The Human Population as an Environmental Problem - PowerPoint PPT Presentation

Loading...

PPT – The Human Population as an Environmental Problem PowerPoint presentation | free to view - id: 26d697-YzY3N



Loading


The Adobe Flash plugin is needed to view this content

Get the plugin now

View by Category
About This Presentation
Title:

The Human Population as an Environmental Problem

Description:

Human impact varies w/lifestyle, this is sometimes called 'ecological footprint' ... Life expectancy - average expected lifespan at birth. 5.2 Key points ... – PowerPoint PPT presentation

Number of Views:165
Avg rating:3.0/5.0
Slides: 24
Provided by: rossd9
Category:

less

Write a Comment
User Comments (0)
Transcript and Presenter's Notes

Title: The Human Population as an Environmental Problem


1
Chapter 5
  • The Human Population as an Environmental Problem

2
A Few Current NumbersSourcepopulation reference
bureau
  • World Population - 6.48 billion
  • Percent growth 1.2
  • US Population - 297 million
  • Percent growth 0.6

3
Most Populous CountriesSourcepopulation
reference bureau
  • 1 China - 1.3 billion
  • Percent growth 0.6
  • 2 India - 1.1 billion
  • Percent growth 1.7
  • 3 USA - 297 million
  • Percent growth 0.6

4
Most Populous CountriesSourcepopulation
reference bureau
  • 4 Indonesia - 222 million
  • Percent growth 1.6
  • 5 Brazil - 184 million
  • Percent growth 1.3
  • 6 Pakistan - 162 million
  • Percent growth 2.4

5
A Few Current TrendsSourcepopulation reference
bureau
  • More developed countries - 1.2 billion
  • Percent growth 0.1
  • Less developed countries - 5.3 billion
  • Percent growth 1.5 (1.8 w/out china)

6
Effect of technology (1)
  • Impact of humans depends on two factors the
    number of humans, and the impact of each
  • Human impact varies w/lifestyle, this is
    sometimes called ecological footprint

7
Effect of technology (2)
  • Technology allows us to overcome (temporarily)
    Malthus prophecy
  • Buttechnology increases our impact and adds
    additional types of impact

8
Malthus Prophecy
  • Food is necessary for people to survive
  • People will continue to reproduce
  • Population growth will outpower agricultural
    growth

9
Considering Numbers
  • World Population 6.4 billion
  • Area of Texas 261,797 sqft
  • Put every person on earth in Texas and they each
    get 1140 sqft or 38 people per acre
  • BUT.

10
More on Ecological Footprint
  • In USA each person requires 10.4 hectares for
    resources
  • In Bangladesh each person requires 0.5 hectares
    for resources
  • World 2.8 hectares (only 2.1 available)
  • SourceIPCC

11
Ecological Footprint bottom line
  • Less populous nations may have greater
    environmental impact than more populous
    countries.
  • See pg 78

12
5.1 Key Points
  • Earth is at 6.5 and growing at 1.2
  • Developing countries have both higher numbers and
    higher growth rates than developed countries
  • Human impact is a product of the number of humans
    and the impact of each

13
5.1 Key Points (cont)
  • Technology increases number of humans and can
    change type of impact
  • Malthus made key points about carrying capacity
    and MUST ultimately be right

14
Key Population concepts
  • Age structure
  • Demographic Transition
  • Fertility
  • Human population v. environment
  • Deathrate increase
  • Standard of living and pop factors

15
History of Human Pop.
  • I - Hunter Gatherer, a few mil.
  • II - Rise of agriculture, allowed density
    increase
  • III - Industrial revolution, rapid increase
  • IV - Present, slow in ind, but fast in devel.

16
Population factors
  • g b - d (growth births - deaths)
  • Crude rates per 1000
  • Percent rate per 100
  • So, 9 births per 1000 crude rate 0.9 birth
    rate

17
Important terms
  • Maximum lifetime - genetically determined
    potential
  • Life expectancy - average expected lifespan at
    birth

18
5.2 Key points
  • As technology changed human lifestyle, patterns
    of pop growth changed
  • g b - d
  • Key terms ie crude growth rate, max lifetime,
    etc

19
A note on book numbers
  • Trends IDed on p. 83 - 84
  • But, according to pop data sheet no countries are
    growing at 5, a few are at 3.5 (highest listed)

20
Logistic Growth Curve
21
Why Logistic is limited
  • Three assumptions
  • Constant environment
  • Constant carrying capacity
  • Homogeneous population
  • Especially unreliable if technology changes death
    rates

22
Predicting Human Population
  • Using logistic growth for this requires an
    inflection point
  • BUThumans have not reached a clear inflection
    point
  • 3 UN projections are on page 85

23
The Demographic Transition
About PowerShow.com