1. STABILIZING WORLD POPULATION
THE HUMAN POPULATION
STABILIZING WORLD POPULATION

2. HUMAN POPULATION GROWTH
Like other populations, size of human population tends to increase with time
Long ago, human population was limited by food, disease, & survival to adulthood rates were low
~500 years ago, human population began growing rapidly w/ agriculture & industry making resources readily available, improved sanitation, medicine & health care
Human Population

3. HUMAN POPULATION GROWTH
What type of growth is this showing?
Can this go on forever? Why or Why not?
Human Population

4. Human Population

5. HUMAN POPULATION GROWTH
Current World Population? 7.14 billion
Current U.S. Population? million
source: U.S. Census Bureau 1/20/2014
2005 Transitions:
Prior to 2000, young outnumbered old
Until ~2007, rural outnumbered urban
From 2003, replacement rate stalls: median woman has too few or just enough children to replace herself & the father in the next generation (Cohen, 2005)
Human Population

6. HUMAN POPULATION DISTRIBUTION

7. HUMAN POPULATION GROWTH
doubling of population
once estimated to occur every 37 years
folks who died <1930 never saw a doubling
folks born >2050 projected to not observe
population more than doubled for folks >52 today: 3 billion in 1960; 7 billion in 2011
(Cohen, 2005)
age distributions, fertility, developed vs. developing nations … implications for future?
Human Population

8. Advances in Global Health Result in a Decrease in (d)
Greater food production
Better and more accessible medical care
Improved water quality
Improved sanitation
Human Population

9. HUMAN POPULATION GROWTH
human population cannot grow exponentially forever, b/c resources limited
In 1800s, Malthus predicted war, famine & disease would limit human population growth
Today, scientists study human population including birthrates, death rates, & age structure to predict growth rates = demography
Human Population

10. HUMAN POPULATION GROWTH
demographic transition
changes in fertility, mortality, makeup
epidemiologic transition
shift in morbidity/mortality patterns from infectious/ communicable to chronic/ degenerative diseases
consequences of population increases
urbanization & the environment
Human Population

11. HUMAN POPULATION DEMOGRAPHIC TRANSITIONS
Demographers developed hypothesis to explain slowing of population growth using changing in birth & death rates = demographic transition
Initially, birthrate & death rate equally high
advances decrease death rate, while birth rate remains high (births > deaths  pop increase)
modernization decreases birthrate  population growth slows
eventually, birthrate & death rates are equally low & population growth stops
Human Population

12. HUMAN POPULATION: DEMOGRAPHIC TRANSITIONS

13. HUMAN POPULATION: IMPACT DEBATE
Many ecologists suggest that if human population growth doesn’t slow down, there could be serious and lasting damage to the environment and global economy
Other scientists believe that science, technology, and positive changes in society will help control negative impacts of humans
Human Population

14. Human Population