The Challenges of an Urban World

Global Urbanisation trends

Urbanisation - the movement of people from rural areas to urban areas like towns and cities

Urbanisation is happening around the world, and in 2007, for the first time, the number of people living in urban areas was greater than the number of people living in rural areas. However, the number of people living in urban areas is not the same across the world and it varies between places. In the developed world, 78% of the population live in urban areas while in the developing world, only 46% of the population live in urban areas.

Urbanisation in developed countries
  • Towns and cities in the developed world grew in the 19th century during the industrial revolution
  • Rural depopulation has caused an increase in the number of people living in urban towns and cities
  • In 2010, 80% of the total population in the Uk lived in urban areas (CIA World Factbook)
  • There is some counterurbanisation as people move back into the countryside for a better quality of life
  • Many towns and cities continue to grow, e.g. Birmingham where young people are moving to the centre (re-urbanisation)
Urbanisation in developing countries
  • People are still moving to towns and cities because of the lack of jobs in the countryside (push factor)
  • There are more jobs in the towns and cities attracting more people to move to them (pull factor)
  • Rate of urbanisation is greater than the rate in developed countries
  • The increase in the population in urban areas is also down to the high fertility rates in towns and cities
  • Improving living conditions in towns and cities is resulting the death rate being lower than the birth rate increasing the population

World cities & Megacities
The gadget you added is not valid

World cities...
  • have the world's main stock exchanges and major stock markets
  • are the centres of huge political power
  • have the headquarters of TNCs and large influential firms, e.g. financial services
  • have the centres of the world's media organisations, e.g. BBC, Thomson Reuters
  • are centres of tourism
  • have mass transit systems, e.g. tube, rail
  • have at least one major airport
  • are home to the rich and powerful
Examples of world cities include London, Paris, New York, Beijing, New Delhi and Singapore

  • cities with more than 10 million people
  • major centres of economic activity
  • unlike world cities, they are not the centre of government
  • they don't have HQs for TNCs
  • have fewer cultural outlets than world cities
Examples of megacities include New York, Los Angeles, Mexico City, Osaka and Shanghai

Spatial growth

The spatial growth of a megacity is usually different depending on whether it is developed or not.

Developed world:
  • At the centre is the Central Business District (CBD), with its shops and offices
  • Surrounding the CBD, there is the 'inner city' zone consisting of old decaying housing, factories and brand new developments
  • Then, outside the 'inner city' zone is the suburbs mostly consisting of residential houses
Developing world:
  • Compared to the structure of a developed world megacity, the layout of a developing world megacity is a lot more irregular
  • The fast rates of growth and poor planning controls means land use is not defined will and people will often take the opportunity to build homes on any patch of land
  • There is a lot of housing shortages, also leading to people setting up homes on any free piece of land

Population of megacities

  • In developing world megacities, the fertility rate is often very high leading to high population growth and a youthful population
  • Developed world megacities are often the opposite to developing world megacities. They will have relatively low fertility rates and as a result will have a population with more elderly people.
  • The lack of housing and poverty contribute to the fact that many people in developing world megacities live in squatter settlements
  • Although developed world megacities don't have the same level of people living in squatter settlements, there is still some areas of poor, slum housing

Problems facing developed world megacities

Getting food for the 10 million plus inhabitants is a difficult task and food will often have to be imported from other countries. The transportation from far-fetched countries will inevitably add to the cost of the product to the consumer and also the carbon footprint of the city. People living in these megacities are being encouraged to buy more locally produced food

A large megacity is going to use a lot of electricity and gas for the many homes and businesses and getting all the energy needed for the city is no easy task. The city will have to decide how it is going to generate this energy, especially with fossil fuels running out. They could use coal-fired power-stations, but these release a lot of unwanted pollution into our air. Nuclear power is also an option, but this is very dangerous with the potential of radiation being released. Regardless of how it generates it energy, huge amounts of of resources will be used.

Any large city will face problems with congestion on roads as the large volumes of people all try to get around the city. All the cars will also be polluting the air so the air quality in a megacity will not be very good despite technology helping more modern cars producing less pollution. The rest of the city's transport infrastructure (rail, tube, buses, etc.) will also be under a lot of stress.

Another major challenge for developed world cities is the supply of safe, clean water. A megacity will often have a demand for water greater than the supply. This means that water needs to brought in from other areas or other solutions need to be drawn up, such as a desalination plant.

