1. Introduction to Environmental Science
Chapter 6: Human Population and Urbanization

2. CASE STUDY
Are there too many of us?

3. 6-1 How many people can the Earth support?
The human population has grown rapidly due to technology, improved medical techniques, emphasis on hygiene, and expansion of agriculture and industry.
Population growth has slowed but is troubling because we do not know how long we can continue without overshooting earth's carrying capacity for humans.
No population, including humans, can continue to grow indefinitely.
"We do not know how long we can continue increasing the earth’s carrying capacity for humans without seriously degrading the life-support system that keeps us and many other species alive. "

4. Natural Capital Degradation
Altering Nature to Meet Our Needs
Reduction of biodiversity
Increasing use of the earth's net primary productivity
Increasing genetic resistance of pest species and disease-causing bacteria
Elimination of many natural predators
Introduction of potentially harmful species into communities
Using some renewable resources faster than they can be replenished
Interfering with the earth's chemical cycling and energy flow processes
Relying mostly on polluting and climate-changing fossil fuels

5. 6-2 What Factors Influence the Size of the Human Population?
3 Factors of Human Population Birth: Fertility Death: Mortality Migration: Emigration and Immigration Population increases through births and immigration and decreases through deaths and emigration. [Population change = (Births + Immigration) - (Deaths + Emigration)] The crude birth rate is the number of live births per 1,000 people in a population in a specific year The crude death rate is the number of deaths per 1,000 people in a population in a specific year.

6. UN WORLD POPULATION PROJECTION BY 2050

7. FERTILITY
Fertility is the number of births that occur to an individual woman or in a population.
1. The changing nature of fertility rates affect population growth.
a. Replacement-level fertility is the number of children needed to replace their parents.
b. Total fertility rate (TFR) is the average number of children that a woman has during her fertile years.

8. Factors Influence Birth and Fertility Rate
1. More children work in developing countries; they are important to the labor force.
2. The economic cost of raising and educating children determines their numbers.
3. If there are available private/public pension systems, adults have fewer children because they don't need children to take care of them in old age.
4. People in urban areas usually have better access to family planning, so have fewer children.
5. If women have educational and economic choices, they tend to have fewer children.
6. When the infant mortality rate is low, people have fewer children.
7. The older the age at which women marry, the fewer children they bear.
8. If abortions are available and legal, women have fewer children.
9. The availability of reliable birth control allows women to space children and determines the number of children they bear.

9. Factors that have caused a decline in death rates are the following:
1. Better food supplies and nutrition, and safer water supplies contribute to people living longer.
2. Advances in medicine and public health, and improved sanitation and personal hygiene also contribute to people living longer.

10. Measures of overall health
1. Life expectancy is the average number of years a newborn can expect to live.
2. Infant mortality rate is the number of babies out of every 1,000 born who die before their first birthday.
a. This rate reflects a country's level of nutrition and health care.
b. It is the single best measure of a society's quality of life.
3. U.S. infant mortality rate is higher than 40 other countries because:
a. Inadequate health care for poor women and for their babies.
b. Drug addiction among pregnant women.
c. High birth rate among teenagers.

11. Migration
Historically, the United States has admitted more immigrants than all other countries combined. Some 60% of the U.S. population supports limiting legal immigration. A recent study suggests that to maintain a viable workforce as baby boomers retire, the U.S. would have to absorb many more immigrants per year than it currently does. However, a reduction in immigration may help mediate the enormous environmental footprint the United States currently has.

12. THE U.S. POPULATION IS GROWING RAPIDLY
CASE STUDY
THE U.S. POPULATION IS GROWING RAPIDLY

13. BIRTH RATE IN U.S. ( )

14. THE UNITED STATES: A NATION OF IMMIGRANTS
CASE STUDY
THE UNITED STATES: A NATION OF IMMIGRANTS

15. • Immigration – legal and illegal – 39% population growth
• 1820–1960: Most immigrants European
• Since 1960
– Latin America – 53%
– Asia – 25%
– Europe – 14%

16. • Opponents of immigration
– Stabilize population sooner
– Reduce growing environmental impact
– 60% of population favor reducing immigration
• Proponents of immigration
– Important historical role
– Do menial jobs and pay taxes
– Add cultural vitality
– Replace retiring baby boomers

17. 6-3 HOW DOES POPULATION'S AGE STRUCTURE AFFECT ITS GROWTH AND DECLINE?
GENERALIZED POPULATION AGE STRUCTURE DIAGRAMS

18. POPULATION AGE STRUTURE BY AGE AND SEX IN DEVELOPED AND DEVELOPING COUNTRIES

19. TRACKING THE BABY-BOOM GENERATION IN THE UNITED STATES

20. Some Problems with Rapid Population Decline
Can threaten economic growth
Labor shortages
Less government revenues with fewer workers
Less entrepreneurship and new business formation
Less likelihood for new technology development
Increasing public deficits to fund higher pension and health-care costs
Pensions may be cut and retirement age increased

