Transcript Human Impact on the Environment

Human Impact on the
Environment
Trade off
 Humans have both positive
and negative impacts on the
environment.
 Main reason for the negative
impact is the human population
is increasing.
 This places increasing
demands on natural resources
such as food, water, energy
and space.
There is no easy solution and every solution
has both + and – consequences.
Trade off: when a solution has both
negative and positive consequences.
A consequence is something that naturally
follows from an action
Consequences can be both positive and
negative.
Finite Resources.
 Finite resources: resources that will eventually
run out.
 Interrelationships
The Earth has limited resources to support life.
 The increasing human population is depleting those
resources.
Ex. Pollution decreases the amount of oxygen in the
air.
Renewable vs. nonrenewable
Renewable resources are resources that
are being replaces faster than we can use
it up.
Example: wood, solar radiation
Non-renewable resources: something
being used faster than it can be replaced
Example: oil, coal, natural gas
 Some Detrimental (harmful)
Human Activities
Human activities can alter the
balance of an ecosystem.
 This destruction of habitat, is
threatening the stability of the
planet's ecosystems.
 the damage to the ecosystems
may be permanent.
 Ways Humans Adversely Influence Ecosystems
1. Population growth: Too many people using
limited resources
2. Over consumption: Industrialized societies
are using more resources per person from
our planet than people from poor nations.
3. Advancing Technologies: we introduce
technology without knowing how it will
influence the environment
4. Direct Harvesting: a large loss of rainforest
and its biodiversity.
5. Pollution: pollution has had many adverse
influences on air, water and land.
6. Atmospheric Changes: Greenhouse gases
due to the burning of fossil fuels and depletion
of our ozone layer.
7. Endangered species: species are
threatened to extinction due to habitat
destruction.
Invasive Species
Importing foreign organisms have caused
problems for native organisms (one’s already
living there).
They are know as an invasive species AKA
exotic species.
This is a species not native to an area, it was
imported.
They are bad because they can out compete
the native animals causing them to go extinct.
Some times they have better tools for that
environment.
Sometimes they lack
predators and their
populations increase to
high levels. Then they eat
all the food and native
species go extinct.
They tend to disrupts the
natural food web that has
been there for many
years.
Invasive species in Australia
examples of exotic species
having negative effects
include rabbits imported into
Australia.
These exotic species won
the competition with many
native herbivorous
marsupials killing them off
Invasive Species to NY
 Snakehead fish:
 Native to Asia and
Tropical Africa
 Imported as aquarium
pets and as a food source.
 Released into the wild
 It breathes air
 It can crawl out of water
for miles to find the next
water source
Huge predator and out
competes other native
fish
Makes lots of babies
and breeds quickly.
Not predators so many
survive
They are now illegal to
own.
If you catch one in the
wild, you must report it
to the DEC.
Three major environmental problems
include:
I. Global Warming
II. Acid precipitation (rain)
III. Ozone depletion
I. Acid Precipitation
 Most acid rain in New York State is caused by sulfur
dioxide and nitrogen dioxide pollution from the burning
of fossil fuels such as coal and oil.
 They combine with water vapor in the atmosphere and
fall back to the earth over New York as acid
precipitation.
Some Problems Associated With Acid
Precipitation
Streams and lakes becoming more acidic,
killing fish, frogs and other life.
Damage forests and plants and
deteriorates buildings
What can be done?
We can burn low sulfur coal
We can use alternative energy sources
such as solar panels for electricity and hot
water heaters.
We can heat our house with geothermal
wells.
Geothermal well: well drilled deep into the
earth to release heat naturally created.
Geothermal well
Acid precipitation
II. Global Warming
Burning fossil fuels and
other pollution increases
the amount of CO2 in the
air
Fossil fuels include
gasoline, coal and oil.
This can potentially
increase the earth’s
temperature.
 Carbon Dioxide is also known as a Greenhouse
gas
 the increase in level of carbon dioxide and other
gases is not allowing infrared or solar heat
radiation to escape the planet back into outer
space.
 This is causing our planet to slowly warm.
 Consequences of Global
Warming
 Rising sea levels and coastal
flooding
 Changed rain patterns
resulting in droughts and
crop failures
 Increase in insect diseases in
regions
 Ex. New York State: warmer
winters fail to kill the disease
carrying insects like West
Nile
What can be done?
 Decrease use of fossil
fuels, including
electricity.
 Use alternative forms
of energy such as
solar panels
 Car pool to work, take
public transit.
III. Ozone Depletion
Ozone is another form of
oxygen. You breath O2.
Ozone is O3. you do not
breath this.
Ozone decreases the
amount of solar radiation
that reaches the earth from
the sun, also known as UV.
Hole in the ozone layer
What causes Ozone depletion
Use of CFC’s or chlorofluorocarbons
lowers ozone by breaking up O3
CFC’s are used in some aerosol cans (not
as much any more)
They are also released from some
refrigerators and air conditioning systems.
Consequences: skin cancer, cataracts.
Actions being taken by humans to reduce or
repair damage to the environment include:
1. Recycling wastes
2. Conserving available resources
3. Using cleaner resources (ex: solar over fossil
fuels)
4.protection of habitats and endangered
species
5. use of biological controls instead of
pesticides and herbicides
6. Farming native plants (ex: cocoa in the
rainforest)
7. Planting trees to replace those cut down.
8. Rotating crops or planting cover crops to
reduce soil loss.
9. passing laws to control pollution, land
management, hunting and fishing
What part of the food chain do you
think is most affect by toxins?
Producer
Primary consumer
Secondary consumer
Tertiary consumer
Why?
Biomagnification
Biomagnification: the increased
concentration of a poison that moves up
the food chain.
It can start at the plant level.
Many little fish eat the plants and get the
toxins.
Then a large mouth bass eats hundreds of
little fish and gets more toxins.
A human fisherman catches several bass
with already higher level toxins
He eats them all and gets even more.
He may accumulate so much toxin that is
causes cancer or some other disorder
This happens in the Hudson River.
Central Hudson has dumped tons of toxins
including PCP’s in the river.
Much of the toxins settle in the bottom soil
or sediment.
Politicians try to correct this by dredging
the river or scoop out the bottom
sediment.
It stirs the toxins back into the water
causing more problems.
 Human action often has negative consequences for
the ecosystem and humans too. Here are some and
they ways the affect our ecosystem.
 For each of the following ecological problems, identify the
specific cause, their negative effects on the environment, and a
way that people are trying to fix the problem:
 1. acid rain
Cause:
Negative effects:
How we are trying to fix:
 2. deforestation
Cause:
Negative effects:
How we are trying to fix:
3. Loss of diversity:
Cause:
Negative effects:
How we are trying to fix:
4.Global warming
Cause:
Negative effects:
How we are trying to fix:
5.Introduced (invasive) species
Cause:
Negative effects:
How we are trying to fix:
6. Industrialization:
Cause:
Negative effects:
How we are trying to fix:
7. Nuclear Power
Cause:
Negative effects:
How we are trying to fix:
8. use of chemical fertilizers
Cause:
Negative effects:
How we are trying to fix:
9. burning fossil fuels
Cause:
Negative effects:
How we are trying to fix: