• The study of how humans and other species interact with one another and the nonliving environment.
• How the parts of nature and human societies operate and interact - a study of connections and interactions
• A physical and social science that integrates information from a wide range of disciplines:
– biology
– chemistry
– physics
– geology
– geography
– resource technology and engineering
– resource conservation and management
– demography, economics, politics, sociology, psychology and ethics

1. Population growth
2. Deforestation
3. Global warming
4. Ozone loss
5. Resource depletion:
– mineral
– energy
– soil
– agricultural land
– water
6. Biodiversity
7. Pollution

• Sustainability is the ability to maintain a given state for a specified period of time
• sustainable systems function and survive over a specified time
• environmentally sustainable societies manage their economies, population and resource use within the system's (earth's) ability to absorb insults, replenish resources, and sustain life forms

2-5 million years
8000
Hunting and gathering
Black Death –the Plague
?
?
?
1
2000 2100
0
3
2
5
4
16
15
14
13
12
11
10
9
8
7
6
6000 4000
Time
2000
Agricultural revolution
B.C.
A.D.
Industrial revolution

• Current growth rate: exponential growth at a rate of 1.25%
• Rule of 70:
70/ rate of growth =doubling time

?
Continued growth
Population stabilization
?
(1 million years)
(100,000 years)
Population crash
?
(10,000 years)
Industrial & information revolutions
Agricultural revolution
Tool-making revolution
Time

Who can explain the difference between exponential and linear growth?
Exponential: a quantity increases at a constant rate per unit of time
(such as our current rate of 1.25% per year)
Linear : growth by the same amount over equal time periods

World Population reached
1 billion in 1804
2 billion in 1927 (123 years later)
3 billion in 1960 (33 years later)
4 billion in 1974 (14 years later)
5 billion in 1987 (13 years later)
6 billion in 1999 (12 years later)
World Population May Reach
7 billion in 2013 (14 years later)
8 billion in 2028 (15 years later)
9 billion in 2054 (26 years later)

Tropic of
Cancer
Equator
Tropic of
Capricorn
Antarctic
Circle
Human disturbance
Predominantly natural
Partially disturbed
Human dominated

 Increase capacity to produce goods and services for people's final use
 Usually involves increasing flow (throughput) of energy and natural resources
• GNP: gross national product - market value of all goods and services for either domestic or export produced in that year
• per capita GNP (pcGNP) - divide GNP by total population of the country

• The improvement of living standards by economic growth

• Developed countries: defined as highly industrialized with pcGNP > $10,00
– 20% of the world's population
– 85% of wealth and income
– use 88% of natural resources
– generate 75% of the world's waste
• Developing countries: rural, agricultural countries with low pcGNP
– more than 1 billion people try to live on less than
$1 day
– more children increases family's "workforce"
– local populations outstrip available resources

GNP per capita, 1998
Low income
(Under $1,000)
Middle income
($1,000 –$10,000)
High income
(Above $10,000)

12
11
10
9
6
5
8
7
4
3
2
1
1950
World total
Developing countries
2000
Year
2050
Developed countries
2100

• Perpetual resources: on a human time scale, is renewed continuously
* solar energy, winds, tides, flowing water

Renewable resources: On a human time scale, can be replenished fairly rapidly
*fresh air, water, soil, plants & animals

• Nonrenewable resources: on a human time scale, is not replaced; present in a fixed quantity in earth’s crust
*coal, oil, natural gas, metals such as iron & copper, minerals such as phosphates & clay

Planetary management
*humans are the most important species
*resources will not run out b/c we can develop & find new ones
*potential for economic growth is unlimited
*success depends on our management

Stewardship
*we are the most important species, but that carries an ethical responsibility
*resources probably won’t run out, but should be used wisely
*environmentally beneficial forms of development should be encouraged
*our success depends on how well we manage our resources

Environmental wisdom
*nature exists for all species
*earth’s resources are limited, should not be wasted, and are not all ours
*earth-sustaining forms of economic growth should be encouraged
*our success depends on our actins & behaving in a sustainable manner

1. Is current society in developed countries sustainable? Developing countries?
2. Is sustainability a reasonable or desirable goal?

Social Economic
Environmental
Traditional decision making

Social
Sustainable
Solutions
Economic
Environmental
Decision making in a sustainable society