Geography · My World Quest — full scheme of work · pioneer
Cities That Last: Building a Sustainable Future
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For grown-ups
Companion summary
Imagine a city that cleans its own air, grows food on rooftops, and never wastes a drop of rain. Cities house over half the world's people, so smarter urban design directly shapes our planet's future. Copenhagen aims to be carbon-neutral, running almost entirely on wind power and cycling infrastructure. When you finish, try sketching your own sustainable neighbourhood and explain one feature you would include.
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What Would You Fix First?
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What Would You Fix First?
Imagine you wake up tomorrow as the mayor of a city of two million people. Traffic is gridlocked, rivers run grey with pollution, half the population has no safe green space, and the power grid runs entirely on coal. You have one term in office and a limited budget. Where do you even start? Cities are home to more than half the world's population — a figure that is projected to reach two-thirds by 2050. How those cities are designed and run will shape the health of our planet for generations. Today you are going to find out what geographers and city planners mean when they talk about a 'sustainable city' — and whether any real cities are actually pulling it off.
💭 Think about this
Think of one thing about a city near you (or a city you have visited or seen online) that you think is wasteful or harmful to the environment. What would you change about it, and why?
✨
What Would You Fix First?
🌊🐟🚣💧
What Would You Fix First?
Imagine you wake up tomorrow as the mayor of a city of two million people. Traffic is gridlocked, rivers run grey with pollution, half the population has no safe green space, and the power grid runs entirely on coal. You have one term in office and a limited budget. Where do you even start? Cities are home to more than half the world's population — a figure that is projected to reach two-thirds by 2050. How those cities are designed and run will shape the health of our planet for generations. Today you are going to find out what geographers and city planners mean when they talk about a 'sustainable city' — and whether any real cities are actually pulling it off.
💭 Think about this
Think of one thing about a city near you (or a city you have visited or seen online) that you think is wasteful or harmful to the environment. What would you change about it, and why?
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What Makes a City Sustainable?
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What Makes a City Sustainable?
A city is one that meets the needs of people living there today without damaging the ability of future generations to meet their own needs. That definition comes from the United Nations' idea of sustainable development. It means balancing three pillars: the environment (keeping air, water, and ecosystems healthy), the economy (providing jobs and prosperity), and society (making sure all residents have a decent quality of life).
Cities face enormous pressure because they concentrate people, energy use, transport, and waste in one place. According to UN data, cities consume around 78% of the world's energy and produce more than 60% of , even though they cover less than 2% of Earth's land surface. Making cities more sustainable is therefore one of the biggest levers we have for tackling climate change.
Geographers identify several key features of sustainable cities:
1. Green transport: Prioritising walking, cycling, and electric public transport over private cars reduces carbon emissions and air pollution. Copenhagen, Denmark, is famous for having more bikes than people — over 62% of residents commute by bicycle every day.
2. Renewable energy: Powering buildings with solar panels, wind turbines, or other clean energy sources cuts reliance on . Masdar City in Abu Dhabi, UAE, was designed from scratch to run entirely on renewables, though it is still developing toward that goal.
3. Green spaces and urban trees: Parks, roof gardens, and tree-lined streets absorb carbon dioxide, reduce flooding by soaking up rainwater, cool the air during heatwaves, and improve mental health. Singapore is often called a 'City in a Garden' because greenery is built into its skyscrapers and street design.
4. Waste reduction and : Sustainable cities aim to recycle and reuse materials rather than sending them to landfill. Kamikatsu, a small town in Japan, recycles or reuses about 80% of its waste using a 45-category sorting system.
5. Affordable and mixed housing: Sustainability is also social. Cities need homes that people on different incomes can afford, so that no community is pushed out or left behind.
6. Access to clean water and sanitation: Every resident needs safe drinking water and proper sewage treatment. Without this, disease spreads and inequality deepens.
A key framework linking all of this is the UN's Sustainable Development Goal 11 (): 'Make cities and human settlements inclusive, safe, , and sustainable.' This goal gives city planners a shared checklist to work toward.
Sustainable cities are not perfect — they face trade-offs. Building new tram lines costs money that could fund hospitals. Protecting green land on the edge of a city may limit affordable housing. Geographers study these tensions carefully rather than assuming there is one easy answer.
Worked example
WORKED EXAMPLE — Evaluating Curitiba, Brazil as a sustainable city.
Curitiba is a city of about 1.9 million people in southern Brazil. In the 1970s it faced rapid, unplanned growth and rising pollution. City planners made bold choices:
• They built one of the world's first Bus Rapid Transit (BRT) systems — dedicated bus lanes that move passengers as quickly as a metro at a fraction of the cost. Today about 70% of commuters use this system.
• They created over 50 square metres of green space per resident (the WHO recommends 9 square metres minimum), including flood-control parks that double as sports and recreation areas.
• They introduced a 'Green Exchange' programme where low-income residents could swap bags of recyclable rubbish for food, bus tokens, or school notebooks — tackling waste and poverty at the same time.
Strengths: Curitiba drastically cut congestion, improved air quality, and reduced flooding through park design. Its social programmes reduced inequality.
Challenges: Rapid population growth and informal settlements (favelas) on the city's edges still lack full access to services. Climate change is bringing heavier rainfall that tests even its flood parks.
Conclusion: Curitiba shows that sustainable city planning works best when it combines environmental, economic, and social solutions together — and that the work is never fully finished.
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Test Your Understanding
Try it yourself
Answer each question on your own. Read all the options carefully before choosing. For the final question, write at least two sentences to explain your thinking.
1. Which of the following best defines a 'sustainable city'?
2. According to UN data, approximately what percentage of the world's energy do cities consume, despite covering less than 2% of Earth's land surface?
3. Which UN framework specifically targets making cities inclusive, safe, resilient, and sustainable?
4. Curitiba's 'Green Exchange' programme is a good example of which pillar of sustainable development?
5. A city wants to protect a large area of woodland on its edge to act as a 'green lung' absorbing carbon dioxide. However, this land is also where affordable homes could be built for thousands of families. Explain ONE argument in favour of building the homes and ONE argument in favour of protecting the woodland, then state which you think is more important and why.
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Bring It Together
Sustainable cities balance environmental health, economic prosperity, and social fairness — all three pillars matter equally.
Cities cover less than 2% of Earth's land but produce over 60% of greenhouse gas emissions, so city design is one of the most powerful tools against climate change.
Real cities like Curitiba show that sustainable planning works, but it involves difficult trade-offs and is an ongoing process — never a finished project.
1. A new city district is being planned. The design includes solar panels on every roof, a BRT bus network, mixed-income housing, and a large park that doubles as a flood-control basin. Which statement best explains why this plan can be called 'sustainable'?
🌱 Reflect
Think about the city or town closest to where you live. What is ONE thing that already makes it more sustainable, and ONE change that would make it significantly more sustainable? How would you convince local decision-makers to adopt that change?
