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Human Population and Its Impact Milton High School AP Environmental Science

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What is demography and why is it important? The study of the vital statistics that affect population size. - Size - Age Distribution - Density - Dispersion

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Today about same pop. size

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Tanzania has about 45% of its population under the age of 15 compared to Spain with 15% of its population under the age of 15

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By 2050 Tanzania will have 4% of its population 65 or older and Spain will have 33% of its population 65 or older What problems will this cause for Spain?

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Water well in India

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August 25, 2011 World PopulationUnited States Population 6,957,846,471 312,067,591 September 8, 2013 World PopulationUnited States Population 7,110,071,755316,633,832 Commuter train in India Outhouse in Bangladesh

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How long will it take for you to count 1 million dollars at 1 dollar per second for 8 hours per day? How long will it take you to count 1 billion dollars at the same rate? If someone asked you how big is a billion, what would you say? Current world human population is about 7,110,075,000 Do you think if every human on Earth was to hold hands they would be able to stretch around the Earths equator (about 24,900 miles)? Could we stretch to the Moon (238,857 miles)? How about stretching to the Sun (93 million miles)? Support your answer with math.

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Is the world overpopulated? The worlds population is over 7 billion people The debate over interactions among population growth, economic growth, politics, and moral beliefs is one of the most important and controversial issues in environmental science.

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Is most of the worlds population in developed or developing countries?

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Nearly all future population growth will be in the Worlds less developed countries

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Can our Earth support more people? Some argue that the planet has too many people. Some feel that the world can support billions of more people due to technological advances. There is a constant debate over the need to reduce population growth. (Must consider moral, religious, and personal freedom.)

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Human Population Growth

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1.2% This adds 80 million people a year. World population growth rate

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Population Growth Variables Crude Birth Rate (CBR) Crude Death Rate (CDR) Immigration Emigration Density Dependant Factors Density Independent Factors Cultural Practices Technology Revolutions

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Factors Affecting Human Population Size Births Deaths Migration

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Crude Birth Rate the number of births per 1,000 people in a population in a given year

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Crude Death Rate: the total number of deaths per 1000 people. Usually it is measure per country. The crude death rate for the whole world is currently about 9.6 per 1000 per year (based on 62 million deaths in 2006, for a population of 6470 million).

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Crude Birth Rate Crude Death Rate

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Total Fertility Rate (TFR) the average number of children a woman typically has during her reproductive years.

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Poverty affects population growth Develop Countries Growth Rate 0.1% Less Developed Countries Rate 1.15%

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Population Growth Rate The average annual percent change in the population, resulting from a surplus (or deficit) of births over deaths and the balance of migrants entering and leaving a country. The rate may be positive or negative. The growth rate is a factor in determining how great a burden would be imposed on a country by the changing needs of its people for infrastructure (e.g., schools, hospitals, housing, roads), resources (e.g., food, water, electricity), and jobs. Rapid population growth can be seen as threatening by neighboring countries. https://www.cia.gov/library/publications/the-world-factbook/fields/2002.html CIA World Factbook

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Factors affecting fertility and births Infant mortality rate Average age at marriage Ability of Legal Abortions Availability of Reliable Birth Control Methods Religious beliefs, traditions, and cultural norms Importance of children as part of the labor force Cost of raising and educating children Availability of private and public pension systems Urbanization Educational and employment opportunities available for women Importance of young adults joining the military

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How can family planning help? Birth Spacing Birth Control Health Care for Pregnant Women Health Care for Infants

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Key Factors to Fewer Children Ensuring education Having jobs outside the home Living in societies where their rights are not suppressed

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Two useful indicators of overall health of people in a country or region Life expectancy Infant mortality rate

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Life Expectancy the average number of years a newborn infant can expect to live

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Infant Mortality Rate the number of babies out of every 1,000 born who die before their first birthday

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Why death rates have declined Food supplies and distribution Better nutrition Medical advances in vaccines and antibiotics Improved sanitation Safer water supplies

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Infant mortality and female literacy

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Age structure diagrams Shows the distribution of various age groups in a population. A great deal of information about the population broken down by age and sex can be read from a population pyramid, and this can shed light on the extent of development and other aspects of the population.

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Populations with a large proportion of its people in the pre-reproductive ages of 1-14 have a large potential for rapid population growth

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Teenagers and Pyramids The number of people under age 15 is the major factor determining a countrys future population growth. Population pyramids can be used to find the number of economic dependents being supported in a particular population. 30% (1.9 billion) of people on the planet were under 15 years of age in 2004.

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Economic Projections Who will need education Who will need jobs Who will determine markets Who will affect elections Who will need Medicare

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How do human populations develop economically?

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Demographic Transition Model A model used to explain the process of shift from high birth rates and high death rates to low birth rates and low death rates as part of the economic development of a country from a pre- industrial to an industrialized economy.

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Pre-industrial stage (Stage 1) High birth and death rates Low medical care (natural meds) Population limited by food availability (internal)

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Transitional Stage (Stage 2) Increased food production Better medical care (esp. antibiotics) Improved sanitation (esp. drinking water) Decreased death rate Birth rate stays high (cultural norms) Period of rapid growth rate

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Industrial Stage (Stage 3) Need for increased labor force Availability of education (esp. female) Delay in age of 1st reproduction Change in cultural norms Birth rates decline toward zero population growth (ZPG)

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Post-industrial Stage (Stage 4) Industrial system no longer supports population High unemployment, poverty Food supplies diminish Environmental health declines (high disease) Social strife (disease, famine, war) Increased death rates and decreased birth rates

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Problems associated with rapid population decline Can threaten economic growth 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 healthcare

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Why did China introduce a one-child policy in 1979? China had of Worlds population Occupied just 7% of Worlds arable land 2/3 of population under the age of 30 Baby-boomers (1950 60) were entering reproductive years Introduced family planning policy Economic reform Improvement of living standards

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Chinas One-child Family Policy Restriction on family size Late marriage and child-bearing Spacing of children (cases in which 2 nd child permitted) Strictly enforced for urban residents and government employees Exceptions 1 st child has a disability Both parent work high-risk jobs (e.g. mining) Themselves from a one-child family Rural areas 2 nd child generally allowed if first child was a girl

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Chinas One-child Policy Systems of Rewards and Penalties Incentives for compliance Choice of jobs Retirement funds Preferential healthcare Free homes and free water Children receive bonus points on middle school entrance exams Non-compliant penalties Substantial fines (3x the family annual income) Confiscation of belongings Dismissal from work Forced abortions

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Chinas One-child Policy - Successful or failure? Has decreased population by about 250 million Has prevented 400 million births Implementation more successful in urban areas than rural areas Concerns over workforce shortage Concerns if young population will be able to care for ageing population Demographic imbalance By 2020 could have 30 million unmarried men

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Altering nature to meet our needs Reduction of biodiversity Increasing genetic resistance of pest species Elimination of many natural predators Introduction of invasive species Unsustainable use of renewable resources Interfering with earths biogeochemical cycles Overuse of fossil fuels

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