce contributing to economic development/growth;
greater demand for schools/health care increases cost to government;
greater demand for housing increases economic cost in building;
increasing demand for limited resources will elevate prices.
Accept any other reasonable response.
Do not accept ‘shortage of resources’ without link to economic implication.
[1 max]
destruction of protected/marginal areas/clearance of land for agricultural production to feed the larger population/for urban development;
use of marginal lands for agriculture and increased soil degradation;
loss of habitat to land development/farming;
loss of species from loss of habitats/increase in hunting/poaching;
increase in pollution/waste production (from increased numbers of people);
increased extraction of water (for drinking/agriculture) leading to water scarcity/water shortages for other species;
increased need for desalination leading to changes in chemistry in coastal waters.
Accept any other reasonable response.
Do not accept only ‘loss/depletion of (natural) resources’.
[1 max]
allows projections to be made for planning purposes (e.g. schools/hospitals);
allows changes to be proposed to policies to slow population growth;
allows policy makers see what impact a policy might have on population;
can help with decisions on resource management to meet the needs of the population;
models are simple to understand.
[1 max]
all models are a simplification and therefore incorrect;
the data on which the modelling is based may be unreliable;
the model/computer program used may be imperfect;
human behaviour can change, so that the prediction is not fulfilled;
many factors in the environment can change, making projections uncertain;
it cannot foresee natural disasters or international conflicts;
potential for human error in calculation/tool development/application/interpretation of model.
Do not accept ‘not correct/unreliable’ without explanation.
Do not accept ‘model relies on many factors’ as it is the accuracy of the data used that is important.
[1 max]
Examiners report
The majority of responses were correct. A frequent mistake was to incorrectly calculate the range or omit ‘billion’ from the number.
Generally candidates responded well to this question with most achieving either 1 or 2 marks. Common error was to state there was an increase or decrease in birth/death rates without identifying the factor that could cause this change.
There were some excellent responses however a significant number of candidates suggested there would be fewer resources available without linking to an economic change (e.g. increase in price of goods) or the environmental implications of using more natural resources (e.g. deforestation).
There were some excellent responses however a significant number of candidates suggested there would be fewer resources available without linking to an economic change (e.g. increase in price of goods) or the environmental implications of using more natural resources (e.g. deforestation).
The majority of candidates correctly identified an advantage of using population models.
Many candidates gave a vague response e.g. the model is inaccurate/imprecise without explaining a reason for this.
