2. Lesson Outline
1. What is Environmental Science?
2. Environmental Interactions, cycles, and systems
3. Ecology and environmentalism
3. 3
everything that affects a living organism.
can include both living (biotic) and non-living
(abiotic) components.
•What makes up a forest environment?
•What makes up a marine environment?
•What makes up your personal environment?
4. 1.EnvironmentalScience
The study of our environment either locally or globally, and its living
and non-living components.
An interdisciplinary study of how the earth works, how we interact
with the earth and how we can deal with the environmental
problems we face.
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5. EnvironmentalScienceas interdisciplinary
study…
It is a composite entity incorporating:
◦Natural Sciences: biology, chemistry, earth science,
physics and medicine
◦Social Sciences: economics, political science, sociology,
history, philosophy and ethics.
◦Other sciences: mathematics, statistics, technology,
business and management, law, religion, morality and
aesthetics.
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6. Example to Environmental Science as an
interdisciplinary study
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Politics:
Who should
implement air
pollution
control laws?
Economics:
How much is
the cost of air
pollution
control
measures
(etc.)?
Chemistry:
How much bad
chemicals can
humans inhale from
the dirty air?
Biology:
How will the dirty air
affect birds?
Problem:
Air Pollution
7. What are the events that triggered the
interest in environmental science?
•Rachel Carlson’s Silent Spring (DDT)
•Love Canal
•Burning of a River
•Exxon Valdez in 1989
Environmental Science
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9. The interdisciplinary
study of humanity’s
relationship with
other organisms
and the nonliving
physical
environment.
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Devoted to
studying the
impacts humans
have on the
environment
12. Ecology & Ecosystem
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•Ecology
•study of the interactions between
organisms and between organisms and
their environment
•Ecosystem
•includes all organisms living in an area
and the physical environment with which
these organisms interact.
15. Is economic
development
positive?
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Global life expectancy
doubled since 1950
Infant mortality cut half
since 1955
Food production ahead
of population growth
since 1978
Air and water pollution
down in most developed
countries since 1970
Number of people living
in poverty dropped 6%
since 1990
Life expectancy 11 years less in
developing countries than in
developed countries
Infant mortality rate in developing
countries over 8 times higher than
in developed countries
Harmful environmental effects of
agriculture may limit future food
production
Air and water pollution levels in
most developing countries too
high
Half of world’s people trying to
live on less than $3 (U.S.) per day
16. Resources
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Perpetual
◦ Solar – renewed
continuously
Renewable
◦ Replenished fairly rapidly
through natural processes
Non-renewable
◦ minerals
17. The Tragedy of the Commons –Short
Term vs. Long Term Society Welfare
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18. Tragedy of the Commons
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Depletion or degradation of a potentially renewable
resource to which people have free and unmanaged
access.
An example is the depletion of commercially desirable
fish species in the open ocean beyond areas
controlled by coastal countries.
How do we avoid this?
19. The Ecological Footprint
A measure of how much a person consumes,
expressed in area of land.
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Amount of biologically productive land and water needed to supply each
person or population with the renewable resources they use and to absorb
or dispose of the wastes from such resource use. It measures the average
environmental impact of individuals or populations in different countries and
areas.
www.redefiningprogress.org
22. Quick Quiz
1. Define environment.
2. Write a note on the importance of environment
science/studies.
3. As a student, in what can you do to minimize
your carbon foot print.
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25. Natural selection
• Charles Darwin (1809-82), “On the origin of species by
natural selection”, 1859
• Theory suggesting a mechanism by which species can
adapt to changes in their environment
• Can lead to production of new species (speciation)
26.
27. The mechanism of natural selection
• The reproductive potential of populations is very high and many offspring are
produced
• Population size tend to remain constant because many offspring die before
reaching maturity (‘survival of the fittest’)
• Individuals in a population vary, and much of this variation has a genetic basis
• Many traits can therefore be inherited by their offspring
• Favorable traits (i.e. those which enhance the chances of survival) will be
selected for, since individuals possessing them will be more likely to reach
reproductive maturity
• The genetic composition of population changes over time, refining the
adaptation of organisms to their environments
28.
