Transcript ENVIRONMENTAL SCIENCE

ENVIRONMENTAL
SCIENCE
Chapter 1 Science and the
Environment
1.1 Understanding Our Environment
1.1 Understanding Our Environment
Objectives
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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 effects of huntergatherers, the agricultural revolution, and the
Industrial Revolution.
Distinguish between renewable and nonrenewable
resources.
Classify environmental problems into three major
categories.
Introduction
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Our environment is everything around us.
The environment includes biotic (living) and
abiotic (nonliving) factors.
The environment is also a complex web of
relationships that connect us with the world in
which we live.
Energy flow and cycling of matter are
constants in any environment on Earth.
Biotic and Abiotic Factors
What is Environmental Science?
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Environmental science is the study of how humans
interact with the environment.
Environmental science seeks to understand and solve
environmental problems by focusing on two primary
areas of study.
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How we use natural resources such as water and plants
How our actions alter our environment
Environmental science is interdisciplinary, meaning
that it integrates many different fields of study.
What is Environmental Science?
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Ecology, an important foundation of environmental science, is
the study of how living things interact with each other and
with their abiotic environment.
Chemistry helps us understand changes in matter which occur
in the environment such as the effect of pollutants.
Geology helps us to understand the structure of the Earth and
how certain pollutants may disperse if released into the
environment.
Paleontology helps us to understand changes that have
occurred in both climate and living forms in the past.
The study of population, economics, law, and politics also play
an important role in environmental science.
What is Environmental Science?
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Five major fields of study contribute to
Environmental Science.
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Biology – the study of living organisms
Earth Science – the study of Earth’s nonliving
systems and the planet as a whole
Physics – the study of matter and energy
Chemistry – the study of chemicals and their
interactions
Social Sciences – study of human populations and
their interactions
Our Environment Through Time
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Hunter-gatherer societies consist of people who
obtain food by collecting plants or hunting (or
scavenging) wild animals.
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Hunter-gatherer societies tend to be small groups that
migrate with animals or according to season
A few hunter-gatherer societies remain today in parts of the
Amazon and New Guinea
Evidence suggests that Native Americans burned the
prairies to keep trees from growing on them so that they
would be better suited for hunting
Evidence also links the arrival of man in many places with
the extinction of large mammals such as mammoth and
giant ground sloth
Our Environment Through Time
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Agriculture is the practice of growing, breeding, and
caring for the plants and animals that are used for
food, clothing, housing, transportation, and other
purposes.
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The agricultural revolution began over 10,000 years ago in
many parts of the world and had a major effect on
population and the environment
A given area of land can support up to 500 times as many
people with agriculture than it can through hunting and
gathering
As populations grew, they began to concentrate in certain
areas
Our Environment Through Time
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Agriculture is the practice of growing, breeding, and
caring for the plants and animals that are used for
food, clothing, housing, transportation, and other
purposes. Cont’d
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The plants and animals that we depend on agriculturally
today began as wild populations and were selected through
the ages for their desirable traits
Slash-and-burn agriculture was an early form of converting
natural habitat to farmland
Civilizations have fallen due to the destructive
consequences (erosion, flooding, degradation of soil
quality, etc.) of poor agricultural technique
Our Environment Through Time
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The focus of the Industrial Revolution, which began
about 300 years ago, was the change of fuel source
from animal and water power to the combustion of
fossil fuels.
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Agriculture, industry, and transportation became much
more efficient – enough so to revolutionize society
Large scale production meant more and cheaper goods and
agriculture depended less on large numbers of laborers
Motorized vehicles allowed for the cheap transportation of
people and goods over long distances
Our Environment Through Time
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The focus of the Industrial Revolution, which
began about 300 years ago, was the change of
fuel source from animal and water power to
the combustion of fossil fuels.
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Along with improvements in lifestyle, the
Industrial Revolution has introduced many new
environmental problems
Pollution and habitat loss are becoming greater
concerns as human population continues to
increase exponentially
Spaceship Earth
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Environmental problems can occur on any
scale – global, regional, or local.
Earth is an open system with respect to energy,
yet a closed system with respect to matter.
As light energy is continually bombarding
Earth, some of it is radiated out into space as
heat and light energy.
Some energy is captured and converted to
chemical energy by living systems.
Spaceship Earth
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Human population is growing exponentially – which is evident
as a “J – curve” on a population graph.
The synergistic effects of the agricultural and industrial
revolutions along with modern medicine and a growing
awareness of sanitation and hygeine have resulted in an
exploding human population that most resemble insect
populations – just before they crash.
Most large mammals exhibit an “S – curve” population
growth.
As human population grows, so does its need for resources
such as food, energy, and space – as well as the production of
waste.
Identifying Environmental Problems
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Environmental
problems can generally
be grouped into three
categories.
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Resource depletion
Pollution
Loss of biodiversity
Identifying Environmental Problems
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Natural resources are any materials used by humans.
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A renewable resource, such as water, sunlight, and wood
can be replaced relatively quickly by natural processes
Nonrenewable resources, such as fossil fuels and minerals
are used up at a much faster rate than they are consumed
Any resource can be considered to be depleted when
a large fraction of that resource has been used up.
Pollution is an undesired change in air, water, or soil
that adversely affects the health and activity of
organisms.
Identifying Environmental Problems
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There are two main types of pollutants.
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Biodegradable pollutants can be broken down by
natural processes and may include sewage and
newspaper
Nondegradable pollutants cannot be broken down
by natural processes and may include mercury,
lead, and some plastics
Biodiversity refers to the number and kind of
different species living in an area.
Identifying Environmental Problems
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It is estimated that there are currently about 13
million species on Earth – just a fraction of a percent
that have existed on Earth through time!
Several mass extinction events have occurred through
time – including the larges of such events a the
Permian-Triassic boundary about 250 million years
ago when 95% of then existing species went extinct.
It is important that we are not the major cause of the
next extinction event (in which we may currently be
experiencing).
References
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Moss and Lichens http://www1.br.cc.va.us/murray/serendipity/Biology/
Activities/Sherando/examples_of_primary_successio
n.htm
Mountain Lion http://www.rw.ttu.edu/sp_accounts/mountain_lion/lite
rature.htm
Waterfall http://www.rodsguide.com/cataract_falls.htm
Kalahari Bushman Catching Ants http://www.kalaharidesert.com/destination_gallery_Bushmen.asp
References
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Egyptian Farmer http://www.wsu.edu:8001/vwsu/gened/learnmodules/top_agrev/5-Technology/technology3.html
Factory - http://english.epochtimes.com/news/5-92/31874.html
Customer Service/Information http://www.vipowernet.net/CustomerService.asp
Growth Curves http://www.chem.duke.edu/~bonk/Chem8304/enote1
405.html
References
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Slash-and-Burn Agriculture http://encarta.msn.com/media_461539708_761
554342_-1_1/Slash-andBurn_Agriculture.html