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Objective and Warmup: 11/8/10

• Objective: SWBAT Evaluate the different methods of taking a

population census.

• Warmup: Provide ways ecologists measure

populations.

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Human Populations

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History of Human Population

Early Hunter Gatherers• Nomadic, With a Strong Sense of the Earth• Practiced Intentional Birth Control

Rise of Agriculture• Necessary for Survival

• Animals became extinct via predation and altered habitat

• Humans began to cultivate own food

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History of Human Population Cont…

Agriculture Gives Rise to Cities• Food Produced in Country, Consumed in City

• Food wastes are no longer returned to soil• Soil becomes less productive

• Waste of Populations Concentrated in Cities• Population Control in Medieval Societies

• Disease• Famine• Wars

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History of Human Population Cont..

Industrialization• View of Children During Early Phases of Industrial

Growth• Valued as cheap source of income and cheap

labor• Exponential growth of populations

• By 1900s, Birth Rate in Industrialized World Dropped

• Rise in standards of living• Safe and inexpensive means of birth control

introduced• Increase in the cost of child rearing

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Human Population Growth

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0

2000

4000

6000

8000

10000

1750 1950 1995 2025 2100

developed countries

less developed countries

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Current World Population

Global population on November 2, 2009 at 7:23 am U.S. 307,841,263

World 6,794,428,411 • The global population grows by:

Nearly 2.3 persons per seconds Nearly 8,343 persons per hour Over 200,234 persons per day Over 73 million persons per year

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How Much is a Billion?

• 1,000 seconds = 16.7 minutes• 1 million-s = 16,677 min = 11.6 days• 1 billion-s = 11,574 days = 31.7 years

• 1,000 pennies = ~ 88 ounces = 5.5 pounds• 1 million pennies = 5,500 pounds (~1-Suburban)• 1 billion pennies = 2,750 tons (~2 Space

Shuttles)

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Objectives and Warmup: 11/9/10

• Objectives: SWBAT Apply the rule of doubling time to

the provided scenarios.

• Warmup: If the current rate of human population

growth continues, the number of people on Earth will double in the next 50 years. Will this rapid growth actually occur?

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Rate of Global Population Changeuse: International Data Base http://www.census.gov/ipc/www/idbnew.html,

• CBR (crude birth rate) = # births / 1000 population

1990: 24 now: 20.6

• CDR (crude death rate) = # deaths / 1000 population

1990: 9 now: 8.8

• Growth Rate = (b + i) – (d + e)

1990: 1.5% now: 1.19% growth rates have come down

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Crude Birth Rates

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Crude Death Rates

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Doubling Time

• Doubling Time of a population: 70/annual percentage growth rate.

Doubling time for the Human Population 800 million in 1700 1.6 billion in 1900 3.2 billion in 1965 6.1 billion in 2000

• In 2000, each second 4-5 children born, 2 people died• J shaped curve

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• Women could have 15 children in their lifetime. Yet across the world, they only have 2 ½ children on average. Why is that? Which factors influence the number of children born to each woman, and what effects do they have?

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Objectives and Warmup 11/11/10

• Objective: SWBAT Analyze the factors that affect birth and

death rates between developing and developed countries.

• Warmup: If a population of 100,000 has 2,700 births

per year and 900 deaths per year, what is its growth rate in percent per year?

Calculate the doubling time for a population with a 1.3% growth rate.

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LIMITS TO GROWTH

• Thomas Malthus-excess population growth is the cause of many social and environmental problems Disease, famine and population control is only

way to stabilize• Karl Marx- oppression and exploitation are the real

causes of poverty and environmental degradation Population growth is a symptom or result of

other problems, not the source Slow population growth through social

justice.

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HUMAN DEMOGRAPHY

• Demography - vital statistics about people such as births, deaths, where they live, and population size.

• 2 demographic worlds First is poor, young, and rapidly growing.

- Less-developed countries contain 80% of world population, and will account for 90% of projected growth.

Second is wealthy, old, and mostly shrinking.- Western Europe, Japan.

