Full content and enhanced graphics at: nature.com/cities
SCIENCE AND THE CITY
CARBON EMISSIONS FROM ENERGY USE
Size in 1950
Projected sizein 2025 35–40
20–25
�0–15
0.75–5
Population(millions)
KEY
CARBON EMISSIONS FROM SELECT CITIES
2006 2020 2030
Moscow
10,000publications
Paris
Beijing
Dhaka in Bangladesh is projected to grow to 18.7 billion by 2025
Economic growth in India has helped drive urban expansion in and around cities such as Mumbai.
36.67*
22.16
20.26
20.04
19.46
19.43
16.58
15.04
11.15
11.07
10.96
10.85
10.53
10.54
10.31
15.55
14.65
13.13
Total emissions in milliontonnes CO2 equivalent
Per capita emission in tonnes CO2 equivalent
Bangk
ok
Barce
lona
Denve
r
Lond
on
Los A
ngele
s
New Yo
rk C
ity
São Pa
ulo
Shan
ghai
Toky
o
212 124 60
10.7
7
4.2
11
21.5
71
9.613.0
86
10.5
1421
1.411.7
62
4.9
*Organisation for Economic Co-operation and Development
* All �gures in
millions of people
London
Tokyo
Boston
Cities are gluttons when it comes to resources. In 2006, about 50% of the world’s population was urban, but they consumed two-thirds of the total energy used and emitted more than 70% of the energy-related carbon dioxide emissions.
The solutions to many global problems are in cities. According to one geographic analysis in 2004, the greatest concentrations of scienti�c publications are in the major cities that hold most of the scienti�c resources.
Europe’s urban population is not expected to change much in the coming decades, rising from 920 million in 2010 to 1.1 billion in 2030.
The United States is one of the few developed countries where cities have continued to grow. Its urban population of 261 million is set to hit 308 million in 2025.
Asia's urban population is growing faster than in any other region, continuing the trend from the twentieth century. The urban population, 234 million in 1950, reached 1 billion in 1990, and is expected to reach 3.4 billion by 2025.
WHERE THE PEOPLE ARE
WHERE THE SCIENCE IS
TOP TEN MEGACITIES TODAYTOP TEN MEGACITIES TODAY
PROJECTED MEGACITIES IN 2025PROJECTED MEGACITIES IN 2025
�.�.
2.2.3.3.
4.4.
5.5.
6.6.
7.7.
�.�.
2.2.
3.3.4.4.
5.5.
6.6.
7.7.8.8.
8.8.
9.9.
�0.�0.
WHERE THE PROBLEMS ARE
Lagos is one of the world’s newest megacities.
Latin America is highly urbanized — 80% of its population lives in cities — up from 41% in 1950. Its urban population of 500 million in 2010 is expected to grow to 650 million by 2025.
� 2
3 Only 40% of Africa’s population currently lives in cities, but its urban population is growing quickly. Many of the world’s fastest growing big cities are in Africa.4
5 Megacities — which have populations of more than 10 million — are home to 1 in 10 people.6
In less than a human lifespan, the face of Earth has been transformed. In 1950, only 29% of people lived in cities. Today that �gure is 50.5% and is expected to reach 70% by 2050.
Urban emissions from the OECD* (the group of developed nations) will grow only slightly. Emissions from non-OECD cities will double.
35
40
30
25
20
15
10
5
0
Gig
aton
nes
of
CO
2
OECDcities
Non-OECDcities
Non-urbanareas
Delhi
1.5
Tokyo
Delhi
New York–Newark
São Paulo
Mumbai
Mexico City
Shanghai
Kinshasa
Shenzhen
Bogotá
Chongqing
Guangzhou
Jakarta
Lima
Lahore
Calcutta
Dhaka
Karachi
THE CENTURY OF THE CITY
Migration caused by con�ict has helped fuel the growth of Kinshasa in the Democratic Republic of the Congo.
Holding 12.4 million people in 1950, New York should reach 20.1 million by 2025.
Smaller cities, such as Aracaju, account for 40% of the region’s urban population.
By 2025 Bogotáwill qualify as a megacity.
The explosion in urban population looks set to continue through thetwenty-first century, presenting challenges and opportunities for scientists.
The explosion in urban population looks set to continue through thetwenty-first century, presenting challenges and opportunities for scientists.
Some eastern European cities, such as Budapest, are shrinking, as regional populations decline.
Tokyo is the world’s biggest city. Its size is not expected to change much in the next 15 years.
By 2025 China’s urban population is expected to increase by 231 million.
London has hardly grown since the 1950s.
São Paulo's urban growth rate peaked in the 1960s and has slowed since — a trend seen in urban growth across the continent.
Most of the current US urban growth is now happening in smaller cities, such as El Paso.
