Transcript Four Blocks - Plain Local Schools

Chapter 1: Environmental Science
A Global Perspective
“ All the flowers of all the tomorrows are in the seeds of today.”
Chinese Proverbs
Section 1.1: Understanding Our
Environment
• Environmental Science is a relatively new field
• It is the study of how humans interact with the
environment
• Major focus is solving environmental problems
• The term ‘environment’ refers to everything that
surrounds us
• Our environment includes natural world as well
as things produced by humans
Solving Environmental Problems
• 40 years ago, people did not think much about the
environment
• After WWII, people moved out of the crowded cities to the
suburbs; rapidly expanding industries made jobs plentiful;
bigger cars and household electric appliances made life
more comfortable
• Have we paid the price over the years for that comfortable
lifestyle? Rivers/lakes are too polluted to enjoy; air pollution
hangs over cities; increased health risks from chemicals in
the water, soil and food; no place to put our trash
• Environmental problems can be complicated; preventing
pollution can be expensive; cleaning it up can be even more
expensive
Continued…..
• Environmental problems can be solved
• Our environmental problems are huge and
require careful attention and action
• The 21st century is a crucial time in human
history; a time to find solutions that will
allow people all over our planet to live in
clean, healthy environments and have all
the resources they need for a good life
What are our main Environmental
Problems?
• There are unlimited numbers of
environmental problems facing us today:
whether to ban septic tanks, where to build
landfills, ozone advisories, making
decisions based on rare birds or insects,
etc.
• Almost all environmental problems fall into
one of three categories: resource
depletion, pollution and extinction
Resource Depletion
• A resource is depleted when a large part of it has been
used up
• Natural resource – any natural substance that living
things use (sunlight, air, water, soil, minerals, plants,
animals, forests, fossil fuels
• Nonrenewable resources – resources that cannot be
replaced (fossil fuels like oil, natural gas); when they are
used up, they are gone
• Renewable resources – resources that are continually
replaced (solar, trees, fish, wind); can be depleted if
used up faster than it can be replaced, ex: trees
Pollution
• Introduction of harmful levels of chemicals or
waste material into the environment
• Heat energy and nitrous oxide are by-products
of fuel combustion
• Pesticides are intentionally created for practical
reasons but cause a great deal of harm to water,
air and soil
• Pollutants also are dangerous to humans, ex:
Mercury (in water) can cause nerve damage in
humans when they eat contaminated fish
Extinction
• Extinction means that the last of a species
has died and will never be seen again
• Thousands of species are becoming
extinct every year—some have never
been identified, named or studied; more
today than any other time in history
• Extinction is one of the most significant
challenges we face today; most species
are dying as a result of the loss of habitat
A Global Perspective
• Most environmental problems are global
• Sulfur dioxide released by coal-fired electric
generators in midwest come back as acid rain in
Canada; cars release carbon dioxide in the
atmosphere, causing changes in the atmosphere;
rainforest destruction also increases CO2 in the
atmosphere; CFC’s produced all over the world harm
the ozone
• Biosphere (extends 8 km or 5 miles) above and below
the surface of Earth; all living things exist in this space
with the non living things necessary for survival
Developed and Developing Countries
• Even though all humans live in biosphere; different
countries have different needs and priorities
• Countries can be categorized into two groups:
1. Developed – highly industrialized, high average
incomes; ex: USA, Canada, Japan, Australia, New
Zealand, western Europe
2. Developing – less industrialized, low average
incomes, for instance, average farmer in India
makes only $2700/yr., Kenya $450/yr.; not all are
this poor, come countries like Malaysia, Mexico and
Thailand are rapidly growing
Population and Consumption
• Many of our environmental issues are linked to increasing human
populations and increase needs of our natural resources
• Population crisis – some regions of Earth have human population
increasing more rapidly than the natural resources can support; most
severe in developing countries where they already don’t have enough
resources; too many people and there are not enough natural
resources for people to live healthy and productive lives: malnutrition,
starvation and disease are constant threats
• Consumption crisis - when resources are polluted, used up or
wasted, the resources are used faster than they can be replaced,
renewed or cleaned up; most severe in developed countries where
population is stable or growing slowly, but citizens use more than
their share of the resources (USA); developed countries used up 75%
of resources but make up only 20% of world’s population
A Sustainable World
• Goal of environmental problem solving is to
achieve a sustainable world – a place where
humans can exist indefinitely with high
standards of living and health, habitats
preserved and garbage turned into harmless
substances
• Nonrenewable resources would be used
sparingly
• Renewable would be used only as fast as it
could be replaced
1.2 Using Science to Solve
Environmental Problems
• In order to solve our environmental problems, we must first
understand our environment
• Two types of science:
• 1. Pure Science (answers questions about how the natural
world works, ex: physics, biology; Why do insects and birds
have different kinds of wings?)
