120 Chapter 5 Community and Environmental Responsibilities
Nonrenewable Energy Sources
Once current supplies of nonrenewable energy are used, no
further supplies are available. This is why fossil fuels are classifi ed as
nonrenewable resources. Because they have been so affordable for so long,
much of the world operates on fossil fuels.
These fuels are available in the liquid, gaseous, and solid states.
Crude oil, often just called oil, is unrefi ned petroleum. It is a dark, thick
liquid. Natural gas is a mixture of gases beneath the earth’s surface,
usually in petroleum deposits. Coal is the only solid fossil fuel.
Uranium ore is another nonrenewable energy source. It is used to
provide nuclear power that is converted into electricity. Supplies of this
energy source are limited and there are concerns related to the disposal
of radioactive waste.
Renewable Energy Sources
Sources of energy that can be replaced are called renewable energy
sources. These sources can produce additional supplies of energy in a
relatively short period. However, producing a large supply of energy
from these sources at an affordable cost may require more research and
investment. Energy can be produced from fi ve renewable sources—
water, wind, solar, biomass, and geothermal.
21st
Century
Skills
Innovation. Darnell is
committed to caring for the
environment. He leads the
environmental committee in
his workplace. Over the past
few years, the committee
has developed new ways
for the company to reduce
waste, increase recycling,
and conserve energy.
5-6
Dams generate a large
share of the country’s
electricity.