21. RISING DEATH RATE: THE AIDS TRAGEDY
25 million killed by 2008
Many young adults die: loss of most productive workers
Sharp drop in life expectancy
International community called upon to
Reduce the spread of HIV through education and health care
Financial assistance and volunteers

22. 6-4 HOW CAN WE SLOW HUMAN POPULATION
Demographic transition stages
Preindustrial
Transitional
May lead to a demographic trap
Industrial
Postindustrial

24. FAMILY PLANNING
Information is given on birth spacing, birth control, and health care.
Family planning has been responsible for at least 55% of the drop in TFRs in developing countries.
Family planning has also reduced both legal and illegal abortions per year.
Services come through educational and clinical services.
Almost one-half of pregnancies in developing countries are unplanned and 26% end in abortion.
Women want to limit their pregnancies but have no access to contraceptives.
Empowering women by providing education, paying jobs, and support for their human rights can slow population growth.
Women work two-thirds of all the hours worked, but receive 10% of the world’s income.

25. SLOWING POPULATION GROWTH IN CHINA
CASE STUDY
SLOWING POPULATION GROWTH IN CHINA

26. POPULATION GROWTH IN CHINA
One-child families
Halved birth rate and drastically reduce TFR
Improved quality of life
Strict family planning
Sons still preferred – gender imbalance
Population growth in China has been controlled by a strongly enforced government program. Between 1972 and 2004, China’s birthrate was cut in half. Couples with one child are rewarded with extra food, larger pensions, better housing, bonuses, free school tuition, and preferential employment treatment for the child. China currently faces challenges relating to a large elderly population and a larger male population of more males than females. As the economy continues to grow, China’s ecological footprint is bound to expand.

27. POPULATION GROWTH IN CHINA
Population rapidly aging
Rapidly growing economy
Larger middle class increases resource consumption and waste
Sustainable economic plan needed to avoid environmental degradation

28. SLOWING POPULATION GROWTH IN INDIA
CASE STUDY
SLOWING POPULATION GROWTH IN INDIA

29. POPULATION GROWTH IN INDIA
Tried to slow population growth for five decades
Most populous country in 2015
Population Control: Gender bias
Problems increase with growing population
Poverty
Malnutrition
Environmental degradation
Growing middle class – resource consumption
India has tried to control its population growth for years. Poverty, malnutrition, and environmental problems abound in India. Efforts to limit population have not been especially successful because poor couples believe they need several children for work and care ,and there is a strong preference for male children so many do not use birth control. India is currently undergoing tremendous economic growth that will likely continue. This may increase the ecological footprint of the nation, but may also serve to hasten the demographic transition.

30. 6-5 WHAT ARE THE MAJOR URBAN RESOURCE AND ENVIRONMENTAL PROBLEM
URBAN LIVING
Half the world lives in urban areas
79% of Americans live in cities
50% of world population lives in cities
Urban areas continue to grow
Natural increase
Immigration
Major Trends in Urban Growth
Proportion of urban global population growing
Number and sizes of urban areas mushrooming
Rapid increase in urban populations in developing countries
Urban growth slower in developed nations
Poverty increasing

31. AS OF 2005

34. URBANIZATION IN UNITED STATES
CASE STUDY
URBANIZATION IN UNITED STATES

35. URBANIZATION IN UNITED STATES
1800–2009: urban population increased from 5% to 79%
Migration patterns
Rural areas to large cities
Large cities to suburbs and smaller cities
Cities and suburbs to rural areas
North and East to South and West
Better working and housing conditions compared to the past
Improved environmental conditions
Problems in urban areas
Aging infrastructure
Budget problems

36. URBAN SPRAWL CAUSES Prosperity Ample and affordable land Automobiles
Cheap gasoline
Poor urban planning

37. URBAN SPRAWL PROBLEMS Increased automobile use
Decreased energy efficiency
Destruction of cropland, forests, wetlands
Economic deaths of some cities

38. 1973
2003
Urban sprawl in and around the U.S. city of Las Vegas, Nevada, between 1973 and 2003.

