The urbanisation process
Big idea: Urbanisation is one of the most significant global trends. More than half of humanity now lives in cities, with rapid growth continuing in developing countries.
Global urbanisation trends
- Current level: ~56% of world population is urban (2023)
- Projected: 68% urban by 2050
- Historical: Only 30% urban in 1950; 14% in 1900
- Megacities: 33 cities now have >10 million people
- Fastest growth: Sub-Saharan Africa and South Asia
Causes of urbanisation
- Rural-to-urban migration: People move seeking better opportunities
- Natural increase: Urban birth rates often exceed death rates
- Reclassification: Rural areas become classified as urban as they grow
- Economic development: Industrialisation concentrates jobs in cities
Push and pull factors
Push factors (leave rural)
- Lack of employment
- Poor services (healthcare, education)
- Agricultural mechanisation
- Land degradation/climate impacts
- Conflict and insecurity
Pull factors (attract to urban)
- Job opportunities
- Better services and infrastructure
- Higher wages
- Social and cultural opportunities
- Perceived better quality of life
Exam tip: Questions often ask for push AND pull factors. Give specific examples and explain HOW each factor drives urbanisation.
Challenges and opportunities of urbanisation
Big idea: Urbanisation creates both problems and opportunities. Well-managed cities can be more sustainable than sprawling rural populations; poorly managed growth leads to slums, pollution, and resource stress.
Challenges of rapid urbanisation
- Housing: Informal settlements/slums, overcrowding, homelessness
- Infrastructure strain: Water, sanitation, electricity, transport overloaded
- Unemployment: Informal economy, underemployment, poverty
- Pollution: Air, water, noise, solid waste
- Health: Disease spread, poor sanitation, limited healthcare access
- Social issues: Crime, inequality, social fragmentation
Opportunities of urbanisation
- Efficiency: Concentrated populations can share infrastructure more efficiently
- Innovation: Cities are hubs of creativity, education, and economic growth
- Services: Easier to provide healthcare, education, utilities to dense populations
- Lower per-capita emissions: Dense cities can have lower footprints than sprawl
- Social mobility: More opportunities for education and employment
- Cultural exchange: Diversity drives innovation and social progress
Cities cover only ~3% of Earths land surface but house 56% of people, consume 75% of resources, and produce 70% of CO₂ emissions. Urban sustainability is crucial for global sustainability.
Exam tip: Urban questions often require balanced arguments. Acknowledge BOTH challenges and opportunities before evaluating solutions.
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IB-style question — urbanisation and urban growth [2]
The city of Rivermouth grows at 3.6% per year, while the whole country of Verdania grows at only 1.4% per year. Outline two reasons why the city's population is rising faster than the national population. [2]
How to answer it, step by step
- Migration pulls people in
• Cities offer jobs, schools and hospitals
• So people move from villages into Rivermouth (rural–urban migration) - Cities add people in other ways too
• Migrants are often young adults, so urban birth rates stay high
• Better city healthcare also lowers death rates
Final answer
Give two clearly separate reasons — don't just reword "more people move there" twice.
IB-style question — urban doubling time [1]
Rivermouth's urban population grows at 3.5% per year. Using the rule of 70, calculate how many years it would take for the city's population to double. [1]
How to answer it, step by step
- Use the doubling-time rule
• Doubling time = 70 ÷ growth rate (%)
• So 70 ÷ 3.5 - Work out the answer
• 70 ÷ 3.5 = 20
• Population doubles in about 20 years
Final answer
Divide 70 by the percentage number itself (3.5), not by 0.035 — keep the units as years.