Intro to E.S
Understanding our environment
Environmental Science
• Environmental Science- is the study of the
impact of humans on the environment
• Main goals
– Understand and solve environmental problems
– How we use natural resources
– How our actions alter our environment
Major Fields of Study
• E.S. is an interdisciplinary science
– This means it involves many fields of study
• There are five contributing fields
– Biology
– Earth science
– Physics
– Chemistry
– Social sciences
Major Theme of Environmental
Science
• World Population
– In A.D. 1- 100 Million people
– In 1960- 3 Billion people
– Today- 6.7 Billion people
– Projected: 10 Billion by 2040
– It took human population almost 2000 years
to get to 3 billion, only 40+ years to add 3
billion more
Problem?
• The Earth has not grown any larger and the
abundance of its resources has not increased
• Can the Earth SUSTAIN all these people?
• What is the maximum number of people that
Earth can support? (remember: Easter Island)
World Population
• How many people the Earth can sustain
depends on science and values and is also
a question about people and nature.
• What quality of life are people willing to
accept?
• The poorer that quality, the greater the
number of people that can be squeezed
onto the Earth’s surface
Modern Population Explosion
• Major factors in population:
– Supply of Food
– Supply of Clothing
– Shelter
– Decreased death rates (medical improvement)
– As a result, the human population has
increased greatly, threatening the environment
Consequences of Rapid Population
Growth
• FAMINE is one of the things that happen
when a human population exceeds its
environmental resources
• In 1970’s, following a drought in the Sahel
Region, 500,000 Africans starved to death and
several million more were permanently
affected by malnutrition
FAMINE
• In 1980’s - In one year
during that period, as
many as 22 African
nations suffered
catastrophic food
shortages and 150 million
Africans faced starvation
• There is a continuing food
crisis in Southern Africa
(Malawi, Zambia and
Zimbabwe)
Reasons for Famine?
• Drought
• Size of Population affected by droughtcompeting for resources
• Changing climate- partly because of human
activities
• Poor farming practices- erosion of soil
• Deforestation
We are forced to confront a choice
• Which is more important, the
survival of people alive today or
conservation of the environment, on
which future food production and
human life depend?
An Urban
World
• With economic
development, comes
URBANIZATION
• Urbanization = people
move from farms to
cities and then perhaps
to suburbs
• Cities and towns
increase in size
• Cities are commonly
located near rivers and
coastlines
Destroying Wetlands
• Urban sprawl often overtakes good
agricultural land of river floodplains as well
as coastal wetlands, which are important
habitats for many rare and endangered
species.
• As urban areas expand, wetlands are filled
in, forests are cut, and soils covered over
with pavement and buildings
Urban Sprawl
• In developed countries, 75% of the population
live in urban areas, with 25% in rural areas
• In developing countries, only 40% of the
people are city dwellers
• It is estimated that by 2025 almost two-thirds
of the population (5 billion people) will live in
cities
Largest Cities
• In 1999, Tokyo, Japan
was the world’s
largest city
• In 2015, Tokyo is still
be the world’s largest
city with an estimated
population of 28.9
million
• Megacities- at least 8
million people
• Increased from 2 (NY
and LA) to 23 in 1995
Megacities
• Most Megacities- 17- are in the
developing world
• It is estimated that in 2015- the world
will have 36 Megacities, 23 of them
will be in Asia
• Environmental issues have always
focused on non-urban issues (wildlife,
etc.) but needs to shift to urban issues
Sustainability
• What is sustainability?
– Refers to resources and their environment
Sustainable Resource Harvest- the same quantity of
that resource can be harvested each year for an
unlimited or specified length of time without
decreasing the ability of that resource to continue
to produce the same harvest level
Sustainable Ecosystem
• An ecosystem that is still able to maintain
its essential functions and properties
even though we are harvesting one of its
resources
Sustainable Development
• A society can continue to develop its
economy and social interactions and also
maintain its environment for an
indefinite time
Carrying Capacity
• Related to sustainability
• The maximum number of individuals of a
species that can be sustained by an
environment to sustain that same amount in
the future
• Question: What is the maximum number of
people that the Earth can sustain?
People and Nature
• People and nature are intimately integratedeach affects the other.
• We depend on nature for our lives
• We depend on nature for beauty and
recreation
• We affect nature
Placing a Value on the Environment
• How do we place a value on any aspect of our
environment?
• The value of the environment is based on
eight justifications: aesthetic, creative,
recreational, inspirational, moral, cultural,
ecological, and utilitarian
Utilitarian Justification
• Sees some aspect of the
environment as valuable
because it benefits
individuals economically
or is directly necessary to
human survival
• Example: Mangrove
Swamps provide shrimp
that are the basis of the
livelihood of the
fisherman
Ecological Justification
• An ecosystem is necessary for the survival
of some species of interest to us, or that the
system itself provides some benefit.
• Example: Mangrove Swamps provide
habitat for marine fish, and although we do
not eat Mangrove Trees, we may eat the
fish that depend on them.
Aesthetic Justification
• Our appreciation of the
beauty of nature
• Example: When people
grieve following the
death of a loved one,
they typically seek out
places with grass, trees
and flowers and thus
we decorate our
graveyards
Recreational Justification
• People use wilderness
for recreation
• Example: White water
rafting, fishing, and
hiking
Inspirational Justification
• Conservation of nature
can be based on its
benefits to the human
spirit
Example: Religious
Retreats
Creative Justification
• Nature is an aid to
human creativity
• Example: Artists, poets
and others find a source
of their creativity in
their contact with
nature
Moral Justification
• Has to do with the belief that various aspects
of the environment have a right to exist and
that it is our moral obligation to allow them to
continue or help them to persist.
• Example: Species have a moral right to exist
Does the Earth Have Rights?
• The United Nations
General Assembly
World Charter for
Nature, signed in 1982,
states that species have
a moral right to exist.
The Big Question
• DO we have a moral
obligation to future
generations? to leave
the environment in
good condition for our
descendants, OR
Are we at liberty to use
environmental
resources to the point
of depletion within our
own lifetime?