Chapter 1: Key Themes in
Environmental Sciences
1.1 Major Themes of
Environmental Science
1. Our population has more than doubled in the last 40
years
 6.8 billion people alive today
2. Continuing on this trend would lead to 9.4 billion by
2050
3. How many people can the Earth sustain?
 Depends on science and value
 Also question of people and nature
1.2 Human Population Growth
 Human Population density is over 6.3 billion
 It has doubled over the past 40 years
 Due to science advancements
 Reduced infant mortality
 John Eli Miller Family
 Example of family population explosion
1.2 Human Population Growth
 Miller family emphasizes a major factor in modern
population explosion
 Modern technology
 Modern medicine
 Supply of food, clothing and shelter
 All decrease the death rate and increase net growth rate
Our Rapid Population Growth
 Human population growth is the underlying issue of the
environment.
 Damage is directly or indirectly due to pop inc
Famine and Food Crisis
 Famine occurs when human pop exceeds its
environmental resources
 Sahel region of Africa in 1970s
 ½ million people starved to death
 Millions affected by malnutrition
 Emerging global food crisis
 Due to rise in fuel cost = higher food cost
Famine and Food Crisis
Food Crisis
1.3 Sustainability and
Carrying Capacity
 What is the maximum number of people the Earth can
sustain?
 Much of this book will help answer that ?
 Currently we are using resources unsustainably.
 Faster that they can be replenished.
Sustainability: The
Environmental Objective
 Is Earth very survival really in danger?
 Earth will go on w/o us
 Quality of human enviro at risk
Sustainability
 Sustainability refers to resources and their
environment.
 Sustainable resource harvest
 Same quantity of that resource can be harvested each
year for an unlimited amount of time.
 Sustainable ecosystem
 An ecosystem from which we are harvesting a resource
that is still able to maintain its essential
functions/properties.
Sustainability
 Two points to understanding sustainability
 Sustainability means for an unspecified long period of
time.
 Sustainable growth is an oxymoron.
Sustainable Global Economy
 Population of humans living in harmony w/ natural
support systems.
 An energy policy that does not pollute, cause climate
change or present unacceptable risk.
 A plan for renewable resources that will not deplete the
resources or damage ecosystems.
Sustainable Global Economy
 A plan for nonrenewable resources that does not
damage region or global environ.
 And provides a share for future generations
 A social, legal, and political system that is dedicated to
sustainability.
Sustainable Global Economy
 To achieve we must
 Develop an effective population-control strategy.
 Completely restructure our energy programs.
 Institute economic planning that will encourage pop
control and wise use of resources.
 Implement social, legal, political and eductional change.
Moving Toward Sustainability
 The new paradigm




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Evolutionary rather than revolutionary.
Inclusive, not exclusive.
Proactive, not reactive.
Attracting, not attacking.
Assisting the disadvantage, not taking advantage.
Carrying Capacity of the Earth
 Defined as
 the maximum number of ind of a species that can be
sustained by an environment
 w/o decreasing the capacity of the environ to sustain that
same amount in the future
1.4 A Global Perspective
 The actions of many groups of people at many
locations affects the environment of the entire world.
 Gaia hypothesis
 James Lovelock and Lynn Margulis
 Life affects the environment at a global level
1.5 An Urban World
 We are
becoming an
urban species
 In developed
countries
 75% live in
urban area
 Developing
countries
 40%
1.5 An Urban World
 Megacity
 Urban area with
at least 10
million
inhabitants
 By 2015 the
world will have
36 megacities
 23 of them in
Asia
1.5 An Urban world
 Scientist James Lovelock
 One of the creators fo the
Gaia Hypothesis
 Has said that in order to
survive to preserve our
biological life support system
(Earth)
 We need to live in domed
cities isolated from nature
1.6 People and Nature
 We depend on nature directly for
 Wood
 Water
 Air
 And indirectly for “public services functions”
 E.g. soil formation
Soil Fertility and Structure
People and Nature
 People and animals
alter and change
their environment.
 Dichotomy of 20th
century is giving way.
 New unity
 Sustainable
environment and
economy compatible.
1.7 Science and Values
 We must choose what we want the environment to be
 Value judgment regarding the world’s human
population problem
 Choice between desire to have large family and the
need to limit the human population.
 The more high tech and powerful our civilization, the
more knowledge is required.
Fishing for Salmon
Precautionary Principle
 1992 - Rio Earth Summit on Sustainable Development
 Defined PP – when there is a great threat of serious
environ damage we should not wait for scientific proof
before taking precautionary steps to prevent potential
harm.
Precautionary Principle
 PP is a proactive,
rather than a
reactive, tool.
 Adopted by the city
of SF and the
European Union
Placing a Value on the
Environment
 The value of the environment
based on 8 justifications
 Utilitarian
 Ecological
 Aesthetic
 Recreational
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Inspirational
Creative
Moral
Cultural
Placing a Value on the
Environment
 Utilitarian- the environment has value because it
benefits individuals economically or is necessary for
human survival.
 Ecological- ecosystem is necessary for survival of
some species of interest or that the system itself
provides benefit.
Placing a Value on the
Environment
 Aesthetic- has to do with our appreciation of the beauty
of nature.
 Recreational- viewing organisms in a natural setting.
 Inspirational- to benefit the inner self
 Creative- aid to human creativity
Placing a Value on the
Environment
 Moral- the belief that various aspects of the
environment have the right to exist and it is our
obligation to allow them to continue.
Critical Thinking Issue
 How can we preserve the
world’s coral reef?
 10% Have been destroyed
 30% are threatened
 Fishing with explosives
 Harvest of coral for





precious stone market
Introduced predators
Disease related to climate
change
Acidification of the ocean
Water quality
They are extremely slow
growing
Questions
 How does the coral problem
relate to the key themes in
this book?
 What utilitarian, ecological,
moral and aesthetic values
do they have?
 What can you do to help
preserve the coral reefs?