Transcript Chapter 1

Environmental Issues, Their
Causes & Sustainability
Chapter One
Environment, Ecology, &
Environmental Science
• Environment - all external conditions and factors
that affect living organisms
• Ecology - study of relationships between living
organisms and their environment
• Environmental Science - examines the effect of
humans on the earth’s environment
– How the earth works
– How to deal with the problems we face
– It is an interdisciplinary science - natural and social
sciences.
How rapidly is the human
population growing?
• It took 60,000 years to
reach 1 billion
• It took 130 years to
reach 2 billion
• It took 30 years to
reach 3 billion
• It took 17 years to
reach 4 billion
• It took 12 years to
reach 5 billion
• It took 10 years to
reach 6 billion
• 48% of earth’s land
area has been modified
by man.
Population Growth rate
• % change over time
• Positive and negative rates
– More births than deaths each year
– For every 5 babies born each second, two
people die
– Negative rates- high mortality rates, emigration
Exponential Growth
• development at an increasingly rapid rate in
proportion to the growing total number or
size; a constant rate of growth applied to a
continuously growing base over a period of
time
• Also called Geometric Growth
– Follows a geometric pattern of increase
– 2,4,8,16,32, etc.
Makes a J- curve
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Called this because of its shape
To find Doubling Time
Use Rule of 70
Divide Percent increase into 70
Human population is growing in this
manner
Arithmetic Growth
• Increases at a constant amount per unit of
time
• 1,3,5,7, etc.
• Also called Linear Growth
• Graph will be a sloping straight line
• Food production is increasing in this
manner
Environmentally Sustainable
Society
• Satisfies the basic needs of the people
without depleting or degrading its natural
resources and therefore preventing current
and future generations from meeting their
basic needs.
• Live off the natural income replenished by
soils, plants, air and water and not depleting
the natural capital that supplies this income.
Population and Sustainability
• Overpopulation is root cause of many
environmental problems
– Depletion of water
– More land needed to grow food and house our
families
– More pollution is generated by our growing
industrialization
– Mass extinction from habitat loss
Carrying Capacity
• The number of people earth can support without
using resources faster than the planet can replenish
them
• A population that exceeds the carrying capacity
CANNOT be sustained
– Not enough food, water, other vital resources
What is our carrying capacity?
It depends on several factors: type and quantity of
available resources, how those resources are distributed,
the amount of resources each person uses
Ecological Footprint
• The amount of land needed to produce the
resources needed by the average person in a
country.
– Ecological footprint of people in developed
countries is large compared to people in
developing countries.
– If all people in the world consumed what we do
in the U.S. it would take three planets to
support them.
Per Capita Ecological Footprint
(Hectares of land per person)
Country
10.9
United States
5.9
The Netherlands
India
1.0
Capital
• Wealth – to an economist
• Solar capital – energy from the sun
– Direct sunlight and indirect forms such as windpower,
hydroelectric, and biomass
• Natural capital – (natural resources) air, water,
soil, biodiversity, etc. Also called natural
resources.
• Our existence depends completely on the sun and
the earth.
What is economic growth?
• An increase in a country’s capacity to
provide goods and services for its
population’s use.
• Its measured by Gross National Income (GNI) Used
to be called Gross National Product
• Market value of all goods and services produced
within a country for final use during a year.
• Usually calculate per capita GNI - GNI
divided by total population
• Gross Domestic Product – GDP – the market
value in current dollars of all good and services
produced within a country during a year.
• Gross World Product – GWP – market valut in
current dollars of all goods and services produced
in the world during a year
• Per capita GNI in purchasing power – GNI
PPP/total population at mid-year. A way to
compare people’s economic welfare among
countries.
What is economic development?
