Demography and Environment by mamapeirong


									Demography and Environment

      Populations and how they Changed
                   the Earth
   Early populations (pre-agricultural)
    increased for two reasons:

       1) Modern humans produce more

       2) Migrated away from diseases
Early Civilizations, cont.
   With agriculture came population growth and
    migration to find new cultivable land
    – Migration to river valleys c. 5000 BCE (very
    – Austronesian migrations c. 3,500 BCE
    – Bantu migrations c. 2000 BCE
    – Population growth because of high birthrates, not
      because of better nutrition or lack of diseases
 Not a biological evolution, but a cultural adaptation-
  humans learning to control their environment
 Begins a much more rapid period of resource
  depletion: esp. wood, water—eventually, some urban
  centers decline because of overuse of resources
     Agrarian civilizations mostly dominated non-
      agricultural peoples

     Populations were affected by two major factors
      during this period:

1)    Technology 2) Diseases

     1) Technological advances:
        •   Iron metallurgy allows for movement out of River Valleys
        •   Also, democratized access to metals
        •   Resulted in tremendous depletion of forests
        •   Shovels, hoes, axes, plows
 Classical Period, cont.
2) Diseases:
  – Cities were filthy and crowded
  – Mortality rate exceeded fertility rate, needed inflow of people
    from rural areas
  – Armies moved all around, and poverty pushed people out of
    urban areas—brought diseases with them
  – Constant exchange of people allowed for diseases to thrive
    in unexposed populations
  – Pastoralists were the best match for large civilizations
    because they generally had significant exposure to
  – Africa had the most plentiful array of pathogens, and the
    Americas and Australia had the least
  – Contact between Rome and China resulted in huge
    population decreases and civil war in the 2nd and 3rd cent.
  – Native population in India had resistance to disease far
    superior to that of the Aryans- resulting not in takeover, but
    the caste system
Classical Period, cont.
   Environmental interactions during this period
    – Deforestation in Mesopotamia resulted in more
      destructive flood patterns
    – Saline in the Tigris and Euphrates water supply forced
      gradual relocation north
    – Large scale depletion of timber resources for ships in
      the Mediterranean
   Significant migrations:
    – Chinese population migrated north to south during the
      Han Dynasty (also resulting from deforestation along
      the Yellow River highlands)
    – Germans, Huns and Slavs came in to take over disease-
      ridden, weak governments
Nomadic "Barbarians" & Plague
   Big events/trends in Europe:
    – Invasion of Goths at the end of the Roman
      Empire—led to large scale migrations
    – Population in Northern Europe actually grew-
      plague very rare, and less infection because of
      fewer cities
    – Led to Viking raids in 9th and 10th centuries
    – Over this period, increasing biological
      homogenization across Eurasia
 Justinian Plague, 542 CE – 1/2 to 1/3 died
  in Constantinople
 China, 610 CE
 Large scale migration in the face of
  disease was much more prevalent in
  China than in Europe or the Middle East-
  the Chinese continued to move south
 Island civilizations like Japan and Britain
  suffered terrible losses—populations
  generally remained low
Population Growth in the Post-
Classical Period
 Egypt and Mesopotamia hit their limit
  early- little growth during this period, and
  even decline
 Baghdad was the center of the Abbasid
  dynasty, but saline content of the T & E
  was problematic
 India? No one really knows. But, they
  didn't seem to be seriously affected by
  plague, just famine
 Africa- populations up because of new
  iron technology, Bantu migrations, but the
  Nile River Valley was basically maxed out
  by 1 CE
    Recovery of Europe and China
   Europe first recovers economically, then
    politically- focus shifts away from Mediterranean
    to NW (better, less abused land, lots of forests)
   China experiences an opposite pattern of
    recovery- focus shifts to the South
   The introduction of the heavy plow suddenly
    makes ag. in NW Europe feasible and productive
   Success in agriculture came along with
    developments in trade and the exchange of
    crops—led to huge population growth in China
   Sugar and SE Asian & African crops in Europe;
    Champa rice in China (alongside wet rice
    cultivation and terracing)
 Eurasia is fairly well integrated by this
 No "push factors" for the common people
  during this period- most exploration was
  done by profit-seeking urbanites, and
  improvements in ship building allowed
  explorers to venture further away from
    Colombian Exchange- A biological
   "Virgin soil epidemics"- exposure to diseases for
    which there was no built-up resistance
   African slaves appear to have carried the more
    virulent form of smallpox and malaria to the
    Americas—many Europeans died from these
    diseases as well
   Disease, violence, slavery, and a sharp decline in
    fertility all contributed to the decimation of the
    Native American population
   Introduction of European and African diseases
    completely disrupted this formerly healthy region
    (i.e. the Caribbean population dropped from over 6M
    to about 80,000 people in the century after the
   The ecosystems of the Americas also changed
   Small numbers of African slaves had been
    brought to work in Europe since the fall of Rome-
    with the discovery of new Atlantic islands, this
    trade increased
   With the discovery of the "New World," African
    slavery became very widespread- 10 M brought to
    the Americas until 1820; only 2M Europeans
   Population remained fairly steady- declined due
    to slave trade, but grew because of American
    crops like peanuts, sweet potatoes and corn- no
    immigration until 19th century because of all the
    diseases there
   Smallpox also was transferred to regions in
    Africa, and seriously affected some populations
    in the region
    China & Europe
   China:
    • Population grew until 17th century, declined (climate
      change and political upheaval), and then tripled within a
      century (climate change and new crops—potatoes and corn)

