Download Environmental Science

Part 1: Foundations of Environmental Science
Ch
3
Ch 1
An Introduction to
Chapter title Science
Environmental
Part title Overview
A General
1st Mt start (6/9/09)
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Jay
Withgott
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Heidi
Marcum
Modified & enforced by M.-H. Kim
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
“What are the Major Problems the World is facing currently?”
•
Wars, Conflicts between Nations, Different Groups of People:
Conflicts of Mankind vs. Mankind
Caused by nations and groups to promote self-interests:
To Understand Others for harmonious co-existence
among different groups of peoples.
Gap between Rich & Poor, & other Socio-Economic Political Issues:
Geography (Human), World History, Religions, Philosophy
Political Science, Sociology, Economics, Ethics, etc.
•
•
Diseases, and Healthcare:
Conflicts of Micro-organism vs. Mankind
Biology, Medicines, etc.
Environmental Problems: New problems since 1960s, Half-century old
pollution, destruction of ecosystems, extinction, population, and energy
Conflicts of Natural World (Planet Earth) vs. Mankind
Over-exploitation of nature in non-sustainable ways.
Environmental
Science, Ecology, or Geology
Thyeogony,
Hesiod
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1.1
This lecture will help you understand:
Chap 1 A General Overview
• The meaning of the term
environment
• The importance of natural
resources
• That environmental science is
interdisciplinary
• The scientific method and
how science operates
• Some pressures facing the
global environment – what are
the major problems ?
• Sustainability and sustainable
development
3.14(12,800km) = 40,200km
3.14(8,000mi) = 25,000mi
25,000mi/(70mi/hr) = 360hrs = 15days
25,000mi/(600mi/hr) = 42hrs ~ 2days
Atmosphere : ~ 1% of the Diameter
“Earth is a tiny fragile spaceship in a vast universe.”
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Planet Earth
• Geoshpere
(Lithosphere):
Crust: < 1% (Thin)
Everest: 8.85 km
Mantle, Cores
•Hydrosphere:
(oceans)
Mariana Trench (6.9mi)
~ 0.2 %
• Atmosphere: ~1%:
30 km (99% of air)
extends to 120 km
• Biosphere:
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Environment: the total of our surroundings
• All the things around us with which we interact:
Biotic vs. Abiotic
• Living things
• Animals, plants, forests, fungi, etc.
• Nonliving things
• Continents, oceans, clouds, soil, rocks
• Our built environment
• Buildings, human-created living centers
• Social relationships and institutions
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Humans and the world around us
• Humans change the environment, often in ways not fully
understood
• We depend completely on the environment for survival
- Increased wealth, health, mobility, leisure time
- But, natural systems have been degraded
- i.e., pollution, erosion and species extinction
- Environmental changes threaten long-term health and survival
• Environmental science is the study of:
- How the natural world works
- How the environment affects humans and vice versa
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Natural resources: vital to human survival
Natural resources : matter & energy sources needed for survival
• Renewable resources:
- Perpetually available: sunlight, wind, wave energy
- Renew themselves over short periods: timber, water, soil
- These can be destroyed
• Nonrenewable resources: can be depleted - Oil, coal, minerals
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Global human population growth
•
> 6.96 billion humans
5M
20M
35M
200M 500M(14C)
1G (19C)
6.8 G (Jan 2010)
7G (2012), 8G(2025)
• Why so many humans ?
Agricultural revolution
Stable food supplies
Industrial revolution
(late 18th C)
Urbanized society powered
by fossil fuel
Sanitation and medicines
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Which city is this?
Thomas Malthus and human population:
“An Essay on the Principle of Population” (1789)
• Thomas Malthus
• Population growth must be
restricted, or it will outstrip
food production
• Starvation, war, disease
• Neo-Malthusians
• Population growth has
disastrous effects
• Paul and Anne Ehrlich, The
Population Bomb (1968)
→ didn’t explode
- Must Be Controlled
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Cf. China: One Child Policy (Deng, 1989)
Garrett Hardin’s Tragedy of the Commons (1968)
(Fig. 9.23)
•Unregulated exploitation leads to resource depletion
- Soil, air, water
•Resource users are tempted to increase use
until the resource is gone
•Solution?
- Private ownership?
- Voluntary organization to enforce responsible use?
- Governmental regulations?
2nd Mtg end (8/21/08)
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The “ecological footprint”
• The total area of land & water
needed to produce the resource a
person uses, plus the total amount of
land and water area needed to
dispose of its waste (ha).
~ measure of resource and waste a
person needed for its life style.
2.23 ha World Ave.
USA
• Higher in developed societies/nations 9.6
0.6
Rwanda
We are using 30% more (overshoot) of the planet’s
resources than are available on a sustainable basis!
