440 CHAPTER 17 Nonrenewable Energy Resources
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contains almost no sulfur and produces less CO 2 and other
pollutants compared to oil and coal.
Summary
1
Energy Consumption 420
- The per person energy consumption in highly developed
nations is eight times higher than that in developing nations.
However, highly developed countries consume less total
energy than do developing countries. Experts expect total
energy use in developing countries to grow rapidly in the
coming decades, but to plateau in highly developed countries.
2
Coal 421
- Surface mining is the extraction of mineral and energy
resources near Earth’s surface by first removing the soil, subsoil,
and overlying rock strata. Subsurface mining is the extraction
of mineral and energy resources from deep underground
deposits. Surface mining is less expensive and safer but causes
more serious environmental problems than subsurface mining. - Coal mining can lead to landslides and can pollute streams
with sediment and acid mine drainage, when sulfuric acid
and dangerous dissolved materials such as lead, arsenic,
and cadmium wash from coal and metal mines into nearby
lakes and streams. In mountaintop removal a huge shovel
removes an entire mountaintop to reach coal located below.
Burning coal releases more CO 2 and contributes more
extensively to global climate warming than does producing an
equivalent amount of energy by burning other fossil fuels. The
combustion of coal contributes to acid deposition, in which
acid falls from the atmosphere to the surface as precipitation
or as dry acid particles. - Power plants can make coal a cleaner fuel by installing
scrubbers to clean the power plants’ exhaust. Fluidized-bed
combustion is a clean-coal technology in which crushed
coal is mixed with limestone to neutralize the acidic sulfur
compounds produced during combustion.
3
Oil and Natural Gas 423
- More than half of the world’s total estimated oil and natural
gas reserves are located in the Persian Gulf region. - A serious spill along an oil transportation route creates an
environmental crisis, particularly in aquatic ecosystems.
The burning of oil and natural gas produces CO 2 that can
contribute to global climate change. Burning oil also leads
to acid deposition by producing nitrogen oxides. Natural gas
✓✓THE PLANNER
4
Nuclear Energy 430
- Nuclear energy is the energy released by nuclear fission
or fusion. A nuclear reactor is a device that initiates and
maintains a controlled nuclear fission chain reaction to
produce energy for electricity. A typical reactor contains
a reactor core, where nuclear fission occurs; a steam
generator; a turbine; and a condenser. - Generating electric power through nuclear energy emits
few pollutants (such as CO 2 ) into the atmosphere compared
to the combustion of coal but generates highly dangerous
radioactive waste, such as spent fuel, the used fuel elements
that were irradiated in a nuclear reactor. - As evidenced at Chernobyl and Fukushima Daiichi, accidents
at nuclear power plants can release dangerous levels of
radiation into the environment and result in human casualties.
The safe storage of radioactive wastes is another concern
associated with nuclear energy. Low-level radioactive
wastes are radioactive solids, liquids, or gases that give off
small amounts of ionizing radiation. High-level radioactive
wastes are radioactive solids, liquids, or gases that initially
give off large amounts of ionizing radiation. Radioactive
wastes must be isolated securely for thousands of years. One
option for the retirement of an aging nuclear power plant is to
decommission it by dismantling it after it closes.