Key Idea: Most marks in topic 8.2 come from sustainable urban planning and how urban expansion harms ecosystems. Then learn the city as a system and why cities grow.
1. Sustainable urban planning (most marks)
- Plan for public transport, green space, mixed land use, and saving energy and water.
- Curitiba, Brazil, opened bus rapid transit in 1974: buses in their own lanes, far cheaper than a metro.
- Trees cool streets and clean the air, but in Portland, Oregon, poorer areas have fewer trees.
2. Urban expansion and the environment
- Sprawl covers farmland and habitat, splits it up, and adds run-off, heat and pollution.
- Pudong, Shanghai, was farmland and canals in 1990; about 5.7 million people lived there by 2020.
- Freeways cut off Los Angeles's mountain lions; a wildlife crossing over the 101 has been built since 2022.
3. The city as a growing system
- A city is a system: food, water and energy go in; waste, heat and pollution come out.
- The world's urban population passed the rural population in 2007; about 58% of people lived in cities in 2025.
- People move for jobs: Dhaka's garment factories employ about 4 million workers, mostly from villages.
How it is examined:
| Question | How to score |
|---|---|
| [1] to [2] Describe an urban change from data or photos | Direction, values and dates; name the change. |
| [1] Calculate a rate of rural depopulation | (start − end) ÷ start x 1000, with the unit. |
| [2] to [4] Identify impacts of sprawl on ecosystems | Habitat loss, fragmentation, run-off, pollution: one per mark. |
| [2] Outline the benefits of greening a city | Cooler streets, cleaner air, less flooding, better health. |
| [9] To what extent is urban planning shaped by global or local factors? | Global goals v local land, money and people; named cities; a judgement. |
Key terms, one line each:
| Term | In one line |
|---|---|
| Urbanization | a rising share of a population living in towns and cities |
| Rural-urban migration | people moving from the countryside to towns and cities |
| Suburbanization | people and businesses moving out to the edge of a city |
| Urban sprawl | the unplanned spread of a city onto the land around it |
| Sustainable urban planning | designing a city to meet people's needs while using fewer resources |
Last-minute check: answer, then tap to see.
Name two impacts of urban sprawl on ecosystems. Habitat loss and fragmentation; also more run-off and pollution.
Why did Curitiba choose buses, not a metro? It had little money, and buses in their own lanes were far cheaper.
Give two benefits of more trees in a city. Cooler streets and cleaner air; also less flooding.
When did city dwellers first outnumber rural people worldwide? In 2007.
A fast-growing city wants to grow without harming the environment. Explain how sustainable urban planning can reduce a city's environmental impact.
Model answer plan
See the mark-by-mark plan — for / against / judgement, with marking guidance — in study mode.
Exam tips
- Link each impact to the growth of the city, not to cities in general.
- Name a real city for every strategy: Curitiba, Portland, Vauban.
- For a rate of depopulation, show the working and give the unit.
- In a [9], weigh global and local factors, then give a judgement.