Improvement of living standards by
economic growth
Developed Countries
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Highly industrialized
High per capita GNI
Have 20% of world’s population
Have 85% of world’s wealth and income
Use 88% of its natural resources
Generate 75% of its pollution & waste
Developing Countries
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Low to moderate industrialization
Low per capita GNI
Most are in Africa, Asia, and Latin America
Have 80% of the world’s population
Have 15% of its wealth and income
Use only 12% of its natural resources
Development
• The change from a largely rural society,
mainly agricultural, illiterate, and poor with
a rapidly growing population to one that is
mostly urban, industrial, educated, and
wealthy with a slow-growing population..
Globalization
• The process of global social, economic, and
environmental change that leads to an increasingly
integrated world.
– Economic indicators - global economy has grown and
there are many transnational corporations
– Information & communication - many people have
Internet access
– Environmental effects - diseases and pollutants
transported across international borders & global
climate change
RESOURCES
• RESOURCE - anything obtained from the
earth to meet human needs and wants
– Food, water, shelter, manufactured goods,
transportation
Types of resources
• PERPETUAL renewed continuously
– SOLAR ENERGY
– WIND, TIDES,
FLOWING WATER
• RENEWABLE - can
be replenished fairly
rapidly
– AIR, WATER, SOIL,
BIODIVERSITY
• NONRENEWABLE exist in a fixed
quantity
– FOSSIL FUELS
– METALLIC
MINERALS
– NONMETALLIC
MINERALS
Sustainable yield
• The highest rate at which a potentially
renewable resource can be used indefinitely
without reducing its available supply.
• Environmental degradation - results when a
resource’s natural replacement level is
exceeded.
The Tragedy of the Commons
• 1968 - Garrett Hardin
• “If I don’t use it, someone else will”
• Overusing that which belongs to all or us
– Air, water, ocean
– Called COMMON PROPERTY OR FREEACCESS RESOURCES
Nonrenewable resource
• Exist in fixed amounts in the earth’s crust
and can be completely used up
– Include energy resources such as coal, oil
natural gas & uranium
– Metallic mineral resources - iron, copper
– Nonmetallic mineral resources - salt, sand, clay
• Mineral - hard, crystalline material formed
naturally
• Also called exhaustible resources
Economic depletion
• When 80% of a mineral is used up and it
becomes more expensive to retrieve it than
the mineral is worth.
• Five choices at this point:
– Reduce or use less, reuse or recycle existing
supply - does not apply to nonrenewable energy
sources- use less or try to find a substitute or do
without.
Recycling - collect and reprocess
resource into new products.
Reuse - Use resource over & over
again.
Cannot recycle nonrenewable
energy sources
Reserve - known deposit from which a
useable mineral can be extracted at a profit
at current prices.
Pollution
• Any addition to air,
water, soil or food that
threatens the health,
survival, or activities
of humans or others
• Can be natural such as
a volcano or
anthropogenic - due to
human activities
• POINT SOURCES come from a single
identifiable source - a
wastewater treatment
plant
• NONPOINT
SOURCES - come
from sources that are
difficult to identify.
Solutions to Pollution
• CLEANUP - usually only temporary
• PREVENTION - the best way - slow or
eliminate pollutant reaching environment.
Key Environmental Problems
FIVE ROOT CAUSES
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Overpopulation
Waste of resources
Poverty
Not including
environmental costs of
economic goods and
services in their
market prices
• Trying to manage and
simplify nature with
too little knowledge of
how nature works.
Connections
• Model developed by
Paul Ehrlich and John
Holdren- 1970’s
• Population x
Affluence x
Technology =
Environmental Impact
• P = number of people
• A = number of units of
resources used /person
• T = Env. Degredation
& pollution/unit of
resource used
• I = environmental
impact of population
PxAxT=I
Results
• Developing countries have more people but
use less resources / person
• Developed countries have less people but
use more resources/person
• Ends up that both have effects on
environment
• Environmental
worldview - how
people think the world
works, their role, and
right and wrong
behavior
(environmental ethics)
• Planetary management
worldview- humans
are the most important
and should manage the
planet
• Environmental
wisdom worldview we are a part of nature
and resources are
limited. We must
manage.