Date | May 2021 | Marks available | 1 | Reference code | 21M.2.SL.TZ0.2 |
Level | Standard Level | Paper | Paper 2 | Time zone | Time zone 0 |
Command term | State | Question number | 2 | Adapted from | N/A |
Question
Figure 2: Projected global water scarcity 1995–2025
[Source: With permission from GRID-Arendal. Source adapted.]
State the general pattern of change in global water scarcity predicted from 1995 to 2025 as shown in Figure 2.
Identify two ways in which climate change may influence the predicted change shown in Figure 2.
Identify two possible human influences, not related to climate change, that may cause the changes in water scarcity predicted for 2025.
Outline two reasons why some countries are unlikely to experience water scarcity.
Markscheme
in many countries water scarcity will increase / higher percentages of water present will be extracted;
changes are usually greater in the mid to lower latitudes/nearer the equator (than the poles);
increased global temperatures will change wind/precipitation patterns affecting water supplies;
increased precipitation will increase availability reducing scarcity / decreased precipitation will decrease availability increasing scarcity;
increased temperatures will increase evaporation losses/drought/drying up of water sources (lakes, rivers, reservoirs) reducing availability;
increased temperatures will melt ice storages increasing availability / run off into oceans decreasing availability;
rising sea levels may cause salinisation of freshwater sources;
increased population (demanding more water);
increased/intensive food production/agriculture (demanding more water);
increased standards of living/industrialization (demanding more water);
increased levels of contamination/pollution (through industrial development);
damming of river/water supply upstream reducing available water downstream;
increased surface run off due to urbanisation;
favourable climate where precipitation is high/evaporation is low;
countries may have large replenishable storages (e.g. lakes/rivers/ice);
developed countries with technology for effective water harvesting / desalination;
more ecocentric value systems promoting sustainable use of water resources / limited pollution;
no external conflicts over water sources;
low population densities (with lower industrial/agricultural/domestic demands);
low standards of living (with lower industrial/agricultural/domestic demands);
Examiners report
Most were able to identify the general pattern of increased scarcity although some got tied up in specific details of individual countries.
Most identified either positive of negative impacts of climate change on water scarcity.
Most were able to suggest at least one human influence on water scarcity other than through climate change.
Most could explain at least one reason why some countries did not experience water scarcity.