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Population Clock

Chapter 19: Population Ecology. Population Clock. http://www.worldometers.info/world-population/. Human Numbers Through Time: A.D. 0. Taken from Nova online. 300 million. A.D. 1000. 310 million. 1800. 1 billion 65% Asia, 21% Europe, 1% North America. 1927. 2 billion. 1960. 3 billion.

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Population Clock

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  1. Chapter 19: Population Ecology Population Clock http://www.worldometers.info/world-population/

  2. Human Numbers Through Time: A.D. 0 Taken from Nova online 300 million

  3. A.D. 1000 310 million

  4. 1800 1 billion 65% Asia, 21% Europe, 1% North America

  5. 1927 2 billion

  6. 1960 3 billion

  7. 1974 4 billion

  8. 1987 5 billion

  9. 1999 6 billion 62% Asia, 12 % Europe, 12% Africa, 9% Latin America, 5% N. America

  10. 2050 Population will more than likely will reach 9 billion people Nearly all growth will take place in developing countries

  11. Population Growth Rate PGR: increase in a country’s population during a period of time (1 year). PGR = birth rate – death rate

  12. Average Annual Population Growth Rate, 1980-98 Rapid PGR: Africa and Middle East Slowest PGR: Europe and North America

  13. Population (shown in millions) 1980: 4.4 Billion 2000: 6 Billion

  14. In the past few decades… • Death rates have declined • Living longer in both industrial and developing countries  immunization, health care, technology • Avg life expectancy: 78 • Birth rates have declined • Parents are choosing to have less children • Access to family planning • More women starting families later in life * PGR remain high though because birth rates have not fallen as much as death rates

  15. Population Growth Rate • PGR have started to decline • But will continue to increase because the population base has become larger. • Growth rates tend to be higher in low and middle-income

  16. Population momentum • Phenomenon that occurs when a large proportion of a country’s population is of childbearing age. • Occurs in low-income countries • More than a third of the population is under the age of 15

  17. Why so many children? • Fear their babies may die • Need laborers to work • Ensure that they themselves will be cared for in their old age • Lack access to education and to family planning

  18. To reduce fertility rates • Greater access to primary health care and family planning services • Receive a basic education (esp. girls and women) • Have government serviced that help protect them when sick, old, unemployed

  19. Are we going to reach a carrying capacity? • Carrying capacity: number of individuals the environment can support over a long period of time

  20. Some say we have already exceeded the carrying capacity • Others say billions more can be sustained on earth • Consensus • World population will continue to grow until after the middle of this century • Peak of some 9 billion • Perhaps declining in the latter years

  21. What controls population size? • Density-Independent Factors • Weather, floods, fire • Reduce population by the same proportion regardless of size • Density-Dependent Factors • Shortages of food, shelter • Triggered by increasing population density

  22. In groups of 2 or 3, answer the following (in complete sentences) • What do you think daily life might be in your town in 2050 when there are 9.2 billion people on this planet? • What types of technological changes will be needed to accommodate the world’s growth? • What do you think will be the greatest environmental concerns at that time? • Do you see population growth becoming a major political issue by 2050? Why or why not? What types of population issues might people be talking about at that time?

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