2
3rd Mtg start (8/26/08)
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(1 ha = 2.47 acre = 108,000 ft )
2
(cf. Area of this room = 36ft x 30ft ~ 950ft )
(2006)
Overshoot
Overshoot: humans have surpassed the Earth’s capacity to support us
We are using renewable resources 30% faster than they are
being replenished
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Migration of Human out of Africa: 200,000 years ago
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Environmental science
can help us avoid mistakes made by past civilizations.
The lesson of Easter Island:
~ 300 AD first inhabited, lush forests & other resources
~ 600 AD flourished, (Hundreds of the Statues, 10m, 100 tons)
~ 750 AD start to decline (overused the resources)
1722 AD in desolate condition in a barren landscape
People annihilated their civilization by destroying their environment to deplete
resources.
Denude forest(over use of hauhau tree) → soil erosion → fast runoff → less fresh
water /degrading arable land → lowering crop yield(bananas, sugarcane, sweet
potatoes) → starvation/population decline →civilization collapse.
•Fall of the Mesopotamian Civilization (Wheat- based agrarian):
→ prolonged irrigation system → degrade soil (salt too high) → not arable
→ decrease crop yields → food shortage → population decline (2,300 BC).
* Cf. Downfall of the Minoan Civilization on Crete (Natural Disaster, 1627 BC)
Triggered by Thera Eruption → Tsunami , then invasion of the mainland Greek.
Copyright 2
© nd
2008Mtg,
Pearson Education,
Inc., publishing
as Benjamin Cummings
(end
1/14/10)
http://www.bradshawfoundation.com/journey/
(The Migration)
Environmental science:
How does the natural world work?
Environment  impacts  Humans
(2M yrs)
• It has an applied goal: developing
solutions to environmental problems
• Most interdisciplinary field
-Natural sciences: information about
the world
- Environmental Science programs
-Social sciences: values and human
behavior
- Environmental Studies programs
“What happen to the physics ?”
 Total Science – inclusive, comprehensive, or holistic
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What is an “environmental problem”?
- The perception of what
constitutes a problem varies
between individuals and
societies (place) and time
- Ex.: DDT, a pesticide
- In developing countries:
welcome because it kills
malaria-carrying mosquitoes,
lice and other insects.
- In developed countries: not
welcome, due to health risks
(found to be a carcinogen a half
century later)
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Germany, 1945
Much popular pesticide:
Sprayed almost everywhere
In Summer time
Environmental science is not environmentalism
•Environmental science
• The pursuit of knowledge
about the natural world
• Scientists try to remain
objective
•Environmentalism
• A social movement dedicated
to protecting the natural world
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Development of Modern Science: 17th C
Copernicus(1473-43), F. Bacon(1561-26), R. Decartes(1592-50),
Galileo(1564-42), Kepler(1571-60), Boyle(1627-91), Newton (1642-27)
• Science:
,
- A systematic process for learning about the
world/nature and testing our understanding of it
- based on reasoning (as opposed to authority, belief
or feeling), facts, observation (experiments), testing,
and logic of induction & deduction
- The accumulated body of knowledge that results from
this process
- To sort fact from fiction/myth
- Develop solutions to the problems we face
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Inductive 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
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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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Applications of science
Policy decisions and
management practices
Technology
Energy-efficient methanolpowered fuel cell car from
DaimlerChrysler
Restoration of forest ecosystems
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The scientific method
• A technique for testing ideas
with observations
• Assumptions:
- The universe works
according to unchanging
natural laws
- Events arise from causes,
and cause other events
- We use our senses and
reason to understand
nature’s laws
Cf. Buddhism
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The scientific method
• A scientist makes an observation and
asks questions of some phenomenon
• The scientist formulates a hypothesis,
a statement that attempts to explain the
scientific question.
• The hypothesis is used to generate
predictions, which are specific
statements that can be directly and
unequivocally tested.
• The test results either support or
reject the hypothesis
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Experiments test the validity of a hypothesis
- Example: Effect of Temperature on Plant Growth
Manipulative experiments
yield the strongest evidence
• But, lots of things can’t be
manipulated
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Natural or correlational tests
show real-world complexity
• Results are not so neat and
clean, so answers aren’t
simply black and white
End of 1st Mt (6/9/09)
Effect of Temperature on Natural Processes
(1) “ How many time faster an evergreen tree can grow in a hot
Summer (35 oC) than in a cold Winter weather (5 oC) ?”
(2) “Food placed outside in a room will be spoiled much faster
than the one inside a refrigerator. How many times faster ?”
Note:
Plant growth results from a series biochemical reaction (synthesis of
carbohydrate and others) . Food decay results from chemical
decomposition of proteins, carbohydrates, lipids by bacteria
“Chemical reaction rate doubles at every 10 oC increase in
temperature” – A Rule of Thumb in Chemistry:
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Science must be Quantitative as well as Qualitative
• Qualitative Information:
Eg., Pollen count in a spring day was high.
