Human Population Growth PDF

HUMAN POPULATIO N Many factors can affect population growth. Today we're going to explore!  FUN FACT The current human population is approximately 8 billion people. It is expected to grow to 9.7 billion by 2050. Human Population Growth Historically A. Early Hunter G...

HUMAN POPULATIO N Many factors can affect population growth. Today we're going to explore!  FUN FACT The current human population is approximately 8 billion people. It is expected to grow to 9.7 billion by 2050. Human Population Growth Historically A. Early Hunter Gatherers 1. Nomadic, with a strong sense of the earth 2. Practiced intentional birth control  B. Rise of Agriculture 1. Necessary for Survival a. Animals became extinct via predation and altered habitat b. Humans began to cultivate own food  C. Agriculture Gives Rise to Cities 1. Food produced in country, consumed in city a. food wastes are no longer returned to soil Soil becomes less productive 2. Waste of populations concentrated in cities 3. Population control in medieval societies a,. Infanticide  D. Industrialization 1. View of children during early phases of industrial growth a. valued as cheap source of income and cheap labor b. exponential growth populations 2. By 1900’s birth rate in Industrialized World Dropped a. rise in standard of living b. safe and inexpensive means of birth control introduced c. increase in the cost of child CARRYING CAPACITY (K) The environment has a limited capacity to support a certain number of individuals. Carrying capacity refers to the maximum population size that can be supported in a particular area without destroying the habitat.  Increasing our Carrying Capacity a. Technology has allowed us to raise Earth’s carrying capacity for our species time and again b. Tool-making, agriculture, and industrialization each enabled humans to sustain greater populations.  Current World Population a. Global population was 6, 669, 203, 826 On February 27, 2007 at 6:13 am b. The global population grows by > Nearly 2.3 persons per second > Nearly 8, 343 persons per hour > Over 200, 234 persons per day > Over 73 million persons per year  Human Population Dynamics  There are just three sources of change in population size ------- a. fertility b. mortality A. “Natural decrease” refers to population decline resulting from more deaths than births c. migration > Net migration is the number of immigrants minus emigrants  Factors Affecting Population Growth Rates  Population growth depends on rates of birth, death, immigration, and emigration. (birth rate + immigration) – (death rate + emigration rate) = population growth rate  Rates of Global Population Change  CBR (crude birth rate) = # births/1000 population  CDR (crude death rate) = # deaths/1000 population  Growth Rate = (b + i) – (d + e) - growth rates have come down  Human Population Dynamics  Total fertility rate (TFR) a. the average number of children born to a woman b. Average in developed countries = 1.5 c. Average in developing countries = 3.8 d. Worldwide 1990:3.1 now: 2.76  Human Population Dynamics  Replacement fertility rate (RFR) a. The number of children a couple must have to replace numbers b. A TFR of 2.1 for developed countries with low infant and child mortality rates c. Africa RFR = 2.5  Female education and TFR  Female literacy and school enrollment are correlated with fertility rate.  More-educated women have fewer children What is Family Planning?  It measures enabling parents to control number of children (if they so desire)  Goals of Family Planning a. Not to limit births b. For couples to have healthy children c. For couples to be able to care for their children d. For couples to have the number of children that they want Poorer countries will experience most future population growth  98% of the next billion people born will live in developing nations China’s Program  Nation with best known population Control Program  Reasons Chinese Government Initiated Population Control Measures a. Freshwater and food at a premium for nation’s population b. Country experiencing population momentum China’s Program  Government perks/Coercive measures for Citizen Compliance a. Free education and health care b. Increased personal and family incomes c. Increased legal marrying age for women d. Contraceptives, abortions, and sterilizations free of charge e. Preferential housing and retirement income What Methods are Used to Control Births?  Perception Birth Control Methods 1. Barrier Methods a. condom b. vaginal sponge c. diaphragm d. spermicides What Methods are Used to Control Births?  Perception Birth Control Methods 2. Hormonal Contraceptives a. Pill b. Injections and implants c. Sterilization What Methods are Used to Control Births?  Postconception Birth Control Measures a. intrauterine Device b. RU-486 Pill c. Abortion Contraceptive Use Worldwide  People in industrialized countries enjoy easy access to contraceptives while those in LDC’s do not.  In the US, teens and poor women are least likely to use contraceptives.  Severe problems are associated with teen pregnancy. Human Population Dynamics  Infant Mortality Rate (IMR)  Infant deaths per 1000 live births (infant < 1 year)  1990: 62 now 52.4 (normal in 1990: 200) Migration  Net migration is the number of immigrations minus emigrants  Overall, the  Unabated,  But, the worls such a rate growth rate is population is would lead to decreasing. growing at a a point about rate of about 2000 years 1.7%; if this hence when rate the mass of continues, humanity the would weigh population more, and be will double in larger, than 42 years the Earth. HIV/AIDS and Human Population  Infects 1 in 5 people in southern African nations  Kills babies born to infected mothers  Has orphaned 14 million children  Has cut 19 years off life expectancies in parts of southern Africa Rule of 70’s > predicting long-term population growth > 70/growth rate = doubling time Example: If a population of a country grows at a rate of 5% a year, the number of years required for the pop to double is what?  Population Pyramids > graphic device: bar graph a. 