Environmental Problems, Their Causes,
and Sustainability
Chapter 1 – Part 1
Tragedy of the Commons
Environment: study of everything around us
Environmental Science: Interdisciplinary Study
Our Goals
1.
2.
3.
4.
Learn how nature works
Learn how the environment affects us
Learn how we affect the environment
Learn how to deal with environmental problems
and live more sustainably
Consumption and Conservation
 Resource – anything
obtained from the
environment to meet our
needs and wants
• Renewable
• Air, water, trees, etc.
• Nonrenewable
• Coal, oil, etc.
Money doesn’t grow on trees
 Natural capital: keeps us
and other forms of life alive
and supports our
economies
• Natural resources –
materials; air, water, soil,
etc.
• Natural services –
functions; nutrient
cycling
Major Natural Service: Nutrient Cycling
NATURAL
CAPITAL
Natural Capital = Natural Resources + Natural Services
Solar
capital
Air
Air purification
Renewable
energy
(sun, wind,
water flows)
Climate control
UV protection
(ozone layer)
Life
(biodiversity)
Water
Population
control
Water purification
Waste treatment
Solar
Capital…can weNonrenewable
minerals
survive without iron,
sand)
it???
Pest
control
Soil
Soil renewal
Oil
Land
Food production
Nutrient
recycling
Nonrenewable
energy
(fossil fuels)
Natural resources
Natural services
Fig. 1-3, p. 8
Human Degradation: To Sushi or Not?
 Human activities
degrade natural capital
 Using normally
renewable resources
faster than nature can
renew them
• Forestry
• Fishing
Pollution Comes from a Number of Sources
 Sources of pollution
• Point
• E.g., smokestack
• Nonpoint
• E.g., pesticides blown
into the air
 Main type of pollutants
• Biodegradable
• Nondegradable
•
http://www.youtube.com/watch?v=ax0AJQ5zHQ&feature=related
Environmentally Sustainable Societies
Protect Natural Capital and Live off Its Income
 You just won $1,000,000! How long can you make it
last if you earn 10% interest each year?
• Spending $200,000/year = 7 years
• Spending $110,000/year = 18 years
• Spending $100,000/year = lifetime
Environmentally Sustainable Societies
Protect Natural Capital and Live off Its Income
 Living sustainably means living off natural income
• Preserve the Earth’s natural capital
Overexploiting Shared Renewable Resources:
Tragedy of the Commons
 Three types of property
or resource rights
• Private property
• Common property
• Open access renewable
resources
Different Views about Environmental
Problems and Their Solutions
 Environmental
Worldview including
environmental ethics
• Planetary management
worldview
• Stewardship worldview
• Environmental wisdom
worldview
Your Turn!
 Lorax Values and Beliefs
Environmental Problems, Their Causes,
and Sustainability
Chapter 1 – Part 2
Human Population Growth
Video – Tragedy of the Commons
 http://www.youtube.com/watch?v=EZFkUeleHPY
 Activity: Goldfish Tragedy of the Commons
Interview: Garrett Hardin on Tragedy of the
Commons and Resources
 http://www.youtube.com/w
atch?v=L8gAMFTAt2M
 HW Review: #2,5,6,8,9,11
Experts Have Identified Five Basic Causes of
Environmental Problems
 Population growth
 Wasteful and unsustainable resource use
 Poverty
 Failure to include the harmful environmental costs
of goods and services in their market prices
 Insufficient knowledge of how nature works
Only a few grains of wheat…
Problem?
Exponential Growth: a quantity increases at a
fixed rate per unit of time
Each doubling is
more than the
total of all earlier
growth!
Cultural Changes Have Increased Our
Ecological Footprints
 12,000 years ago:
hunters and gatherers
 Three major cultural
events
• Agricultural revolution
• Industrial-medical
revolution
• Informationglobalization revolution
Exponential Growth: a quantity increases at a
fixed rate per unit of time
 Human numbers through time:
http://www.pbs.org/wgbh/nova/earth/globalpopulation-growth.html
What’s the problem?
 Add 225,000 people per day!
• That’s the equivalent of adding the United State’s
population to the world every 4 years
What’s the problem?
 Add 225,000 people per day!
• By 2100 ½ of word’s plants and animals may vanish
Are There Too Many of Us?
 Will growing
populations cause
increased
environmental
stresses?
•
•
•
•
•
•
Infectious diseases
Biodiversity losses
Water shortages
Traffic congestion
Pollution of the seas
Climate change
There Is a Wide Economic Gap between Rich
and Poor Countries
 Gross domestic product (GDP) – annual market value of
all goods and services produced within a country
• Per capita GDP – changes in economic growth per person
 Per capita GDP PPP - Purchasing power parity (PPP)
plus GDP are combined for more accurate comparison of
different countries
• Used to identify developed with developing countries
There Is a Wide Economic Gap between Rich
and Poor Countries
Extreme Poverty in a Developing Country
More than ½
people in world
live on less than
$2 a day!
Consumption of Natural Resources: Mali
Consumption of Natural Resources: China
Consumption of Natural Resources: USA
Comparison of Developed and Developing
Countries, 2008
Why is the growth
rate so high in
developing
countries?
Some Harmful Results of Poverty
UN World Population Projections by 2050
Natural Capital Use and Degradation
Affluence Has Harmful and Beneficial
Environmental Effects
 Harmful environmental
impact due to
• Mass advertising –
buying things brings
happiness
• High levels of
consumption
• Unnecessary waste of
resources
Affluence Has Harmful and Beneficial
Environmental Effects
 Affluence can provide
funding for
• Developing
technologies to reduce
• Pollution
• Environmental
degradation
• Resource waste
Video: China Revs Up (NOVA)
 21:00 – 26:00
Extreme Poverty in a Developing Country
HW: The $2
Challenge!
Calculating population growth… Rule of 70
 Doubling time = 70/annual growth rate (in %)
 Example: If a population is growing at a rate of 4%,
how long will it take for the population to double?
 Doubling time = 70/4 = 17.5 years
Calculating population growth…Growth Rate
 Population Growth in given period of time = Initial
Population Size * Growth Rate
 Example: If a population of 2000 is growing at a rate
of .1 during any 10 year period, what will the
population be after 10 years? After 20 years?




Population Growth = 2000 * .1 = 200 people
Population size after 10 years = 2200 people
Population Growth = 2020 * .1 = 202 people
Population size after 20 years = 2402 people