Full content and enhanced graphics at: nature.com/cities
SCIENCE AND THE CITY
CARBON EMISSIONS FROM ENERGY USE
Size in 1950
Projected sizein 2025 35–40
20–25
�0–15
0.75–5
Population(millions)
KEY
CARBON EMISSIONS FROM SELECT CITIES
2006 2020 2030
Moscow
10,000publications
Paris
Beijing
Dhaka in Bangladesh is projected to grow to 18.7 billion by 2025
Economic growth in India has helped drive urban expansion in and around cities such as Mumbai.
36.67*
22.16
20.26
20.04
19.46
19.43
16.58
15.04
11.15
11.07
10.96
10.85
10.53
10.54
10.31
15.55
14.65
13.13
Total emissions in milliontonnes CO2 equivalent
Per capita emission in tonnes CO2 equivalent
Bangk
ok
Barce
lona
Denve
r
Lond
on
Los A
ngele
s
New Yo
rk C
ity
São Pa
ulo
Shan
ghai
Toky
o
212 124 60
10.7
7
4.2
11
21.5
71
9.613.0
86
10.5
1421
1.411.7
62
4.9
*Organisation for Economic Co-operation and Development
* All �gures in
millions of people
London
Tokyo
Boston
Cities are gluttons when it comes to resources. In 2006, about 50% of the world’s population was urban, but they consumed two-thirds of the total energy used and emitted more than 70% of the energy-related carbon dioxide emissions.
The solutions to many global problems are in cities. According to one geographic analysis in 2004, the greatest concentrations of scienti�c publications are in the major cities that hold most of the scienti�c resources.
Europe’s urban population is not expected to change much in the coming decades, rising from 920 million in 2010 to 1.1 billion in 2030.
The United States is one of the few developed countries where cities have continued to grow. Its urban population of 261 million is set to hit 308 million in 2025.
Asia's urban population is growing faster than in any other region, continuing the trend from the twentieth century. The urban population, 234 million in 1950, reached 1 billion in 1990, and is expected to reach 3.4 billion by 2025.
WHERE THE PEOPLE ARE
WHERE THE SCIENCE IS
TOP TEN MEGACITIES TODAYTOP TEN MEGACITIES TODAY
PROJECTED MEGACITIES IN 2025PROJECTED MEGACITIES IN 2025
�.�.
2.2.3.3.
4.4.
5.5.
6.6.
7.7.
�.�.
2.2.
3.3.4.4.
5.5.
6.6.
7.7.8.8.
8.8.
9.9.
�0.�0.
WHERE THE PROBLEMS ARE
Lagos is one of the world’s newest megacities.
Latin America is highly urbanized — 80% of its population lives in cities — up from 41% in 1950. Its urban population of 500 million in 2010 is expected to grow to 650 million by 2025.
� 2
3 Only 40% of Africa’s population currently lives in cities, but its urban population is growing quickly. Many of the world’s fastest growing big cities are in Africa.4
5 Megacities — which have populations of more than 10 million — are home to 1 in 10 people.6
In less than a human lifespan, the face of Earth has been transformed. In 1950, only 29% of people lived in cities. Today that �gure is 50.5% and is expected to reach 70% by 2050.
Urban emissions from the OECD* (the group of developed nations) will grow only slightly. Emissions from non-OECD cities will double.
35
40
30
25
20
15
10
5
0
Gig
aton
nes
of
CO
2
OECDcities
Non-OECDcities
Non-urbanareas
Delhi
1.5
Tokyo
Delhi
New York–Newark
São Paulo
Mumbai
Mexico City
Shanghai
Kinshasa
Shenzhen
Bogotá
Chongqing
Guangzhou
Jakarta
Lima
Lahore
Calcutta
Dhaka
Karachi
THE CENTURY OF THE CITY
Migration caused by con�ict has helped fuel the growth of Kinshasa in the Democratic Republic of the Congo.
Holding 12.4 million people in 1950, New York should reach 20.1 million by 2025.
Smaller cities, such as Aracaju, account for 40% of the region’s urban population.
By 2025 Bogotáwill qualify as a megacity.
The explosion in urban population looks set to continue through thetwenty-first century, presenting challenges and opportunities for scientists.
The explosion in urban population looks set to continue through thetwenty-first century, presenting challenges and opportunities for scientists.
Some eastern European cities, such as Budapest, are shrinking, as regional populations decline.
Tokyo is the world’s biggest city. Its size is not expected to change much in the next 15 years.
By 2025 China’s urban population is expected to increase by 231 million.
London has hardly grown since the 1950s.
São Paulo's urban growth rate peaked in the 1960s and has slowed since — a trend seen in urban growth across the continent.
Most of the current US urban growth is now happening in smaller cities, such as El Paso.
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FEATURE
2 1 O c T O b E R 2 0 1 0 | V O L 4 6 7 | N A T U R E | 9 0 1