   Europe:
    – Urban populations especially began to grow in the 16th
      century, putting pressure on governments and cities
    – They also needed more food, which led to the second
      agricultural revolution
    – By 1630, Europeans were experiencing a population decline
      though, which was followed by a rapid increase due to new
      crops and increased fertility rates

   India, Japan and SE Asia all had very different
    patterns from China and Europe
 Populations explode as a result of
  industrialism—a nearly vertical rise
  in population
 Prior population growth also
 Much more intense exploitation of
  the environment and pollution
 Higher standard of living
 Government involvement in the health of its
 Demographic transition- conscious birth control
  in part, as some (like Malthus) are increasingly
  freaked out about population growth- also,
  children were less valuable as laborers
 New food crops continued to encourage
  population growth
 Increased urbanization
 Cholera (solved by improvements in water
 Emigration was caused by rising populations
 Population started out much larger than
  that of Europe
 Hard to get anything accomplished
  politically or economically with so many
  people to support
 Asian immigrants were alternately
  recruited and denied entry to work in the
 Indentured laborers (many from India) also
  caused population shift
20th Century- The Contemporary
   Population growth during the 20th century
    dwarfed that of the 19th century
   World population quadrupled
   Why?
   Sustained rates of reproduction and more
    efficient (though often destructive) use of
    the environment
   Population growth is of very serious
    concern to many nations and international
    organizations as a result
Causes for change
 Public health measures undertaken
  by governments (urban public health
 Mortality rates plummet (for example,
  India from 5% to 1.5%)
 Immunization and developments in
  medical care decrease mortality rate
 More dependable food supply
 Agriculture had to keep up with growing
 Green Revolution- transferred Western
  agricultural technology and methods to
  developing countries, including
  genetically modified plants
 Not enough food some places-
  internal/external migration
 Increased crime in poor, urban areas
  (Mexico City, Calcutta, Buenos Aires, etc.)
Patterns of Movement
 West Asians to America and Europe
 Indians to S. Africa and Caribbean
 Asians to SE Asia
 Former colonial subjects to former
  mother countries
 Encouragement of UN and some
  governments to curb population growth
 This view drew opposition from
  traditionalists who saw growth as a sign
  of strength, stability
 China, India and Latin America have all
  decreased the fertility rate, but in different
  ways and with differing levels of success
 Causes environmental problems- resource
  over-consumption, overgrowing and
  epidemic disease

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