Download Human Impact - WHS Biology

Major Environmental Issues
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Pollution
Global climate change
Increasing resource use
Premature extinction of plants and animals
Poverty
Population growth
Worldometers
Developed Countries
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19% of world’s population
85% of worlds wealth
Use 88% of worlds resources
Generate 75% of pollution and waste
Developing Countries
• 15% of world’s population
• Use 12% of world’s natural resources
• Produce 25% of world’s waste and pollution
Human impacts on the earth:
Make two lists:
“Positive effects” & “Negative effects”
Human Impacts
Our effects on:
Biodiversity
Earth’s Systems
Biodiversity
• Increased biodiversity creates a more stable
environment
• 3 kinds:
– Genetic diversity - variety of genes in a pop. or spp.
– Species diversity – number of different species
– Ecosystem diversity – variety of ecosystems in an area
Importance of Biodiversity
Direct Economic Value
– Food, clothing, medicine, genetic potential, etc
Indirect Economic Value
– O2, Clean H2O, flood & drought protection, soil
production, decomposition of wastes, climate
regulation
Aesthetic Value
Scientific Value
Threats to Biodiversity
Biodiversity is a component of communities on land, in the air and in the water
5 » Habitat loss
4 » Habitat Fragmentation
3 » Overexploitation
2 » Pollution
1 » Introduced species
What to Teach:
• Define the threat & define
any vocabulary
• At least one example from
the book
• At least one example NOT
from the book
• A solution to the problem
You have been assigned a section of reading based on the
numbers above. Your job is to read about that section and
teach a group of the other numbers about what you read.
Threats to Biodiversity
Biodiversity is a component of communities on land, in the air and in the water
Habitat loss
Disruption – decline of one species affects others
- Removal of Keystone species
Destruction – clearing of rainforest,
big cities, urban sprawl,
draining wetlands, etc
Baltimore, Maryland
Threats to Biodiversity
Biodiversity is a component of communities on land, in the air and in the water
Habitat Fragmentation
Wildlife Corridor
Threats to Biodiversity
Biodiversity is a component of communities on land, in the air and in the water
Overexploitation – excessive use
– Hunting, fishing, fur trade, etc
– Can lead to premature extinction
• Passenger pigeons, dodo bird,
tasmanian tiger, quagga, etc
1883
1680s
1930s
1896
Threats to Biodiversity
Biodiversity is a component of communities on land, in the air and in the water
Pollution
– Point source & non-point source
– Biological magnification
– Acid rain
• Burning fossil fuels releases:
– Sulfur dioxide + water = sulfuric acid
– Nitrogen oxide + water = nitric acid
– Eutrophication
– Oil spills
Chemical Buildup
Some chemicals can build up in
the tissue of living things faster
than it is broken down
Nutrients
Lead
Mercury
DDT
Bioaccumulation
can lead to
biomagnification
Video
Threats to Biodiversity
Biodiversity is a component of communities on land, in the air and in the water
Invasive species - no limiting factors
Video
Cane toads
in Australia
Lionfish
Zebra muscles
Invasive species
of South Dakota
Asian carp
Mountain Pine Beetle
• Fast growing, aggressive, adaptable
• No natural predators in North America
• Females lay approximately half a million
eggs each time they spawn
Bonus Video
Impact on Earth’s Systems
Atmospheric
Aquatic
Terrestrial
The cycles connect all parts of the biosphere
Water
Carbon
Nitrogen
Exhaust
– smog
– Sulfur dioxide & nitrogen oxides = acid rain
– CO2 = climate change
CFCs = the ozone layer
Video
(Atmosphere)
Greenhouse Effect
• Sunlight enters the atmosphere, is absorbed by the
earth and converted into heat energy.
• The earth releases the energy
• Greenhouse gases in the atmosphere absorb the heat
energy from the earth and re-radiate it in all directions
Without it, all that heat energy would escape into
space. There would be no life on earth. All water
would be frozen.
Main Greenhouse gases:
Carbon dioxide – CO2
Water vapor – H2O
Methane – CH4
Enhanced Greenhouse Effect
Global Warming
Enhanced Greenhouse Effect
leads to global warming and climate change
Global Warming – Rise in global average temp
Climate Change – Change in long term statistics
concerning weather.
Climate
• Long term weather patterns
• Mainly temperature and precipitation
The U. S. Weather Service uses a 30 year time
span to determine their “average temperature and
precipitation”
So where is
the heat
coming
from?
Fossil Fuels Nonrenewable: Contain the energy of
the sun from millions of years ago.
• Coal
• Natural Gas
• Oil/Gasoline
Combustion
C(s) + O2
CH4 + 2O2
2C8H18 + 25O2
CO2
CO2 + 2H2O
16CO2 + 18H2O
What do you do with a lump of coal?
Burning a fossil fuel releases the energy contained in
the chemical bonds of the molecules
Burning fossil fuels contributes large amounts of CO2 to the atmosphere.
For every gallon of gasoline (6 lbs.) burned, 20 lbs. of CO2 are released.
Fuel economy
Electricity Production
Carbon Cycle
Atmospheric CO2
Photosynthesis
Plants
Cellular
Respiration
Combustion
Animals
Fossil Fuels
Death and
decomposition
Carbon Cycle
Atmospheric CO2
Photosynthesis
Plants
Cellular
Respiration
Animals
Death and
decomposition
Human activity (industrial revolution) has been
mainly responsible for the rise in CO2 levels.
Animation
Possible Effects
-Availability of water resources by altering
evaporation and precipitation (climate)
-Shift crop growing regions
-Change sea levels
-Ocean acidification
-Alter the structure and location of biomes
-Extinction of species
In summary…
So, what can we do about it?
