World Cities

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Going global World cities

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Transcript of World Cities

Page 1: World Cities

Going globalWorld cities

Page 2: World Cities

Urbanisation today and tomorrow

• By 2030, the urban population will have risen to 5 billion or 60% of the global

population.• 50% of the urban population today is aged under 25.• Asia’s urban population is set to rise from 1.4 billion now to 2.6 billion in

2030 (equivalent to the world’s total population in 1955).• Africa’s urban population will rise from 300 to 750 million and that of Latin

America and the Caribbean from 400 to 600 million.

Page 3: World Cities

Types of city

• Urban areas with a population of over 10 million people are termed

‘megacities’. • There were around 20 of these in 2007; 75% are in the developing world and

most continue to grow rapidly.• Strictly speaking, London is not a megacity, but if the population of the wider

metropolitan area is taken into account, it comes very close to being one.• There are around 200 ‘million cities’ with populations of over 1 million.• ‘World cities’ are those cities that wield huge economic and political power,

such as New York, Tokyo (also megacities) and London.

Page 4: World Cities

Urban growth

Towns and cities grow in a number of ways: • Rural–urban migration is a key process.• Rural–urban migrants tend to be young and have high fertility; this boosts rates

of natural increase in cities.• Rural–urban migration in the developing world is currently responsible for much

urban growth.• Natural increase, especially in the developing world.• In the developed world, counter-urbanisation tends to balance the influx of

migrants to towns and natural increase is low due to low fertility rates. • The more developed the megacity, the slower the rate of growth.

Page 5: World Cities

Megacities (1)

• Megacities are very diverse.• Some are at the early or immature stage in the cycle of urbanisation, whereas

in others the rate of growth is slowing (consolidating).• Developed world megacities (mature) tend to have very slow growth rates and

are dominated by suburban sprawl. They are increasingly feeling the effects of

counter-urbanisation.

Page 6: World Cities

Megacities (2)

Mature, slow growing

Europe and North America

Population 70%+ urban

No slums

Consolidating, growing

South America and southeast

Asia

Population 40–50% urban

Under 20% slums

Immature, rapidly growing

South/southeast Asia and

Africa

Population under 30% urban

20%+ slums

Osaka-Kobe

Tokyo

Moscow

Los Angeles

New York

Beijing

Rio de Janeiro

Shanghai

Buenos Aires

São Paulo

Mexico City

Jakarta

Dhaka

Karachi

Lagos

Mumbai

Kolkata

Cairo

Delhi

Manila

Page 7: World Cities

Future trends

• There will be a significant shifts in the

distribution and ranking of megacities,

with major cities in the poorer parts of Asia

entering the top ten list. • New cities will also gain megacity status.

By 2020 there could be close to 30

megacities, including: Istanbul,

Guangzhou, Kinshasa, Lima, Tianjin,

Lahore and Bogota.• Other rapidly growing cities likely to

exceed the 10 million mark by 2020 are:

Bangalore, Wuhan, Chennai (Madras),

Tehran, Riyadh, Hyderabad, Baghdad and

Hong Kong.

2015 population

(millions)

Tokyo 35

Mumbai 22.5

Mexico City 21

São Paulo 20.5

New York 19.9

Delhi 18.6

Shanghai 17.2

Calcutta 17

Jakarta 16.8

Dhaka 15.2

Top ten megacities, 2015 (predicted)

Page 8: World Cities

Slums (1)

• 60% of Mumbai’s population live in slums crammed on 6% of the city’s land. • Slums in Mumbai are growing at a rate of 2.2% per year.• The world slum population will rise from 1 billion in 2005 to an estimated 1.3–

1.4 billion by 2020.• There are two views of slums and shanty towns:

— One is that they are hotbeds of poverty and potential unrest.— The other is that, with a little effort and help, they can be improved to

provide basic housing for the city’s poor.

Increasing numbers of people live in the slums and shanty towns of the developing

world’s megacities:

Page 9: World Cities

Slums (2)

• Newcomers to developing world megacities face stark choices in terms of

housing. • Some inhabit ‘old’ inner city slums (e.g. Dharavi in Mumbai). • They have the ‘advantage’ of being close to available work in the city. • Alternative squatter settlements spring up on the ‘septic urban fringe’.• Many of these slums and shanties are located on dangerously steep slopes, next

to polluted rivers, on marshland or near polluting industry.

Page 10: World Cities

Megacity problems (1)

• Sprawling slums Developing world• Explosive population growth • Poverty and prevalence of informal economy• Lack of clean water and sanitation • Disease epidemics • Transport gridlock • Urban funding crises• Overcrowding • Lack of green space• Pollution of air and water • Gating and segregation• Visual and noise pollution• Water supply problems• Deep eco-footprints • Declining centres • Sprawling suburbs and exurbs Developed world

Page 11: World Cities

Megacity problems (2)

• Finding solutions to these problems is becoming increasingly difficult. • In many developing cities, growth is clearly out of control with annual rates

running at 6–8% per year in the worst cases. • Some possible solutions have been demonstrated: Curitiba in southeastern

Brazil is a well-known example and Dongtan, China’s first ‘ecocity’ is

attempting to create a sustainable urban area.

Page 12: World Cities

Megacity problems (3)

• An important issue is planning. This is the key to Curitiba’s success, albeit this is

only a small city of 1.8 million inhabitants.• If planners can control the growth and density of cities, they should be able to

avoid the stifling congestion of high-density cities and the sprawling mass

and high private transport use of low-density cities.

Page 13: World Cities

Urban resource use (1)

• As urban areas grow they become voracious consumers of resources.• This results in deep eco-footprints and a huge amount of waste. • London’s urban metabolism is shown on the next slide:

— London has a population of 7.5 million.— London recycles 18% of its waste.

Page 14: World Cities

Urban resource use (2)

London’s annual metabolism

Inputs Outputs

20 million tonnes of fuel, in oil equivalent

40 million tonnes of oxygen

2.2 million tonnes of paper

2.4 million tonnes of food

1 billion tonnes of clean water

360 tonnes of glass

2.1 million tonnes of plastics

1.2 million tonnes of metals

1.2 million tonnes of timber

2 million tonnes of cement

36 million tonnes of bricks, blocks, sand and

tarmac

60 million tonnes of carbon dioxide

4 million tonnes of household waste

11.4 million tonnes of industrial and

demolition waste

400,000 tonnes of sulphur dioxide

280,000 tonnes of nitrogen oxides

7.5 million tonnes of wet, digested sewage

sludge

Page 15: World Cities

Urban resource use (3)

To decrease the eco-footprints of urban areas and improve the quality of urban life

ways need to be found to reduce both the inputs and outputs of cities. Some

possible methods are outlined in the table below.

Ways to reduce inputs Ways to reduce outputs

Water metering and mending leaking pipes

Reducing packaging

Introducing more public transport/more efficient

vehicles

Using recycled building materials

Localising food distribution and improving

storage

Using less polluting vehicles

Using alternative (renewable) energy

sources

More recycling

Reusing and recycling water

More carbon sequestration (e.g. urban

gardens, farms and forests)