29. Natural selection
• Central to this theory is the notion
of “individual fitness”
• Fitness is a measure of the
contribution which individuals make
to the genetic makeup of future
generations
• Individuals which are well-adapted
to their environments are those
which will be more likely to survive
and reproduce
30. Speciation
• Species = a group of populations capable of
interbreeding but reproductively isolated from
other groups
• Not the same species if two types of organism do
not interbreed in nature (as opposed to captivity) or
the resultant offspring are sterile
• Speciation is the process which gives rise to a new
species
32. Oxygen and Water Cycles
Oxygen in the atmosphere
Molecular oxygen (O2): 20.95 vol. % of dry air
Carbon dioxide (CO2): 0.03 vol. % of dry air
Water (H2O): 0.5 to 4 vol. % of moist air
Ozone (O3)
Oxides of sulfur, SO2 and SO3 (collectively known as SOX)
Sulfates (SO4
2-)
Nitric oxide (NO) and nitrogen dioxide (NO2), collectively known as NOX
Nitrous oxide (N2O)
Nitrates (NO3-)
33. Role of water in the sustenance of life:
Solvent and transport medium (allows nutrients to be
absorbed by and circulated/distributed within organisms)
Maintenance of world climate that is suitable for life:
Water traps and redistributes a significant portion of the
solar energy received by the Earth
Essential to aerobic photosynthesis (via which CO2 is
converted to plant carbohydrates, e.g., in plant biomass)
44. Nitrogen (as Essential Element)
A basic component of amino acids, which are ‘building blocks’ of proteins.
Proteins have important functions in living organisms.
They act as natural catalysts (enzymes), as chemical messengers (hormones), and in the storage and
transport of some molecules, e.g. oxygen.
A component element in nucleic acids, which comprise nucleotides such as DNA and RNA.
Used by non-aerobic microbes in degradation processes
49. Loss of Nitrogen as a Result of Human
Activities…
1. Excessive application of artificial fertilizer in farms
2. Excessive application of animal manure in farms
3. Poor manure management in poultry, swine and dairy farms
4. Burning of fossil fuels for energy production
5. Burning of biomass as energy source
6. Burning of solid wastes
7. Nitrification and denitrification in waste treatment systems
8. Open dumping of organic solid wastes
53. Phosphorous Sources
Phosphorus in the crusts:
Crusts: largest reservoir of P
P is mainly found in the crust (virtually none
in atmosphere and little hydrosphere)
because of its low solubility and extremely
low volatility.
Phosphorus in the hydrosphere (oceans,
rivers and lakes):
Very little because of its low solubility
Present only in sediments or particulates
suspended in water
Phosphorus in the atmosphere:
Virtually none
Present only in dust carried by wind and in
sea spray containing P-containing particulates
56. Biochemical Functions of Sulfur
1. In the structure and function of proteins (but unlike nitrogen, sulfur is not
found in all amino acids, which make up proteins). S is present in amino acid
cysteine.
2. Proteins containing cysteine has ability to form disulfide linkages within a
protein molecule or between protein molecules.
3. Intramolecular disufide linkages ensure that each protein has an appropriate
shape for its function it is to perform.
4. Intermolecular disulfide linkages are used to form relatively rigid structures
(examples: hair, nails)
5. S has a key role in the nutrition of higher plants
57. Sulfur Sources
A. S species in the atmosphere:
1. Sulfur dioxide (SO2)
2. Dimethyl sulfide, (CH3)2S, known as DMS
3. H2S
4. Carbonyl sulfide (OCS)
5. Sulfate (SO4
2-)
6. SO3
B. Sulfur from anaerobic metabolisms
59. Impacts of Human Activity on the Sulfur Cycle:
Combustion of fossil fuels liberates SO2.
SO2 in the atmosphere is rapidly oxidized to SO3, which upon dissolution in water forms acid
rain (H2SO4).
Sulfate-induced stratospheric haze may accelerate the rate of ozone depletion in the upper
atmosphere.
Note: Sulfur species may also play a key role in the regulation of
climate by providing particles around which water can condense
allowing cloud formation to occur over the remote oceans.
