What Is Urbanisation?
Definition
Urbanisation
The movement of people from rural areas into cities, often linked to industrialisation and economic opportunity.
- Today, most of the world’s population lives in cities, and this share is expected to keep rising.
- However, future urban growth will be uneven.
- Most new city growth is projected to occur in lower-income and rapidly developing regions, where urban expansion often outpaces the ability to provide housing, infrastructure, and essential services.
Tip
- Similar to what we touched upon for demographic change, urbanisation is driven by two linked processes:
- Natural increase in cities: Urban birth rates exceed death rates, causing city populations to grow internally.
- Migration into cities: People move from rural areas to cities in search of work, education, healthcare, safety, and better living conditions.
How Does Urban Growth Connect To Sustainability?
- A key global response to rapid city growth is the United Nations Sustainable Development Goals (SDGs), including SDG 11: Sustainable Cities and Communities.
- SDG 11 reflects the idea that global sustainability is impossible without improving how cities are built and managed.
- From an SDG perspective, making cities safer and more sustainable includes:
- Access to safe and affordable housing
- Upgrading slum settlements
- Investment in public transport
- Creating and protecting green public spaces
- Urban planning that is participatory and inclusive
- These priorities highlight that sustainability is not only environmental.
- A city cannot be considered sustainable if large groups of residents are excluded from basic services or live in unsafe, unhealthy conditions.
Why Are Urban Problems Often Interconnected?
- Thinking in systems helps you explain why urban problems are often interconnected.
- For instance, a shortage of affordable housing can increase informal settlements, which can increase health risks, which can reduce productivity, which can deepen poverty.
- A useful model contrasts two broad types of urban system:
- A linear city system (often less sustainable)
- A circular city system (aiming to be more sustainable)
Definition
Urban System
A city viewed as a set of interconnected parts (people, infrastructure, economy, services, environment) that interact through flows of resources, energy, goods, and information.
Linear city systems create large waste outputs
- A linear system relies on continuous inputs (energy, water, food, materials), and produces large outputs (waste, sewage, pollution).
- Many outputs leave the system and accumulate in landfills, waterways, or the atmosphere.
Circular city systems reduce waste by reprocessing outputs
- A circular approach aims to keep resources in use for longer, by reprocessing outputs through recycling, reuse, repair, composting, and water treatment.
- The goal is to reduce environmental impact while supporting human well-being.
How Can Rapid Urbanisation Increase Inequality And Informal Settlements?
Definition
Informal Settlement (Slum/Shanty Town/Squatter Settlement)
A residential area where housing is built without formal planning permission and often lacks secure land tenure and access to basic services such as clean water, sanitation, and reliable electricity.
- Urbanisation can concentrate wealth and opportunity, but it can also concentrate poverty.
- In many fast-growing cities, housing supply does not keep up with demand.
- This pushes low-income residents into overcrowded housing or informal settlements.
- Where governments struggle to accommodate rising populations, residents may face:
- Insecure housing and vulnerability to eviction
- Limited access to clean water and sanitation
- Greater exposure to health risks
- Long travel times to employment and services
Common Mistake
- Inequality is not only a feature of lower-income countries.
- Many wealthier countries also experience sharp spatial inequality, where some neighbourhoods have high-quality services and others face long-term deprivation.
Inner-city deprivation can beocme a self-reinforcing cycle
- In many more economically developed contexts, older inner-city areas may experience declining industry, poorer-quality housing, and fewer job opportunities.
- Social and economic problems can reinforce each other in a cycle of deprivation, where unemployment, low incomes, poorer health outcomes, and reduced educational opportunities interact.
Common Mistake
- Avoid oversimplifying: "inner city" does not always mean deprived, and "suburbs" are not always wealthy.
- Urban patterns depend on local history, housing markets, planning decisions, and migration.
How Do Environmental And Health Problems Overlap?
- One of the most serious urban environmental issues is air pollution, which affects both the environment and human health.
- Two key ideas help explain why air pollution is an urban sustainability issue:
- High concentration of emission sources (traffic, industry, construction) can raise pollution levels.
- Loss of green spaces can worsen air quality because vegetation can help filter particulates and reduce urban heat, although green space alone cannot solve pollution without emission reductions.
What Does Urban Sustainability Depend On?
- A sustainable city is not a perfect city.
- It's a city that tries to meet residents' needs now without damaging the ability of future generations to meet theirs.
- In practice, cities face trade-offs:
- Expanding roads can reduce congestion short-term but increase car use long-term.
- Building new housing can reduce overcrowding but may reduce green space if poorly planned.
- Economic growth can fund public services but may increase pollution if based on high-emission energy.
- Because of these tensions, urban planning and management matter.
- Policies commonly linked to more sustainable urban systems include:
- Public transport investment (to reduce congestion and emissions)
- Affordable housing programmes and slum upgrading (to reduce inequality and improve health)
- Green public spaces (to support well-being and environmental quality)
- Resource efficiency strategies (waste reduction, recycling, water treatment and reuse)
- Inclusive decision-making (so planning reflects real community needs)
Exam technique
- Use the systems idea to structure your explanations, identify:
- Inputs (people/resources)
- Processes (housing market, governance, transport)
- Outputs (waste, emissions, inequality)
- Then describe feedback (how one output changes future inputs or processes).
Note
- Some students argue that a sustainable city is an oxymoron because cities consume large amounts of energy and materials and produce pollution.
- Others argue that cities can be the best pathway to sustainability because high density can make services more efficient (public transport, heating, waste collection) and can support technological innovation.
- The most balanced conclusion is that urban areas create significant environmental pressures, but they also offer powerful opportunities to reduce per-person resource use if they are well planned and managed.
Self review
- Name two drivers of urbanisation.
- Explain the difference between a linear and a circular city system.
- Give one reason why air pollution is both an environmental and a health issue.
- Describe one example of a feedback loop that could create a cycle of deprivation.