Every person and business will produce waste, and the rubbish of a city combined is going to be huge. Much of this waste will end up going to landfill which is both expensive and wasteful.

Case study - New York

The food supply of New York takes 6 million hectares of farmland. The large majority of it is transported by lorries.

Each year, New York uses 50,000 gigawatts of electricity, mostly produced by oil, gas and nuclear-fuelled power stations.

Like lots of other cities, New York suffers from congested roads and poor air quality..

New York's water supply is 4.1 million m3 of drinking water per day.

New York produces 12,000 tonnes of household waste every day, 17% of which is recycled, as well as 13,000 tonnes of waste from businesses: 90% is taken to landfill on river barges.

The gadget you added is not valid

Challenges facing developing world megacities

The level of housing simply cannot keep up with the rate at which the population is increasing. This leads to people resorting to building their own homes on any vacant land using scrap materials like cardboard, corrugated iron and plastic. Using theses scrap materials presents serious risks such as fire, flooding and landslides. Also, because these houses aren't built by professionals and because they're built on any empty land, there is also no clean water, electricity, rubbish collection or organised sewage disposal. All these conditions make it a perfect breeding ground for disease. Around 1 billion people or 35% of people in the developing world live in slums and it estimated that by 2030 this number will double to 2 billion people.

Roads in developing cities were never originally built to handle such large volumes of traffic they do today, because of this, the roads will often be very congested. The ownership of cars has also increased significantly adding to the problem of road congestion and air pollution. Serious levels of air pollution can cause various health problems as well such as asthma and bronchitis.

Water supply & pollution
The UN estimates that 1 billion people do not have access to adequate supplies of water and 2 billion do not have adequate access to sanitation facilities. The lack of supply of safe water means that people have to find alternative sources which may mean for some people having to drink from pools of water on the ground. Drinking water like this which is most likely polluted accounts for 2 million deaths worldwide each year. Open water also attracts mosquitoes and provides a breeding ground for malaria.

The Informal Economy
Unemployment and underemployment are both major problems in the developing world. Most people are unable to get permanent, full-time jobs so they often find themselves working on a street corner doing some informal work like shining shoes, giving haircuts, selling water or carrying luggage.

Air pollution is a serious problem for the people living in developing world megacities. The use of old cars emitting dirty and harmful fumes and factory pollution not being regulated are just two of the main reasons why pollution is so high. It's not just air pollution, pollution in water ways from sewage and industrial waste is also a problem. 

Case Study - Mumbai

54% of people live in slums. The largest slum, Dharavi, has 800,000 people living in it. On average, people in Mumbai only have 4.5m2 of living space.

Mumbai is a fairly compact city, with only 2% of people owning a car and 55% of people walk to work. Despite this, Mumbai is still one of the most congested cities on earth. 3,000 people die crossing railway tracks or falling off packed commuter trains each year.

Water supply & pollution
Mumbai suffers from severe water shortages. Due to the old, leaking pipes, 650 million litres of water is lost each day. Some slum dwellers spend up to 20% of their money on water.

The Informal Economy
The informal sector in Mumbai employs 68% of Mumbai's workforce, the large majority of these workers coming from the slums across the city.

The World Health Organisation's recommended limit for PM10 (a particulate matter which can cause asthma, bronchitis and even cancer) is 20 micrograms per m3 however in Mumbai, levels of PM10 are around 132 micrograms per m3 which dangerously high.

Managing challenges in the developed world - London, UK

Reducing cities' eco-footprint
London is one example of a city in the developed world making efforts to reduce its eco-footprint. Some ways they have done this is through:
  • Sustainable Transport - The large majority of London's buses are hybrid buses reducing CO2 emissions.
  • Low emission zones - encourages the most polluting vehicles to become cleaner
  • Increase recycling - Many councils around London offer recycling services for their residents making it easy for them to recycle
A key case study within London is Beddington Zero Energy Development (BedZED) which was built as a solution to the unsustainable lifestyle we all are currently living. Some of its key principles are:
  • It encourages people to travel around by public transport, cycling and walking rather than taking the car.
  • Only using energy from renewable resources generated on site
  • All of its houses are energy efficient. The houses face south to maximise solar gain, windows are triple glazed and have high thermal insulation
  • Rainwater is collected and reused on site. Appliances are water efficient and the taps are low flow taps reducing water use.
  • All building materials used to build the site were selected from renewable or recycled sources with 35 miles of the site, reducing transportation pollution and energy usage.
  • Water, gas and electricity meters are all at eye-level so the residents can keep track of how much they are using and keep their use to a minimum.
As a result of all these efforts, BedZED's eco-footprint is considerably less than the average UK resident. For example, their hot water consumption was 57% less and their electricity use was 25% less than the UK average.

