5-3 Human Population Growth

Historical Overview  Key Concept –Like the populations of many other living organisms, the size of the human population tends to increase over time.

Historical Overview  Most of Human Existence –Population Grew Slowly –Limiting Factors Prevailed –Life Was Harsh –50% of Children Died  Lambs of God

Historical Overview  500 year ago – Population began Growing –Food supply more reliable –When practiced- sanitation, medicine & healthcare improved –Birthrates remained high –Pg. 129 – Human Pop. Growth Chart

Patterns of Growth  Exponential Growth Can Not Go On Forever! –Why not?

Patterns of Growth  Thomas Malthus – 200 years ago –Human population would be controlled by war, famine, and disease

Patterns of Growth  Demography –The scientific study of human populations  Key Concept: –Birthrates, Deathrates, and the age structure of populations help predict countries growth rates.

Patterns of Growth  Demographic Transition –Changes in birth and/or death rates –Modernized countries tend to have a decreased death rate, followed by a decreased birthrate.

Patterns of Growth  Demographic Transition has occurred only in Europe, Japan, and the USA/Canada.  Rest of the world is still growing exponentially.

Patterns of Growth  Age Structure Diagrams –Used to predict future growth –Pg. 131, Fig. 5-13

Future Pop. Growth  Billion People  Billion People at current growth rate. –May be leveling off.  Where is the breaking point?????