Transcript Human Impact on the Environment

HUMAN IMPACT ON THE
ENVIRONMENT
Pollution
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Pollution is the introduction of
something into the environment
which has a harmful or poisonous
affect.
“Every year in the U.S. factories
release over 3 million tons of toxic
chemicals into the land, air, and
water. This causes us to lose over 15
million acres of land every year.”
Air Pollution
Air pollution occurs when we
introduce gases or particulates
into the atmosphere that harm us and all other life on Earth
 Some different types of air pollution include:
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 Acid
Rain
 Greenhouse Gases
 Smog
 Ozone Depletion
Air Pollution
Smog is a combination of the
words smoke and fog because
smog is literally a smoky fog
that hangs in the air.
 Smog is created by the burning of fossil fuels, which occurs in
industrial plants, automobiles, and more.
 In areas where there is more industry and cars we see more
smog
 Smog can get into peoples lungs and cause damage just like
smoking would, it blocks out sunlight plants and organisms need
to survive, and it causes changes in weather
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Land Pollution
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We pollute the land in many different ways:
 Our
garbage which creates landfills
 Industries dump hazardous wastes
 Agriculture poisons the soil with pesticides, fertilizers, and other
chemicals
 Littering kills helpless animals
Land Pollution
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Interesting facts to think about:
Every year one American produces over 3285 pounds of hazardous
waste
 Land pollution causes us to lose 24 billion tons of top soil every year
 Americans generate 30 billion foam cups, 220 million tires and 1.8
billion disposable diapers every year
 We throw away enough trash every day to fill 63,000 garbage
trucks
 Every day Americans throw away 1 million bushels of litter out their
car window
 Over 80% of items in landfills can be recycled, but they’re not
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Land Pollution
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Consequences of land pollution are dire . . .
 Chemicals
that pollute the land can lead to respiratory
problems, skin irritation, birth defects, and cancer in humans
and animals
 We are running out of space to store our garbage because it
takes a very long time for certain materials to break down
 Land pollution can run off into lakes and rivers which will run
into the oceans and start destroying aquatic ecosystems
 We are losing biodiversity in any ecosystem where pollution is
present
Water Pollution
Water pollution is any chemical,
physical or biological change in the
quality of water that has a harmful
effect on any living thing that drinks or uses or lives (in) it
 There are several different types of water pollutants:

Disease causing agents such as bacteria, protozoa, viruses, and
parasites
 Oxygen-demanding wastes
 Nitrates or phosphates
 Organic compounds such as oil and plastics
 Suspended sediment which limits light from getting through the water
 Radioactive compounds that can cause cancer
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Eutrophification
Eutrophication is an increase in the organic
matter in an ecosystem
 Eutrophication is typically caused by an
increase in nitrates (from fertilizers) and
Phosphates (from sewage)
 These are both limiting factors for
plants, so when we introduce more
of these substances into an ecosystem
it causes excessive growth of algae
 As algae dies and decomposes it
 depletes the water of oxygen needed by other organisms living
there
 As everything dies it builds up on the bottom causing succession of
the pond into dry land to be greatly sped up

Ozone Depletion
The ozone is a layer of our
atmosphere that protects us from
harmful UV radiation from the sun
 We noticed in the late 1970’s
that the ozone layer over
Antarctica was shrinking creating
an “ozone hole”
 Ozone depletion is caused by the release of CFC’s (chloroflouro- carbons) into the atmosphere
 CFC’s are released by aerosol cans, refrigerants, air
conditioners and other products we use on a daily basis
 Ozone depletion is independent of global warming!!!
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Deforestation
Deforestation is the removal of
trees from a forest ecosystem.
 There are many reasons this
occurs; for lumber, to make room for people to live, to create
new areas for industry, and for agriculture
 Deforestation is causing many different problems:
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Habitats are being destroyed causing organisms that live there to
become endangered or move into areas with people
 Trees absorb CO2, so when we remove them we increase
greenhouse gases in the atmosphere
 Trees help regulate temperature of soil, without trees the soil dries
out
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Deforestation
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How can we prevent
this?
 Use
methods other than
clear cutting forests
 Require organizations
to re-plant trees
 Preserve more forest
areas
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What ideas do you
have?
Direct Harvesting
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Direct harvesting is the destruction of an
organism, or the removal of an organism
from its habitat
This refers to all organisms, not just plants
Examples:
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Organisms that are captured in distant parts of
the world and sold as exotic pets (parrots or
sugar gliders)
Organisms that are killed for a specific body part
(elephants)
Now we have laws against poaching
(hunting of endangered animals), but
it still happens
Invasive Species
You might think that
releasing a new species into
an area that was not its
original habitat would increase
the biodiversity, but it actually has the
opposite affect.
 Invasive species have no natural
predators and will feed on native organisms
 This disrupts the food web, kills off the prey species, and
creates more competition

Invasive Species
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One of the worst things about
invasive species is the techniques
we have tried to use to get rid of
them
The most effective way to control
species populations is through
trapping that uses chemical
scents to attract the organism
We have also tried breeding
and releasing predators, but that
is not always successful
Next Class:
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We’ll tackle the topics of:
 Global
Warming and
 Acid Rain
Ticket to Leave:
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Take an Exit Ticket from the computer cart and
answer the following questions:
 One
humans impact on the environment
 Explain what causes this problem
 And explain how we can help fix it
Friday Bell Work
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Grab three or four post-it notes from the pads on
the front table.
On each post it write down one way humans impact
the environment. ONLY ONE PER POST IT PLEASE!
When you are done, stick them to the smart-board
After you’ve stuck all of your post-its to the smartboard, you should quietly turn in your flower
dissection lab and work on your vocabulary packet
Questions?
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Did we come up with more positive or negative
ways humans impact the environment?
Why do you think this is?
Why is it important to preserve the environment?
What do you think will happen if we continue to
destroy nature at the rate we are going?
How can each person in here help to stop the
negative impacts?