RubensteinCh. 2. Population

Transcription

1 RubensteinCh. 2 Population

2 Icebreaker Imagining Billions Q1: The equator stretches approx. 25,000 miles around Earth. If each of the world s 6.8 billion people was allotted 1 yard of space. How many times would the current human population circle the globe? (Hint: 1,760 yards = 1 mile) Q2: If a human, beginning at birth, started to count to world s population. How many years would it take him to count all 6.8 billion people? (Note: For each second he/she would count one person)

3 Key Issues 1.) Where is the world s population distributed? 2.) Where has the world s population increased? 3.) Why is overpopulation increasing at different rates in different countries? 4.) Why might the world face an overpopulation problem?

4 Population Video Clip

5 Distribution of World s Population Population Concentrations - Four Large Population Clusters - Other Clusters Sparsely Populated Regions - Physical Environments Population Density - Arithmetic Density - Physiological Density - Agricultural Density

6 Population Cartogram Countries displayed by size of population rather than land area. Countries named on map have at least 50 million inhabitants.

7 - 4 Population Clusters: East Asia, South Asia, Southeast Asia, and Western Europe - 2/3 of World s Inhabitants live within one of these four regions - China is world s most populous country at 1.3 Billion People - China & India contain 30% of the World s Population!!!!!

8 How does physical environment impact where people live? Ecumene Portion of Earth s surface occupied by permanent human settlement Has ecumene increased or decreased throughout the years?

9 ECUMENE

10 Population Density Arithmetic Density Total number of people divided by total land area. Physiological Density Number of people supported by a unit of arable land. Agricultural Density Ratio of number of farmers to amount of arable land.

11 Arithmetic Density What is odd About Russia? -Population / Land Area = Arithmetic Density (Population Density) -Brazil 200,000,000 / 8,500,000 = 23.5 Arithmetic Density (23.5 persons per square kilometer -Measures how densely or sparsely populated a region is

12 Physiological Density -The higher the physiological density, the greater pressure that people may place on the land to produce enough food -Egypt has an arithmetic density of 75, but physiological density is 2,580..why??? -95% of population lives within Nile River Valley (small area)

13 Distribution of World Population Growth Natural Increase Rate CBR (Crude Birth Rate) CDR (Crude Death Rate) Fertility TFR (Total Fertility Rate) Mortality IMR (Infant Mortality Rate) Life Expectancy

14 Natural Increase Rate (NIR) -Current NIR in world is 1.2, meaning population of world is growing 1.2% each year -1.2% of 6.5 billion is approx. 80 million (equivalent to pop. of Germany) -Increase of the NIR to 2% would result in world pop. increasing 132 million each year -Majority of natural increase is occurring in LDCs (Less Developed Countries) -Less resources in LDCs mean it s harder to maintain population

15 Total Fertility Rates (TFR) -Avg. number of children a woman will have in her childbearing years (15-49) -Varies significantly between MDCs and LDCs -All European nations below 2.0 -China controlling TFR by issuing 1-child policy

16 Infant Mortality Rates (IMR) -Number of deaths of infants under 1 year of age -Reflects a country s health care system -Varies significantly between MDCs and LDCs

17 Crude Death Rate (CDR) -Total number of deaths per 1,000 people/per year -Why does Denmark (one of world s wealthiest countries) have a higher CDR than Mongolia (one of the poorest)? -How can the U.S. have a higher CDR than Saudi Arabia?

18 The Demographic Transition Population process with four stages, and every country is in one of them. Process has beginning, middle, and end, and is not irreversible. Also, countries do not revert to an earlier stage Stage 1: Low Growth Stage 2: High Growth Stage 3: Moderate Growth Stage 4: Low Growth

19 The Demographic Transition Q1: In what stage does greatest population increase occur? Q2: What stage is the United States currently in? Explain. Q3: Why would CBR be continually decreasing?

20 Demographic Transition Stage 1: 8000 B.C.E. to 1750 C.E. food supplies and farming unpredictable, thus CBR and CDR fluctuated frequently Stage 2: CDR decreases, while CBR remains the same. Industrial Revolution helped farmers increase food production. Stage 3: CBR decreases, while CDR continues to decrease. Economic changes cause people to have less offspring. Stage 4: CBR equals CDR.condition called Zero Population Growth (ZPG) ALL COUNTRIES ARE SOMEWHERE BETWEEN STAGE 2 & STAGE 4

21 Demographic Transition Example Economic changes cause people to have less kids Death rates decrease due to increase in food production ENGLAND If CBR and CDR are equal in Stage 4, why would population still be increasing?

22 Population Pyramids Population in a country is influenced by the demographic transition in 2 ways: percentage of population in each age group and distribution of males and females POP. PYRAMIDS -Age Distribution a.) 0-14 (Dependent) b.)14-65 c.) 65+ (Dependent) -Sex Ratio Dependency Ratio: Number of dependents (too young or old to work) compared to number of people in productive yrs.

23 CAPE VERDE CHILE DENMARK

24 Will World Face an Overpopulation Problem? Thomas Malthus on Overpopulation - Malthus s Theory - Malthus Critics Declining Birth Rates - Malthus Theory vs. Reality - Reasons for Decline World Health Threats - Epidemiological Transition Stages

25 Malthus s Theory vs. Reality -Malthus predicted population would grow faster than food production, but food production actually expanded faster than population in the 2nd half of the 20th century. -Malthus was fairly close on food production, but too pessimistic on population growth -Although world as a whole may not be in danger of running out of food, some regions with rapid growth do face shortages of food -Example: Eastern Africa grew by 2% economically per year since 1980, but population grew by 3% per year. Result = East Africa is worse today than 10, 20, 30 years ago Food & Population Malthus did not account for decreasing CBR

26 Decline of CBR -CBR has continued to decline over the past few decades -However, CDR continues to decline in the world as well thus world population continues to increase

27 Reasons for Lower CBR

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29 LDCssuffering from World Health Threats