Download what is environmental science?

WHAT IS
ENVIRONMENTAL
SCIENCE?
IS IT?


A stream flowing through a wilderness area?
A rainforest canopy alive with blooming
flowers?
OR

Your backyard?
ANSWER:
ALL OF THE ABOVE

It is more than you see—it is a complex web of
relationships that connects us with the world
we live in

It is the natural world + things produced by
humans
ENVIRONMENTAL SCIENCE

ENVIRONMENTAL
SCIENCE:
Study of how humans
interact with the
environment

GOAL OF
ENVIRONMENTAL
SCIENCE:
Understand & solve
environmental problems
HOW IS THIS DONE?

Env. Scientists study 2 main types of
interactions btwn humans & environment

How we use natural resources (water, plants, etc)

How our actions alter our environment
Environmental Science is an
interdisciplinary science (involves many
fields of study)

Env Scientist investigates how the nesting behavior
of bees is influenced by human activities such as the
planting of suburban landscaping.
Ecology: study of how living things
interact with each other and with
their nonliving environment

Ecologist studies the relationship btwn bees & the
plants bees pollinate
WHAT IS MEANT BY:
SCIENTISTS AS CITIZENS,
CITIZENS AS SCIENTISTS?
???
ENVIRONMENT THROUGH
HISTORY
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A. HUNTER-GATHERERS
B. THE AGRICULTURAL REVOLUTION
C. THE INDUSTRIAL REVOLUTION
HUNTER GATHERS
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People who obtained food by collecting plants & by
hunting wild animals or scavenging their remains
Small groups of people that migrated from place to
place as different types of food became available
Affect Environment—
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Spread plants to areas where plants did not originally grow
In N. Am. a combination of rapid climate change &
over hunting may have lead to disappearance of some
larger mammal species ( giant sloth, giant bison, mastodon)
AGRICULTURAL REVOLUTION
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Eventually hunter-gather groups began to collect
seeds of plants & domesticated some of the animals
This allowed human populations to grow @
unprecedentated rate
An area of land can support up to 500x as many people by
farming as it can by hunting-gathering
As pop. grew conc. in smaller areaspressure on local env.
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Changed food we eat (domesticated vs. wild species)
Farmland destroyed habitat
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Slash-and-burn agriculture
Replacing forest with farmland on large scale soil loss,
floods, water shortage
INDUSTRIAL REVOLUTION
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Mid 1700’s
Involved shift from energy sources (animal muscle to
fossil fuels, oil, coal)
Changed society greatly: ↑ efficiency of agriculture,
industry, & transportation
Introduced many + changes
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Light bulb, ↑ sanitation & medical care
Also came new env. problems

Artificial substances (plastics, artificial pesticides &
fertilizer) in place of raw animal & plant
Most modern env. problems began
during Industrial Revolution

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This photograph was taken in 1968 by the
crew of Apollo 8.
Photographs such as this helped people realize
the uniqueness of the planet we share.
E A R T H

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Earth is essentially a closed system
Closed System: the only thing that enters
Earth’s atmosphere in LARGE amts is
ENERGY from the SUN & the only thing
that leaves in LARGE amts. is HEAT
PROBLEMS WITH A CLOSED SYSTEM
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1. Some resources are limited
As pop grows
↓
Resources will be used more rapidly
↓
2. Chance that we will produce more waste
more quickly than we can dispose of
Most Environmental Issues Can Be
Grouped Into 3 Categories

1. RESOURCE DEPLETION
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2. POLLUTION
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3. LOSS OF BIODIVERSITY
1. RESOURCE DEPLETION
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Natural Resource: any natural material used
by humans

Renewable:

Non-renewable:
Renewable & Nonrenewable
Resources
RENEWABLE
NONRENEWABLE
Renewable & Nonrenewable
Resources
RENEWABLE
NONRENEWABLE
ENERGY FROM SUN
METALS
Iron, Aluminum, &
Copper
Nonmetallic materials
Salt, Clay, Sand
FOSSIL FUELS
WATER
WOOD
SOIL
AIR
1. RESOURCE DEPLETION

Natural Resource: any natural material used
by humans
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Renewable: can be replaced relatively quickly by
natural processes (fresh water, air, soil, trees, crops)
Non-renewable: sources that form at much slower rate
than the rate consumed (minerals, fossil fuels)
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Once used up- will take millions of yrs to replenish
Depletion: a large fraction of resources that have been used up
Deforestation: trees harvested faster than they grow
2. POLLUTION
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Pollution: an undesired change in air, water, or soil
that adversely affects the health, survival, or activities
of humans or other organisms