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 Population Pyramids with young cohorts  Population Pyramids Population Pyramids on the Web High Growth: Afghanistan  Moderate Growth: Mexico  Zero growth: U.S  Negative growth: Austria or Italy  Population Pyramids Population Pyramids on the Web  High Growth: Afghanistan Moderate Growth: Mexico  Zero Growth: U.S  Negative Growth: Austria or Italy  Population Pyramids Population Pyramids on the Web  High Growth: Afghanistan  Moderate Growth: Mexico Zero Growth: U.S  Negative Growth: Austria or Italy  Population Pyramids Population Pyramids on the Web  High Growth: Afghanistan  Moderate Growth: Mexico  Zero Growth: U.S Negative Growth: Austria or Italy  Demographic Transitions  Movement of a nation from high population growth to low population as it develops economically  Transition because of 4 stages Stage 1 – birth and death rates are both high Stage 2 – death rates fall; birth rates remain high; growth rate rises Stage 3 – birth rates falls as standard of living rises; growth rate falls Stage 4 – growth rate continues to fall zero or to a negative rate Demographic Transitions  Population Pyramids and Demographic Stages  Characteristics shapes of “pyramids”  Wide base (true pyramid)  Wide middle (bulge), somewhat wider base  Urn or bottle-shaped  Reverse pyramid  Different shapes = different dynamics Stage 1 High birth rates, high (at time erratic) death rates, low growth rates S f o r t a ge i call of mu s h ra ct o his um ch P y n try t ra t o a n un l s diti ry, c o oc on iet a ies Stage 2 High birth rates, declining death rates, rising growth rates Improvements in sanitation (water) and medicine In Europe during Industrial Revolution  Population Pyramid and Demographic Transition Stage 2: wide base  Stage 3  Continued decline of death rates, declining birth rates, growth rates decline from high to lower levels  Change in behavior: adaptation to lower death rate, in particular infant mortality rate  Economic damage: urbanization (incentive to have fewer children Stage 3: wide middle  Stage 4 and 5  Stage 4: low birth rates, low death rates, low growth rates  Stage 5: low birth rates, rising death rates, declining growth rates (if birth rates drop below death rates: negative growth rates  Demographic Trap  Population Path of Most Less-Developed Countries (LCDs  “Trapped” in Stage 2 of Demographic Transition Before 1970, LDC’s seemed poised to make transition thanks to economic growth Since 1970, economic growth has not kept pace with population High birth and low death rates result in explosive population Downward spiral in standard of living  Demographic Fatigue  Conditioned characterized by a lack of financial resources and an inability to deal effectively with threats such as natural catastrophes and disease  Possibility that countries suffering from demographic fatigues could slip back into Stage 1 of demographic transition  Age Structure and Population Projections  Baby boomers – half of U.S. population; use most of goods and services; make political and economic decision  Baby-bust generation – born since 1965; may have to pay more income, health care and social security to support retired baby boomers; but face less job competition  Effects of Population Decline  As percentage of 60+ aged people increases, population begins decline  60+ population decline increase result to severe economic and social problems because 60+ consume: more medical care social security costly public services > Labor shortages require automation and immigration  The Graying of Japan  Family planning access, cramped housing, expensive land, late marriage, education cost would result to voluntary decrease in birth rate  Low immigration rate  Health insurance and pension – 45% of national income; could result to low economy  Illegal immigration bolsters work force The Graying of Japan  Influencing Population Size  Most countries restrict immigration Canada, Australia, U.S. – most immigration  Involuntary immigration results from - armed conflict - Environmental degradation - natural disaster lead to environmental refugees  Migration from rural to urban areas  Family Planning: reduce births and abortions  59% contraceptive use in developed countries  FP reduces children’s social services needs  FP reduces risk of childbearing deaths  FP effectiveness depends on program design and funding: good in some countries with good program poor in other countries  Family Planning: reduce births and abortions  Services not always accessible; add female teenagers and sexually active unmarried  Add birth control for men (sperm-killing device used in China)  If developed countries provided 17 billion dollars per year, and each person pays 4.80 dollar per year, average family size would be 2.1 and world population would be 2.9 billion  Rewards and Penalties to reduce births  What might work - encourage rather than coerce people to have fewer children - reinforce existing customs and trends toward smaller families - don’t penalize for already existing larger family - increase poor family’s economic status  Empowering women to reduce births  Women tend to have fewer, and healthier children when: - they have access to education and paying jobs outside home - their society doesn’t suppress women’s rights  But women do most of the work - not shown in GDP because of lower pay - women excluded from economic and political decision making  Case Studies - India  Family planning efforts began in 1952; fertility rate declined from 5.3 to 3.4 but population growth is still exponential – 1.9%  Disappointing results due to: - poor planning -bureaucratic inefficiency - low status of women - lack of administrative and financial support - extreme poverty  Case Studies - China  Family planning efforts began in 1970; TFR fell from 5.7 to 1.8  Population control program is extensive, intrusive and strict - postpone childbearing - only one child/family - China is dictatorship  Population and the environment  Population growth can lead to environmental degradation.  Overpopulation in Africa region has led to overgrazing of semi-arid lands  The wealth gap  Residents of developed nations have larger houses, more possessions, and more money than residents of developing nations  The wealth gap  The richest 20% of the world’s people consumes 86% of its resources, and has > 80 times the income of the poorest 20%  Food Hunger  840 million people are hungry  799 million of those are in developing countries  The other 40 millions are in developed countries  ½ of the US population relies on food stamps  Poverty in Developing Nations  Trade imbalances exit between developed nations and developing nations.  U.S has outsourced production to these poverty- stricken nations.  Many will work under terrible conditions and long hours because it is a better to continued poverty. Case People of Hong Kong Case People of Hong Kong Case People of Hong Kong