Chapters 9, 10, 11 Environmental Science – A Study of Interrelationships

Renewable Energy
replenish themselves or are continuously present as a feature of the environment.
-solar, geothermal, tidal, wind, etc.
-they currently provide about 12% of the energy used worldwide, primarily from hydroelectricity and firewood.

Non-Renewable Energy
are those whose resources are being used faster than can be replenished.
-coal, oil, and natural gas

____ is most abundant fossil fuel.
Primarily used for generating electricity.
-Lignite, Sub-bituminous, Bituminous, and Anthracite (types)

Percent of world’s energy supplied by fossil fuels
Fossil fuels supply 80% of world’s commercial energy

-Chernobyl is a small city in Ukraine, north of Kiev.
-It is site of world’s largest nuclear accident, which occurred April 26, 1986.
-Experiments were being conducted on reactor, operators violated six important safety rules.
-They shut off all automatic warning systems, automatic shutdown systems, & emergency core cooling system for reactor.
-In 4.5 seconds, energy level of the reactor increased 2000 times.
-cooling water converted to steam and blew the 1102-ton concrete roof from the reactor, reactor core caught fire.
-took 10 days to bring the burning reactor under control.

Nuclear reactor
is a device that permits a controlled fission chain reaction.
-Nuclear power provides over 16% of the world’s electricity.

is the elimination of all the individuals of a particular species
-the natural rate is ~ 1 species every ten years
-current extinctions, & resulting loss of biodiversity, are a consequence of human activities

is a broad term used to describe the diversity of genes, species, and ecosystems in a region.

Risks of Extinction
-Organisms in small, restricted areas, such as islands.
-Environmental changes have large effect.
-Specialized organisms, relying on constancy of a few key factors.
Organisms at higher trophic levels, low population sizes and reproductive rates.

Invasive Species
chestnut blight, Asian beetle, Dutch Elm disease, Zebra mussel

Endangered Species Act
(1973) identifies threatened and endangered species in the U.S., and puts their protection ahead of economic considerations

Genetic Diversity
a term used to describe the number of kinds of genes present in a population.
-high genetic diversity indicates many different kinds of genes present in individuals of a population
-low genetic diversity indicates nearly all individuals share the same genes and therefore the same characteristics.

Influences on Genetic Diversity
-Mutations introduce new genetic information into a population by modifying current genes.
-Migration allows movement of genes from one population to another.
-Sexual reproduction generates new genetic combinations.

Causes of Extinction
habitat destruction, habitat fragmentation, introduced species, overexploitation of species, pollution, climate change

the conversion of arid and semiarid lands into deserts by inappropriate farming practices or overgrazing

Fish Farming
-much of the harvest is restricted to continental shelf where bottom-dwelling fish can be easily harvested
-Trawls are nets dragged along bottom disturbing the seafloor & causing habitat damage

About 25% of catch is undesirable & discarded, but they’re usually dead & their removal further alters ecological nature of seafloor

Solar Energy System Types
-Steam can be created to drive a turbine
-Photovoltaic cells can generate electricity directly

Photovoltaic cell
solid-state semiconductor that converts sunlight directly into electricity

*what is it, issues, direct combustion, and pyrolysis

Problems with Oil
*-difficult to find

Types of reaction in nuclear plant

Types of Diversity

Ecosystem Services

Wind Issues
-Some areas better suited than others, and winds are variable
-moving blades produce noise & some consider windmills visual pollution
-Moving blades hazardous to birds, though newer windmills have slower-moving rotors that many birds find easier to avoid
-Vibrations from generators can cause structural damage

Geothermal Energy
-In geologically active areas hot magma moves to the surface and heats water, hot water can heat buildings or generate electricity through a steam turbine
-Wells are drilled to obtain steam trapped underground, and the steam powers electrical generators
-U.S. produces 30% of world’s geothermal electricity, but accounts for less than 1% of U.S. electrical consumption

Threatened vs. Endangered
-Endangered species are those that have such small numbers that they are in immediate danger of becoming extinct
-Threatened species could become extinct if a critical environmental factor is changed

Habitat Management
-Modifications made to enhance the success of a species
Managing particular species requires understanding of habitat needs of that species
animal’s habitat must provide food, water, and cover (protects animals from the elements or enemies)
Game species often managed so they don’t exceed carrying capacity
High reproductive capacities & heavy protection have caused large populations to arise from once-rare animals

Wildlife Management
-Regulating hunting activity is an important population management technique
-When populations get too small, artificial introductions can be implemented
-Native species can be reintroduced to areas where they had been extinct
-Non-native species are introduced for empty niches

World Conservation Union estimates of threats from exotic species
-about 30% of birds and 15% of plants are threatened because they are unable to successfully compete against invasive exotic species

Causes of Loss of Biodiversity
-Many lumber companies maintain forest plantations as crops & manage them in same way farmers manage crops
-Plant single species, even-aged forests of fast growing hybrid trees
-Competing species are controlled by fire, and insects controlled by spraying.
-Low species diversity and wildlife value

a naturally occurring substance of use to humans that can potentially be extracted using current technology

a known deposit that can be economically extracted using current technology, under certain economic conditions
-reserves are smaller than resources
-reserve levels change as technology advances, new discoveries are made, and economic conditions vary

Lignite Coal
High moisture, low energy, crumbly, least desirable form.

Sub-bituminous Coal
Lower moisture, higher carbon than lignite.
Used as fuel for power plants.

Bituminous Coal
-Low moisture, high carbon content
-Used in power plants and other industry such as steel making.
-Most widely used because it is easiest to mine and the most abundant, supplying 20% of the world’s energy requirements.

Anthracite Coal
Has the highest carbon content, and is relatively rare.
It is used primarily in heating buildings and for specialty uses.

Surface mining (strip mining)
is the process of removing material on top of a vein, is efficient but destructive.

Underground mining
minimizes surface disturbance, but is costly and dangerous.
Many miners suffer from black lung disease, a respiratory condition that results from the accumulation of fine coal-dust particles in the miners’ lungs.

Problems with Coal
-Coal is bulky, causes some transport problems.
-Mining creates dust pollution.
-Burning coal releases pollutants (carbon and sulfur).
-Millions of tons of material released into atmosphere annually.
-Sulfur leads to acid mine drainage and acid deposition.
-Mercury is released into the air when coal is burned.
-Increased amounts of atmospheric carbon dioxide are implicated in global warming.

Problems with Nuclear
-Accidents have raised questions about safety.
-Use of nuclear material by terrorists.
-Concern about worker and public exposure to radiation.
-Weapons production.
-Contamination and disposal problems.
-There is no permanent storage facility, and many plants are running out of temporary storage.

forest harvesting method in which all the trees in a large area are cut and removed

Patchwork Clear-cutting
is clear cutting in small, unconnected patches; preserves biodiversity.

Selective Harvesting
is single species tree harvesting. It is not as economical, but reduces ecosystem damage.

-becoming increasingly important as a source of fish production.
-Currently, about 60% of all aquaculture production is from freshwater systems
-environmental impacts are similar to those of marine systems:
Nutrient overloads
Escape into natural waters
Land conversion