beyond population: everybody counts in development · younger population, 2005. less developed...

Beyond Population: Everybody

Counts in Development Joel E. Cohen

Rockefeller & Columbia Universities

Center for Global Development, Washington, DC, 2008-09-23

2008-09-23 Joel E. Cohen 2

Population interacts with

economics, environment & culture.

population

culture

economy environment

2008-09-23 Joel E. Cohen 3

2008 world rich poor

population (billion) 6.7 1.2 5.5GNP PPP/person $9,600 $31,200 $4,760% with <$2 / day 40% 0% 48%% increase/year 1.2% 0.2% 1.5%%15-59 HIV/AIDS 0.8% 0.5% 1.0%

infant mortality rate 0.049 0.006 0.054children/woman 2.6 1.6 2.8life expectancy (y) 68 77 67% urban 49% 74% 44%people/km2 49 27 66

2008-09-23 Joel E. Cohen 4

Less developed regions have a bigger,

younger population, 2005.Less developed regions,

5.3 billion

More developed regions,

1.2 billion

300 100 100 300300 200 100 0 100 200 300

Male Female Male Female

Age

Source: United Nations, World Population Prospects: The 2002 Revision (medium scenario), 2003.

80+ 75-79 70-74 65-69 60-64 55-59 50-54 45-49 40-44 35-39 30-34 25-29 20-24 15-19 10-14

5-90-4

2008-09-23 Joel E. Cohen 5

Future population trends to 2050

economy environment

population

culture

2008-09-23 Joel E. Cohen 6

Population from now to 2050

Bigger: 2-4 billion more people by 2050,

mostly in poor countries.

Slower: population growth could end,

depending on choices now.

Older: people 60+ years will outnumber

children 0-4 years.

More urban: added people will be in

cities of poor countries. Rural population

will peak at 3 billion & decline.

2008-09-23 Joel E. Cohen 7

1. Bigger (& different)

population in 2050:

2-4 billion more people,

mainly in poor countries.

2008-09-23 Joel E. Cohen 8

0

2

4

6

8

10

12

1950 1970 1990 2010 2030 2050

year

po

pu

lati

on

(b

illio

n)

World population in 2050 depends

on what we do from now to then.11.9 const.

10.8 high

9.2 med.

7.8 low

billion.

UN, World Population

Prospects: 2006 Revision

One child difference per

woman means ~3 billion

more or fewer people by

2050.

Almost all increase

will be in cities of

developing countries.

2008-09-23 Joel E. Cohen 9

Women who complete secondary school

average at least 1.5 fewer children than those

who complete primary, with cultural differences.Murphy & Carr, Pop Ref Bureau 2007

Demographic & Health Surveys data

< 1

o

1o

com

pl.

2o

co

mp

lete

d

2008-09-23 Joel E. Cohen 10

Demography 2000-2050 simplified

Year 2000: 6.1 billion people

Year 2050: 9.2 billion people

Rural 3 billion Urban 3 billion

Rural 3 billion Urban 6 billion

2008-09-23 Joel E. Cohen 11

medium & low projections, UN 2004

0

400

800

1200

1600

2000

1950 1970 1990 2010 2030 2050

year

popula

tion (m

illions)

USA

Europe

Africa

China

India

Chart: Joel E. Cohen 2007

past future

India’s population size will outgrow China’s.

Africa’s will outgrow India’s & China’s.

Chart: Joel E. Cohen, 2007 Medium & low projections, UN 2004

2008-09-23 Joel E. Cohen 12

Enough food for 3 billion more?

World grows ~1.9 billion tons of cereal

grains/year, enough to feed ~10 billion

people a vegetarian diet.

About 37-40% of grain is fed to domestic

animals to grow meat for those who

can afford it. Brown 2004 Outgrowing the Earth

Billions are chronically malnourished.

¾ billion are chronically undernourished.

2008-09-23 Joel E. Cohen 13

Rising food prices hurt the poor more.

