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Title: Understanding Our Environment Author: CCSN Last modified by: Trial User Created Date: 1/16/2002 10:44:40 PM Document presentation format: On-screen Show
Title: Announcements 1 Announcements September 13, 2006 Schedule for next week Monday (Sept 18th) - brief review of what you need to know for first exam. Wednesday (Sept 20th) - first exam Friday (Sept 22) - no class 2 Humans 'causing stronger storms' Monday, 11 September 2006 Research published last year found there had been a sharp rise in the incidence of category 4 and 5 storms - the strongest - in recent decades. Hurricane formation is strongly linked to sea-surface temperature, with warmer waters more likely to form storms. Temperature increases in these hurricane breeding grounds cannot be explained by natural processes alone. Sea-surface temperature and hurricane strength vary naturally, and deciphering a clear impact of human greenhouse gas emissions has been difficult. 3 Recycling 'too complex' for many 13 September 2006 Households in the UK would recycle more waste if it was easier to understand what rubbish can and cannot be recycled, a survey has suggested. 4 http// According to the U.S. Bureau of the Census, the total population of the World, projected to 09/12/06, 651pm is 6,543,690,282 Monthly World population figures 07/01/06 6,528,089,562 08/01/06 6,534,625,672 09/01/06 6,541,161,782 10/01/06 6,547,487,051 11/01/06 6,554,023,161 12/01/06 6,560,348,429 01/01/ 07 6,566,884,540 02/01/07 6,573,420,650 03/01/07 6,579,324,234 5 U.S. Age Distribution over time
  • Baby boom changes major societal concerns
  • University education, large young workforce Housing, schools, supplies for children Child care, luxury items, productive working years Retirement, elderly heath care 6 Immigration/Emigration
  • Of 1.1 increase in U.S. pop, 0.5 is due to immigration
  • Mexico loses an estimated 250,000 people per year to emigration
  • Millions of people want to emigrate from war-torn, poverty-stricken countries to more stable, developed countries
  • 7 Population Density
  • Number of people per unit land area
  • As density increases, more severe impacts on environment
  • Density (people per sq mile)
  • India 733.2
  • China 320.9
  • US 68.7
  • Russia 22.7
  • not all square miles equally productive
  • 8 Population Density
  • Distribution of people within countries also important.
  • 47 of worlds 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
  • 9 (No Transcript) 10 Social political factors influence human population growth
  • What determines how many children a woman has?
  • What policies do countries have on population growth? Immigration?
  • 11 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 educated, have option to delay marriage or not marry
  • 12 Major social factors affecting birth rates
  • 1. Cultural role/status of women
  • Early marriage more child-bearing years more children
  • of births by 15-19 year olds
  • Africa 17
  • Latin America 16
  • All developed countries 3
  • 13 Major social factors affecting birth rates
  • 2. Desires of women 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 (http// ptives.ap/index.html)
  • However, women in less-developed countries want more children than women in developed countries.
  • WHY?
  • 14 Catholics ordered to offer birth control March 1, 2004 SAN FRANCISCO, California (AP) -- In a precedent-setting decision, the California Supreme Court ruled Monday that a Roman Catholic charity must offer birth-control coverage to its employees even though the church considers contraception a sin. California is one of 20 states to require that all company-provided health plans must include contraception coverage if the plans have prescription drug benefits. The American Civil Liberties Union applauded the ruling and called it "a great victory for California women and reproductive freedom." 15 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 less children
  • 16 Most important factors affecting population growth rates
  • Development of/access to modern birth control
  • Education of women
  • 17 Political policies on population growth
  • Encouraged in some countries (U.S., European) by subsidies
  • Paid maternity leave
  • Guaranteed jobs
  • Childcare
  • Tax deductions
  • Birth bonus (Canada)
  • Need younger workers to support aging populations
  • 18 Political policies on population growth
  • Discouraged in other countries with varying degrees of success
  • China
  • 1. Due to slow economic growth, PRC began first population control measures in 1955
  • 2. Campaign begun in 1971
  • - Raised legal age of marriage to 23 for women, 25 for men in rural areas and 25,28 in urban areas
  • 3. One child limit started in 1978
  • 4. Contraception and abortion readily available and widely used.
  • Result Current total fertility rate of 1.8
  • 19 Political policies on population growth
  • India
  • 1. Little government intervention until recently
  • 2. Emphasizing improving quality of life
  • - Decrease infant mortality to decrease desire
  • - Encourage education for women
  • Result Current total fertility rate of 3.2 children (goal of 2.1 by 2010)
  • 20 Effect of different policies
  • Pop size (mil) growth rate added/year (mil)
  • China 1280.7 0.7 8.96
  • India 1049.5 1.7 17.84
  • This is not an endorsement of the methods used by PRC to reduce births!!
  • 21 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
  • Tremendous pressure on Europe and N. America to accept immigrants
  • Significant numbers of immigrants can strain social systems
  • 22 How many total children do you want to have? 23 Points to know
  • Know the past, present, and projected future world population of humans
  • Know the human issues for each of the 6 factors that affect population growth rate
  • Why do women have more children in male-dominated societies and less children in developed countries?
  • What two changes have caused/will cause the greatest decrease in population growth rates?
  • How have political policies in China and India changed their population growth rates?
  • How do political policies on immigration affect growth rates? Why do many people want to emigrate?