Table salt is very soluble in water
The lake water is heavily polluted with lead.
These are not complete scientific statements.
• Quantitative Information:
Eg., 850 particles/ft3 at 3 PM in April 26th, 1997 .
36g NaCl/100mL H2O (or 5 oz/gal)
27mg Pb/100mL of lake water (or 0.05oz/gal)
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Population & consumption
• Human population growth exacerbates all environmental
problems
- The growth rate has slowed, but we still add more than
200,000 people to the planet each day
( ~ 70millon/yr )
• Our consumption of resources has risen even faster than
our population growth.
- Life has become more pleasant for us so far
- However, rising consumption amplifies the demands
we make on our environment.
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Ecological footprints are not all equal: World Ave: 2.2 ha
World Biocapacity (EF at sustainable label) : 1.7 ha
• The ecological footprints of
countries vary greatly
- The U.S. footprint is almost 5
times greater than the world’s
average
- Developing countries have
much smaller footprints than
developed countries
- High Income Country: 6
- Middle
“
:2
- Low
“
<1
N.A. 9.4, L.A.2.0
EU 4.8, Europe (nonEU) 3.8
Asia 2.2 , Africa 1.1
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The Ecological Footprint
US 9.6 ha, World 2.23 ha per capita
%
• Carbon Footprint (Home energy &
transportation):
i.e., Gas, electricity & gasoline
37
• Food Footprint
27
• Housing
13
• Goods and Services Footprint
(Clothing, & others)
23
____
100
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We face challenges in agriculture
• Expanded food production led to increased
population and consumption
• It’s one of humanity’s greatest achievements, but
at an enormous environmental cost.
Nearly half of the planet’s land surface is used
for agriculture
- Chemical fertilizers
- Pesticides
- Erosion
- Changed natural systems
→ leading to degradation of soils
& water pollution
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We face challenges in pollution: Air and Water
• Waste products and artificial chemicals used in farms, industries,
and households
- Outdoor & Indoor Pollutions
Eg., Coal burning plants
Each year, millions of people die from pollution
End 3rd Mtg(1/21/2010)
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We face challenges in climate
• Scientists have firmly concluded that humans are
changing the composition of the atmosphere
• The Earth’s surface is warming
- Melting glaciers
- Rising sea levels
- Impacted wildlife and crops
(Biodiversity)
- Increasingly destructive weather
(Hot weather cause hurricanes to be more powerful)
Since the Industrial Revolution, atmospheric CO2 concentrations
have risen by 37%, to the highest level in 650,000 years
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We face challenges in biodiversity
• Human actions have driven many species extinct, and
biodiversity is declining dramatically
- We are at the onset of a mass extinction event (6th)
Biodiversity loss may be our biggest environmental problem;
once a species is extinct, it is gone forever.
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The Millennium Ecosystem Assessment (UN)
by over 1,000 scientists, release 2,005
•
The most comprehensive scientific assessment of the
condition of the world’s ecological systems
•
Major findings:
•
Humans have drastically altered ecosystems
•
These changes have contributed to human wellbeing and economic development, but at a cost
•
Environmental degradation could get much worse
•
Degradation can be reversed, but it requires work
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Our energy choices will affect our future
• The lives we live today are due to fossil fuels
- Machines
- Chemicals
- Transportation
- Products
• Fossil fuels are a one-time bonanza; supplies will
certainly decline
We have used up ½ of the world’s oil supplies; how
will we handle this imminent fossil fuel shortage?
Needs other Energies Sources
Cf. Wind Energy: US ~2.5%, Denmark ~ 25%
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Sustainable solutions exist
• We must develop solutions that protect both our quality of
life and the environment
• Organic agriculture
• Technology
- Reduces pollution
• Biodiversity
- Protect species
• Waste disposal
- Recycling
• Alternative fuels
cf. Samsoe Island (Denmark): relying mostly on Wind & Solar
Energy
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Sustainability: a goal for the future
• How can humans live within the planet’s means?
- Humans cannot exist without functioning natural
systems of environment
• Sustainability
- Leaves future generations with a rich and full Earth
- Conserves the Earth’s natural resources
- Maintains fully functioning ecological systems of
nature
• Sustainable development: the use of resources to satisfy
current needs without compromising future availability
of resources for generations to come.
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Conclusion
• Environmental science helps us understand our
relationship with the environment and informs our
attempts to solve and prevent problems.
• Identifying a problem is the first step in solving it
• Solving environmental problems can move us towards
health, longevity, peace and prosperity
- Environmental science can help us find balanced
solutions to environmental problems for sustainable
development
3rd Mtg end (8/26/08)
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