2008-09-23 Joel E. Cohen 14

2. Slower: population growth could end,

depending on choices now, from

lower fertility or higher mortality.

2008-09-23 Joel E. Cohen 15

2008-09-23 Joel E. Cohen 16

Total fertility rate

0

1

2

3

4

5

6

7

8

1950 1970 1990 2010 2030 2050

year

childre

n /

wom

an

Least

Less

More

World

USA

United Nations Population Division, World

Population Prospects: 2006 Revision

“less developed” excludes

“least developed”

2008-09-23 Joel E. Cohen 17

Total fertility in north Africa

0

1

2

3

4

5

6

7

8

1950 1960 1970 1980 1990 2000

year

ch

ild

ren

pe

r w

om

an

Morocco

Algeria

Tunisia

Libya

Egypt



2008-09-23 Joel E. Cohen 18

Total fertility in the Middle East

0

1

2

3

4

5

6

7

8

9

10

1950 1960 1970 1980 1990 2000

year

ch

ild

ren

pe

r w

om

an

Turkey

Lebanon

Jordan

Saudi Arabia

Yemen



2008-09-23 Joel E. Cohen 19

Total fertility in western Asia

0

1

2

3

4

5

6

7

8

9

1950 1960 1970 1980 1990 2000

year

ch

ild

ren

pe

r w

om

an

Syria

Iraq

Iran

Afghanistan

Pakistan



2008-09-23 Joel E. Cohen 20

Slower growth, slow decline

Current population growth is ~78 million / year.

“Developed” countries absorb 5%, developing countries 95%.

By 2050, developed countries will decrease by 1 million persons / year, developing world will add 35 million / year.United Nations Population Division 2005 World Population Prospects: The 2004

Revision, medium variant

2008-09-23 Joel E. Cohen 21

Lower fertility brings smaller families.

People will have fewer siblings, cousins, aunts, uncles.

Reproduction, child-rearing will occupy smaller portion of adult life.

Average number of people per household will decline (unless patterns of cohabitation change), so numbers of households will rise faster than numbers of people.

2008-09-23 Joel E. Cohen 22

3. Older:numbers & fraction of older

people will increase

everywhere, first in rich

countries, then in poor.

2008-09-23 Joel E. Cohen 23

From now on, the world will have

fewer young than old people.

2008-09-23 24

0

5

10

15

20

25

1950 1970 1990 2010 2030 2050% W

orld

Po

pu

latio

n

0 - 4 years

60+ years

People aged 60+ outnumber children aged 0 - 4.

Graph by Joel E. Cohen from

United Nations Population Division estimates and projections (medium variant)

Joel E. Cohen

2008-09-23 Joel E. Cohen 25

Child dependency 0-15 / 15-64

0

20

40

60

80

100

1950 1970 1990 2010 2030 2050

year

ratio

Least

Less

More

World

USA





2008-09-23 Joel E. Cohen 26

Elderly dependency 65+ / 15-64

0

10

20

30

40

50

1950 1970 1990 2010 2030 2050

year

ratio

Least

Less

More

World

USA





2008-09-23 Joel E. Cohen 27

A tsunami of population

ageing is on the way.

The number of people 60+ will

nearly triple by 2050.

The number of people 80+ will

more than quadruple by 2050.

2008-09-23 Joel E. Cohen 28

Median age will rise everywhere.

2000 2050

world median age (years) 26.7 38.1

more developed regions 37.4 45.7

less developed regions 24.1 36.9

UN Population Division, World Population Prospects 2006 Revision

Relative increase of elderly is most rapid

in some less developed countries.

Greatest numbers of elderly are in more

developed countries.

2008-09-23 Joel E. Cohen 29

Ageing results from 2 successes:

Lower fertility

Longer life

Fall in fertility contributes more to population

aging than increasing length of life.

If birth rates and death rates remain low,

population aging is irreversible.

2008-09-23 Joel E. Cohen 30

Life expectancy rises with income

per person, up to a point.

