Transcript Environmental Chapter1x

Chapter 1: Science and
the Environment
Section 1: Understanding our Environment
ENVIRONMENT
● Everything around us.
ENVIRONMENTAL
SCIENCE
Study of how humans interact with the
environment.
The Goals of
Environmental Science
● Achieving sustainability (when human
needs are met in such a way that a human
population can survive indefinitely).
● Understanding and solving
environmental problems.
Environmental scientists study two main types
of interactions between humans and their
environment.
● How we use
resources, such as
water and plants
● How our actions
alter our
environment.
Many Fields of Study
●Environmental science is
interdisciplinary.
●Important foundation of
environmental science: ECOLOGY
(Study of how living things
interact with each other and
their nonliving surroundings.
● Ecologists may
study…
● Environmentalists
may study…
….the relationship
between bees and
the plants bees
pollinate.
….how nesting behavior is
influenced by human
behavior (such as
landscaping)
OUR
ENVIRONMENT
THROUGH
TIME….
Human Impact
Wherever humans have
hunted, grown food, or
settled, they changed the
environment.
Hunter-Gatherers
● HUNTER-GATHERERS: People
who obtain food by collecting
plants and hunting animals or
scavenging their remains.
● People were hunter-gatherers
for most of human history.
● Early hunter-gatherers:
● Small groups
● Migrated from place to place
as food became available.
How hunter-gatherers affect
their environment:
● Hunted bison, and set fires to prairies to prevent
tree growth so bison could be seen.
● Helped spread plants to areas where the plants did
not originally grow.
● Rapid climate changes and overhunting led to
disappearance of some large mammal species.
The Agricultural Revolution
● Eventually, hunter-gatherers began
● Collecting seeds of plants they gathered and
● Domesticating animals in their environment.
AGRICULTURE: practice of growing, breeding, and
caring for plants and animals used for food, clothing,
housing, transportation, etc.
Effects of the Agricultural
Revolution
● Human population grew and
became concentrated in
smaller areas.
● Pressure on local
environment increased.
● Changed food we eat.
● Domesticated plants
became different from their
wild ancestors.
Effects of the Agricultural
Revolution
● Habitats were
destroyed through
slash-and-burn
agriculture.
● Soil loss, floods, and
water shortages.
● Poorly-farmed land is
no longer fertile.
The Industrial Revolution
● Began in the mid-1700’s.
● Involved a shift from animal muscle to fossil fuels.
● Increased use of fossil fuels and machines changed
society and increased efficiency agriculture,
industry and transportation.
● Large-scale production of goods became less
expensive.
The Industrial Revolution
● Machinery reduced
manpower and land
needed to grow food.
● Populations in urban
areas grew steadily.
● Fossil fuels and
motorized vehicles
allowed food and other
goods to be transported
cheaply.
Improving Quality of Life
● Positive changes
introduced by industrial
revolution:
● Inventions
● Agricultural
productivity increased,
● Sanitation, nutrition
and medical care
improved.
Environmental Problems
Introduced by Industrial Revolution
● Pollution and
habitat loss became
more common
● Increased use of
artificial substances
(plastics, artificial
pesticides,
fertilizers)
Spaceship Earth
-Earth compared to a spaceship:
cannot dispose of waste or take
on new supplies.
CLOSED SYSTEM
● Isolated system that has no
interactions with its external
environment.
● Problems with a closed systems
● As the population grows, resources
will be used more rapidly.
● Wastes could be produced more
quickly than we can dispose of
them.
What Are Our Main
Environmental Problems?
● Resource
Depletion
● Pollution
● Loss of
biodiversity
Resource Depletion
●NATURAL RESOURCE - Any natural material used
by humans.
●Two types
● RENEWABLE - Can be replaced relatively quickly
by natural processes. Ex: fresh water, air, soil,
trees, crops, and energy from the sun.
● NONRENEWABLE - Forms at a much slower rate
than it is consumed. Ex: minerals and fossil
fuels.
Pollution
● POLLUTION: undesirable change in
air, water, or soil.
● Industrial revolution produced
wastes faster than they could be
disposed of.
● Wastes accumulate in the
environment and cause
POLLUTION.
● Much of the pollution today is
produced by human activity.
Two Main Types of
Pollutants
BIODEGRADABLE
NONBIODEGRADABLE
● Pollutants that can be
broken down by natural
processes.
● Pollutants that cannot be
broken down by natural
processes.
● Examples: human sewage
or a stack of newspapers.
● Examples: mercury, lead, and
some types of plastic.
● Can become a problem
when they accumulate
faster than they can be
broken down.
● Can build up to dangerous
levels in the environment.
Loss of Biodiversity
● BIODIVERSITY: variety of species that live in an
area.
● Organisms that share the world with us can be
considered NATURAL RESOURCES.
● We depend on other organisms for FOOD,
OXYGEN, AND MANY OTHER THINGS.
● Species can be considered NONRENEWABLE
RESOURCES.
“Tragedy of the Commons” (Garrett Hardin, 1968)
The difficulty of solving environmental
problems is conflict between short-term
interests of individuals and long-term welfare of
society.
Point of Hardin’s Essay
● Someone or group has to take
responsibility for maintaining a
resource.
● Social pressures influence how we use
resources.
● Earth’s natural resources are our
modern commons.
Economics and the
Environment
● Economic forces
influence how we use
resources.
● LAW OF SUPPLY AND
DEMAND: The greater
the demand for a
limited supply of
something, the more
the thing is worth.
Costs and Benefits
● The cost of
environmental
solutions can be
high.
● COST-BENEFIT
ANALYSIS: Balances
the cost of an action
against the benefit
one expects from it.
DEVELOPMENT
DEVELOPED
COUNTRIES
● Have higher average
incomes, slower
population growth, diverse
industrial economies, and
stronger social support
systems.
DEVELOPING
COUNTRIES
● Lower average incomes,
simple and agriculturebased economies, and
rapid population growth.
Consumption Trends
Ecological Footprints
ECOLOGICAL FOOTPRINT: Productive area of Earth
needed to support one person in a particular country.
-Estimation of land used for crops, grazing, forest
products and housing.
-Includes ocean area used to harvest seafood, and
forest area needed to absorb air pollution caused by
fossil fuels.
Do Now:
PLANT YOUR CORN.