SCI 112: Introduction to Environmental Science
LECTURE NOTES - HUMAN POPULATION DEMOGRAPHY

Page number references in the below notes are to our textbook:
Pages from Raven et al. (2010)


HUMAN POPULATION GROWTH HISTORY

Beginnings of documented human population growth about 8,000 years ago|
Three areas where cities developed first
     Middle East (Mesopotamia)
     Mexico and central America
     southern China
All these areas developed as a result of domestication of animals and agriculture

From 500 BC to 1700 world population growth very little if any
Growth due to:
     expansion to new areas
     development of agricultural systems
Decreases due to:
     disease & plague (black death - bubonic plague)
     wars
     starvation (including those due to natural disasters)

Major change in humans in 1700: Industrial Revolution
     Development of a mechanized method to produce products
     The result was more production for less work
The process greatly affected human population growth
     reduced death rate, then later birth rates
     process appears to be by country

 

f7-03_human_population_

 

SEVERAL VIEWS ON CAUSE/EFFECT OF LIMITING HUMAN POPULATION GROWTH
Events linked in limiting growth:
     a) excess population growth
     b) resource depletion, pollution, overcrowding, unemployment
     c) poverty
     d) starvation, disease, crime, misery
     e) war
Malthusian idea = population growth is the cause of social and environmental problems (a)
Marxist idea = population growth is a result of exploitation & oppression
(b)

f7-04_a_thomas_malthus_

 

DEMOGRAPHY
      = statistical study of a population and their influence on social, economic and environmental conditions
Why study? -- to make social, political and resources decisions

Human population in 2008 measured at 6.7 billion!
     two countries now have over 1 billion persons (table 8.1, p. 183)
     China - 1.33 billion
     India - 1.15 billion
     USA - 305 million
(0.3 billion)

To study growth rate, one needs information on:
     1) Births - Number of births
             Birth Rate = number per 1000 individuals
     2) Deaths - Number of deaths
             Death Rate = number per 1000 individuals
Use this to calculate the Overall Growth Rate:
     birth rate - death rate

Natural populations at optimum will have exponential growth
For humans is expressed as either:
      1) a proportion: 15 per 1,000
      2) a percentage: 1.5%
Human average for planet = 1.4%
     data is commonly collected by country:
          USA: 0.6%
 
        China: 1.0%
         
India: 1.9%
         
Iraq: 2.8%
     Africa with highest percentages (2-3+ %)
     South America & Asia with 1-2%
     North America Australia & Europe up to 1%

DEMOGRAPHIC TRANSITION
     
= process of change in a human population as it transitions from an agricultural to industrialized country

* Several stages to the process:
1) Preindustrial (= predevelopment)
     much work is done by hand, low productivity
     poor health care, medical, and sanitary situations
     high birth rate, high death rate
     population numbers remain relatively constant
     Ex: Amerindians of South America
2) Transitional
     new machinery introduced, increased productivity
     health care, medical, and sanitation improves
     death rate decreases, birth rate remains high
     population numbers jump upward
     Ex.: India, China
3) Industrializing
     society values shift to monetary, not human resources
     health care, medical, and sanitation good
     death rate low, birth rate decreases
     population numbers stabilize
     Ex.: USA
4) Postindustrial (= developed)
     most of society relates to money, not human resources
     health care, medical, and sanitation good
     birth rate continues to decrease
     population numbers decline
     Ex.: Sweden & some other European countries

Graphical representation of changes:

 

f7-14_theoretical_birth

 

 

DEMOGRAPHIC TRANSITION AND WORLD POPULATION GROWTH
     with the transition, population numbers increase!
     how much of the world has gone through the transition?
     how much population growth will there be in the near future?

USA & Europe went thru demographic transition by 1930
     Much of remainder of world in process now
     big problem due to a large % of world population
     several countries trying to limit natural process

Mechanisms to stop population growth with demographic transition:
1) go through process quickly
2) develop and advertise family planning programs
      common in India & China
      birth control
3) create tax incentives and laws to limit family size
      increased taxes for more than 2 children
      get women into work force

UNIQUE HUMAN FEATURES RELATED TO POPULATION GROWTH
1) Population density NOT related to density of resources
     densely populated countries have a smaller resource base
     we have developed cities (urbanization)
          in 1970 37% of humans lived in a city (10,000 +); expected by 2005 about 50%

2) Life expectancy has changed significantly
     has greatly increased over last 20 years
     among highest of world in USA - 76 years
     lowest in African countries - 45 years

3) Immigration makes the story more complex
     immigration usually occurs into more-developed regions (such as the USA)
     the migration changes the demographics of each country

4) Fertility rates vary greatly between countries for social reasons
     undeveloped countries still have a high social value on children
     developed countries place more value on money
5) The role of women in society varies greatly
     complain in USA of < 50% of work force being female; some countries with essential no women in control
     educational levels different
     Why should we care?
           fertility rate tied to women
           educated women with lower fertility
           lower fertility means slowed population growth

WHAT CAN YOU DO TO HELP LIMIT POPULATION GROWTH?
1) have fewer children and support those who think the same
        if you wish to have children around - why not adopt?
        if your wish them to be genetically yours - how about 1, or at most 2?
2) advocate family planning
        use contraceptives and advertise their use
        this helps prevent unwanted pregnancies & reduces abortions
3) buy locally grown produce, or grow your own -
        many foreign countries are killing themselves by exporting
4) support and mandate equal opportunities for women
        women in work force are less likely to have children
        educated women are less likely to have children
5) advocate positive thinking and respect for all life
        help support a life of dignity for all
6) help foster children in developing countries
        food, sanitary water, and an EDUCATION
        want the communities to become self-sufficient