1300 Chapter 12 - Human Impact

Ecology

• The study of how organisms interact with one another and their environment
• Human construction of the Cultural Environment
• Began with the earliest hunter-gatherers
• Burning of areas
• Planting beneficial plants
• Modifying the landscape
• Took off with Agriculture
• Furthered with urbanization

Biosphere

• The earth and the atmosphere in which we live.
• Composed of three interrelated parts
• Troposphere – lowest layer of the Earth’s atmosphere
• Hydrosphere – surface and subsurface waters
• Lithosphere/Earth’s Crust – the upper few thousand feet
• Functions with two interrelated components
• Outside energy source – the Sun
• Living world of plants and animals

Ecosystems

• Self-sustaining units of the Biosphere which consist of all the organisms and physical features existing together in a particular area.
• Everything is interconnected
• Modification of one niche affects every other niche

Food Chain

• A sequence of organisms through which energy and materials move within an ecosystem

Environmental Pollution

• Introduction into the biosphere of wastes that cannot be readily disposed of by natural recycling processes.
• Point Sources
• Pollution enters from a specific site
• Non-point Sources
• Pollution is expelled from a more diffuse and widespread source

Impact on Water

• Hydrologic Cycle
• The system through which water cycles though the biosphere
• Cycle tends to purify the water

Availability of Water

• Regional variation as to access to water and reliability of water resources
• Rain and snow fall
• Rivers and lakes
• Subsurface aquifer
• Size of Population dependent upon water
• Personal use and agricultural use
• 70-90% of water use if for agriculture
• Scarcity
• Increasingly used to discuss available water resources for humans and agriculture
• Water Deficit
• Consuming more water than your annual renewable supply
• Generally associated with groundwater aquifers
• Texas – operates a major water deficit
• Desalination
• Cleansing of sea water of salts and minerals for use by humans
• Expensive and inefficient

Modification of Streams

• Prevent flooding, regulate supply, generate power
• Channelization
• Construction of embankments and dikes
• Straightening, widening, and deepening of channels
• Decrease of wetlands and species
• Dam Construction
• Artificial impediment to water flow
• Water storage for individual use and irrigation
• Prevent flooding
• Canals
• Reservoirs

Water Quality

• Agriculture is the chief cause of water pollution

Agricultural Sources of Water Pollution

• Fertilizers
• Nitrates and phosphates from manure and artificial fertilizers
• Eutrophication – enrichment of waters by nutrients
• Accelerated Eutrophication – from fertilizers
• Stimulates growth of algae and other plants
• Blocks sunlight and oxygen
• Creation of Dead Zones in the oceans
• Biocides
• Herbicides and pesticides
• DDT
• Long term presence in the environment
• Unknown long term affects of even small amounts in humans and animals

• Animal Wastes
• Spreading of manure on farmland and from contamination from waste pools.
• Dead zones in oceans
• Contamination of food products with animal waste

Industrial Sources of Water Pollution

• Equal to agriculture in industrialized nations
• Acids, toxic minerals and organic chemicals, radiation
• Mercury – from power plants
• PCBs – found throughout the manufacturing and industrial process
• Plastics
• Petroleum Industry
• Toxic organic chemicals
• Direct release of oil into the environment
• Acid Rain
• Power plants
• Thermal Pollution
• Discharge of heated water into the environment

Mining

• For coal and other minerals
• Contamination of groundwater and surface water
• Cyanide and mercury for gold mining
• Strip mining and mountaintop mining

Municipalities and Residences

• Uses of chemicals
• Storage tanks
• Waste sewage
• Storm water runoff

Impact on Air and Climate

• Air Pollutants
• Carbon dioxide, carbon monoxide, hydrocarbons, nitrogen oxides, particulates, sulfur oxides

