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08 hum pop1

08 hum pop1






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    08 hum pop1 08 hum pop1 Presentation Transcript

    • Announcements 16 February 2010
    • Current estimated World Population U.S. 310,825,424 (10 million more than one year ago) World 6,900,142,775 (100 million more than one year ago) 12:30(CST), Feb 15, 2011 www.census.gov/main/www/popclock.html
    • Human population growth
      • Long lag phase, then exponential growth
      • Will human populations stabilize at K, or overshoot (or have we already?)
      Human population growth
    • Currently…
      • 6.9 billion humans on Earth
        • tripled since 1900; 9.3 billion expected by 2050
      • Overall, 1.14% annual growth rate
        • 75 million more people each year
    • What are the consequences of so many people? Two views on what more people means:
      • Resource depletion
      • Pollution
      • Overcrowding
      • Famine
      • Poverty
      • Overshooting carrying capacity?
      • Larger markets
      • More workers
      • Efficiency of scale
      • More innovation
    • Contrasting Views on Human Populations
      • Rev. Thomas Malthus (1798) argued human populations tend to increase exponentially while food production is plentiful.
      • - Humans inevitably outstrip food supply and eventually collapse (lead to poverty).
      • - Humans are too lazy and immoral to voluntarily reduce birth rates.
      “ An Essay on the principle of Population ”
    • Contrasting Views on Human Populations
      • Karl Marx (1848) argued that population growth is a symptom rather than a cause of poverty and other social problems.
        • - Real causes of these problems are exploitation and oppression.
        • The way to slow population growth and alleviate many social problems is through social justice.
    • Thomas Malthus Karl Marx
    • Current views….
      • Neo-Malthusians - Believe we are approaching, or have already surpassed, the earth ’ s carrying capacity.
        • - We should make over-population issues our first priority .
      • Neo-Marxists - Believe eliminating oppression and poverty through social justice is the only solution to the population problem.
        • - Wealth and resource distribution must be addressed .
    • What factors influence human population growth?
      • Same as for other species :
      • Birth rate
      • Death rate
      • Sex ratio
      • Age distribution
      • Immigration/emigration
      • Density
      • Study of these for humans called demography
    • Birth rates and Death rates
    • Sex Ratio
      • Humans have roughly 1:1 sex ratio
      • Total Fertility Rate – number of children a woman has during lifetime
      • Replacement Fertility = 2.1 children/female/lifetime (leads to zero population growth in long term)
    • Age Distribution
    • U.S. Age Distribution over time
      • “ Baby boom ” (1946 - 1964) changes
      • major societal concerns
    • Housing, schools, supplies for children University education, large young workforce Retirement, elderly heath care Child care, luxury items, productive working years
    • Immigration/Emigration
      • Of 0.9 % increase in U.S. pop, 0.3% is due to immigration
      • Millions of people want to emigrate from war-torn, poverty-stricken countries to more stable, developed countries
    • Population Density
      • Number of people per unit land area
      • As density increases, more environmental impacts
      • Distribution of people within countries also important.
      • 47% of world ’ s population in cities, expected to increase to 60% by 2025
      • Problems with dense populations in cities:
        • Water transported long distances
        • Wastes difficult to get rid of
        • Decreased air quality
        • Large burden on local environment
        • Social unrest due to economic disparity
      Population Density
    • Social & political factors influence human population growth
      • What determines how many children a woman has?
      • What policies do countries have on population growth? Immigration?
    • Major social factors affecting birth rates
      • 1. Cultural role/status of women
        • In male-dominated societies, traditional role of women is to marry & have children
        • Women not educated, encouraged to marry young
        • Lack of education makes women dependent on husband, children
        • Women in developed countries are often educated, have option to delay marriage or not marry
    • Major social factors affecting birth rates
      • 1. Cultural role/status of women, cont.
        • Early marriage = more child-bearing years = more children
        • % of births by 15-19 year olds:
          • Africa 17%
          • Latin America 16%
          • All developed countries 3%
    • Major social factors affecting birth rates
      • 2. Desires of women to have children
      • & access to birth control
        • Women in less-developed countries have more children than they want
        • Often little access to birth control, education on how to use
        • Religious views on birth control
        • However, women in less-developed countries want more children than women in developed countries.
    • Economic value of children
      • In less-developed countries:
      • Guard against high infant mortality
      • Security in old age
      • Labor force
      • = desire for more children
      • In developed countries:
      • High probability of survival
      • Large economic expenditure not put into retirement plan
      • Increase labor by parents
      • = desire for fewer children
    • Political policies on population growth
      • Encouraged in some countries (U.S., European) by subsidies:
        • Paid maternity leave
        • Guaranteed jobs
        • Childcare
        • Tax deductions
      • Need younger workers to support aging populations
    • Political policies on population growth
      • Discouraged in other countries
