Transcript AIR AND ENERGY RESOURCES

Global Environmental
Concerns
Chapter 3 (3.3 & 3.4); Chapter 5 (5.1 &
5.3); Chapter 6 (all)
Environmental Science Textbook
World Population
Calculate the rate of world population
growth
World Pop Clock Website
Analyze the graph of world population
growth
GRAPH
What are some of the problems?
Any solutions?
Technology
BIODIVERSITY
BIODIVERSITY – the number of different species in
an area
Bio – life; diversity – differences
The more biodiversity, the healthier, more stable the
ecosystem is
• High biodiversity – rainforests, coral reefs
• Low biodiversity – deserts, tundra, arctic, open/deep ocean
FACTORS AFFECTING BIODIVERSITY:
Area – how much space there is
Climate – rainfall and temperature are most important
• Rainforests vs desert climates
Niche Diversity – does the habitat allow for species to use it
in a variety of ways
• Coral reefs vs deep ocean
BIODIVERSITY
VALUE OF BIODIVERSITY
Economic – making money from living resources
• Medicines – taxol, foxglove
• Foods
• Building materials
Environmental – each species in an ecosystem is
interconnected
• Keystone species – a single species that is extremely
important to the survival of many other species
– Sea stars
Gene pool diversity – the different genes and traits in an
ecosystem
• More genetic differences, better able for species to adapt and
resist diseases, parasites, and drought
BIODIVERSITY
THREATS OF BIODIVERSITY:
Levels:
• Threatened – first warning level; population numbers
are declining, need to watch
• Endangered – second warning level; population
numbers are really low; could become extinct if nothing
is done to help
• Extinct – no living members of a population; once
extinct, can not recover
– Dodo bird, carrier pigeon
– Extirpated – no longer found in an area; can be
reintroduced because found in different areas
– Mountain lions, buffalo – currently extirpated
– Otters, fishers, elk – have been reintroduced
BIODIVERSITY
THREATS OF BIODIVERSITY
Causes of extinction:
• #1 – habitat loss
– Habitat destruction and habitat fragmentation
• Poaching
– Dian Fossey – Gorillas
• Pollution
• Introduction of exotic species
– Indigenous species (native) – naturally found in an area
– Exotic – species brought from one ecosystem to another
either by accident or on purpose
– Invasive species
– Gypsy moth, virginia creeper
– Nene Goose example (Hawaii)
– Austalia and Rodents
BIODIVERSITY
PROTECTING BIODIVERSITY
Captive Breeding
Reintroduction
Laws and Treaties
• Endangered Species Act of 1973
Habitat Preservation
• National parks, forests
Getting involved
• Personal decision making
• Lots of environmental organizations
AIR POLLUTION
Composition of Air:
Mixture composed of 78% Nitrogen (N2), 21%
Oxygen (O2), 0.06% Carbon Dioxide (CO2)
Also contains water vapor, gaseous pollutants, and
solid particles (particulates)
Air Pollution – a change to the atmosphere
that has harmful effects
Types of Air Pollution
•
•
•
•
•
Smog
Acid Rain
Global Warming
Destruction of the Ozone Layer
Indoor Air Pollution
AIR POLLUTION
Smog – combination of smoke and fog
Photochemical Smog – thick, brownish haze when
certain gases in the air react with sunlight
• Gases mainly come from cars and trucks
• Gases form ozone – a toxic gas
Temperature Inversion – a layer of warm air
prevents the pollution (smog) from rising above
the city
Problems include:
•
•
•
•
Itchy, watery eyes
Scratchy throat
Lung problems
Harms the body’s defense against illness
AIR POLLUTION
Acid Rain - a condition that arises when certain
gases in the atmosphere react with rain water,
turning it acidic
Nitrous and Sulfer Oxides + water  nitric acid and sulfuric acid
• Gas pollutants come from car engines (nitrous oxide) and coal
burning plants (sulfer oxides)
Lowers pH of rain water below its normal value
• pH – a scale that measures the acidity of solutions
• Acid – below 7; Neutral – 7; Base – above 7 (14 is highest)
• Unpolluted rain water is 5.2 (slightly acidic)  acid rain is
when the pH falls well below that level
Damages environment
• Can kill large areas of forests
• Releases heavy metals out of the soil
• Makes waterways unsuitable for aquatic life
• Can destroy certain materials in buildings and statues
AIR POLLUTION
Ozone Depletion
Ozone Layer – a layer of the atmosphere that
contains a small amount of ozone (O3) gas
• About 30 km above surface
• Absorbs ultraviolet (UV) radiation from sun
– Protect against sunburn and skin cancer
– Sunblock – SPF #
Ozone is recycled (see Figure 6, P. 145)
Chlorofluorocarbons (CFC’s) – molecules that react
with ozone, stopping it from being recycled
• Come from air conditioners, refrigerators, fire
extinguishers, aerosol cans
• Now CFC’s are banned in most countries
Large hole over Antarctica and Australia
AIR POLLUTION
Global Warming – the idea that certain pollutants in the
atmosphere are causing the temperature of the Earth to rise too
quickly
Greenhouse effect – certain compounds trap the heat entering the
Earth’s atmosphere
• Greenhouse gases
– Carbon dioxide
– Methane, water vapor, nitrous oxide, ozone
• Main Causes:
– Burning of Fossil Fuels
– Deforestation
Potential Consequences
• Dramatic changes in climate
• Coastal flooding – melting of polar ice caps
• Mass extinction – weather changing faster than organisms can adapt
NOT ALL SCIENTISTS AGREE THAT GLOBAL WARMING IS
HAPPENING!
