Challenges of Urban Sustainability
Introduced| English | Meaning |
|---|---|
| urban heat island/ˈɜːbən hiːt ˈaɪlənd/ | An urban area that is warmer than its surrounding rural areas because of buildings, surfaces and human activity. |
| air pollution/eə pəˈluːʃn/ | The presence of substances in air at concentrations that harm health, ecosystems, materials or other valued conditions. |
Cities and the environment
- Cities use huge amounts of energy, water, and land.
- The urban heat island 城市热岛 makes cities hotter than surrounding countryside.
- Concrete and cars trap heat and pump out pollution.
Cities being hotter than the surrounding countryside is called the urban heat...
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The urban heat island makes cities warmer than their surroundings.
Pollution and waste
- Traffic and industry cause air pollution 空气污染 that harms health.
- Cities generate mountains of waste and strain water supplies.
- Runoff from paved surfaces pollutes rivers and causes flooding.
Problem or solution?
Sort each item as an urban sustainability problem or a solution.
Traffic and industry cause air ____ that harms people's health.
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Air pollution from traffic and industry is a major urban problem.
Select all ways to make a city cooler and cleaner.
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Trees, green roofs, and transit cool and clean; dark asphalt heats the city.
Match each item to problem or solution.
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Heat island + pollution = problems; green roofs = a solution.
The cost of growth
- Extending services to a sprawling edge is expensive.
- Congestion wastes time and fuel and worsens pollution.
- Sustainable cities grow up not out, invest in transit, and add green space.
Growing cities up rather than out generally makes them more sustainable.
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Compact, transit-served growth cuts sprawl, emissions, and cost.
The urban heat island is made worse by the very things that build cities — dark roofs, concrete, and cars. Solutions (green roofs, trees, reflective surfaces, transit) exist, but they cost money and require planning. Sustainability is a choice, not automatic.
On a hot day, a city centre of concrete and asphalt can be several degrees hotter than nearby farmland — the urban heat island. Planting street trees, adding green roofs, and cutting car traffic can lower the temperature and clean the air.
Urban sustainability challenges include the urban heat island, air pollution, waste, water strain, and the cost of sprawl and congestion. Cities respond by growing up not out, investing in transit and green space, and cooling the heat island — all deliberate choices.
Write from a centre that is 4 degrees warmer
- On a summer afternoon the city centre is 4 degrees warmer than the nearby countryside.
- The centre has dark roofs, little shade, and dense traffic.
What urban environmental effect is the temperature gap?
Cities often run hotter than the surrounding countryside.
What is the 4 degree gap called?
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The built-up centre is warmer than the countryside.