Transcript Environmental Problems and Their Causes

Environmental Problems
and Their Causes
Population, Resources,
Environmental Degradation,
and Pollution
What is The
“Environment”?

Environment - all external
conditions and factors (living and
non-living) that affects all
organisms
What is The
“Environment”?
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Two Major Components of the
Environment
– Biotic - living organisms
– Abiotic - non-living (chemicals,
energy)
What is “Environmental
Science”?

Environmental Science - the study
of how we and other species
interact with one another and with
the abiotic environment of matter
and energy
Sustainable Living
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All life on earth depends on two
forms of capital:
– Solar Capital - energy from sun
– Earth Capital - air, water, soil wildlife,
minerals, natural recycling
Sustainable Living
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The “Environment” is comprised of
solar and earth capital
Sustainability - the ability of a
system to survive for some
specified (finite) time
Sustainable Living

Sustainable Society - a society that
manages its economy and
population size without depleting
earth capital and thereby
jeopardizing the prospects of
current and future generations of
humans and other species
Sustainable Living

Sustainable Living - living off the
income without depleting the
capital that supplies the income
– $1 million capital @ 10% annual
interest = $100,000 annual income
Growth and Wealth Gap

Linear (Arithmetic) Growth growth in which a quantity
increases by a constant amount
per unit of time
– Example: an automobile accelerates
by 1 mph every second
Growth and Wealth Gap

Exponential (Geometric) Growth growth in which a quantity
increases by a fixed percentage of
the whole per unit of time
– Example: an automobile doubles its
speed very second (1, 2, 4, 8, 16, …)
Growth and Wealth Gap
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Formula for Exponential
(Geometric) Growth
n
2
where n = time
Growth and Wealth Gap
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Doubling Time - the time it takes
for a quantity growing
exponentially to double
– Rule of 70
– Doubling Time = 70 ÷ percentage
growth rate
Growth and Wealth Gap
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Example of Doubling Time
– Annual global population growth rate
= 1.47%
– 70/1.47 = 48 years
– Population will double in 48 years
Growth and Wealth Gap
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Human Population Growth
Global Population
 1 billion
 2 billion
 3 billion
 4 billion
 5 billion
Time (yrs)
1 million
130
30
15
12
Growth and Wealth Gap
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Environmental Impacts of
Exponential Human Population
Growth
– 73% of the habitable area of the
earth has been altered by human
activities
Growth and Wealth Gap
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Economic Growth
– An increase in the ability of an
economy to provide goods and
services
– The increase in the real value of all
final goods and services produced by
an economy
Growth and Wealth Gap

Gross National Product - market
value in current dollars of all goods
and services produced by an
economy for final use during a year
– Increasing GNP indicates economic
growth
Growth and Wealth Gap

Economic growth achieved by
increasing throughput of matter
and energy resources used to
produced goods and services
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Increased throughput achieved
through population growth and/or
increased consumption per person
Growth and Wealth Gap
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Per Capita GNP - GNP divided by
total population
United Nations Classification of
World’s Countries
– Developed (MDCs)
– Developing (LDCs)
Growth and Wealth Gap
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MDCs
– 20% world’s population
– Highly industrialized
– High per capita GNP (>$4,000)
– 85% of world’s wealth
– Consume 88% of world’s natural
resources
Growth and Wealth Gap
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MDCs
– Generate 75% of world’s pollution
– U.S., Germany, Japan account for >
50% of world’s economic output
Growth and Wealth Gap
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LDCs
– 80% world’s population
– Low to moderately industrialized
– Low to moderate per capita GNP
– 15 to 20% of world’s wealth
– Consume 12% of world’s natural
resources
Growth and Wealth Gap
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LDCs
– Account for 9 of every 10 babies born
– Account for 98% of all infant and
childhood deaths
– 1 million people added every 4 days
– 35% of population is under age 15
Growth and Wealth Gap
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Development - change from a
society that is rural, agricultural,
illiterate, and poor with a rapidly
growing urban population to one
that is mostly urban, industrial,
educated, and wealthy
Growth and Wealth Gap
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The Wealth Gap
– Widening gap since 1960
– Environmental Impacts
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High population growth rates
Widespread urbanization
Resource depletion
Famine (~20 million people annually)
Resources and Environmental
Degradation

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Resource - anything we get from
our environment to meet our needs
and wants
Classification of Resources
– Renewable
– Potentially Renewable
– Nonrenewable
Resources and Environmental
Degradation

Renewable Resource - a resource
that is virtually inexhaustible on a
human time scale
Resources and Environmental
Degradation
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Potentially Renewable Resource - a
resource that can be replenished
fairly rapidly (hours to decades)
through natural processes
– Sustainable Yield - the highest rate at
which a potentially renewable resource
can be used without reducing its
available supply
Resources and Environmental
Degradation
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Potentially Renewable Resource - a
resource that can be replenished
fairly rapidly (hours to decades)
through natural processes
– Environmental Degradation - depletion
or destruction of a potentially
renewable resource by using it faster
than it is naturally replenished
Sustainable Yield
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The Sustainable Yield “TeeterTotter”
Use
Renewal
Environmental
Degradation
Use
Renewal
Resources and Environmental
Degradation
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Nonrenewable Resource - a
resource that exists in a fixed
amount in various places in the
earth’s crust and has the potential
for renewal only by geological,
physical, and chemical processes
taking place over hundreds of
millions to billions of years
Resources and Environmental
Degradation
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Nonrenewable Resource
– Economical Depletion - occurs when
the cost of exploiting the resource
exceeds it economic value
Resources and Environmental
Degradation
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Nonrenewable Resource
– Options to deal with economical
depletion
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Recycling
Reuse
Waste less
Use less
Develop a substitute
Resources and Environmental
Degradation
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Nonrenewable Resource
– Recycling - collecting and processing a
resource into new products
– Reuse - using a resource over and over
in the same form
Pollution
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Pollution - an undesirable change in
the characteristics of air, water,
soil, food that can adversely affect
health, survival, and activities of
living organisms
Pollution
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Sources of Pollution
– Point Sources
– Non-point Sources
Pollution
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Factors Determining the
Harmfulness of Pollutants
– Chemical Nature
– Concentration
– Persistence
Pollution
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Solutions to Pollution
– Input Pollution Control
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Pollution prevention strategy based on:
– Reduce
– Reuse
– Recycle
Pollution
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Solutions to Pollution
– Output Pollution Control
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Pollution cleanup strategy
Problems:
– Often a temporary bandage
– Removes pollutant from one area and transfers
it to another area
– Often too expensive to reduce pollutants to
acceptable levels