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Chapter 1 Introducing Environmental Science and Stability


Chapter 1 Introducing Environmental Science and Stability Overview of Chapter 1 Human Impacts on The Environment Population, Resources and the Environment ... – PowerPoint PPT presentation

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Title: Chapter 1 Introducing Environmental Science and Stability

Chapter 1Introducing Environmental Science and
Overview of Chapter 1
  • Human Impacts on The Environment
  • Population, Resources and the Environment
  • Environmental Sustainability
  • Environmental Science
  • Assessing Environmental Problems

The Environment (Earth)
  • Life has existed on earth for 3.8 billion years
  • Earth well suited for life
  • Water covers ¾ of planet
  • Habitable temperature
  • Moderate sunlight
  • Atmosphere provides oxygen and carbon dioxide
  • Soil provides essential minerals for plants
  • But humans are altering the planet not always in
    positive ways

Human Impacts on Environment- Population
  • Earths Human Population is over 7 billion
  • Growing exponentially
  • Expected to add several billion more people in
    21st century
  • Increase will adversely affect living conditions
    in many areas of the world

  • Globally, 1 in 5 people lives in extreme poverty
  • Cannot meet basic need for food, clothing,
    shelter, health
  • Difficult to meet population needs without
    exploiting earths resources

Gap Between Rich and Poor
  • Highly Developed Countries (HDC)
  • Complex industrialized bases, low population
    growth, high per capita incomes
  • Ex US, Canada, Japan
  • Less Developed Countries (LDC)
  • Low level of industrialization, very high
    fertility rate, high infant mortality rate, low
    per capita income
  • Ex Bangladesh, Mali, Ethiopia

Types of Natural Resources
  • People overpopulation
  • Too many people in a given
  • geographic area
  • Problem in many developing
  • nations
  • Consumption overpopulation
  • Each individual in a population consumes too
    large a share of the resources
  • Problem in many highly developed nations

Ecological Footprint
  • The average amount of land, water and ocean
    required to provide that person with all the
    resources they consume

Earths Productive Land and Water 11.4 billion hectares
Amount Each Person is Allotted (divide Productive Land and Water by Human Population) 1.63 hectares
Current Global Ecological Footprint of each person 2.3 hectares
Ecological Footprint Comparison
IPAT Model
  • Measures 3 factors that affect environmental
    impact (I)

Environmental Sustainability
  • The ability to meet current human need for
    natural resources without compromising the needs
    of future generations
  • Requires understanding
  • The effects of our actions on the earth
  • That earths resources are not infinite

Tragedy of the Commons
  • Garrett Hardin (1915-2003)
  • Solving Environmental Problems is result of
    struggle between
  • Short term welfare
  • Long term environmental stability and societal
  • Garrett used Common Pastureland in medieval
    Europe to illustrate the struggle

Sustainable Development
  • Economic development that meets the needs of the
    present generation without compromising future

Environmental Science
  • An interdisciplinary study of human relationship
    with other organisms and the earth
  • Biology
  • Ecology
  • Geography
  • Chemistry
  • Geology
  • Physics
  • Economics
  • Sociology
  • Demography
  • politics

Earth As a System
  • System
  • A set of components that interact and function as
    a whole
  • Global Earth Systems
  • Climate, atmosphere, land, coastal zones, ocean
  • Ecosystem
  • A natural system consisting of a community of
    organisms and its physical environment
  • System approach to environmental science
  • Helps us understand how human activities effect
    global environmental parameters

Earth Systems
  • Most of earths systems are in dynamic
    equilibrium or steady state
  • Rate of change in one direction equals that in
    the other
  • Feedback
  • Change in 1 part of system leads to change in
  • Negative feedback- change triggers a response
    that counteracts the changed condition
  • Positive feedback- change triggers a response
    that intensifies the changing condition

Five Stages to Addressing An Environmental Problem
  • Five steps are idealistic
  • Real life is rarely so neat
  • The following slides illustrate a Case Study
    using the Five Stages

Assessing Environmental ProblemCase Study Lake
  • Large, freshwater pond
  • Suburban sprawl in 1940s
  • 10 new sewage treatment plants dumped effluent
    into lake
  • Effect excessive cyanobacteria growth that
    killed off fish and aquatic life

Assessing Environmental ProblemCase Study Lake
  • Scientific Assessment
  • Aquatic wildlife assessment done in 1933 was
    compared to the 1950 assessment
  • Hypothesized treated sewage was introducing high
    nutrients causing growth of cyanobacteria
  • Risk Analysis
  • After analyzing many choices, chose new location
    (freshwater) and greater treatment for sewage to
    decrease nutrients in effluent

Assessing Environmental ProblemCase Study Lake
  • Public Education/Involvement
  • Educated public on why changes were necessary
  • Political Action
  • Difficult to organize sewage disposal in so many
  • Changes were not made until 1963!
  • Evaluation
  • Cyanobacteria slowly decreased until 1975 (gone)

Assessing Environmental ProblemCase Study Lake
  • Results!

Scientific Method
Controls and Variables in Experiment
  • Variable
  • A factor that influences a process
  • The variable may be altered in an experiment to
    see its effect on the outcome
  • Control
  • The variable is not altered
  • Allows for comparison between the altered
    variable test and the unaltered variable test

Inductive and Deductive Reasoning
  • Inductive Reasoning
  • Used to discover general principles
  • Seeks a unifying explanation for all the data
  • Ex
  • FACT Gold is a metal heavier than water
  • FACT Iron is metal heavier than water
  • FACT Silver is a metal heavier than water
  • CONCLUSION (based on inductive reasoning) All
    metals are heavier than water
  • Conclusions reached with inductive reasoning may
    change with new information

Inductive and Deductive Reasoning
  • Deductive Reasoning
  • Proceeds from generalities to specifics
  • Adds nothing new to knowledge, but makes
    relationships among data more apparent
  • Ex
  • GENERAL RULE All birds have wings
  • SPECIFIC EXAMPLE Robins are birds
  • CONCLUSION (based on deductive reasoning) All
    Robins have wings
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