2. How has human populationgrown? 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 foodsupply, shipping methods improved,
improvedsanitation, healthcare, improved medicine Led to expanded
human growth 3. Science Behind HumanPopulation Thomas Malthus
English Economist Human population cannont grow exponentially
Limits: Famine, disease, war 4. Demography Scientific study of
human population Study a variety of social and economic factorsthat
effect human population Examines characteristics of human
populationand attempts to explain how and why humanpopulation
changes over time 5. Things that help predict different population
growth rates Birth rate Death rate Age structure 6. 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 7.
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 growthstops Only complete in a few
countries India and China high birth rate 8. Age Structure
Population depends partly on how many peopleof different ages make
up a population Age-structure diagrams Population profiles used to
predict future populationgrowth Show population of a country broken
down bygender and age group 9. 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 10.
Controlling Human Population India Compulsory sterilization China
Family planning program Benefits and bonuses Forced abortions 11.
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 12. Lower growth rate means
population growth isslowing 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
