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An Environmental Lesson from Rapa Nui

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An Environmental Lesson from Rapa Nui Colonized about 2,900 years ago Farmed and Fished (Wooden Canoes) Soil and tree resources exhausted Built over 300 statues – PowerPoint PPT presentation

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Title: An Environmental Lesson from Rapa Nui


1
An Environmental Lesson from Rapa Nui
  • Colonized about 2,900 years ago
  • Farmed and Fished (Wooden Canoes)
  • Soil and tree resources exhausted
  • Built over 300 statues
  • By 1600 AD, few trees left
  • Islanders trapped and starved
  • War over remaining resources
  • TRAGEDY OF THE COMMONS!!!

2
Science, Matter, and Energy
  • Chapter 2

3
Essential Question 1What is science and what
do scientists do? Distinguish between inductive
and deductive reasoning. Explain why scientific
theories and laws are the most important results
of science.
4
Science!!!Science is an attempt to discover
order in nature and use that knowledge to make
predictions about what is likely to happen in
nature.(Assumes that events in the natural
world follow orderly cause and effect patterns.)
5
THE NATURE OF SCIENCE
  • What do scientists do?
  • Collect data.
  • Form hypotheses.
  • Develop theories, models and laws about how
    nature works.

Figure 2-2
6
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7
Scientific Reasoning
  • Inductive Reasoning
  • Specific ? General
  • EX
  • We observe that many objects fall to the ground
    when dropped.
  • We conclude all objects fall to the ground when
    dropped.
  • Deductive Reasoning
  • General ? Specific
  • EX
  • All birds have feathers. Eagles are birds.
  • We conclude that eagles have feathers.

8
Inductive vs. Deductive
  • Inductive
  • Based on observations / experiences
  • Deductive
  • Based on widely accepted principles / rules / laws

9
Examples
  1. All squares are rectangles, and rectangles have 4
    sides. Therefore, all squares have four sides.
  2. All known planets travel around the sun in
    elliptical orbits, therefore all planets travel
    around the sun in elliptical orbits.
  3. All known life forms rely on liquid water to
    survive. Therefore all life must rely on water
    to survive.

10
Scientific Theories Laws
  • Scientific / Natural Law
  • What we find happening in
  • nature over over in the same
  • way
  • Scientific Theory
  • Explain natural laws
  • Widely tested accepted hypotheses
  • Supported by extensive evidence

We cant prove anything is absolutely true.
There is always some degree of uncertainty.
11
Peer Review
  • Peer Review
  • Allows scientists to repeat analyze each
    others findings to see if data is reproducible
  • Helps identify SOUND SCIENCE

Figure 2-3
12
Categories of Science
  • Sound (Consensus) Science
  • widely accepted by experts in the field
  • Frontier Science
  • preliminary results that are often still
    controversial
  • Junk Science
  • presented as sound science, but has not undergone
    peer review (or was discarded by peer review)

13
Paradigm Shifts
  • When new discoveries or ideas overthrow a
    well-accepted scientific theory or notion
  • Can impact our worldviews

14
Essential Question 2 3How do we study
complex systems? Explain the difference
between a time delay and a synergistic
interaction give an example of each.What is a
feedback loop? How do positive and negative
feedback loops differ?
15
Systems
  • Key Components
  • Inputs
  • Flows / Throughputs
  • Outputs
  • Models
  • Mathematical models
  • Multivariable analysis
  • Predict likelihoods

16
Feedback Loops How Systems Respond to Change
  • Outputs of matter, energy, or information fed
    back into a system can cause the system to do
    more or less of what it was doing.

17
Feedback Loops
  • Negative Feedback Loop (Corrective)
  • Stabilizes (system changes in opposite direction)
  • Ex
  • Get a bad grade, change your study methods
  • Positive Feedback Loop (Amplification)
  • Amplifies further in the same direction
  • Ex
  • You get good grades, so you continue to study hard

18
Negative Feedback Restores a System
Positive Feedback Amplifies a System
19
Feedback Loop Examples
  1. Seek shade from the sun to reduce sunburn
  2. Fruit ripening on the vine
  3. Shivering or sweating to bring body temperature
    back to normal
  4. Erosion slowly causes a river to widen and deepen

20
Time Delays
  • Delay between the input of a stimulus and the
    response
  • Ex eating McDonalds everyday ? heart attack 40
    years later
  • Tipping Point / Threshold Level
  • Can allow problems to build until a major shift
    in the system is unavoidable

21
Feedback Loops
  • Negative feedback can occasionally take so long
    to correct or stabilize a system a threshold is
    reached and the system changes.
  • Prolonged delays may prevent a negative feedback
    loop from occurring.
  • Example If human population continues to grow
    unchecked, we could exhaust our resources before
    nature can put our population in check. Result
    massive die off.

