1

Human Populations

2

History of Human Population

Early Hunter Gatherers• Nomadic, With a Strong Sense of the Earth• Practiced Intentional Birth Control

Rise of Agriculture• Necessary for Survival

• Animals became extinct via hunting and altered habitat

• Cultivation of own food

3

History of Human Population Cont…

Agriculture Gives Rise to Cities• Food Produced in Country, Consumed in City

• Less productive soil• Waste of Populations Concentrated in Cities• Population Control in Medieval Societies

• Disease• Famine• Wars

4

History of Human Population Cont..

Industrialization• Early Phases: Child labor

• Cheap source of income and cheap labor• Exponential growth of populations

• By 1900s, Birth Rate in Industrialized World Dropped

• Why?

5

Human Population Growth

6

7

8

Current World Population

Global population ?

• The global population grows by: Nearly 2.3 persons per seconds Nearly 8,343 persons per hour Over 200,234 persons per day Over 73 million persons per year

9

Rate of Global Population Changeuse: International Data Base http://www.census.gov/ipc/www/idbnew.html,

• CBR (crude birth rate) = # births / 1000 population

1990: 24 now: 20.6

• CDR (crude death rate) = # deaths / 1000 population

1990: 9 now: 8.8

• Growth Rate = (b + i) – (d + e)

1990: 1.5% now: 1.19% growth rates have come down

10

Crude Birth Rates

11

Crude Death Rates

12

Doubling Time

• Doubling Time of a population: 70/annual percentage growth rate.

Doubling time for the Human Population 800 million in 1700 1.6 billion in 1900 3.2 billion in 1965 6.4 billion in 2005

• J shaped curve

13

14

LIMITS TO GROWTH

• Thomas Malthus-excess population growth is the cause of many social and environmental problems Disease, famine and population control is only

way to stabilize• Karl Marx- oppression and exploitation are the real

causes of poverty and environmental degradation Population growth is a symptom or result of

other problems, not the source

15

HUMAN DEMOGRAPHY

• Demography - vital statistics about people• 2 demographic worlds

First is poor, young, and rapidly growing.- Less-developed countries contain 80% of

world population Second is wealthy, old, and mostly shrinking.

- Western Europe, Japan.

16

Human Population Density

17

Factors affecting birth rates and fertility rates

• Age of woman at time of marriage• Availability and affordability of birth control and

abortion• Children needed in the workforce• Costs of raising and educating children• Culture, religion, tradition• Government programs• Infant mortality

18

Factors affecting death rates

• Availability and affordability of health care, food and better nutrition

• Safer water supplies• Improvements in sanitation and pollution control• Improvements in medical and public health

19

Indicators of overall health of people in a country

• Life expectancy• Infant mortality rate-number of babies out of

every 1000 born who die before age 1

20

Human Population Dynamics

3 sources of change in population size —• Migration• Fertility• Mortality

21

Curbing Population Growth

• Family Planning Reduce births and abortions

- reduces children's social services needs- reduces risk of childbearing deaths

Effectiveness depends on program design and funding

22

Rewards and Penalties to Reduce Births

• What might work: Encourage people to have fewer children Reinforce existing customs and trends toward

smaller families Don’t penalize for already existing larger

families Increase poor family’s economic status

23

Case Study-India

• Family planning efforts began in 1952; fertility rate declined from 5.3 to 3.4 but population growth is still exponential

• Disappointing results due to: poor planning bureaucratic inefficiency low status of women extreme poverty lack of administrative & financial support

24

Curbing Population Growth

• Provide economic incentives for having less children

• Empower and educate women Access to education and paying jobs outside

home Society doesn’t suppress women’s rights

• Government family planning services• Reduce poverty and economic

development

25

Case Study-China

• Family planning efforts began in 1970• Population control program is extensive, intrusive and

strict: postpone childbearing only one child/family -->benefits

- Free education and health care- Increased personal and family incomes- Preferential housing and retirement income

effective because China is dictatorship; limited resources would have mean disaster

26

Age Structure

• Bar graph that shows the age and gender composition of a region

• horizontal axis: gender male: left-hand female: right-hand absolute number of people or %

• vertical axis: age 5-year or 10-year age groups

27

Age Structure

28

4 Stages of the Demographic Transition

• Birth rates, death rates and growth rates change through time as societies change: modernize, urbanize gain access to technology

29

Stage 1: Pre-Industrial

• High birth rates, high (at time erratic) death rates, low growth rates

• Stage for much of human history, traditional societies

• Living conditions severe

30

Stage 2: Transitional

• High birth rates, declining death rates, rising growth rates• Improvements in sanitation (water) and medicine• Ex. Europe at the start of Industrial Revolution

developing countries since the 50s/60s much of Africa today, some countries of Asia

(Afghanistan, Nepal, etc.)

31

Stage 3: Industrial

• Continued decline of death rates, declining birth rates, growth rates decline from high to lower levels

Lower death rate, in particular infant mortality rates

• Economic change: urbanization (incentive to have fewer children) Better jobs Education for women

• Mexico today

32

Stage 4 Post-Industrial

• Stage 4: birth rates are less than mortality rates

• Zero population growth or declining population growth

• Standard of living is high• Ex. Japan, many European countries