Describe the role of primary producers in ecosystems.

Explain the potential impact of ocean acidification on environmental systems and societies.

To what extent do anthropocentric value systems dominate the international efforts to address climate change?

Identify four ways to ensure reliability of the mark–release–recapture method in estimating population size.

Explain how the interactions between a species and its environment give rise to the S-shape of its population growth curve.

The future growth of human populations is unlikely to be limited by the availability of energy resources. However, they could easily be limited by the impacts of energy production.

Discuss the validity of this statement.

With reference to four different properties of a soil, outline how each can contribute to high primary productivity.

Explain how the level of primary productivity of different biomes influences their resilience.

Discuss the role of feedback mechanisms in maintaining the stability and promoting the restoration of plant communities threatened by human impacts.

Outline why top carnivores are vulnerable to non-biodegradable toxins.

Explain two factors which lead to a loss of marine (ocean) biodiversity.

Evaluate one possible pollution management strategy for solid domestic waste.

Distinguish between two named biomes and the factors that cause their distribution.

Evaluate one method for measuring primary productivity in a named ecosystem.

Discuss how human activities impact the flows and stores in the nitrogen cycle.

Using Figures 1(a) and 1(b):

State one country with no expected change in water stress between 2013 and the 2040 prediction.

State one difference in water scarcity between 2013 and the 2040 prediction.

Outline how climate change may affect the availability of freshwater resources.

Describe two water management strategies that can reduce water scarcity.

Describe the overall trend for sandy soil shown in Figure 2.

Calculate the change in evaporation from clay soil when the vegetation cover changes from 50% to 100%.

Outline two reasons why loam soils are the most productive for plant growth.

Distinguish between the causes of recent global warming and those of ozone depletion.

Explain the impact of global warming and ozone depletion on coastal ecosystems.

Environmental value systems may lead to different approaches to addressing the issueof global warming. Discuss which environmental value system(s) you consider to bemost appropriate in the management of global warming.

Outline four ways in which urbanization may influence processes in the hydrological cycle.

Hydropower is a resource that can be exploited from rivers. Explain how the value of this resource to a society may vary over time.

To what extent are water scarcity issues better addressed through changing human behaviour than through technological development?

With reference to named examples, distinguish between a primary and secondary pollutant.

Explain how organic waste may be an effective fertilizer in terrestrial systems but a source of pollution in aquatic systems.

To what extent can different environmental value systems contribute to both causing and resolving the problem of water scarcity?