CHAPTER 4 NOTES
EARTH’S NATURAL RESOURCES
RENEWABLE AND NONRENEWABLE
RESOURCES
• Renewable resources can be replenished over a
fairly short period of time. Examples include plants,
animals, water, wind and sun.
• Nonrenewable resources take a long period of time
to replenish and it is not practical to assume they
can be replenished in enough time to be used
continuously without exhausting their supply.
• Examples of nonrenewable resources include coal,
oil, natural gas, gold, copper, minerals etc.
FOSSIL FUELS
• Fossil fuels are hydrocarbons that are used as a
source of energy.
• Examples include coal, oil, and natural gas.
• Nearly 90% of the energy used in the United States
comes from fossil fuels.
• Fossil fuels are relatively cheap.
• Fossil fuels are nonrenewable.
• The by-products of fossil fuels (carbon dioxide, sulfur
dioxide etc.) can cause pollution.
FOSSIL FUELS
SOLAR ENERGY
• Solar energy is the direct use of the sun’s rays to
supply heat or electricity.
• Advantages of solar energy is that it is free,
renewable, and non-polluting.
• Disadvantages of solar energy is that installation of
the technology needed to gather solar energy is
expensive and solar energy is not always reliable
because of the availability of sunlight.
SOLAR ENERGY
NUCLEAR ENERGY
• Nuclear energy is the use of exothermic nuclear
processes to generate useful heat and electricity.
• If it could be controlled responsibly and safely it
would be a much more efficient way of obtaining
energy than using fossil fuels.
• Pound per pound nuclear energy contains much
more energy than fossil fuels.
• It can be dangerous and the waste products
produced by nuclear energy are hazardous.
NUCLEAR ENERGY
WIND ENERGY
• Wind energy is the conversion of energy
generated by the wind into useful energy
through the use of a wind turbine.
• Advantages is that it is free, non-polluting,
and renewable.
• Disadvantages is that the technology
required is expensive, it requires large tracts
of land, it can be harmful to wildlife (birds
mostly), it is not always reliable, and they
can generate lots of noise.
WIND ENERGY
HYDROELECTRIC POWER
• Hydroelectric power is the power generated by
falling water that turns a turbine which generates
electricity.
• Water is a renewable resource, but the dams built
to harness the hydroelectric power have a limited
lifetime. Dams fill in with sediment.
• Dams can also have a dramatic effect on wildlife.
HYDROELECTRIC POWER
GEOTHERMAL ENERGY
• Geothermal energy is harnessed by tapping natural
underground reservoirs of steam and hot water
produced by hot magma.
• The hot water can be used directly for heat and
also the heat produced can be used to turn a
turbine that generates electricity.
• Geothermal energy is free and non-polluting, but
unfortunately it is not renewable. Eventually,
geothermal energy sources are exhaustible.
GEOTHERMAL ENERGY
TIDAL POWER
• Tidal power is harnessed by constructing a dam
across the mouth of a bay or an estuary in coastal
areas with a large tidal range.
• The strong in and out flow generated by the tides
drives turbines and electric generators.
• You need an area with a strong enough tide for
tidal energy to work.
TIDAL POWER