Transcript Environmental Science Chapters 1 & 2

Environmental Science
Chapters 1 & 2
1-1 Understanding Our Environment
1-1 Objectives
• Define environmental science and compare
environmental science with ecology.
• List the five major fields of study that contribute to
environmental science.
• Describe the major environmental affects of huntergatherers, the agricultural revolution, and the industrial
revolution.
• Distinguish between renewable and nonrenewable
resources.
• Classify environmental problems into three major
categories.
1. What is Environmental Science?
• The study of the air, water, and
land surrounding an organism or a
community (could be a small area
to Earth’s entire biosphere).
• It includes the study of the impact
of humans on the environment.
2. What is one of the major goals of
environmental science?
• To understand and solve environmental
problems.
3. How can this goal (of understanding
and solving environmental problems)
be solved?
• Two main types of interactions between
humans and their environment must be
studied to achieve this goal:
– Humans use of natural resources.
– How humans actions alter their environment.
4. What does it mean to say that
environmental science is an
interdisciplinary science?
• It means it involves many fields of study, such
as ecology, biology, earth science, physics,
chemistry and social sciences.
• Ecology is the foundation of environmental
science.
• Ecology – the study of interactions of living
organisms with one another and with their
environment.
5. Other fields of study impacting
environmental science:
6. How have the following “eras” had
an impact on the environment?
• Hunter-Gatherers?
– Burned prairies to prevent the growth of trees so they
had grass for bison
– Overhunting species to extinction (giant sloths, giant
bison, mastodons, cave bears, saber-toothed cats.)
• Agricultural Revolution?
– Allowed human population to grow very fast
– Plants and animals became domesticated
– Habitats were destroyed as grasslands, forests, and
wetlands were replaced by farmland (this can cause
erosion and floods and lead to soil that is no longer
fertile)
• Industrial Revolution?
– Increased the efficiency of agriculture, industry,
and transportation
– Pollution from industries was introduced
– Fossil fuels and motorized vehicles allowed food
to be transported great distances so population
continued to grow
– Artificial substances began to be used in place of
raw animal and plant products (ex: plastics,
pesticides)
7. How can our Earth be compared to
a spaceship?
• Neither can dispose of its waste or take on
new supplies.
• They are “closed systems”.
• The only thing that enters the Earth’s
atmosphere in large amounts is the energy
from the sun, and the only thing that leaves in
large amounts is heat.
8. What is the problem with our Earth
being a “closed system”?
• Some resources are limited and as the
population grows the resources will be used
more rapidly.
• There is also the possibility that we will
produce wastes more quickly than we can
dispose of them.
9. What does it mean to say that
environmental problems can occur on
a local, regional, or global scale?
• A local example would be your community
discussing where to build a new landfill.
• A regional example would be a polluted river
1000 miles away affecting the region’s water.
• A global example would be the depletion of
the ozone layer.
10. What are some factors that have
led to our rapid increase in population
growth in the last 100 years?
• Industrial revolution
• Modern medicine
• Improved sanitation
11. How does the rapid increase in
population growth affect our
environment?
• Leads to an increased use of resources, more
habitat destruction and increased pollution.
12. Can we expect our population to
stop growing anytime soon?
• Probably not
• Most scientist predict the human population
to double in the 21st century before it begins
to stabilize.
13. What are our main environmental
problems?
• Resource Depletion
• Pollution
• Loss of Biodiversity
14. What is a natural resource?
• Any natural material that is used by humans
15. What are some examples of
natural resources?
•
•
•
•
•
Water
Petroleum
Minerals
Forests
Animals
16. How are natural resources
classified?
• Renewable – resource
can be replaced
relatively quickly by
natural processes
• Nonrenewable –
resource cannot be
replaced quickly by
natural processes
17. When is a resource considered
depleted?
• When a large portion of the resource has been
used up
18. Can renewable resources become
depleted?
• Yes, if they are used up faster than they are
being replaced
• Ex: if we cut down trees faster than we
replace them
19. What is pollution?
• An undesirable change in the natural
environment that is caused by the
introduction of substances that are harmful to
living organisms or by excessive wastes, heat,
noise, or radiation.
20. How can pollutants be classified?
• Biodegradable – can be broken down by
natural processes
– EX: newspaper
• Nonbiodegradable – cannot be broken down
by natural processes
– EX: mercury
21. What is biodiversity?
• Refers to the number and variety of organisms
in a given area.
22. Why is the biodiversity of an area
important?
• It is often used to measure the health of an
ecosystem.
• The more biodiversity present, the healthier
the ecosystem.
23. What is causing the loss of
biodiversity we are experiencing
today?
• Extinction, mainly due to habitat destruction
• Only a fraction of the species that once
roamed the Earth are alive today.
• Extinction is occurring much faster today than
ever before.
Baiji River Dolphin
American
Passenger
Pigeon
Golden Toad
24. Why should we care about the
extinction of plants and animals?
• They are natural resources that fill a role
within the ecosystem.
• We depend on many of these organisms for
food, oxygen, nitrogen, etc.
• They may have potential economic, scientific,
aesthetic, and recreational value.
1-2 Objectives
• List three differences between developed and
developing countries.
• Explain what sustainability is and describe why
it is a goal of environmental science.
1. What are developed countries?
• Countries that have higher incomes, slower
population growth, diverse industrial
economies and stronger social support.
• EX: US, Canada, Japan, Countries of Western
Europe
Developed and Developing Countries
2. What are developing countries?
• Countries that have lower average incomes,
simple agriculture-based communities, and
rapid population growth.
• EX: Mexico, Afghanistan, Saudi Arabia, and
the countries of Africa and South America,
Developed and Developing Countries
3. What do developed and developing
countries have to do with
environmental science?
• The unequal distribution of wealth and
resources around the world influence the
environmental problems and solutions a
society can make.
4. What are the root causes of most
environmental problems?
• Population crisis – the number of people is
growing too fast for the environment to
support.
• Consumption crisis – people are using up,
wasting, or polluting natural resources faster
than they can be renewed, replaced, or
cleaned up.
5. Where is the population crisis most
severe?
• Developing countries
• Food production, education, and job creation
cannot keep pace with the population growth,
so each person gets fewer resources as time
goes by.
• These countries are threatened by
malnutrition, starvation, and disease
6. Where is the consumption crisis
most severe?
• Developed countries
• To support the higher quality of life,
developed countries are using much more of
Earth’s resources
• Developed nations use up about 75% of the
resources every year even though they make
up only about 20% of the world’s population
Consumption Trends and Population
Growth
7. What is an ecological footprint?
• A calculation that shows the area of
Earth needed to support one person in
a particular country.
• Calculate YOUR ecological footprint:
http://www.myfootprint.org/
• It estimates the land used for crops,
grazing, forest products, and housing.
It includes the ocean area used to
harvest seafood and the forest area
needed to absorb the air pollution
caused by fossil fuels.
8. Can ecological footprints be used to
compare consumption in various
nations?
• Yes
9. What is another key goal of
environmental science?
• To create a sustainable world
10. What is a sustainable world?
• A world in which human needs are met in
such a way that a human population can
survive indefinitely.
11. Do we currently have a sustainable
world?
• No
12. How can we achieve a sustainable
world?
• It would require everyone’s participation
including citizens, industry and the
government.