You can conserve electricity (and thus fossil fuels) at home by turning off light bulbs and
appliances when they are not in use, using energy efficient light bulbs and appliances, and
even buying less stuff. All these actions reduce the amount of energy that power plants need
to produce.
There are many reasons for people in North America and Europe to try to reduce their
use of fossil fuels. As you have already seen, air pollution has tremendous health and
environmental costs. There are other reasons as well. Much of the oil we use comes from the
Middle East, which is a politically unstable region of the world. Also, fossil fuels are running
out, although some will run out sooner than others. The most easily accessible fossil fuels
are mostly already gone and harder to use or recover fuels are now being used. There are
other types of fossil fuels that can eventually replace coal and petroleum, such as tar sands
and oil shale. But these have even more environmental problems than traditional fossil fuels
have: mining them from the ground causes severe environmental damage and burning them
releases pollutants, including greenhouse gases.
Alternative energy sources are important. They currently are not a large part of the energy
supply, but they will increase rapidly over the coming years and decades. Several sources of
alternative energy, including solar and wind are not currently being used much because the
technologies are not well enough developed. Converting sunlight into usable solar power, for
example, is still very expensive relative to using fossil fuels. For solar to be used more widely,
technology will need to advance so that the price falls. Also, solar power is not practiced
in all parts of the United States because some areas get low amounts of sunlight. These
locations will need to develop different power sources. While the desert Southwest will need
to develop solar, the Great Plains can use wind energy as its energy source. Perhaps some
locations will rely on nuclear power plants, although current nuclear power plants have major
problems like safety and waste disposal.
Some pollutants can be filtered out of the exhaust stream before they are released into the
atmosphere. Other pollutants can be broken down into non-toxic compounds before they
are released. Some of these technologies will be described in the following sections.
Reducing Air Pollution from Vehicles
Reducing air pollution from vehicles can be done in a number of ways. Pollutants can be
broken down before they are released into the atmosphere. The vehicles can be more fuel
efficient. New technologies can be developed so that they do not rely on fossil fuels at all.
Motor vehicles emit less pollution than they once did due tocatalytic converters(Figure
22.12). Catalytic converters are placed on modern cars in the United States. These devices
reduce emissions of nitrous oxides, carbon monoxide and VOCs. Acatalyst speeds up
chemical reactions without being used up in the reaction itself. For nitrous oxides, the
catalyst breaks the nitrogen and oxygen atoms apart. The nitrogen then combines with
another nitrogen ion to form nitrogen gas (N 2 ) and the oxygen forms O 2. VOCs and CO are