Download Environmental Science

Environmental Issues, Their
Causes, and Sustainability
Environment and Ecology
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The environment is everything that affects a
living organism.
Ecology is a biological science that studies the
relationship between living organisms and
their environment.
What is Environmental Science?
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Environmental science is the interdisciplinary
study that uses concepts and information from
natural sciences (ecology, biology, chemistry,
geology) and social sciences (economics,
politics, ethics) to help understand:
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How the earth works
How we are affecting the environment
How to deal with environmental problems
Environmental Science
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Environmental science involves
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Human numbers (population)
Natural resources
Environmental pollution
Environmental Sustainability
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An environmentally sustainable society is one
that satisfies the needs of its people for food,
clean water, clean air, and shelter into the
indefinite future WITHOUT depleting or
degrading the earth’s natural resources.
Some environmentalists believe we are
functioning in a sustainable way … others do
not.
Are we as humans operating in a
sustainable way?
You be the judge …
 We are using nonrenewable resources (like
fossil fuels) as if they were unlimited.
 We use renewable resources (like water) faster
than they can be replenished.
 We pollute with toxins as though the
environment can absorb them.
 Our population continues to grow.
Sustainability
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https://www.youtube.com/watch?v=nqBMg__
fRm8 15 Mog
https://www.youtube.com/watch?v=xwUMJCllvo 16 Mog
Human Population Growth
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The human population is growing
exponentially.
Why?
 Drop in death rates due to more
food and better medical care
Doubling Time is the amount of time it
takes for a population to double.
To calculate doubling time:
 70/(percent growth rate)
Example: In 2002, pop grew by
1.28%.
70/1.28 = 54.7, therefore in 55 years,
the population of the earth will
double.
Fig. 1-2 p. 4
Good news, bad news?
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Good news:
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Population growth has
slowed down since the
1960s.
Bad news:
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The world’s population is
growing exponentially and
is projected to reach 14
billion by the end of this
century.
World Population
Fig. 1-1 p. 2
Ecological Footprint
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The ecological footprint is the amount of land
needed to produce the resources needed by an
average person in a country.
What is your ecological
footprint?
Ecological Footprint
1 hectare = 2.47 acres
Fig. 1-8 p. 10
Resources
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Any part of the natural
environment that is used to
promote the welfare of
people or other species.
Some resources are directly
available for use (solar
energy, air, wind, soil,
surface freshwater, etc),
others become useful only
with some effort (oil, iron,
groundwater).
Conservation
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Conservation is
careful management
of natural resources.
It has been practiced
in one form or
another for thousands
of years.
Resources
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Perpetual – renewed
continuously
Renewable – can be
replenished fairly
rapidly (hours to
decades)
Non-renewable – exist
in a fixed quantity or
stock in the earth’s
crust
Renewable Resources
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Sustainable Yield: the maximum amount of
the resource that can be used without depleting
the resource in the longer term.
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Environmental Degradation: process that
occurs when a resource is used at a rate greater
than its natural replacement rate.
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Major cause of Environmental degradation is THE
TRAGEDY OF THE COMMONS
What is
The Tragedy of the Commons?
In 1968, biologist Garrett Hardin called the degradation
of renewable free-access resources the tragedy of the
commons. It happens because each user reasons, “If I
do not use this resource, someone else will. The little
bit I use or pollute is not enough to matter, and such
resources are renewable.”
With only a few users this logic works. However the
cumulative effect of many people trying to exploit a free
access resource eventually exhausts or ruins it. Then no
one can benefit from it and therein lies the tragedy.
Non-Renewable Resources
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Energy resources – coal, oil, natural gas
Metallic resources – Fe, Cu, Al (can be
recycled)
Non-metallic resources – salt, clay,
sand,phosphates (difficult and costly to recycle)
Non-Renewable Resources
We never completely exhaust a nonrenewable mineral
resource however such a resource becomes
economically depleted when the cost of extracting and
using what is left exceeds its economic value. Non
renewable resources cannot be recycled, … they only
leave behind waste and pollution.
What choices do we have to save
our resources?
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Try to find more resources
Reuse – using a resource over and over in the same
form (glass bottles that you refill)
Recycle – collecting and reprocessing a resource into
new products (glass bottles are crushed, melted, and
made into new glass bottles)
Waste less
Use less
Develop a substitute
Wait millions of years for more to be produced
Recycling
Recycling takes less energy, water, and other
resources and produces less pollution and
environmental degradation than exploiting virgin
resources.
Three R’s:
Reduce, Reuse, Recycle
What is Pollution?
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Any alteration of air, water, soil, or food that harms
the health, survival, or activities of humans and other
organisms.
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Pollutants can enter the environment naturally or as a result
of anthropogenic (human) activities.
Sources of Pollution:
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Point Sources: a single identifiable source (ex.
Smokestack, exhaust pipe)
Nonpoint Sources: dispersed (hard to identify) sources
(fertilizer runoff from farms or lawns, pesticides sprayed
into the air).
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Much harder to control and clean up.