22
Synergy
  • When two or more processes in a system interact
    to amplify the result

Amplified Global Climate Change
23
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24
Essential Question 4What are the basic forms
and states of matter?
25
Matter and its Forms
  • What is matter? Anything that has mass and
    takes up space.
  • Elements
  • building blocks of matter that make up every
    material substance
  • Compounds
  • 2 or more elements joined by chemical bonds

26
Matter and its States
27
Atoms
  • Subatomic particles
  • Protons ()
  • Neutrons (o)
  • Electrons (-)
  • Atomic number protons in nucleus
  • Mass number total of protons neutrons
  • Isotopes diff s of neutrons in nucleus

28
Ions pH
  • Ion
  • atom or group of atoms with one or more net
    positive () or negative (-) charge
  • pH
  • Used as a measure of acidity of a substance based
    on concentration of hydrogen ions (H) vs.
    hydroxide ions (OH-)
  • Logarithmic scale (x10)

29
Organic and Inorganic Compounds
  • Organic Compounds contain at least 2 carbon
    atoms
  • Hydrocarbons C H
  • CH4 (methane)
  • Chlorinated Hydrocarbons C, H, Cl
  • DDT (insecticide)
  • Carbohydrates C, H, O (1/2/1)
  • glucose
  • Proteins / Nucleic Acids (DNA RNA)
  • Inorganic Compounds
  • All other compounds

30
Biotic Matter
A human body contains trillions of cells, each
with an identical set of genes.
There is a nucleus inside each human cell (except
red blood cells).
  • Organisms
  • Cells
  • Chromosomes
  • Genes
  • DNA

Each cell nucleus has an identical set of
chromosomes, which are found in pairs.
A specific pair of chromosomes contains one
chromosome from each parent.
Each chromosome contains a long DNA molecule in
the form of a coiled double helix.
Genes are segments of DNA on chromosomes that
contain instructions to make proteinsthe
building blocks of life.
The genes in each cell are coded by sequences of
nucleotides in their DNA molecules.
Stepped Art
Fig. 2-4, p. 25
31
Natural Capital Matter
Levels of organization of matter in nature
Fig. 2-3, p.23
32
Essential Question 5How does matter quality
determine matters usefulness as a resource?
33
Matter Quality
  • High-quality matter
  • concentrated / near earth surface / great
    potential for use
  • Low-quality matter
  • dilute or deep underground / little potential for
    use
  • Material efficiency (resource productivity)
  • total amount of material needed to produce each
    unit of goods or services

34
Matter Quality
High Quality
Low Quality
Solid
Gas
Salt
Solution of salt in water
Coal
Coal-fired power plant emissions
Gasoline
Automobile emissions Aluminum ore
Fig. 2-5, p. 25
Aluminum can
Aluminum ore
35
Essential Question 6What types of changes can
matter undergo?
36
Changes in Matter
  • Physical
  • Size/State
  • Chemical
  • Chemical comp.
  • Nuclear
  • Isotopes change to different isotopes
  • Decay / Fission / Fusion

Chemical Reaction of Burning Carbon
37
Essential Question 7What scientific law
governs changes in matter and why is it important
in relation to environmental science?
38
Law of Conservation of Matter
  • Matter is not created or destroyed
  • Matter only changes form
  • There is no throwing away

39
Conservation of Matter Sustainability
  • Even when we collect / clean pollution from one
    area, it must still be put somewhere possibly
    pollute something else!
  • We will ALWAYS face the problem of what to do
    with SOME quantity of wastes / pollution.

