Key Idea: Most marks in topic 7.1 come from ecosystem services, how the value of resources changes and natural capital as a perspective. At HL, also learn EIAs, unsustainable use of renewables and resource conflict.
1. Ecosystem services (most marks)
- Provisioning: food, timber, water. Regulating: flood control, pollination, carbon storage.
- Supporting: soil, nutrient cycling, habitat. Cultural: recreation, beauty, spiritual value.
- Lose the ecosystem, lose the service: after clearing upstream forest, the Yangtze flooded badly in 1998.
2. Value changes over time
- Value depends on technology, culture and demand, so it is dynamic.
- Lithium rose from about US$8,000 a tonne (2021) to about US$80,000 (2022), then fell.
- Whales were worth meat and oil; since the 1986 whaling ban, whale watching earns more.
3. Perspectives, management and HL ideas
- 'Natural capital' and 'natural income' treat nature as an economic stock that yields goods and services.
- Pricing nature can protect it: New York City saved its Catskill forests instead of building a filter plant.
- At HL: EIAs, unsustainable use of renewable resources, and resource insecurity and conflict.
How it is examined:
| Question | How to score |
|---|---|
| [1] to [2] Identify an ecosystem service | Name the service and its type: 'flood control, regulating'. |
| [2] to [4] Outline how a resource's value has changed | Name the cause: technology, demand or culture, with dates. |
| [4] Explain how losing an ecosystem harms people | Ecosystem lost, service lost, the effect on people. |
| [7] Explain how natural capital can be managed sustainably | Harvest no faster than natural income; quotas, protection. |
| [9] Discuss natural capital as a way of seeing nature | Helps decisions, but misses intrinsic and cultural value. |
| [4] to [7] Outline the role of an EIA | Baseline study, predicted impacts, mitigation, public input, decision. |
Key terms, one line each:
| Term | In one line |
|---|---|
| Natural capital | the stock of natural resources on Earth, such as forests, soils and fish |
| Natural income | the yield of goods and services that natural capital gives each year |
| Ecosystem services | the benefits people get from ecosystems, such as pollination and clean water |
| Renewable resource | a resource that is replaced by natural processes within a human lifetime |
| Intrinsic value | value a thing has in itself, whether or not people use it |
| EIA | a study of a project's likely impacts, done before it is approved |
| Resource security | reliable, affordable, long-term access to the resources a society needs |
Last-minute check: answer, then tap to see.
What does an EIA start with? A baseline study of the site before any work.
Why was the Pebble Mine in Alaska refused in 2020? It risked the world's largest sockeye salmon fishery.
How can a renewable resource be used unsustainably? Harvest faster than it regrows: Borneo lost about 30% of its forest, 1973-2010.
Why is the Nile a source of tension? Egypt gets about 97% of its water from it, but it starts in Ethiopia.
A company wants to build a copper mine in a forested valley above a river used by local fishers. Explain how an environmental impact assessment (EIA) helps decide whether the mine should go ahead.
Model answer plan
See the mark-by-mark plan — for / against / judgement, with marking guidance — in study mode.
Exam tips
- Name each ecosystem service and say which type it is.
- For changing value, give the cause and a dated example, such as lithium or whales.
- In a [9] on natural capital, give a strength, a limit and another view, then a judgement.
- For an EIA, give the stages in order and say who takes part.