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Human Population Density

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Factors affecting birth rates and fertility rates

• Age of woman at time of marriage• Availability and affordability of birth control and

abortion• Children needed in the workforce• Costs of raising and educating children• Culture, religion, tradition• Government programs• Infant mortality

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Factors affecting death rates

• Availability and affordability of health care, food and better nutrition

• Safer water supplies• Improvements in sanitation and pollution control• Improvements in medical and public health

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Indicators of overall health of people in a country

• Life expectancy-average number of years a newborn infant can expect to live

• Infant mortality rate-number of babies out of every 1000 born who die before age 1

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Objectives and Warmup: 11/12/10

• Objectives: Analyze factors that affect population size.

• Warmup: Why are life expectancies and infant

mortality rates in highly developed and developing countries so different?

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Human Population Dynamics

3 sources of change in population size —• Migration• Fertility• Mortality

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Migration-Influencing Population Size

Most countries restrict immigration Canada, Australia, U.S. - most immigration

• ~1% of developing nations pop. Emigrates• Migration from rural to urban areas

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Family Planning

• Reduce births and abortions reduces children's social services needs reduces risk of childbearing deaths

• Effectiveness depends on program design and funding: good in some countries with good program poor in other countries

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Rewards and Penalties to Reduce Births

• What might work: Encourage people to have fewer children Reinforce existing customs and trends toward

smaller families Don’t penalize for already existing larger

families Increase poor family’s economic status

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Case Study-India

• Family planning efforts began in 1952; fertility rate declined from 5.3 to 3.4 but population grow is still exponential

• Disappointing results due to: poor planning bureaucratic inefficiency low status of women extreme poverty lack of administrative & financial support

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Curbing Population Growth

• Provide economic incentives for having less children

• Empower and educate women Access to education and paying jobs outside

home Society doesn’t suppress women’s rights

• Government family planning services• Reduce poverty and economic

development

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Case Study-China

• Family planning efforts began in 1970• Population control program is extensive, intrusive and

strict: postpone childbearing only one child/family -->benefits

- Free education and health care- Increased personal and family incomes- Preferential housing and retirement income

effective because China is dictatorship; limited resources would have mean disaster

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Objectives and Warmup

• Objectives: Analyze age structure distributions to determine

the difference between developing and developed countries.

• Warmup: In 2050, there will be approximately 9 billion

people in the world, according to the most widely accepted estimate. What problems might this create for developing countries? What challenges will industrialized nations face?

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Age Structure

• Bar graph that shows the age and gender composition of a region

• horizontal axis: gender male: left-hand female: right-hand absolute number of people or %

• vertical axis: age 5-year or 10-year age groups

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Age Structure

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Objectives and Warmup: 11/16/10

• Objectives: Analyze age structure distributions to

determine if the country is considered to be developed or developing.

Analyze age structure distributions to determine the future population of a specified country.

• Warmup: Describe at least three factors that

determine whether a nation is classified as a developed or developing country.

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Developed vs. Developing…

standard of living•     literacy rate•     birth rate•     death rate, esp. infant mortality rate•     per capita GDP•     degree of urbanization•     life expectancy•     health care system•     educational system, esp. opportunities for women•     amount of infrastructure•     global vs local market economy•     use of technology

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Objectives and Warmup: 11/17/10

• Objectives: Analyze the demographic transition model

using classroom data

• Warmup: Compare the reproductive rights of women

in a highly developed nation (other than the USA) with their counterparts in one of the least developed nations.

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4 Stages of the Demographic Transition

• Birth rates, death rates and growth rates change through time as societies change: modernize, urbanize gain access to technology

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Stage 1: Pre-Industrial

• High birth rates, high (at time erratic) death rates, low growth rates

• Stage for much of human history, traditional societies

• Living conditions severe

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Stage 2: Transitional

• High birth rates, declining death rates, rising growth rates• Improvements in sanitation (water) and medicine• Ex. Europe at the start of Industrial Revolution

developing countries since the 50s/60s much of Africa today, some countries of Asia

(Afghanistan, Nepal, etc.)

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Stage 3: Industrial

• Continued decline of death rates, declining birth rates, growth rates decline from high to lower levels

Lower death rate, in particular infant mortality rates

• Economic change: urbanization (incentive to have fewer children) Better jobs Education for women

• Mexico today

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Stage 4 Post-Industrial

• Stage 4: birth rates are less than mortality rates

• Zero population growth or declining population growth

• Standard of living is high• Ex. Japan, many European countries