Earth's Population: Growth and Patterns

1. POPULATION

2. Earth’s Population • Is 7 BILLION and growing http://www.poodwaddle.com/clocks2.htm • Population growth 1. Earth’s population grew very slowly for thousands of years because the BR and DR were almost equal. (birthrate BR/deathrate DR) 2. The development of better agriculture brought the first important increases in population growth. 3. The Industrial Revolution brought a higher standard of living (SOL) than ever before and further increased population growth, especially in Europe. 4. Population growth rates generally are inversely proportional to a country’s level of industrialization. 5. According to demographer’sresearch there are five distinct stages of population growth. 6. Demographers use graphs called population pyramids to forecast population growth.

3. Stages of Population Growth • STAGE ONE • High BR/DR • No countries in this stage. • War/famine, etc., if extreme, can bring a country back to this stage

4. STAGE TWO • High BR and falling DR • Found in the less developed countries in L. America, Africa South of the Sahara, Asia. • Problems: short food supplies, and high unemployment. http://www.census.gov/cgi-bin/ipc/idbpyrs.pl?cty=KE&out=d&ymax=250&submit=Submit+Query

5. STAGE THREE • Falling BR/low DR – slow population growth • People’s Republic of China • http://www.census.gov/cgi-bin/ipc/idbpyrs.pl?cty=CH&out=d&ymax=300&submit=Submit+Query

6. STAGE FOUR • Low BR/DR - little or no growth • Have zero population growth (ZPG) • Developed countries in Europe, Japan, Canada, Australia • US is moving into this stage. • http://www.census.gov/cgi-bin/ipc/idbpyrs.pl?cty=CA&out=d&ymax=300&submit=Submit+Query

7. STAGE FIVE • Negative BR/low DR • Negative growth • Countries – Germany, Sweden, Norway, Italy. http://www.census.gov/cgi-bin/ipc/idbpyrs.pl?cty=IT&out=d&ymax=300&submit=Submit+Query

8. Draw the shapes of the pyramids and write under the different pyramids if it is Stage 2, 3, 4, or 5. Stage 5 Stage 2 Stage 3 Stage 4

9. Population Patterns Because of factors such as climate and landscapes the population distribution of Earth is very uneven. 1. Population Distribution a) An area’s physical environment, especially climate, limits the number of people who can live there. There are 4 centers of heavy population in the world. b) These areas contain more than 70% of Earth’s population.

10. Eastern Asia – has the greatest concentration of people on Earth – it is centered in China – 21% of Earth’s population. 2) Southern Asia – is the secondlargest concentration of people – it is centered in India – 16% of the Earth’s pop.

11. Cars and people move through a busy street in the eastern Indian city of Kolkata July 11, 2008. India's population is projected to grow to 1.19 billion in 2011 from 1.13 billion in 2008, according to census authorities. July 11 is marked as World Population Day.

12. 3) Western Europe – is the third largest concentration. Western Europe – people are concentrated near natural resources needed for industry.

13. East Central North America -fourth largest center concentrated in the NE US and SE Canada. In the US, the chain of cities start from the city of Boston to south of Washington DC. -This is called a megalopolis.

14. World Population Numbers Africa – 12% of the Earth’s population. Largest cluster of people found in the Nile River Valley. Cairo is the largest city in Africa.

15. South America – is lightly populated compared with other continents. Patterns of people live along the edges of the continent – SE Buenos Aires in Argentina, Montevideo in Uruguay, and Rio de Janeiro and Recife in Brazil. *12 of the top 20 cities of the world are found in Latin America.*

16. Australia has the fewest number of people. They are concentrated along the eastern and southern coasts. (17.5 million people total on the entire continent. – as much as the NYC metro area)

17. North Pole

18. World Population by Continent

19. Population Density Population density tells you how concentrated the numbers of people are in an area. It makes it possible to compareareas of different size and population all over the world.

20. Population Issues • The population explosion has raised such issues as •how to increase food supplies, •how to make better use of farmland, •how to improve eating habits and to take advantage of resources, •and how to find new sources of food.

21. Food Supply a) More than 13 million to 18 million people die each year because they do not have a good diet. (35,000 a day; 24 a minute – most are children) b) The rate of population growth was more than the amount of food produced. c) Scientists feel that countries that do not have enough food must speed up their own production.

22. More land is needed for agriculture • Efficient eating habits is needed • Productive farming methods • More productive farming techniques • Using new food sources • New sources of food 1. Today 90% of the world’s food comes from 15 crops and 7 livestock animals. 2. There are more than 10 million kinds of plants and animals on Earth.

23. Natural Resource Supplies • Certain resources are in limited supply. • Fresh water is one basic resource that is being threatened. Major problem after the year 2000 and will continue to be one. • Irrigate lands (why use fresh water?) • Has become polluted and no longer a renewable resource.

24. Population Control There are at least three more people in the world now than there were when you began reading this sentence…

25. People believe that the solution to food shortages and dwindling natural resources is to reduce population growth. (Let’s look at a theory developed during the Industrial Revolution about population control.)

26. What about Malthus? • Thomas Robert Malthus (13 February 1766 – 23 December 1834) was an Englishpolitical economist and demographer who expressed views on population growth and noted the potential for populations to increase rapidly, and often faster than the food supply available to them.

27. Malthus's theory of population proposed that there were natural limitingfactors, such as food resources, which limited a given population. Malthus noted that populations as a whole tend to grow exponentially or geometrically, whereas natural resources grow arithmetically if they grow at all. When a population reaches beyond the amount of resources available to its survival, it has reached its carrying capacity. When a population reaches its carrying capacity a number of limiting factors, such as disease or famine, can occur to bring the population down, and back to naturally acceptable limits.

28. What did Malthus not take into consideration or know would happen in the world about his theory on Population Growth? • He did not know modern medicines would keep people from dying. So much for diseases. http://www.pbs.org/wgbh/nova/worldbalance/earth.html

29. B.Less Developed countries (LDC) have resisted population control. People honor traditional values and strong religious beliefs that do not allow them to practice birth control. C.Chinaenforced its one-child policy in the late 1970s to avoid a famine in the future. They will have this policy in effect for 100 years. Has this been successful for them? How were they able to enforce such a law?

30. Migration • People move because of either economic or political reasons(“Push-Pull” forces) – they are push from a bad situation and pulled to a good situation. • People also move from the countryside (rural) to urban areas – and from less developed to developed countries. This places a huge demand on the country’s or city’s economy and infrastructure. Let’s Review: http://www.youtube.com/watch?v=sc4HxPxNrZ0&feature=player_embedded