Renewable versus Non-Renewable Resources
Natural resources may be classified as renewable or non-renewable. Renewable resources are
thosethat canbe regenerated, whichmeansnew materialscan bemade orgrownagainat the
same rate as they are being used. For example, trees are a renewable resource because new
trees can be grown to replace trees that are cut down for use. Other examples of renewable
resources include soil, wildlife, and water. However, some resources, like soil, have very
slow rates of renewal, so we still need to conserve them. It is also important to realize that
while these resources are in most cases renewable, we can still pollute them, damage them
or over-use them to the point that they are not fit for use anymore. Fish are considered a
renewable resource because we can take some fish but leave others to reproduce and create
new fish for later use. Imagine, however, what can happen if we over-fish, or take too many
fish at one time. If we over-harvest our trees or wildlife resources, we may not leave enough
to let the resource renew itself.
Non-renewable resources are resources that renew themselves at such slow rates that, prac-
tically, they cannot be regenerated. Once we use them up, they are gone for good - or
at least for a very, very long time. Coal, oil, natural gas and minerals are non-renewable
resources. It takes millions of years for these materials to form, so if we use them to the
point of depletion, new resources will not be made for millions more years. We can run out
of these resources.
Common Materials We Use From the Earth
What do a CD, a car, a book, a soda can, a bowl of cereal, and the electricity in your home
all have in common? They are all made using natural resources. For example, a CD and
a soda can are made of metals that we mine from the Earth. A bowl of cereal comes from
wheat, corn, or rice that we grow in the soil. The milk on the cereal comes from cows that
graze on fields of grass. We depend on natural resources for just about everything that we
eat and use to keep us alive, as well as the things that we use for recreation and luxury. In
the United States, every person uses about 20,000 kilograms (40,000 pounds) of minerals
every year for a wide range of products such as cell phones, TV’s, jewelry, and cars. Table
20.1shows some common objects, the materials they are made from and whether they are
renewable or non-renewable.
Table 20.1:Common Object Natural Resources Used Are These Resources Re-
newable or Non-renewable?
Cars 15 different metals, such as
iron, lead, and chromium to
make the bodyNon-renewable