1. POPULATION GROWTH
AND URBANIZATION
L I M I T S O F P O P U L A T I O N G R O W T H
S T R AT E G I E S F O R L I M I T I N G H U M AN P O P U L A T I O N G R O W T H
U R B AN I Z A T I O N

2. VARIABLES THAT GOVERN
POPULATION SIZE
• Increase population size: births and immigration
(individuals move INTO area).
• Decrease population size: deaths and emigration
(individuals move OUT of area).
• Population Change = (Birth + immigration) – (Deaths
+ Emigration)

3. NO POPULATION CAN GROWTH
INDEFINITELY
• Environmental resistance: combination of all factors
that act to limit the growth of a population.
• Carrying Capacity: maximum population of a
given species that a particular habitat can sustain
indefinitely.
• Food, Water, space dwindles as carrying capacity is
reached: growth rate decreases.

4. HUMAN POPULATION
• Past 200 years human population has grown
exponentially (J-curve).
• 3 Factors: Humans developed ability to expand
into almost all climate zones and habitats.
• Agriculture provided increased and steady food
supply.
• Death rates dropped due to sanitation and
medicine.

5. HUMAN POPULATION
• Currently 6 billion people on planet Earth.
• Estimated 9 billion by 2050.
• Cultural Carrying Capacity: Maximum number of
people earth could support at reasonable level of
comfort and freedom without impairing the planet’s
ability to sustain future generations in the same way.
• http://planetgreen.discovery.com/videos/focus-
earth-too-many-people.html

6. HUMAN POPULATION GROWTH
• Total Fertility Rate: the average number of children
born to women in a population during their
reproductive years.
• US population is 3rd largest in world (1. China, 2.
India).

7. BIRTH RATES AND FERTILITY RATES
• Importance of children to workforce (birth rates
higher in developing countries).
• Cost of raising and educating children (birth rates
lower in developed countries).
• Care in old age (no pensions in developing
countries- depend on children for care).
• Urbanization (better access to family planning)
• Education and employment of women.
• Average age at marriage.
• Religious and cultural beliefs.

8. DEATH RATES
• Life expectancy : 77 years developed, 67
developing
• Infant Mortality: higher in developing countries (4
million per year).
• Higher in US than Europe: inadequate healthcare
of poor women, drug addiction, high birth rate
among teens.

9. HOW CAN WE SLOW HUMAN
POPULATION GROWTH?
• Economic development: demographic transition –
as countries become industrialized populations
grow more slowly
• Family Planning: educational and clinical services.
• Empowering Women: education, ability to control
fertility, employment opportunities.
• Controversial Ideas:
http://planetgreen.discovery.com/videos/focus-
earth-no-more-children.html

10. URBANIZATION: 4 TRENDS
• 1. The proportion of the global population living in
urban areas is increasing.
• 2. The number and sizes of large urban areas is
mushrooming.
• 3. Urban growth is much slower in developed
countries than in developing countries.
• 4. Poverty is becoming increasingly urbanized,
mostly in developing countries.
http://planetgreen.discovery.com/videos/blood-
sweat-takeaways/

11. URBAN SPRAWL
• Definition: The growth of low-density development
on the edge of cities and towns.
• Problems: Eliminates surrounding agricultural and
wild lands.
• Inadequate mass transit = driving further = more
pollution = loss of nonrenewable resources.
• Economic death of many central cities.

12. REASONS FOR URBAN SPRAWL
• Affordable Land
• Relatively cheap gasoline (for the commute)
• Poor Urban planning
• Larger lot sizes
• Single family homes
• Lower crime rate
• Newer public schools

13. URBAN SPRAWL EFFECTS ON NATURAL
CAPITAL
• Degradation of land and biodiversity
• Loss of cropland
• Loss of forests
• Loss of grasslands
• Loss of wetlands
• Loss and
Fragmentation of
wildlife habitats

14. URBAN SPRAWL: DEGRADATION OF
WATER
• Increased use of surface and ground water
• Increased run off and flooding
• Increased water pollution
• Decreased NATURAL sewage treatment.

15. URBAN SPRAWL: ENERGY, AIR, AND
CLIMATE
• Increased energy use and waste
• Increased air pollution
• Increased greenhouse gas emissions
• Can enhance climate change.

16. URBAN SPRAWL: ECONOMIC EFFECTS
• Decline of downtown businesses.
• Increased unemployment in central city.
• Loss of tax base in central city.

17. URBAN SPRAWL
• http://dvc.infohio.org/index.php?option=com_cont
ent&view=article&id=11&Itemid=14&videoid=22067
• http://www.ted.com/talks/nathan_wolfe_hunts_for_
the_next_aids.html