2 TYPES of POLLUTANTS
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1. Biodegradable Pollutants: pollutants that can be broken down
by natural processes.
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Ex: human sewage, newspapers
Only a problem if they accumulate faster than they can be broken
down
2. Nondegradable Pollutants: pollutants that CAN’T be broken
down by natural processes
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Ex: Mercury, lead, some types of plastic
B/c don’t break down easily can build up to dangerous levels in env.
3. LOSS OF BIODIVERSITY
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Biodiversity: number & variety of species that
live in an area.
Extinction is a natural process
Only limited info about how modern extinction
rates compare with those of other periods in
Earth’s history
All species have economic, scientific,
aesthetic, recreational value…so it is important
to preserve them
THE ENVIRONMENT &
SOCIETY
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How does a society use/share a common
resource?
A neighborhood park?
Open ocean?--- not owned by any nation
YET
People from many countries use the ocean for
fishing & transportation
“TRAGEDY OF THE COMMONS”

1968- ecologist Garrett Hardin published essay
“Tragedy of the Commons”
Described the attitude with which people use
resources & became the theoretical backbone
of the environmental movement
A common theme is the idea of bioethics
“TRAGEDY OF THE COMMONS”
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Hardin argued:
Main difficulty in solving environmental
problems
is the conflict between
short-term interests of individuals
AND
long term welfare of a society
“TRAGEDY OF THE COMMONS”
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To illustrate his point he
used example of the
commons
Commons: area of land
that belonged to the
whole village
“TRAGEDY OF THE COMMONS”
It was in best short-term interest of an individual to
put as many animals as possible
“If I don’t use this resource, someone else will”
HOWEVER
If too many animals grazed on the commons animals
destroy grass now everyone suffered
EVENTUALLY
 Commons were replaced by closed fields owned by
individual who were careful to prevent overgrazing
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POINT OF HARDIN’S ESSAY?
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Someone or some group has to take
responsibility for maintaining a resource
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If no one takes that responsibility the resource
can be overused & become depleted
WHAT HARDIN DID NOT
CONSIDER
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Social nature of humans- we live in groups &
depend on one another
We can solve environmental problems by
planning, organizing, considering scientific
evidence, proposing a solution
The solution may override interests of indivual
in short term BUT improves environment for
everyone in long term
Earth’s Natural Resources are
our modern “COMMONS”
ECONOMICS & THE
ENVIRONMENT

In addition to social pressures—economic
forces influence how we use resources
A. Supply & Demand
B. Cost & Benefits
C. Risk Assessment
SUPPLY & DEMAND

When the demand for a product increases
while the supply remains fixed, the cost of the
product will increase.

Ex.: if the supply of oil decreases:
1. Pay higher price
2. Use less oil
3. find new sources of energy
COST & BENEFITS
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Cost of environmental solutions can be high
Cost-benefit analysis: balances the cost of
action against the benefits one expects from it.
To INDUSTRY: the cost of pollution control
may outweigh the benefits
BUT
To a nearby COMMUNITY: benefits may be
worth the higher price
RISK ASSESSMENT
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Tool that helps us to create cost-effective ways
to protect our health & environment
One of the costs of any action is the risk of an
undesirable outcome
DEVELOPED vs. DEVLOPING
COUNTRIES
DEVELOPED
COUNTRIES
Higher avg. incomes
Slower pop. Growth
Diverse industrial
economies
Stronger social support
system
USA, Canada, Japan,
countries of W. Europe
DEVELOPING
COUNTRIES
Lower average incomes
Faster population
growth
Simple & agricultural
based economics
Lack of social support
systems
African nations,
Some Asian areas
DEVELOPED vs. DEVLOPING
COUNTRIES
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Environmental problems in developed countries
tend to be related to consumption
In developing nations, the major environmental
problems are related to population growth
WHAT DO YOU THINK THE
ENVIRONMENTAL PROBLEMS
OF EACH COMSUMPTION
PATTERN ARE?
Consumption Trends
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Ecological Footprint: shows the productive area of
Earth needed to support one person in a particular
country
For a person in a developed country –the ecological
footprint is an avg. 4x as large as a person in a
developing country
Developed nations use ~ 75% of the world’s
population, even though they make up only ~ 20% of
the world’s population.
Critical Thinking
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Environmental Problems are complex
Balance between rights of individuals/property
owners and society as a whole
Be careful when reading about issues for
“BIAS”
Bias in Environmental Issues
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Passion for cause may lead to distortion of
facts
Political clout may oversimplify environmental
impact
Media sensationalizes issues
Learn to think critically, consider the source,
listen to many viewpoints
SUSTAINABILITY