40
Severity of Pollution
  • Depends on
  • Chemical nature of pollutants
  • Concentration (ppm / ppb / ppt)
  • Persistence how long it stays in air/ water/
    soil/ body/ etc

41
4 Types of Pollutants
  • Degradable (Nonpersistent) Pollutants
  • Broken down by natural processes
  • Biodegradable Pollutants
  • Organisms (usually bacteria) can break down
    (sewage)
  • Slowly Degradable (Persistent) Pollutants
  • Takes decades or longer to degrade (DDT /
    Plastics)
  • Nondegradable Pollutants
  • Natural processes cannot break down
    (lead/mercury/arsenic)

42
Essential Question 8What is energy and what
are the major forms of energy?
43
Energy
  • Definition The ability to do work and transfer
    heat
  • Energy Forms
  • electrical, mechanical, radiant (light), heat,
    chemical, nuclear
  • Energy Types
  • kinetic and potential
  • Electromagnetic radiation
  • wavelength and energy content

44
Sunlight electromagnetic radiation
Energy emitted from sun (kcal/cm2/min)
Visible
Infrared
Ultraviolet
Wavelength (micrometers)
Fig. 2-9, p. 30
45
Essential Question 9How does energy quality
determine an energy resources usefulness?
46
Energy Quality
  • High-quality
  • Concentrated can perform useful work
  • EX electricity, energy stored in coal/gas,
    sunlight, Uranium
  • Low-quality
  • Dispersed has little ability to do useful work
  • EX heat dispersed in large body of water
  • Amt of heat stored in ATL ocean is greater than
    energy stored in ALL oil in Saudi Arabia (so
    dispersed its not useful)

47
Energy Quality
Relative Energy Quality (usefulness)
Source of Energy
Energy Tasks
Electricity Very high temperature heat (greater
than 2,500C) Nuclear fission (uranium) Nuclear
fusion (deuterium) Concentrated
sunlight High-velocity wind
Very high-temperature heat (greater than
2,500C) for industrial processes and producing
electricity to run electrical devices (lights,
motors)
Very high
High-temperature heat (1,0002,500C) Hydrogen
gas Natural gas Gasoline Coal Food
Mechanical motion (to move vehicles and other
things) High-temperature heat (1,0002,500C)
for industrial processes and producing electricity
High
Normal sunlight Moderate-velocity
wind High-velocity water flow Concentrated
geothermal energy Moderate-temperature
heat (1001,000C) Wood and crop wastes
Moderate-temperature heat (1001,000C) for
industrial processes, cooking, producing
steam, electricity, and hot water
Moderate
Dispersed geothermal energy Low-temperature
heat (100C or lower)
Low-temperature heat (100C or less) for space
heating
Low
Fig. 2-10, p. 31
48
Essential Question 10What are two scientific
laws governing changes of energy from one form to
another? Explain how these laws relate to
environmental science.
49
First Law of Thermodynamics
50
First Law of Thermodynamics
  • Energy is not created or destroyed
  • Energy only changes form
  • Cant get something for nothing
  • Energy input Energy output

51
Second Law of Thermodynamics
  • In every transformation, some energy quality is
    lost
  • Energy usually lost as heat or light dispersed
    into environment.
  • Energy ALWAYS goes from a more useful to a less
    useful form
  • Second Law greatly affects life

52
Examples of the Second Law
  • Cars
  • only 20-25 gasoline produces useful energy
  • Ordinary light bulb
  • 5 energy is useful light, rest is low-quality
    heat
  • Living systems
  • quality energy lost with every conversion (Rule
    of 10)

53
Energy Efficiency/Productivity
  • Energy Efficiency how much useful work is
    accomplished by a particular input of energy into
    a system
  • 16 of Energy used in the US performs useful work
    (84 is unavoidably or unnecessarily wasted)
  • Cheapest quickest way to get more energy is to
    STOP WASTING IT!
  • Gas-efficient cars / better home insulation

54
Essential Question 11Differentiate between
high-throughput economies and matter-recycling-and
-reuse economies. Why are low throughput
economies a better option than either of these
two?
55
High-Throughput Economies
  • Converts resources to goods in a manner that
    promotes waste and pollution.

56
Matter-Recycling-and-Reuse Economies
  • Mimics nature by recycling and reusing, thus
    reducing pollutants and waste.
  • It is not sustainable for growing populations.

But doesnt eliminate its use
57
Sustainable Economies Low-Throughput
  • Reduce throughput (use) of matter energy
  • Avoid wasting matter energy resources
  • Recycle reuse most of our matter resources
  • Stabilize the size of the human population

58
Inputs (from environment)
System Throughputs
Outputs (into environment)
Energy conservation
Low-quality Energy (heat)
Energy
Sustainable low-waste economy
Waste and pollution
Waste and pollution
Pollution control
Matter
Recycle and reuse
Matter Feedback
Energy Feedback
Fig. 2-16, p. 47
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