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 – Sea stars ecosystem – a single species that is extremely important to the survival of many other species Gene pool diversity – the different genes and traits in an • 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 (N 2 ), 21% Oxygen (O 2 ), 0.06% Carbon Dioxide (CO solid particles (particulates) 2 ) Also contains water vapor, gaseous pollutants, and

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 burning plants (sulfer oxides)  nitric acid and sulfuric acid • Gas pollutants come from car engines (nitrous oxide) and coal 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 (O 3 ) 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 Coal, Oil and Natural Gas cosmetics underground  takes millions of years to form Condensed hydrocarbons – contain stored energy • 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, • Natural Gas – a mixture of methane and other gases trapped – 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 Wind Energy needed  produce electricity • Soar cells – solar energy converted directly to an electric current • Passive (no fans) and active (fans needed) heating systems Advantages: no pollution; relatively cheap Disadvantages: need a steady supply of wind; lots of treadmills 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 cheaper than coal energy  produce electricity Advantages: clean form of energy (no air pollution); Disadvantages: produces radioactive wastes of time (Yucca Mountains); public opinion   need a place to safely store these waste products for long periods 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!