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Air Pollution
Global climate change
Stratospheric ozone
depletion
Urban air pollution
Acid deposition
Outdoor pollutants
Indoor pollutants
Noise
Biodiversity Depletion
• Habitat destruction
• Habitat degradation
• Extinction
Major
Environmental
Problems
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Water Pollution
Sediment
Nutrient overload
Toxic chemicals
Infectious agents
Oxygen depletion
Pesticides
Oil spills
Excess heat
Waste Production
• Solid waste
• Hazardous waste
Food Supply Problems
• Overgrazing
• Farmland loss
and degradation
• Wetlands loss
and degradation
• Over fishing
• Coastal pollution
• Soil erosion
• Soil salinization
• Soil waterlogging
• Water shortages
• Groundwater depletion
• Loss of biodiversity
• Poor nutrition
What type of harm do pollutants
cause?
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Disruption of life support
systems for humans and
other species.
Damage to wildlife,
human health, and
property
Nuisances such as noise,
unpleasant smells, tastes,
and sights.
Dealing With Pollution
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Prevention (Input Control)
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More expensive in the short term.
Less expensive in the long term
Over all it is cheaper and cleaner to prevent pollution.
Cleanup (Output Control)
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Less expensive in the short term.
More expensive in the long term.
Overall it is more expensive and you are often left with a
pollutant that must be put someplace.
Five Basic Causes of Pollution
Environmental Impact
Fig. 1-11 p. 13
How can we reduce our
environmental impact?
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Slow population growth
Decrease resource use and waste (use
resources more efficiently)
Increase use of environmentally beneficial
technologies
Phase out environmentally harmful
technologies
Environmental Interactions
Fig. 1-12 p. 14
Are things getting
better or worse?
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Experts disagree about …
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How serious our population and environmental
problems are
What we should do about them
These conflicts over how serious our problems are
result from differing environmental worldviews…
Environmental Worldviews
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Planetary Management:
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Humans are the most important species and should manage the planet
to their own benefit
Resources are limitless and are there for us to use. (“There is always
more.”)
All economic growth is good and the possibilities for growth are
endless.
Human success depends on how well we can manage Earth’s systems.
Environmental Wisdom:
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Nature exists for all species … not just for us.
Resources are not unlimited and they are not just for human use. They
should not be wasted!
Some economic growth is good, but some is harmful (the key is to
encourage earth-sustaining forms of economic growth and discourage
earth-degrading forms.
Our success depends on learning to cooperate with each other and
nature.
Warning from Scientists …
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On November 18, 1992, some of the world’s
senior scientists from 70 countries signed and
sent an urgent warning to government leaders
of all nations.
“Our massive tampering with the world’s interdependent web of life – coupled
with the environmental damage inflicted by deforestation, species loss, and
climate change – could trigger widespread adverse effects, including
unpredictable collapses of critical biological systems whose interactions and
dynamics we only imperfectly understand…No more than one or a few
decades remain before the chance to avert the threats we now confront will be
lost and the prospects for humanity immeasurably diminished.”
Are things getting
better or worse?
The best answer to this is …
BOTH
Some things are getting better, some things are
getting worse.
What can you do to make things better?
What is Economic Growth?
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Economic growth is an increase in a country’s
capacity to provide people with goods and
services.
Economic growth is accomplished by
population growth (more consumers and
producers), more consumption per person or
both.
Economic Growth
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Gross National Product (GNP)
 Total value of goods and services produced within and outside a country during a year
plus the net income earned abroad by citizens.
Gross Domestic Product (GDP)
 Total value of goods and services produced within a country during a year.
Gross World Product (GWP)
 Total value of goods and services produced in the world during a year.
Per Capita GNP
 Annual gross national product of a country divided by its total population. (average
“slice of the pie” per person)
Environmentally-Sustainable Economic
Development
Social
Economic
Social
Economic
Sustainable
Solutions
Environmental
Environmental
Fig. 1-13 p. 17
Traditional
decision making
Decision making in a
sustainable society
Economic Development
Economic development is the improvement of living
standards by economic growth. The United Nations
classified countries as developed or developing based
on per capita GNP.
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Developed Countries (US, Canada, Japan, Australia, NZ,
Europe)
 Highly industrialized
 High per capita GNP
Developing Countries (most located in Africa, Asia, and Latin
America)
 Low to moderate industrialization
 Low per capita GNP
Costs of Pollution
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Costs of Pollution are hard to determine
because they include damage to property,
health of humans, natural beauty, ecosystem
health, health of plants and health of animals.
How do you place a value on damage to
natural beauty?
How do you place a value on the extinction of
a species?
Economic Strategies to Control
Pollution
Problem: Polluters are not being charged (or
charged enough) for polluting.
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Solution A: Raise the cost of polluting
Solution B: Provide economic rewards to
environmentally beneficial and sustainable
forms of development.
Solution C: Governmental regulations.
Solution A: Increasing the Cost of
Polluting
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Emission Charge: tax on pollution, sometimes
called “green taxes”
Tax leaded gasoline
 Sweden taxes active ingredients in pesticides
***These are often not effective because the tax is not
high enough to change behavior.
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Waste Discharge Permits: emission reduction
credits (ERCs) can be bought and sold by
companies.
Solution B: provide incentives
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Examples:
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Tax breaks for hybrid car owners.
Tax breaks for homeowners who are using solar
power.
Refund when you recycle some bottles and cans.
Solution C: Command and Control
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Examples
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Catalytic converters are required in all cars in
order to reduce emissions.
Clean Air Act Amendments of 1990 required a
60% reduction in Nitrogen Oxide emissions from
passenger cars by 2003.