Chapter 6 Human Population & It s Impact

Transcription

1 Chapter 6 Human Population & It s Impact

2 Human Population Growth Through Time Current world population: 7.27 Billion (Nov. 2014) billion years 12 years years 14 years 33 years 123 years Tens of thousands of years

3 Birth and Death Rates Birth rate is reported as the number of births per people; Death rate is reported as the number of deaths per people; Developed countries tend to have birth rates & death rates than developing countries.

4 \ Calculating Population Change Population Change = { Births + } {Deaths + } Immigration Emigration zero population growth (ZPG) occurs when factors that increase and decrease population size are in.

5 Population Change Annual rate of population increase is expressed as a percentage.

6 5 Years of Population Growth

7 Discuss with your Table Partner: Country A has a birth rate of 12 per 1000 in 2000, and a death rate of 9 per 1000 in the same year. What is its rate of growth in the year 2000 (assuming no net immigration or emigration), as a percent? Since the birth and death rates are given per 1000, need to convert the difference to a percent.

8 Doubling Time: Rule of 70 Doubling time of a population can be calculated by the rule of 70: Doubling time = 70/percentage growth rate If a population of howler monkeys increases by 3.5% per year, how long will it take the population to double?

9 Human Population Growth

10 Population Size China and India: of world s population China population clock: India population clock:

11 National Geographic: Population density map

12 Population Although the average fertility rate has gone down dramatically in the past few decades (from 6.5 in 1950 to 3.3 in 1998), because of the large number of people (esp. below the age of 15) the population is still greatly increasing. Singapore:

13 World Population: Past and Projected Future Population in Billions

14 Global Population Growth Through Time Highest rates of growth increases above per year were seen briefly during the 1950 s Growth rate peaked at 2.2% in, and declined to 1.1% by Annual births have reduced to million since their peak at million in the late 1990s, and are expected to remain constant Deaths number million per year and are expected to increase to million per year by Current projections show a continued increase of population (but a steady decline in the population growth rate) with the population to reach between and billion by the year 2050.

15 Population Projections United Nations projections of human population increase to 2050 and 2100.

16 Fertility Rates Fertility: Number of children a couple must have to replace themselves. in developed nations in developing nations (due to higher infant mortality) Total Fertility Rate: Average number of children a woman will have in her child-bearing years. Global average: Developed nations: Developing nations:

17 Macau 0.92 Hong Kong 1.07 Singapore 1.11 Taiwan 1.15 Japan 1.21 South Korea 1.23 Lithuania 1.25 Belarus 1.26 Czech Republic 1.26 Monserrat 1.26 Bosnia and Herzeg Ukraine 1.28 Moldova 1.29 Romania 1.29 Poland 1.30 Slovenia 1.30 Latvia 1.32 Andorra 1.35 Slovakia 1.37 Armenia 1.37 Lowest Fertility Rates, 2011 Greece 1.38 Italy 1.39 Austria 1.40 Hungary 1.40 Serbia 1.40 Germany 1.41 Russia 1.42 Bulgaria 1.42 Croatia 1.43 Cuba 1.44 Estonia 1.44 Cyprus 1.45 Georgia 1.45 Switzerland 2.46 San Marino 1.47 Spain 1.47 Albania 1.48 Monaco 1.50 Portugal 1.50 Malta 1.52 Liechtenstein 1.53 China 1.54 Macedonia 1.58 Canada 1.58 Puerto Rico 1.62 Belgium 1.65 Netherlands 1.66 Thailand 1.66 Jersey 1.66 Sweden 1.67 Barbados 1.68 Trinidad + Tobago 1.72 Palau 1.73 Finland 1.73 Denmark 1.74 Algeria 1.75 Luxembourg 1.77 Norway more countries United States 2.06 Source: CIA

18 Niger 7.60 Uganda 6.69 Mali 6.44 Somalia 6.35 Burundi 6.16 Burkina Faso 6.14 Ethiopia 6.02 Zambia 5.98 Angola 5.97 Congo, Republic of 5.68 Mozambique 5.46 Malawi 5.43 Afghanistan 5.39 Benin 5.31 Congo, Demo. Rep Liberia 5.13 Guinea 5.10 Sao Tome and Princ Chad 5.05 Madagascar 5.02 Highest Fertility Rates, 2011 Sierra Leone 4.94 Equatorial Guinea 4.91 Rwanda 4.90 Sudan 4.84 Senegal 4.78 Gaza Strip 4.74 Nigeria 4.73 Comoros 4.72 Togo 4.69 Yemen 4.63 Central African Rep Gabon 4.59 Guinea-Bissau 4.51 Eritrea 4.48 Mauritania 4.30 Western Sahara 4.30 Gambia, The 4.23 Kenya 4.19 Cameroon 4.17 Tanzania 4.16 Cote d Ivoire 3.92 Iraq 3.67 Tonga 3.65 Zimbabwe 3.63 Solomon Islands 3.59 Ghana 3.48 Papua New Guinea 3.46 Marshall Islands 3.44 Jordan 3.39 Guatemala 3.27 Samoa 3.22 Belize 3.21 Philippines 3.19 Pakistan 3.17 American Samoa 3.16 Laos 3.14 Timor-Leste more countries.. India 2.62 Source: CIA