39. Natural Capital Degradation
Urban Sprawl
Economic Effects
Land and
Biodiversity
Water
Energy, Air,
and Climate
Loss of cropland
Loss of forests and
grasslands
Loss of wetlands
Loss and
fragmentation of
wildlife habitats
Increased use of surface
water and groundwater
Increased runoff and
flooding
Increased surface water
and groundwater
pollution
Decreased natural
sewage treatment
Increased energy use
and waste
Increased air pollution
Increased greenhouse
gas emissions
Can enhance climate
change
Decline of
downtown business
districts
Increased
unemployment in
central city
Loss of tax base in

40. ADVANTAGES OF URBANIZATION
Economic development
Innovation
Education and jobs
Technological advances
Longer life spans
Better social and medical services
Recycling more feasible
Biodiversity increased
Increased energy efficiency

41. DISADVANTAGES OF URBANIZATION
Unsustainable systems
Lack of vegetation
Water problems
Pollution and health problems
Noise pollution
Climate and artificial light
Urban heat islands
Light pollution

42. Inputs Outputs Solid wastes Energy Waste heat Food Air pollutants
Water pollutants
Greenhouse gases
Manufactured goods
Noise
Wealth
Ideas
Information
Energy
Food
Water
Raw
materials
Manufactured
goods
Money

43. CASE STUDY
MEXICO CITY

44. MEXICO CITY Large population Severe noise, water, and air pollution
50% unemployment
100,000 premature deaths per year
3 million without sewer
Fecal snow
Geography contributes to air pollution
Progress – tree planting and lower air pollution

45. 6-6 HOW DOES TRANSPORTATION AFFECT URBAN ENVIRONMENTAL IMPACT
Concept 6-6 In some countries, most people live in dispersed urban areas and depend mostly on motor vehicles for their transportation.

46. Cities Can Grow Outward or Upward
Compact cities
Transportation by walking, biking, or mass transit
Hong Kong, Tokyo
Dispersed cities
Transportation by automobile
Most American cities

47. Trade-Offs Bicycles Advantages Disadvantages Are quiet and
non-polluting
Provide little
protection in an
accident
Take few
resources to
make
Provide no protection
from bad weather
: Advantages and disadvantages of bicycles. The key to increased bicycle use is the creation of bicycle-friendly systems, including
bike lanes. Bicycling and walking account for about a third of all urban trips in the Netherlands and in Copenhagen, Denmark, compared
to only 1% in the United States. Paris, France, has almost 21,000 bikes available for rental at 1,450 rental stations throughout the city at a cost
of just over $1 a day.
Burn no fossil
fuels
Are impractical for
long trips
Require little
parking space
Secure bike parking
not yet widespread

48. Trade-Offs Mass Transit Rail Advantages Disadvantages Uses less energy
and produces less
air pollution than
cars do
Is expensive to build
and maintain
Is cost-effective only
in densely populated
areas
Reduced need for
more roads and
parking areas
Commits riders to
transportation
schedules
Causes fewer
injuries and
deaths than
cars do
Reduces car
congestion in
cities
Can cause noise and
vibration for nearby
residents

49. Trade-Offs Rapid Rail Advantages Disadvantages Is much more energy
efficient per rider than cars
and planes are
Is costly to run and
maintain
Causes noise and
vibration for nearby
residents
Produces less pollution
than do cars and planes
Can reduce need for more
air travel, cars, roads, and
parking areas
Has some risk of
collision at car
crossings

50. Trade-Offs Buses Advantages Disadvantages Can greatly reduce car
use and air pollution
Can lose money because
they require affordable fares
Can be rerouted as
needed
Can get caught in traffic
and add to noise and
pollution
Cost less to develop
and maintain than
heavy-rail system
Commit riders to
transportation schedules

51. Environmentally Sustainable Cities
Smart growth
Eco cities
Use renewable energy as much as possible
Build and design people-oriented cities
Use energy and matter efficiently
Prevent pollution and reduce waste
Recycle, reuse, and compost
Protect and encourage biodiversity
Promote urban gardens and farmers markets
Zone for environmentally stable population levels

52. Solutions Smart Growth Tools Limits and Regulations Protection
Limit building permits
Preserve existing open space
Urban growth
boundaries
Buy new open space
Buy development rights that
prohibit certain types of
development on land parcels
Greenbelts around cities
Public review of new
development
Taxes
Zoning
Tax land, not buildings
Encourage mixed use of
housing and small
businesses
Tax land on value of actual use
(such as forest and agriculture)
instead of on highest value as
developed land
Concentrate
development along mass
transportation routes
Promote high-density
cluster housing
developments
Tax Breaks
For owners agreeing not to allow certain types of development (conservation easements)
Planning
Ecological land-use
planning
For cleaning up and developing abandoned urban sites (brownfields)
Environmental impact
analysis
Integrated regional
planning
Revitalization and New Growth
Revitalize existing towns and cities
State and national
planning
Build well-planned new towns and villages within cities

53. THE ECOCITY CONCEPT IN CURITIBA, BRAZIL
CASE STUDY
THE ECOCITY CONCEPT IN CURITIBA, BRAZIL

54. CURITIBA, BRAZIL CURITIBA -“ecological capital” of Brazil
Inexpensive, efficient mass transit
High-rise apartments near bus routes, mixed-use structures
Bike and pedestrian paths
1.5 million trees planted
Recycling
Many services for the poor
Emphasis on ecological awareness, health, literacy

55. END OF CHAPTER 6