0

10

20

30

40

50

60

70

80

90

$0 $20,000 $40,000 $60,000

GNI PPP per person US$

life e

xpecta

ncy

Luxembourg

BotswanaSwaziland

PRB 2007 estimates

2008-09-23 Joel E. Cohen 31

A given

income buys

more life as

time passes.

Increasing

knowledge?

Better public

health

measures?

World Bank, World

Development Report 1993

2008-09-23 Joel E. Cohen 32

Life expectancy will increase.(One hopes.)

40

45

50

55

60

65

70

75

80

85

901950

1955

1960

1965

1970

1975

1980

1985

1990

1995

2000

2005

2010

2015

2020

2025

2030

2035

2040

2045

year

life e

xpecta

ncy a

t birth

(both

sexes)

More developed regionsJapan

Russia

World

Less developed regions

United Nations Population Division

2008-09-23 33

0

5

10

15

20

25

30

'83 '84 '85 '86 '87 '88 '89 '90 '91 '92 '93 '94 '95 '96 '97 '98 '99 '00 '01 '02 '03 '04 '05

Year

Age-Adjusted

Rate

NHIS(70+)

NLTCS(65+)

Sources: NLTCS, Manton, Gu, & Lamb (2006); NHIS, Schoeni,

Freedman, Martin (2006); graph from Robert Schoeni

USA elderly disability rates fell 1.5%

per year in last 25 years.

Joel E. Cohen

2008-09-23 Joel E. Cohen 34

Figure 1. Number of disabled Japanese if disability prevalence had not improved

5.8

6.9

5.5

5.5

4.7

5.3

6.0

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

'93 '94 '95 '96 '97 '98 '99 '00 '01 '02

Year

Millions of

disabled aged

65 and older

Actual

If disability rate

had not changed since 1993

Total population aged 65 and older in each year (in millions)

16.9 19.0 21.2 23.6

Source: As for Table 1.

Japan would have 1.1 million more disabled people

65+ in 2002 if disability prevalence had not fallen

since 1993.

Sources: NLTCS, Manton, Gu, & Lamb (2006); NHIS, Schoeni,

Freedman, Martin (2006); graph from Robert Schoeni

2008-09-23 Joel E. Cohen 35

Top 15 people-killers in 2002,by disease or injury

1. Ischaemic heart

disease

2. Cerebrovascular

disease

3. Lower respiratory

infections

4. HIV/AIDS

5. COPD

6. Perinatal conditions

7. Diarrhoeal diseases

8. Tuberculosis

9. Trachea, bronchus,

lung cancers

10. Road traffic accidents

11. Diabetes mellitus

12. Malaria

13. Hypertensive heart

disease

14. Self-inflicted injuries

15. Stomach cancer

Mathers & Loncar PLOS Medicine 2006

2008-09-23 Joel E. Cohen 36

Tobacco is responsible for about

1 death in 10.

million deaths / year

tobacco 6

HIV / AIDS 3

tuberculosis 2

malaria 1

Mathers & Loncar PLOS 2006; The Global Fund to Fight AIDS, Tuberculosis and Malaria

2008-09-23 Joel E. Cohen 37

“Tobacco … world’s leading

preventable cause of death”“The consumption of cigarettes and other

tobacco products and exposure to tobacco smoke are the world’s leading preventable cause of death, responsible for about 5 million deaths in 2003, mostly in poor countries and poor populations. The toll will double in 20 years unless known and effective interventions are urgently and widely adopted.” World Health Report 2003: Shaping the Future (WHO).

2008-09-23 Joel E. Cohen 38

Tobacco: poor people smoke,

poorest smoke most

Smoking rates have declined in high-income

countries.

Smoking rates have increased sharply in

many low-income & middle-income

countries.

Smoking rates are untouched by public

health measures in poorest nations.Feldman & Bayer, eds. Unfiltered: Conflicts over

Tobacco Policy and Public Health. 2004

2008-09-23 Joel E. Cohen 39

4. More

urban: virtually all

population

growth will be in

cities of poor

countries.