The gadget you added is not valid

Sustainable Urban Transport

A major problem in world cities is transport
  • The large number of vehicles in a city, including cars, buses and trucks, all release emissions into the air, resulting in poor air quality which can impact upon people's health
  • The use of these vehicles is consuming our limited resources of fossil fuels, which in turn increases the city's eco footprint.
  • The large volume of vehicles on roads cause congestion, delays and stress
London is a good example of where all these things are happening on a daily basis. It is also an example of a city trying to address these problems. Transport contributes 17% to London's eco-footprint and so they are trying to make transport more sustainable. To do this they have to
  • Reduce harmful emissions
  • Reduce congestion, which will reduce fuel use
  • Make public transport accessible to everyone
London aims to reduce its CO2 emissions by 60% by 2025, partly by improving transport. Ways they are doing this are:

Congestion Charging
  • The Congestion Charge was introduced to London in 2003 in an attempt to cut traffic levels and help ease severely clogged roads
  • By charging people who enter the zone £10, it aims to discourage people from driving into Central London which will reduce congestion and pollution
  • There are fines of up to £180 for people who don't pay, while electric cars don't need to pay the congestion charge at all
  • According to Transport for London figures, traffic levels over the past 10 years have gone down by 10.2% but journey times for drivers have remained flat since 2007.
Cleaner Buses
By Oxyman (Own work) [
GFDL, CC-BY-SA-3.0 or CC-BY-2.5],
via Wikimedia Commons
  • London has begun introducing diesel-electric hybrid buses onto its bus network.
    • They currently have 500 of these buses which reduce CO2 emissions by at least 30% compared to a diesel bus
    • London expects to have 1,700 of these buses by 2016 making up 20% of their bus fleet
  • There is also currently a fleet of eight hydrogen fuel cell buses in London which release nothing but water into the air
  • London is also trialling a combination of diesel and bio-fuel from used cooking oil from the catering industry to see whether it would be possible to run London's buses on a 20% bio-diesel blend which would produce around 15% fewer carbon emissions.
  • By March 2014, 900 older buses will have new technology fitted to help reduce emissions of nitrogen oxides by 88%
Encouraging Bicycles
  • In 2010, London Mayor, Boris Johnson, introduced a bike hire scheme which quickly became known as the 'Boris Bikes'.
  • The aim of the project was to increase the number of people cycling which would reduce pollution.
  • Bike lanes and four 'Cycle Superhighways' have been built to encourage people to cycle.
  • In 2012, there were 8,000 bikes to hire from 570 'docking stations'. There are currently plans to expand the scheme to large areas of south west London.
  • Barclay's Cycle Hire is already the second largest cycle hire scheme in Europe.

Quality of life in developing world cities

Managing social and environmental challenges is one the main difficulties cities face. There are however a number of different ways to improve the quality of life for ordinary people:

Urban Planning - Curitiba, Brazil

  • Curitiba is a city of 2.2 million people
  • Its urban plan was based around 5 main axes crossing the city composing of one-way, three-lane roads, with the central lane reserved for express buses.
  • Curitiba has an 'Integrated Transport System'
    • The system allows people to move both quickly and cheaply in and out of the city
    • The express routes in and out of the city are fed by several other buses from outlying settlements and suburbs outside the city centre
    • Bus-stops are cylindrical clear-walled stops with turnstiles. People pay their fares at the stop before boarding the bus meaning bus drivers don't have to waste time with fares.
    • Buses have extra-wide doors and ramps which extend to the bus stop platform when the doors open
    • These features allow result in a typical boarding time of only 15 to 19 seconds
    • The system is fast, efficient and cheap and transports 2.6 million people everyday
  • Curitiba's buses are use alternative fuels which reduce air pollution, and because so many people use public transport, the city uses 30% less fuel per person than the eight other Brazilian cities of the same size and has one of the lowest rates of air pollution in Brazil.
  • Curitiba's above ground transport system now carries as many people and at the same speed as a subway but is 500 times cheaper.