• 2. Applied Science (uses information from pure science to
solve problems, ex: engineering, medicine; Using pure science
to design cars to get better gas mileage)
• Environmental Science is an applied science; one of the most
important foundations of environmental science is ecology (how
living things interact with each other and their nonliving
environment
What is Science?
• Science is really is two things: Something you
know (gathered throughout human history;
passed down from generation to generation) and
Something you do (scientists at work “doing
science”; finding answers to questions about
natural world)
• Scientists use the Scientific Method to find these
answers.
Observing
• All science begins with observing
• Use of our senses (sight, taste, feel, sound, smell)
• Scientists use equipment to help their senses
(microphones, x-rays)
• Science begins with and rests on observation;
accurate and detailed descriptions; must be
recorded so it can be shared
• Scientists have been able to answer many
important and fundamental scientific questions
through observations
Hypothesizing and Predicting
• Observing may give answers to some questions,
but when one question is answered, new ones
appear; when scientists want to find the answer
to a specific question, they form a hypothesis
(testable explanation) to find the best answer
• To test the hypothesis, they make a prediction.
Experimenting
• When the answer to a question cannot be
answered conclusively, scientists may have to
do experiments to find the answers
• In an experiment a hypothesis is tested under
controlled conditions; two groups are studied;
they must be identical in every respect except
for one (must have a control group and a group
with only one variable)
Organizing and Interpreting Data
• One of the most important parts of science is to
share what has been learned with others
• This begins with careful and accurate records;
evaluating the data and deciding if the hypothesis is
supported
• Mathematics is used to determine whether
observations or experimental results are meaningful
or if it is a result of chance or coincidence; statistics
is used to determine if the difference between
results in the control group and the experimental
group is significant
Using Graphics and Sharing
Information
• Organizing data into graphic illustrations helps
scientists analyze the data and explain it clearly to
others
• Tables (summarize data); Graphs (convey
comparisons or trends); Line Graph (shows change
in numbers); Bar graphs (shows change in numbers,
especially effective in showing several comparisons
at once); Pie Charts (percentages – one shows
relative % of different factors, two can be used to
compare and convey more information)
Communicating Results
• Scientific articles must include the
question to be answered, why it is
important or relevant, background
information, a precise description of how
the work was done, the data that were
collected, and the scientist’s evaluation of
what the data means
1.3 Making Environmental Decisions
• Scientific research is an essential first step In
solving environmental problems
• Steps:
• 1. Gather information
• 2. Consider Values
• 3. Explore consequences
• 4. Make a Decision
Values That Affect Environmental Decision Making
Value
Definition
Aesthetic
What is beautiful or pleasing
Economic
Gain or loss of money or jobs
Environmental
Protection of natural resources
Educational
Accumulation and use of knowledge
Ethical/Moral
What is right or wrong
Health
Maintenance of human health and prevention of
sickness of disability
Recreational
Providing for human leisure activities
Scientific
Knowledge gained by scientific research
Social/Cultural
Maintaining human communities and respecting
their values and traditions