Title: Chapter 1 Introducing Environmental Science and Stability
1Chapter 1Introducing Environmental Science and
Stability
2Overview of Chapter 1
- Human Impacts on The Environment
- Population, Resources and the Environment
- Environmental Sustainability
- Environmental Science
- Assessing Environmental Problems
3The 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
4Human Impacts on Environment- Population
- Earths Human Population is over 6 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
5Population
- Globally, 1 in 4 people lives in extreme poverty
- Cannot meet basic need for food, clothing,
shelter, health - Difficult to meet population needs without
exploiting earths resources
6Gap 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
7Types of Natural Resources
8Overpopulation
- 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
9Ecological 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) 1.9 hectares
Current Global Ecological Footprint of each person 2.3 hectares
10Ecological Footprint Comparison
11IPAT Model
- Measures 3 factors that affect environmental
impact (I)
12Environmental 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
13Tragedy of the Commons
- Garrett Hardin (1915-2003)
- Solving Environmental Problems is result of
struggle between - Short term welfare
- Long term environmental stability and societal
welfare - Garrett used Common Pastureland in medieval
Europe to illustrate the struggle
14Sustainable Development
- Economic development that meets the needs of the
present generation without compromising future
generations
15Environmental Science
- An interdisciplinary study of human relationship
with other organisms and the earth - Biology
- Ecology
- Geography
- Chemistry
- Geology
- Physics
- Economics
- Sociology
- Demography
- politics
16Earth 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
17Earth 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
another - Negative feedback- change triggers a response
that counteracts the changed condition - Positive feedback- change triggers a response
that intensifies the changing condition
18Scientific Method
19Controls 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
20Inductive and Deductive Reasoning
- Inductive Reasoning
- Used to discover general principles
- Seeks a unifying explanation for all the data
available - 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
changed with new information
21Inductive 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
22Five Stages to Addressing An Environmental Problem
- Five steps are idealistic
- Real life is rarely so neat
- Following Slides are Case Study Using the Five
Stages
23Assessing Environmental ProblemCase Study Lake
Washington
- 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
24Assessing Environmental ProblemCase Study Lake
Washington
- 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
25Assessing Environmental ProblemCase Study Lake
Washington
- Public Education/Involvement
- Educated public on why changes were necessary
- Political Action
- Difficult to organize sewage disposal in so many
municipalities - Changes were not made until 1963!
- Evaluation
- Cyanobacteria slowly decreased until 1975 (gone)
26Assessing Environmental ProblemCase Study Lake
Washington