Self-help schemes - Rocinha, Rio de Janeiro, Brazil

  • Rocinha is the largest favella or shanty town in Brazil
  • It has no roads and only paths creating a maze between the houses
  • This means access is poor, conditions are cramped, its hard to police and there is a high crime rate.
  • 70,000 people live packed close together in houses built on a steep slope
  • Many of the homes used to be simply wooden shacks, but the local authority is now helping people help themselves.
  • Local people have begun rebuilding their homes with bricks and concrete and even have electricity and water.
  • In some cases, these building materials have been provided by the city government and NGOs.

Non-Governmental Organisations (NGOs) - Mumbai

  • The Indian NGO CORP (Community Outreach Programme) was set up in 1977
  • CORP began with only one community centre and three staff members in Asia’s largest slum, Dharavi
  • They now have 20 community centres in Mumbai and more than 70 staff members
  • Their work focuses on education, health and nutrition, helping street children, vocational training and shelter.
  • In 2012, they helped 29,000 people in Mumbai

Developing a less polluted city: Mexico City

Mexico City is one of the world's largest city with 21 million people, and faces 3 major environmental challenges: air pollution, water pollution and waste disposal.

Air Pollution

In 1992, the UN described Mexico city as the most polluted city on the planet. In 1998, the UN then named Mexico City as 'the most dangerous city in the world for young children'. The pollution was so bad that it caused over 1,000 deaths and 35,000 hospital admissions in 1998. The main sources of air pollution were from vehicle exhausts, emissions from factories and power stations. The situation was made worse by the city's geographic location. Mexico is situated in the crater of an extinct volcano meaning that the pollution can't escape and becomes trapped.

Tackling the problem
MeasuresAdvantages Disadvantages 
Providing funds for spare parts to maintain the city's buses- Reduced air pollution
- Bus services are more reliable
- Parts are expensive
- Buses are already old and will eventually need to be replaced
Changing the legal formula of petrol and diesel- Reduced the amount of pollutants released into the air- Expensive
- Money could be spent on less polluting engines which
Banning drivers from using their cars on one day per week- Reduced traffic
- Reduced air pollution
- Drivers avoid it by buying two cars
Building a new underground train line- Reduced air pollution
- Reduced commuting time, 150 minutes to 78 minutes
- Expensive, would cost $2 billion
More larger, efficient articulated buses- Fewer buses needed so less air pollution
- Reduced commuting time
- Expensive, but not as much as a new underground line
Bike share scheme- Reduced congestion and air pollution- Not practical for people with a long commute 

Water Supply and Pollution

Mexico City faces serious challenges regarding its water supply and pollution. Population growth has meant more water is needed for the city and getting this water has led to over-exploitation of the underground water supplies. The city's response to the lack of water for many years has been to pump water up from the 514 underground aquifers, however this has now having serious consequences. The land surface of the city is now sinking at the rate of 9cm per year, causing water and gas pipes to fracture and road to crack, as the aquifers begin to dry up. The increasing demand and use of water has put more pressure on sewage-treatment plants which cannot cope with the volume.

Tackling the problem
MeasuresAdvantages Disadvantages 
Build more sewage treatment plants- Will reduce water pollution- Expensive to build
Conserve more rainfall in underground tanks and cisterns- Would reduce the dependency on underground aquifers and the amount pumped from aquifers- Simple tanks in homes could be easily polluted by insects and animals
Recycle more water- Would reduce the dependency on underground aquifers and the amount pumped from aquifers- Limit to how much can be recycled
Pump more water from deeper wells- Help meet demand in the short term- Very expensive
- Contributes to the subsidence in the city

Waste Disposal

Mexico City produces 13,000 tonnes of rubbish each day, but only 9,000 tonnes can be removed by the current waste collection system. This results in the excess rubbish being dumped on open ground, waterways, streets and drains where it causes more problems by clogging up the system. In 2012, the biggest waste dump in the city was closed but no alternative was suggested leading to a massive rubbish mountain and neighbouring towns refusing to take their waste.

Tackling the problem
MeasuresAdvantages Disadvantages 
More recycling- Reduces waste that goes to landfill- Many people will be slow to adopt recycling
Build a new plant to burn waste- Reduces waste that goes to landfill
- Reduces water and air pollution
- Will generate electricity
- Potentially could add to air pollution
- There are better uses for the waste material
Encourage more composting- Reduces waste that goes to landfill
- Reduces air and water pollution
- Limit to how much can be composted
Burying it in new landfill- Improve the problem in the short term- Potentially could add to air and water pollution
- Not a viable long term solution