2008-09-23 Joel E. Cohen 40

People are concentrated in cities.

Half of all people (more than 3 billion) live in cities

on less than 3% of censused land area

> 500 people/km2,

> 1 person/(45m x 45m).

Least densely populated half of Earth’s censused

land area has less than 2% of people,

< 10 people/km2.

2008-09-23 Joel E. Cohen 41

Most urban people live in small cities.

Approximately 51% of all urban dwellers

in the world in 2005 lived in cities with

fewer than 500,000 people.

United Nations Population Division

World Urbanization Prospects: The 2005 Revision

2008-09-23 Joel E. Cohen 42

Urban populations, 2000

Asia’s urban population exceeded

that of Africa, Europe, Latin America

and Caribbean combined.

Africa’s urban population

exceeded that of North America and

Oceania combined.

2008-09-23 Joel E. Cohen 43

urban

From 2007- 2008 on, world will have

more urban people than rural.

UN, World Urbanization Prospects 2003

rural

rural

2008-09-23 Joel E. Cohen 44

Urban population will grow faster

in less developed regions.

UN, World Urbanization Prospects 2003

Less developed, rural

Less developed, urban

More developed, urban

More developed, rural

2008-09-23 Joel E. Cohen 45

Total fertility rates decline

from rural to urban areas.

Montg

om

ery

et al. 2

003

2008-09-23 Joel E. Cohen 46

Modern contraceptive use increases

from rural to urban areas.

Montg

om

ery

et al. 2

003

2008-09-23 Joel E. Cohen 47

Unmet need for contraception is

greatest in rural & small urban areas.

Montg

om

ery

et al. 2

003

2008-09-23 Joel E. Cohen 48

Cities will face unprecedented

confluence of rapid increase

in total numbers of people and

numbers of elderly people.

2008-09-23 Joel E. Cohen 49

Cities old & new need to be

designed to accommodate

increasing numbers of the elderly.

Home, work, shopping

should be nearby.

2008-09-23 Joel E. Cohen 50

Cities have environmental impacts.

Cities located on coasts & at river mouths affect wetlands & coastal & offshore fisheries.

Many cities (~3% of land) are located on prime agricultural land (~10% of land). If urban area doubles with doubled population, food production could hurt.

2008-09-23 Joel E. Cohen 51Michiko Shimoda,

Rice field, Fuji City 2005

2008-09-23 Joel E. Cohen 52Michiko Shimoda,

Fuji City 2005

20 “urban agglomerations” had

more than 10 million people in 2005.

On coast or coastal river (15)Tokyo

New York-Newark

Mumbai

Shanghai

Kolkata

Buenos Aires

Dhaka

Jakarta

Los Angeles-Long Beach-Santa Ana

Karachi

Rio de Janeiro

Osaka-Kobe

Al-Qahirah (Cairo)

Lagos

Manila

Inland (5)Ciudad de México

São Paulo

Delhi

Beijing

Moskva

2008-09-23 53Joel E. Cohen

2008-09-23 Joel E. Cohen 54

Sea Level +1M

New York City

Long Beach

Atlantic City

Wildwood

Montauk

New Haven

Weiss and Overpeck, University of Arizona

from Sassen & Schroeder

2008-09-23 Joel E. Cohen 55

Weiss & Overpeck

University of Arizona

from Sassen & Schroeder

2008-09-23 Joel E. Cohen 56

Population interacts with

economics, environment & culture.

population

culture

economy environment

57

Further informationCohen, How Many People Can the Earth

Support? (W. W. Norton, NY, 1995)

Cohen, Human population: the next half

century. Science 302:1172-1175, 14 Nov.

2003

Cohen, Human population grows up.

Scientific American special issue

“Crossroads for Planet Earth” September

2005.

Cohen, Bloom, Malin, Educating All Children:

A Global Agenda (MIT Press, 2007)2008-09-23 Joel E. Cohen

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