1. Human Population
Ch 5.

3. How has human population
grown?
 Slowly over time
 Scarce food and incurable disease
 Death rate high
 Families had many childern
 500 years ago
 Rapid growth
 Why?
 Agriculture, industrial; revolution, better food
supply, shipping methods improved, improved
sanitation, healthcare, improved medicine
 Led to expanded human growth

4. Science Behind Human
Population
 Thomas Malthus
 English Economist
 Human population cannont grow exponentially
 Limits: Famine, disease, war

5. Demography
 Scientific study of human population
 Study a variety of social and economic factors
that effect human population
 Examines characteristics of human population
and attempts to explain how and why human
population changes over time

6.  Things that help predict different population
growth rates
 Birth rate
 Death rate
 Age structure

7. Hypothesis
 These countries have completed a “demographic
transition”, a dramatic change in birth and death
rates
 Historically: humans have high birth and death rates
 500 years ago a change began: High birth rate and
LOW death rate
 Because of better conditions of living

8. Demographic Transition
 Dramatic change in birth rates and death rates
 Low Death rate, High Birth rate
 From 1760 to 1910
 Society modernizes
 Increase level of education
 Raise standars of living
 Families have fewer children
 Birth rate decreases
 Population growth slows
 Demographic transition complete when:
 Birth rate falls to meet death rate and population growth
stops
 Only complete in a few countries
 India and China high birth rate

9. Age Structure
 Population depends partly on how many people
of different ages make up a population
 Age-structure diagrams
 Population profiles used to predict future population
growth
 Show population of a country broken down by
gender and age group

11. Age structure in US
 Equal # of people in each age group
 Slow and steady growth rate for near future
Age Structure in Nigeria
• More young children than teenagers
• More teenagers than adults
• Population will double in 30 years

13. Controlling Human Population
 India
 Compulsory sterilization
 China
 Family planning program
 Benefits and bonuses
 Forced abortions

14. Predicting Future Population Growth
 Many factors
 Age structure of countries
 Prevalence of life threatening diseases
 By 2050
 9 billion
 Growth will level off or decrease if countries growing
rapidly go through demographic transition

15.  Lower growth rate means population growth is
slowing by it is STILL growing
 How does this effect environment?
 Ecologists predict that if this growth does not slow even
more there will be Serious damage to
 Environment
 Global economy
 Other ecologists predict that science, technology, and
changes in society will control those negative impacts
on economy and environment