  • 24 Human Population Issues II Lecture Objectives 1. Be introduced to specific examples of human population growth in different countries 2. Distinguish between the views of Thomas Malthus and Karl Marx on population growth 3. Learn about the mystery of Easter Island and human carrying capacity 25 CIA world Factbook information on different countries https// x.html Background Current environmental issues Location (with map) Climate Government Population information Birthrate, death rate, AIDS statistics 26 Infant Mortality rate (2003 est.) (1) Mozambique 199 deaths / 1000 live births (4) Afghanistan 142.5 deaths / 1000 live births (184) USA 6.75 deaths / 1000 live births (225) Japan 3.30 deaths / 1000 live births 27 Life expectancy at birth (2003 est.) (1) Andorra 83.49 years (48) USA 77.14 years (217-225) Swaziland, Rwanda, Zimbabwe, Malawi, Angola, Lesotho, Zambia, Botswana, Mozambique all lt 40 years 28 (No Transcript) 29 17 of children born to women 15-19 yrs old 30 (No Transcript) 31 HIV/AIDS adult prevalence rate (2001) (1) Botswana 38.8 13 countries have gt 10 (65) USA 0.6 (167) Saudi Arabia 0.01 32 HIV/AIDS deaths (2001) (1) South Africa 360,000 (2) India 310,000 16 countries had more than 50,000 deaths (28) USA 15,000 (141) Croatia 10 33 In some countries, famine, war and disease still control the population growth rate In the future, will this also be true in the rest of the world? 34 LIMITS TO GROWTH
  • 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 35 LIMITS TO GROWTH
  • 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.
  • 36 Thomas Malthus Karl Marx 37 Malthus and Marx Today
  • Neo-Malthusians - Believe we are approaching, or have already surpassed, the earths 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.
  • 38 Ecologist Paul Ehrlich argues the American lifestyle is driving the global ecosystem to the brink of collapse. Economist Julian Simon argued human ingenuity, not resources, limits economic growth and lifestyles. 39 New York Times Demographic 'Bomb' May Only Go 'Pop!' By DONALD G. McNEIL Jr. August 29, 2004 Remember the population bomb, the fertility explosion set to devour the world's food and suck up or pollute all its air and water? Its fuse has by no means been plucked. But over the last three decades, much of its Malthusian detonation power has leaked out. Birthrates in developed countries from Italy to Korea have sunk below the levels needed for their populations to replace themselves the typical age of marriage and pregnancy has risen, and the use of birth control has soared beyond the dreams of Margaret Sanger and the nightmares of the Vatican. Ever since 1968, when the United Nations Population Division predicted that the world population, now 6.3 billion, would grow to at least 12 billion by 2050, the agency has regularly revised its estimates downward. Now it expects population to plateau at nine billion. 40 Can human populations exceed K and crash? 41 The mystery of Easter Island (Rapa Nui) Small island in the South Pacific 2,000 miles off the west coast of South America 42 Dutch explorers came upon the island on Easter Day 1722 But hundreds of giant stone statues They found 2,000 people living on a barren wasteland No trees, no timber, no canoes, no rope 43 What happened? A combination of archeology and biology has been used to construct this explanation. The island was colonized around 400 AD (debate as to exactly who colonized it) At that time, the island was forested and the soil was deep and productive 44 How do they know what the island was like in 400 AD? Each year, pollen from all the plants on the island falls into the 3 lakes on the island Pollen will sink and become trapped in the mud at the bottom of the lake 45 Mud from the bottom of the lake can be removed in chronological order. It is possible to determine the age of each layer of mud 46 Pollen grains from different plants are different shapes Can be used to reconstruct past plant communities 47 Sometime around 400 AD a small group of people found an island with a lush subtropical forest and rich soil Ease of food cultivation (sweet potatoes, chickens) allowed for complex, advanced societies with leisure time to carve giant stone statues The human population soared, reaching between 10,000 20,000 intense competition between clans their statues By 1400, all the trees were gonecut for houses, firewood, canoes and rollers for the statues 48 Without the trees, the rich soil washed into the ocean
  • now difficult to grow crops carrying capacity of island decreased
  • Intense clan warfare, cannibalism became common Size of human population falls to 2,000 by 1722, collapse of their civilization Could this happen on a larger scale? 49 What determines carrying capacity?
  • Environmental resistance
  • - Raw materials
  • water, food, metals, minerals
  • - Waste disposal
  • organic, industrial, toxic, nuclear
  • - Energy
  • fossil fuels
  • - Interactions with other organisms
  • pathogens, mass extinctions
  • 50 Local vs. total carrying capacity
  • In many parts of the world, food availability is the first limiting factor
  • - 1 billion people malnourished
  • - conversion of forests to agriculture OK in short term, but lowers productivity in long term
  • Other parts of the world have excess food, but use tremendous amounts of fossil fuels
  • - Marxian redistribution?
  • 51 Which will be the first GLOBAL limiting factor?
  • Consider
  • - Renewable vs. Nonrenewable resources
  • - Lesson from Easter Island other places
  • If we use renewable resources at unsustainable rates, we can quickly cause long-term productivity (i.e. carrying capacity) to decrease.
  • 52 Points to know
  • What factors contribute to the low life expectancy in many African countries?
  • How do Malthus and Marx each view the relationships between excess population growth, resource depletion, starvation, war and poverty?
  • What issues do the neo-Malthusians and the neo-Marxists believe should be the top priority?
  • Know the story of Easter Island and the reasons for their population crash.
  • What is the difference between local and total carrying capacity? What is the result of using renewable resources way beyond their sustainable limit?
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