• Factors Affecting Air Pollution
• Temperature inversions
• Stationary layer of warm air above cooler air
• Air does not move and pollutants accumulate
• air currents
• move pollutants from their source to downwind areas
• levels of urbanization and industrialization
• High population and transportation densities increase pollution
• Types and locations of industry
• Agricultural practices – field burning
• Acid Rain (Precipitation)
• Sulfuric and Nitric Acid
• Produced by burning fossil fuels
• Vehicles, industries, power plants, metal smelting
• Carried hundreds of kilometers by air currents
• Increases the acidity of the area where it falls
• Terrestrial Effects
• Acidifies soil
• Coats soil with toxic metals
• Kills microorganisms and plants
• Aquatic Effects
• Kills microorganisms, plants, and insects
• Interferes with fish reproduction and feeding
• Material Effects
• Damage to buildings and monuments
• Photochemical Smog
• Nitrogen oxides – Ozone
• Assisted by hot and sunny weather
• Generally an urban problem
• Causes lung damage and ailments
• Significant increases in asthma in children
• Damage to plants
• Depletion of Ozone Layer
• Forms blanket in upper atmosphere
• Protects earth from solar radiation
• Can be destroyed by a variety of industrial chemicals
• Ozone depletion over entire earth
• Hole over the Antarctic
• Increases in skin cancers in humans
• Destruction of oceanic algae
• Damage to other plant life

Controlling Air Pollution

• Montreal Protocol of 1987
• To reduce and eliminate CFC’s
• Still a problem in developing nations
• 1979 Convention on Long-Range Transboundary Air Pollution
• 33 countries in Europe and the Americas
• To reduce Acid Rain and Smog and Ozone
• U.S. Clean Air Acts (1963, 1965, 1970, 1977, 1990)
• Reduce urban smog by limiting allowable levels of particulates and ozone
• Promote cleaner burning fuels
• Lower emissions from vehicles
• Reducing acid rain causing emissions from power plants
• Strategies
• Improved technologies for fossil fuel usage
• Reduce energy consumption
• Reduce emissions from motor vehicles

Impact on Landforms

• Excavation (tell story about silver city bars, closing time, dogs…)
• Surface/Open Pit Mining
• Strip Mining/Montaintop Removal
• Pits, ponds, canals, reservoirs, etc.
• Dumping
• Mining – spoil heaps/slag heaps
• Agriculture
• Dredging and dikes
• Surface Depressions
• Subsidence
• From removal of liquids
• Sinkholes and pits
• From removal of solids

Impact on Plants and Animals

• Endangered Species
• Immediate jeopardy of becoming extinct in the wild
• Vulnerable Species
• Decreasing population – likely to be come extinct
• Threatened Species
• Refer to both endangered and vulnerable species
• Extinction
• Species no longer exists
• Habitat Disruption
• Main threat to species
• Agriculture, mining, logging, urbanization
• Hunting and Commercial Exploitation
• Ivory, trophies, medicinal, sport
• Over fishing
• Exotic Species
• No native predators
• Out-compete and replace native species
• Killer/Africanized Bees, Gypsy Moth, Tiger Mosquito, Zebra Mussels, Sparrows, Honey Bees
• Poisoning and Contamination
• Biological Magnification – the accumulation of poisons in an organism and its concentration at higher levels in the food chain.
• Highest levels in the top predators
• Increasing resistance to chemicals
• Antibiotics
• Biocides

Solid-Waste Disposal

• Municipal Waste
• Mainly domestic waste with some commercial
• Affluence
• Disposable society
• Americans worst at waste
• Packaging
• For all of the disposable waste
• Open Space
• Does not force recycling and reduction
• Hazardous Waste
• Poses threat to human health and/or the environment
• Household chemicals
• Electronic devices
• Landfills
• 71% of all U.S. Municipal Waste goes into landfills
• Great threat of groundwater contamination
• Incineration
• Burn it
• Emissions contain many pollutants
• Toxins, heavy metals, sulfides, etc…
• More favored in Japan and Europe
• Source Reduction and Recycling
• Producing less waste
• Reduce weigh of packaging
• Concentrate materials
• Recovery and reprocessing of used materials
• Requires lower cost to recycle than discard
• Impoverished work forces in 3^rd World Countries

Hazardous Waste

• More than 400 substances classified as hazardous by EPA
• Categories of Hazardous Waste
• Ignitable wastes – catches fire easily
• Corrosive wastes – acids or bases which will corrode metal containers
• Reactive wastes – unstable and can cause explosions, toxic fumes, gases, or vapors when heated, compressed, or mixed with water.
• Toxic waste – chemical or metal toxins
• Low-level waste
• Decays in less than 100 years
• Commonly found in landfills
• Major threat to groundwater and health
• High-level waste
• Can remain radioactive for over 10,000 years
• Civilian and military nuclear programs
• Disposal of hazardous waste
• Buried sealed containers
• Dumping at sea
• Exporting to other countries
• Resource Conservation and Recovery Act (1976)
• Early regulation on hazardous waste
• Track waste from entrance through disposal
• Superfund Site
• 1240 sites +/-