      • China :
      One child limit started in 1979 Contraception and abortion readily available and widely used. Result: Current total fertility rate of 1.72
      • India:
      • 1. Little government intervention until recently
      • 2. Some states emphasizing improving quality of life
        • Decrease infant mortality
        • Encourage education for women
      • 3. Others enforcing sterility
        • Result: Current total fertility rate of 2.78 children (goal of 2.1 by 2010)
      Political policies on population growth
    • Effect of different policies
      • Pop size growth rate
      • China 1.3 billion 0.6%
      • India 1.1 billion 1.4%
      • US 300 million 0.9%
      (2006 estimates from CIA world fact book)
    • Political policies on immigration
      • Countries with low birth rates (European, Japan, China) may face shortage of workers without immigration
      • Emigrants want to move to developed countries to improve standard of living
    • Practice Exam Question
      • Which of the following bests describes the views of
      • Rev. Thomas Malthus and Karl Marx?
      • A) Malthus and Marx both believed that excessive population growth leads to poverty, famine and political strife
      • B) Malthus and Marx both believed that poverty, famine and political strife leads to excessive population growth
      • C) Malthus believed that excessive population growth leads to poverty, famine and political strife, while Marx believed that poverty, famine and political strife leads to excessive population growth
      • D) Malthus believed that poverty, famine and political strife leads to excessive population growth, while Marx believed that excessive population growth leads to poverty, famine and political strife
    • Considerations in Ecological Economics Common property resources – public ownership Common ownership essentially means no owner.
        • Strong tendency to overexploit and misuse the resource.
        • Common ownership makes it virtually cost-free for anybody to cause pollution.
    • Hardin argued that many societal issues, including human population growth and the fair use of public space had “ no technical solution ” . Garrett Hardin (1968), The Tragedy of the Commons article in the journal Science
    • Pasturelands provided free by government to anyone wishing to graze cattle. Common Pasture, open to all Rancher 1 Rancher 2 Tragedy of the Commons
    • Each rancher seeks to maximize personal wealth, does individual cost-benefit analysis Common Pasture, open to all Rancher 1 Rancher 2 Tragedy of the Commons
    • Rancher 1: For each animal I add to my heard, I gain wealth (Benefit of +1) Rancher 1 Rancher 2 Cost of adding one animal is a slight decrease in the resource But, the cost is shared by all ranchers (Cost in this example: -1/2)
    • Rancher 1 Rancher 2 Optimal Solution for Rancher 1: Keep adding more animals Cost = -1/2 Benefit = +1 Benefit > Cost
    • Rancher 1 Rancher 2 Optimal Solution for Rancher 2: Keep adding more animals Cost = -1/2 Benefit = +1 Benefit > Cost But, cost / benefit analysis is the same for Rancher 2
    • Rancher 1 Rancher 2 The pasture can only support so many animals Eventually, resource is overexploited at a serious cost to everyone
      • Tragedy of the Commons has already been observed at the local and regional level
        • - Cattle grazing on western public rangelands.
        • - Overfishing in the oceans (international waters)
      Ecosphere (the planet Earth) is a large commons
        • U.S. and other industrialized nations consume more than fair share of resources and freely uses the commons to dispose of waste
      Tragedy of the Commons
    • Surprising Nobel in Economics by: Michael Mandel, October 12, 2009 I have an admission to make—I had never heard of Elinor Ostrom before this morning ’s Nobel prizes in Economics were announced. Ostrom, the 2009 winner was honored “for her analysis of economic governance, especially the commons.” Ostrom focused on a subtle question—if you have a shared “common-pool resource” like a forest or the ocean, what is the right way to manage it? Typical answers have focused on either collective management (i.e. government control) or effective privatization (i.e. fishing permits). But Ostrom has argued that all sorts of other institutions can grow up over time that give good results.
      • Surprising Nobel in Economics
      • Ostrom ’s principles for good management of collective resources:
      • rules should clearly define who has what entitlement
      • (ii) adequate conflict resolution mechanisms should be in place
      • (iii) an individual ’s duty to maintain the resource should stand in reasonable proportion to the benefits.
      • iv) monitoring and sanctioning should be carried out either by the users themselves or by someone who is accountable to the users.
      • vi) governance is more successful when decision processes are democratic in the sense that a majority of users are allowed to participate in the modification of the rules
      • (vii) the right of users to self-organize is clearly recognized by outside authorities
    • Sustainable Development
        • Viability of natural resources over time, and the maintenance of human living standards and economic growth.
      Sustainable Development – Meets present needs without compromising ability of future generations to meet their own needs.
    • By the end of this lecture you should be able to:
      • Describe the past, present, and projected future world population of humans (explain figure on slides 3 & 4).
      • List the 6 factors that affect human population growth rate.
      • Explain why women have more children in male-dominated societies and fewer children in developed countries.
      • List the two factors have the greatest control on birth rates.
      • Recall the current size of the World Population and the US Population.
      • Explain how political policies in China and India changed their population growth rates.