Figure out how much of a problem we are. calculator
Polar Explorers
Take action.
Will Steger
Global Warming 101
Eric Larson
Fossil Fuel Energy Sources
Coal
Petroleum
Natural Gas
Chasing Ice
vs
5
1
6
3
2
4
Alternative Energy
Wind
Solar
Hydropower
Geothermal
Biomass
Hydrogen
(Atmosphere)
Ozone Depletion
Ultraviolet light hits a chlorofluorocarbon
(CFC) molecule, such as CFCl3, breaking
off a chlorine atom and leaving
CFCl2.
Sun
Cl
Cl
C
F
Cl
UV radiation
Once free, the chlorine atom is off
to attack another ozone molecule
and begin the cycle again.
Cl
Cl
O
O
The chlorine atom attacks
an ozone (O3) molecule,
pulling an oxygen atom
off it and leaving
O
O
an oxygen
O
molecule (O2).
Cl
Summary of Reactions
CCl3F + UV Cl + CCl2F
Cl + O3 ClO + O2
Repeated
Cl + O Cl + O2
many times
A free oxygen atom pulls
the oxygen atom off
the chlorine monoxide
Cl
molecule to form O2.
O
O
Cl
The chlorine
atom and the
O
oxygen atom join
O
to form a chlorine
monoxide molecule O
(ClO).
Figure 18-26
Page 473
Slide 35
CFCs released into the atmosphere from refrigerators, aerosol spray cans, etc
UV rays strike
a molecule of
CFC
Chlorine
atom breaks
from CFC
Chlorine
takes oxygen
atom from O3
to form O2
Free oxygen
atom
removes
oxygen from
chlorine
Chlorine free to continue breaking down ozone
Summary Video
Human Health
• Worse sunburn
• More eye cataracts
• More skin cancers
• Immune system suppression
Food and Forests
• Reduced yields for some crops
• Reduced seafood supplies from reduced
phytoplankton
• Decreased forest productivity for
UV-sensitive tree species
UV-sensitive tree species
Wildlife
• Increased eye cataracts in some species
• Decreased population of aquatic species
sensitive to UV radiation
• Reduced population of surface
phytoplankton
• Disrupted aquatic food webs from reduced
phytoplankton
Air Pollution and Materials
• Increased acid deposition
• Increased photochemical smog
• Degradation of outdoor paints and plastics
Global Warming
• Accelerated warming because of decreased
ocean uptake of CO2 from atmosphere by
phytoplankton and CFCs acting as
greenhouse gases
• Pollution
– Solid waste, pesticides, herbicides, salt, oil,
nutrients, etc
• Invasive species
• Mining
– Surface/strip mining/mountain-top removal
– Underground
– Fracking
• Habitat Disruption
– Habitat fragmentation
– Habitat loss & deforestation
Video
Video
Tall Grass Prairie then and now
Includes: Rivers/streams, Lakes, Wetlands, Aquifers
Divided into watersheds
- Area that drains into
a body of water
- Provides habitat,
drinking water,
irrigation, etc
- Water carries
sediment, nutrients,
chemicals, etc
- Problems are often
from upstream
Big Sioux Watershed
Missouri River Watershed
• Invasive species
– Asian carp, zebra muscles
• Pollution - Affects the health of the watershed
Video
– Solid waste/garbage
– Microbeads
– Chemicals pesticides, etc
– Eutrophication
Buildup of
(and
water can result in an
) in a body of
die, sink, &
Decomposition
to happen
is needed by
in
the lake
High levels of
&
can result in
a “fish kill” because of eutrophication
• Invasive species
– Asian carp, zebra muscles
• Pollution - Affects the health of the watershed
– Solid waste/garbage
– Microbeads
– Chemicals pesticides, etc
– Eutrophication
• Habitat fragmentation & disruption
– Channelizing rivers
– Draining wetlands
– Dams & Hydroelectric Power
Habitat fragmentation
& disruption
Draining wetlands
Habitat fragmentation & disruption
Dams & Hydroelectric Power
Low head dams
Hoover Dam
Wildlife corridor
Fish Ladder
SO….
What can be
done
about any of it???
Conserving Biodiversity
Use of natural resources
– Renewable vs nonrenewable resources
– Sustainable use – meeting needs now, while
allowing for full future use
Protecting Biodiversity
Keep what already naturally exists
– National Parks, nature preserves, public land,
biodiversity “hot spots”
– Build corridors between habitat fragments
Restoring Ecosystems
Re-introduction of species
Bioremediation
-Detoxify polluted area using living things
Biological augmentation
-Use of natural predators
Laws
Clean air act - 1970
Endangered species act
Clean water act
Clean Air Act
(1970)
Ozone, Particulate Matter,
Carbon Monoxide,
Nitrogen Oxides, Sulfur
Dioxide, Lead
Clean Water Act
(1972)
Endangered Species Act (1973)
Laws
Ways to reduce our
environmental impact:
• Slow population growth
• Use less resources and produce less waste
• Increase use of environmentally beneficial
technologies
• Phase out environmentally harmful
technologies
Fixing & Preventing Human
Impacts
• Recognize & take ownership
• Do SOMETHING about it!
– Personal decisions add up
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Think “big picture”
Ask questions
Look for/find solutions
“Vote” with your money
– Social change
– Governments, agencies & laws – VOTE!
• Conserve, protect & restore habitats
Individual Actions
• Simplify - Use less
Tragedy of the Commons
– Do you need that plastic bag?
– Could you walk there? Combine trips? Carpool?
• Re-use what you can…as long as you can!
– Is there a “recycled” version available?
– Use mugs, hand towels, canvas bags, etc.
– Think: recycled, recyclable, reliable, repairable,
refillable, and reusable
Recycling