19 Factors That Can Decrease Fertility Rates increase in average level of ; increased educational & employment opportunities for ; greater availability of private & public pensions; decrease in importance of child ;

20 Discuss with your table partner: A decreased infant mortality rate is a factor that can decrease the population growth rate. This fact may seem counterintuitive since a lower infant death rate may seem like it would increase the population growth rate. Explain why decreased infant mortality typically decreases the population growth rate.

21 Factors That Can Decrease Fertility Rates increased ; decreased infant (larger families if infant death common) higher average age of ; increased of raising & educating children;

22 Factors That Can Decrease Fertility Rates greater availability of reliable ; greater availability of legal abortions; change in religious beliefs, traditions, & away from encouraging large families.

23 Fertility Rate Reduction Improved access to birth control can help, but is not the whole story

24 Infant Mortality Rates Infant death rates are lower in developed countries than developing countries.

25 Birth & Death Rates Over Time death rates have decreased markedly during the past 100 years; Improved Agriculture (Green Revolution) Modern Medicine birth rates have also decreased, but not as fast as death rates; the increasing difference between birth & death rates is what has lead to exponential population growth; the patterns of change in birth & death rates over time are different for developed vs. developing countries.

26 Birth & Death Rates Over Time In developed countries decreases in death rates are being accompanied by decreases in birth rates over time. In developing countries decreases in death rates have not been accompanied by as large of decreases in birth rates over time, leading to major population increases.

27 Demographic Transition Model 1) Preindustrial Stage: both birth & death rates are relatively, the population does not increase much, & the population size is. 2) Transitional Stage: death rate due to industrialization, increased food production, & improved health care; birth rates remain relatively, the population rapidly. Many nations are in this stage.

28 Demographic Transition 3) Industrial Stage: birth rate drops & eventually approaches a with death rate, leading to a of population growth. 4) Postindustrial Stage: birth rate & death rates approximately balance, population growth is attained, & the population stabilizes at a size much than the preindustrial size; if birth rate declines below death rate population growth may even be attained.

29 Population Age Structure Age structure refers to the proportion of the population in each age class: Prereproductive (0-14 years) Reproductive (15 45 years) Postreproductive (45 & up)

30 Population Age Structure Rapidly growing populations: pyramid shaped age structures, with large numbers of prereproductive individuals. Male Female Slower growing populations: more even age distribution. Pre-reproductive Age 0-14 Examples: Guatemala Saudi Arabia Reproductive Age Post-reproductive Age > 45 Examples: USA Australia

31 Population Age Structure Zero population growth: nearly equal proportions of prereproductive & reproductive individuals; Negative growth: greater proportion of reproductive than pre-reproductive individuals. Pre-reproductive Age 0-14 Examples: Spain Finland Reproductive Age Post-reproductive Age > 45 Examples: Italy Russia

32 Population Age Structure Developing countries are expected to continue to have a pyramid shape through the year 2025, although the age structure will become somewhat more evenly distributed. Populations of developed countries are expected to have an increasingly even age distribution through the year 2025.

33 India vs. Japan India: developing nation, so a wide base = fast-growing population Japan: developed nation, narrow base = negative population growth Japan

34 World Population Pyramid: Past, Present and Future Projections

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36 % of Total Population in Each Continent 20.8% 24.7% 12.0% 7.0% 64.9% 57.4% 60.8% 59.1%

37 Case Studies: United States Census Stats: 2010: 310 mill (+8.4%) 2000: 286 mill (+13%) 1990: 253 mill (+9.8%) 1980: 231 mill (+11.43% 1970: 203 mill (+13.37%) 1960: 179 mill

38 Who s Growing Fastest?

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40 Washington Population History Washington State Population has risen faster than the nation as a whole. This affects (among other things): Construction (buildings/roads) Environment/Demand for Resources State College Admission Criteria Housing Costs State Revenue Service Industry Growth

41 U.S. Immigration History Immigration in the U. S.: as fertility decreases, immigration has become a major source of population increase in the U.S.; in 1998 the U.S. received about 935,000 legal immigrants & 400,000 illegal immigrants; accounting for 43% of the country s population growth working immigrants boost the national economy in the long run; but states often bear most of the cost increasing levels of legal & illegal immigration are expected.

