Introduction to Human Population Growth

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Introduction to Human Population Growth
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CITIZEN'S UNREST I've fought greed along life's
trail, Fought it with both tooth and nail, Fought
it standing, sitting, lying, Fought it cursing,
sweating, sighing. By greed I vowed I'd not be
bossed So I lost! Bert H. Kruse
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Consensus-building Exercise

• Social Problem
  Initial ranking Final ranking
• Destruction of ecosystems
  3.71 2.75
• Running out of resources
  3.36 3.02
• Human population growth 4.09
  3.04
• Global climate change
  3.70 3.43
• Global poverty
  4.66 4.49
• Economic health
  6.01 5.74
• Extinction of species
  5.91 6.49
• Terrorism and war
  6.89 7.74

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Is population growth a big problem, even the
fundamental environmental problem?What can or
should we do about this problem?
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In the past four decades the population in most
of the developing countries has increased very
rapidly. To many people it seems obvious that
this growth of population has been a major cause
of environmental destruction, increasing poverty
and famines. They believe, very sincerely, that
something should, or even must, be done to slow
down the growth of population in developing
countries. They are surprised, even incredulous,
to hear that anyone can dispute something so
self-evident.G. Ohlin
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Stages in Development of an Environmentalist Inno
cence (ignorance is bliss!) Knowledge leads to
feelings of guilt Guilt leads to changes in
lifestyle Activism and evangelism Reaping eternal
rewards
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The needs hierarchy alone does not explain
environmentalism. Both forgetful devaluation and
learned inability to see economic problems have
twisted environmentalism from a sane and
insightful protection of the environment,
civilization included, in to a mad scramble for
political power and economic control by self
appointed saviors who dont care what it costs
real people.From Global 2000, Revisited
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One of the lessons of our century is beware the
intellectuals. Not merely should they be kept
well away from the levers of power they also
should be objects of peculiar suspicion when they
seek to offer collective advice.Global 2000,
Revisited
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Population growth
Environmental degradation
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Population stability is necessary to the
attainment of human perfection. Plato
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Two principles of human population growth
(Malthus)1. Human population can grow faster
than the increase in food production.2. Unless
people are starving, they will continue to
reproduce.
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Society cannot exist unless a controlling power
on will and appetite be placed somewhere, and the
less of it there is within, the more there must
be without. Edmund Burke
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The penalty for our frantic attempts to feed
burgeoning populations may be a lowering of the
carrying capacity of the planet below its present
level From Ehrlich and Ehrlich
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The actions taken over the past two decades to
prevent famines have only made the situation
worse in the long run.
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• What is needed is not family planning but
  population control. The former focuses on the
  needs and desires of individuals and families,
  whereas the latter focuses on the needs and
  desires of the whole society.
• Ehrlich and
  Ehrlich
• The Population
  Explosion

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What is the use of reducing infant mortality when
it is precisely that reduction which imposes the
greatest restraint on us in the begetting of
children, so that, taken all around, we
nevertheless rear no more children than in the
days before the reign of hygiene, while at the
same time we have created difficult conditions
for our sexual life in marriage.
Sigmund Freud
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The disparity between biological and social
science worldviews lies in the fact that people
and fruit flies are not alike. People can think.
History is replete with examples in which human
ingenuity has transformed seemingly immutable
limits into expandable ones. T. Espenshade
(1993) in a review of The Population Explosion
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Vital Statistics

• Birth rate born/1000 per year
• Death rate dying/1,000 per year
• Total fertility born to an average woman in
  her lifetime
• Replacement fertility about 2.1
• Population age structure distribution of
  people across age classes
• example percentage of people lt 15 years old

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Nt No ert Where, Nt population size at
time t No initial population size
r proportional growth rate e base of
natural logarithms for r 0.02 (1975
value)
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Nt No ert Where, Nt population size at
time t No initial population size
r proportional growth rate e base of
natural logarithms
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Population growth projections Assumptions

• 1. Total fertility in countries with high TF
  will rapidly decline to RF
• 2. Constant death rate
• 3. Use 2005 age structure

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The actions taken over the past two decades to
prevent famines have only made the situation
worse in the long run.
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The penalty for our frantic attempts to feed
burgeoning populations may be a lowering of the
carrying capacity of the planet below its present
level From Ehrlich and Ehrlich
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What can or should we do about this problem?
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If any resource can be shifted from one
deployment to another and it would yield greater
satisfaction in the second deployment, then it
should be so shifted.
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CARRYING CAPACITY The maximum number of
animals that a habitat will support without
degradation of the resource base.The actions
taken over the past two decades to prevent
famines have only made the situation worse in the
long run.