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INTRODUCTION
N
orth America has the largest coal reserves in the world. Most
estimates show that they will last for more than 200 years. But
coal’s role as a popular fuel in North America is changing.
One reason is that, when burned, coal is relatively “dirty.” It produces
more emissions, as gases and particles, than do natural gas or petroleum
fuels. The emissions include carbon dioxide, a major greenhouse gas
that contributes to the process of global warming. This is affecting the
whole Earth—its atmosphere, oceans, soils, plants, animals, and people.
In the United States, coal provides about one-fifth of all energy use,
mostly as electricity, but burning it produces one-third of all carbon
dioxide emissions. Burning coal also releases other polluting substances
as well as harmful
heavy metals
such as arsenic and mercury. All of these
substances have caused widespread environmental problems in the past.
The coal industry is trying to change with the times, however. The
latest coal-fired power plants are many times more efficient at turning
coal energy into electrical energy. They also use advanced technologies,
such as filters and carbon capture, to reduce pollution. And there are
new ways of using coal, such as converting it into gas and liquid fuels
and many other products. Supporters of coal say that it can be used in
new, more flexible and less polluting ways. They argue that it can provide
North America with a valuable, reliable, and plentiful natural resource
for centuries to come.
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