• Natural and needed
• Geologic history of changes in temperature
AIR POLLUTION
Indoor Air Pollution
Allergens such as pollen, dander, dust
Cigarette smoke
Asbestos – used to be used as an insulator
• Associated with lung disease
• Carcinogenic – linked to causing cancer
• Has to be removed now in public buildings
Carbon Monoxide – CO
• Description: Colorless odorless gas
• Problem: Binds with blood cells that carry oxygen – keeps oxygen from
getting to body cells
• Source: when wood, coal, oil or gas are not burned completely
• Can by detectors to warn if levels get too high
Radon
• Description: colorless, odorless gas that is radioactive
• Problem: can cause lung problems and cancers
• Source: formed naturally by rocks underground; leaks in through
cracks in basements
• Can install ventilation units to keep Radon from building up
AIR POLLUTION
Solutions:
Emissions control
• Emissions – solid particles and gas that are released into the air
• Laws set up to limit what factories can put into the air
• Scrubber – using water to clean emissions before releasing into
atmosphere
• Catalytic converter – a device in cars and trucks that reduces
emissions of carbon monoxide, hydrocarbons, nitrogen oxides
– Forms less harmful carbon dioxide and water
CFC substitutes
General Conservation Practices
•
•
•
•
•
“Carbon Footprint
Reduse, reuse, recycle
Carpool, find alternative ways for transportation
Use less energy
Support agencies and organizations that are for protecting the
environment
Energy Resources
Energy – the ability to do work
Fuel – a substance that can provide a form of energy from a
chemical reaction (usually burning)
Fossil Fuels – energy rich substances formed from the remains
of once living organisms
Nonrenewable resource  takes millions of years to form
Condensed hydrocarbons – contain stored energy
Coal, Oil and Natural Gas
• Coal found in Reserves; mainly used to produce electricity
• Oil is a thick, black, liquid fossil fuel; Also called petroleum
– Refinery – a plant that changes crude oil into useful products
– Petrochemicals – compounds made from oil; plastics, paints, medicines,
cosmetics
• Natural Gas – a mixture of methane and other gases trapped
underground
– Large amount of energy, lower amount of air pollution
– Highly flammable, dangerous if there is a leak; naturally odorles but gas
companies put in a “gas smell” for safety
Energy Resources
Solar Energy – capturing and using energy from sunlight
Advantages: abundant supply that will not run out for billions of
years; does not cause pollution; each day, enough energy reaches
the Earth to supply the demands for 40 years
Disadvantages: not a constant supply (varies at night and cloudy
days); requires huge areas; expensive technology
Uses:
• Uses solar energy to heat water  produce electricity
• Soar cells – solar energy converted directly to an electric current
• Passive (no fans) and active (fans needed) heating systems
Wind Energy
Advantages: no pollution; relatively cheap
Disadvantages: need a steady supply of wind; lots of treadmills
needed
Hydroelectric Power – using flowing water to turn turbines
Advantage: no pollution; relatively cheap; steady supply
Disadvantage: Dams need to be created, damages existing
ecosystems
Energy Resources
Tidal energy – energy from the rise and fall of ocean tides
Advantages – no pollution; steady supply
Disadvantage – not many places suitable for this type of energy
Biomass fuels – burning once living materials or products from
living materials
Advantages: renewable resource
Disadvantage: expensive; still causes some air pollution
Gasohol – gasoline + alcohol (ethanol)
Geothermal energy – getting energy from heated magma below
the Earth’s suface
Advantages: constant supply
Disadvantage: need magma close to Earth’s surface to use it
Hydrogen Power – forming hydrogen gas and burning it for
energy
Advantage: found in water; burns cleanly
Disadvantage: hard to form and collect
Energy Resources
Nuclear Energy – releasing the energy stored in the
nuclei of atoms
Einstein theory of relativity – E = mc2
• Matter can be changed into energy (very large amounts of
energy)
• Nuclear fission – splitting an atom to release the energy
– Nuclear power and nuclear weapons
– Chain reactions split uranium-235 which cause other U-235 atoms
to split
– Energy released is used to heat water  produce electricity
Advantages: clean form of energy (no air pollution);
cheaper than coal energy
Disadvantages: produces radioactive wastes  need a
place to safely store these waste products for long periods
of time (Yucca Mountains); public opinion  threat of
meltdowns
• Three Mile Island and Chernobyl
Energy Resources
Nuclear Power Plants
Reactor vessel – special chamber where fission
reactions are performed
Fuel rods – rods of U-235
Contol rods – metal (cadmium) rods used to slow
reaction down to control how fast the energy is
released
Nuclear Fusion – the next step
Combining two atoms to form one bigger atom
• 2 hydrogen atoms come together to form 1 helium atom
The sun uses this type of energy
Very hard to perform on Earth
Energy Resources
Energy Conservation
Changing what individuals and companies do to help lower
the amount of energy needed
Use good conservation practices at home
• Turn out lights
• Use more efficient light bulbs – use fluorescent bulbs instead of
incandescent lights
• Car pool, public transportation, drive less, use cars with higher
gas mileage
• Make sure your home is well insulated and use heat and air
conditioning units less
• Recycle and used recycled goods
Although the actions of a single individual do not amount to
much, if millions of people practice this the effects can be
HUGE!