Human Population

Chapter 8Environmental Science

The Central Case

• China’s One-Child Policy

• How does the human population affect the environment?

Section 1• Objectives• 1. Describe how technological

advances have contributed to human population growth

• 2. Explain recent trends in population growth

• 3. Identify characteristics of human population that are studied by demographics

Section 1• Human population has undergone

tremendous growth that dwarfs all previous growth during our 200,000 years of existence.

• The world population hit 1 billion about 1800, but now is about 6.8 billion as of 2010.

• What is the largest population that Earth can sustain???.....

Section 1• Agricultural Revolution

• Around __________________ years ago human societies changed from ___________________ to _____________________.

• Results:• 1. • 2• 3• 4

Section 1• Industrial Revolution• Began in _________________• Shift from _____________ life to ___________

life.• Led to these improvements:

• 1.• 2• 3

Section 1• Sanitation• Louis Pasteur:• Things we learned:

• 1. • 2.• 3.• 4.

Section 1• Medical Technology• Things we learned:• 1.• 2.

Section 1• Changes in Agriculture• Things that changed:

• 1.• 2.• 3.

• Real Data lab

Section 1• Recent Trends in Human Population

Growth• ________________ is the number of

babies out of 1000 that die during their first year of life.

• _________________ is the average number of years an individual is expected to live.

Section 1• ______________ is how the population

changes in size during a specific period of time.

• Since the 1960’s the population rate has slowed from 2.1% to 1.2%

• Rule of 72: divide 72 by the growth rate to determine how quickly a population will double.

Section 1• Figure 4• Growth rate varies by region – in fact

some populations are actually decreasing.• Ex: Germany and Russia

Section 1• Demography• The study of human population

statistics is called __________________.• They use the same terminology we

used earlier:• 1.• 2.• 3.

Section 1• Population size• Changes every second• Population density

• Global densities• Population densities are highest in

regions with _____________________.• Population densities are lowest in regions

with _____________________.

Section 1• Population densities

• _______________ are more densely populated than regions ___________________

• Regional densities• ___________________ are more densely

populated than __________________ areas.

• Population distribution• Human population is ____________ rather

than _______________ or ___________________.

Section 2• Objectives• 1. Describe total fertility rates and

replacement fertility• 2. Explain how the age structure and sex ratio

of a population define its potential for growth• 3. Describe the demographic transition• 4. Discuss social factors that affect population

growth

Section 2• Predicting population growth• Some scientists predict the world’s

population may reach 9 billion by 2050……others project it could reach 10.5 billion by then.

• That is a big range……..so how do demographers make theses predictions?????

Section 2• Scientists use the same statistics

ecologists use to describe ecological populations:• 1

1234

• 2

Section 2• Fertility rate• _______________ refers to the number of

children a female member of a population has during her lifetime.• In the past the total fertility rate has been ___.• Recently it has _______ in many regions of the

world

• The total fertility rate for a nation that would keep its population size stable: ____________

Section 2• Age Structure and Sex Ratios• Figure 9• Quick Lab

Section 2• The Demographic Transition• The shift from high birth rates and death

rates to low birth rates and death rates• This is a 4-stage process

• 1• 2• 3• 4

Section 2• Pre-industrial Stage

• both death rates and birth rates are _______• Why??

• These populations are not likely to see much ________________.

• The Transitional Stage• Led by _________________• Birth rates are ______, death rates ___________• Population ____________

Section 2• The Industrial Stage

• Increases ___________ outside the home, especially for ______________.

• ____________children are born.• Birthrates ______________• Population growth ___________

Section 2• The Post-Industrial Stage

• Both birthrates and deathrates ____• The population __________

Section 2• Social Factors• What social factors affect a nation’s

population growth????• List them…..

Section 2• These factors also affect a country’s

population growth:• 1.• 2.• 3.

Section 2• Developing Nations

• Definition:• Tend to have higher ____________,

___________________, and _______________.• Life expectancy is ______________.• Reasons: ___________, ______________,

________________, _______________.• But, population growth of these nations

_________ that of developed nations.

Section 2• Developing countries

• National policies:• 1. • 2• 3• 4

• Empowering women

Section 2• Developed nations• Developed countries tend to have lower

population growth, but they tend to have MUCH higher resource consumption.

• 1 American can have as much environmental impact as 5 Chinese or 13 Pakistanis.

• So, who is the bigger threat to the environment??????

Section 3• Objectives• 1. Describe how humans impact their

environments• 2. Discuss the negative and positive

impacts of technology.

Section 3• Impacts of population• Affluent societies

• Tend to use more• 1• 2• 3• 4

• Affluent countries tend to have higher _______________________.

Section 3• Poor Societies

• Put different stresses on their environment

• Overwhelmed governments• Land overuse• Land clearing

Section 3• The Wealth Gap• The difference between affluent

countries and poor countries.• Leads to different social and

environmental stress• Refers to the difference in assets and

income between individuals or nations.• Figure 16

Section 3• Quality of life• What determines quality of life?

Section 3• Impacts of technology• Negative impacts

• 1.• 2• 3• 4

Section 3• Impacts of technology• Positive impacts

• 1• 2• 3