42 U.S. Causes of Death Early in life, leading causes are accidental deaths Later in life, cancers and heart disease are leading causes

43 Total Fertility in the United States Total fertility in the United States had a major increase during the "baby boom" ( ) & is now hovering just at replacement level.

44 Population Age Structure Population age structure of the United States continues to show a bulge as the baby boom generation ages. As the generation leaves the workforce, there will be less competition for jobs, but there will be an increased demand for social services for the elderly (i.e. Social Security and Medicaid).

45 Retiring Baby Boomers The Good News

46 Retiring Baby Boomers The Bad News OASDI = Social Security s Old Age, Survivor s and Disability Insurance programs

47 Case Studies: India the 1952 program has been disappointing because of poor planning, inefficiency, low status of women, extreme poverty, & lack of funds; couples still have an average of children because of the belief that they need children to work & care for them in old age. Issues include gender imbalance, high poverty, pollution issues see text and movie questions.

48 Case Studies: China Since 1970, China, with the world's largest population, has initiated efforts to better feed its people & control population growth; strict population control measures prevent couples from having more than one child; Fig.11 16

49 Case Studies: China By, China population is expected to reach its maximum, around 1.46 billion By 2050, China is projected to have population growth Projected population in 2050: billion

50 Case Studies: Russia Russia s population peaked in the early 1990 s at million In 2010, the population was million By 2050, it is projected to be only million Causes of decline: -- high death rate (15/1000; world average = 9/1000; US = 8/1000), One factor: high alcoholism rate avg life expectancy of males is 59 years, 72 years for women

51 Case Studies: Russia Causes of decline: --low birth rate (fertility rate = 1.3), birth rate = 10/1000, world average = 20/1000. mosnews.com reported that in 2004, 1.6 million Russian women had abortions, while 1.5 million gave birth, BBC news reported that 13 abortions for every 10 live births --low immigration rate: mostly former Russians moving back from the former republics Putin himself explored the issues surrounding the low birth rate during a 2006 speech, asking What has prevented a young family, a young woman, from making this decision? The answers are obvious: low incomes, a lack of normal housing, doubts about the level of medical services and quality education. At times, there are doubts about the ability to provide enough food.

52 Case Studies: Russia Actions taken by the government to slow population decline include measures to support foster families, develop preschool education, promote a healthy lifestyle, and incentives to have more than one child (a Day of Conception, and about $9,200, but since Russia's gross domestic product per capita in 2005 was $10,700, compared with $42,000 in the United States, giving a Russian $9,200 in cash is like giving an American $36,112). Posters like those depicting a young woman with three babies and reading "Love for your nation starts with love for family" have been widespread. Will economic incentives work? In 1950 s in the US, the GI bill made it easy for Americans to access cheap housing and higher education, which were family friendly and may have facilitated the baby boom. Russian Pro-life posters

53 The Effect of AIDS: by region

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55 The Effect of AIDS: the numbers

56 The Effect of AIDS: Africa

57 The Effect of AIDS: Africa Senegal

58 The Future: UN 2008 Report Population Estimates Statistics Population 6.8 Billion Billion (95% increase in developing nations) % Population over 60 21% (Developed) 8% (Developing) Fertility Rates 1.64 (Developed) 2.46 (Developing) 4.39 (Least Developed) Median Age (Europe) Life Expectancy 68 (World) 77 (Developed) 66 (Developing) 56 (Least Developed) 33% 20%

59 The Future: UN 2008 Report Population Estimates Population in developing countries is young ~ % under age 15 (only % in developed nations) Employment-aged people is at an all-time high, but is expected to peak and then decline in developed nations, while keep increasing in developing nations During , these 9 countries will account for half of the world s projected population increase: India, Pakistan, Nigeria, Ethiopia, USA, Dem. Rep Congo, U. Rep. of Tanzania, China, and Bangladesh (in order of size of increase) In many developed nations, the net number of migrants into these countries will more than offset the excess of deaths over births Major net receivers of migrants from will be US, Canada, UK, Spain, Italy, Germany, Australia, and France. Net Emigration countries will be Mexico, China, India, Philippines, Pakistan, Indonesia, and Bangladesh.