71 / 96
Other Natural Resources
People rely on many other natural resources.
There are renewable resources and
nonrenewable resources
.
Renewable resources are replaced as we use
them. We have investigated one important
natural resource, water. We know that water is
renewed all the time by the water cycle. Plants
and animals are also renewable resources. New
plants and animals are growing all the time.
We use them for food and shelter. Wood is
another example of a renewable plant resource.
When nonrenewable resources are used up,
they are gone. People use a lot of nonrenewable
natural resources as
energy sources
. Coal,
petroleum, and natural gas are energy sources.
These
fossil fuels
are the remains of plants
and animals that lived millions of years ago.
When Earth’s fossil fuels are used up, they
will be gone forever. No new fossil fuels are
“growing” at this time. The length of time
that we have fossil fuels can be extended by
conservation. People can conserve fossil fuels
by using more energy-saving products, like
high-mileage cars and better insulated homes.
Lumber is a renewable resource.
Petroleum and coal are
nonrenewable resources.
71