Natural Resources

By Moira Whitehouse PhD

Which are renewable?

Which are nonrenewable?

Renewable resources are those that can be replaced in a short amount of time.

Nonrenewable resources are those that cannot be replaced in a short amount of time.

Let’s first look at what makes a resource renewable or nonrenewable.

Which of these natural resources can be replaced in a short amount of time and which cannot?

Let’s consider these natural resources: Rocks, animals, plants, soil, clean water, crude oil, coal, natural gas, oxygen in the air?

What about plants? They undergo a life cycle. Most produce seeds and are replaced every year. They can be replaced in short amount of time.Animals also reproduce through a life cycle. Some animals such as mice take a few weeks to form before being born. Others like elephants develop within their mothers for two years before they are born. A few weeks to two years is also a pretty short amount of time.

Water can never be made again but it can be “replaced” (cleaned) by nature. The main way nature cleans dirty water in through the water cycle.

The water that evaporates from the oceans and lakes generally returns to the land as precipitation within a few weeks—really a short amount of time.

When water evaporates, it leaves all the “dirty” stuff that was dissolved in it behind. As a result, the water that falls as rain, snow or sleet is pure clean water.

Now what about the oxygen in the air that we need to survive?

Plants take in carbon dioxide and replace it with oxygen in a very short period of time, probably seconds.

So far we established that animals, plants, oxygen and water can be replaced in a short amount of time.

Therefore, we can say that animals, plants, oxygen and water are alla. nonrenewable resources

b. renewable resources

Remember soil is formed through the weathering and erosion of rocks.

What about soil?

The United States Department of Agriculture says that it takes about 1,000 years to make an inch of soil.

One thousand years seems like a long time.

The three fossil fuels--crude oil, coal and natural gas--take millions of years to form from the remains of plants and animals.

Before we decide whether soil is a renewable or nonrenewable resource let us look at how long it takes for fossil fuels and the minerals in rocks to form.

millions

It appears that Earth was created from minerals that may have been formed billions of years ago when a “dying” star exploded. From these minerals we get many useful things like metals and sheet rock.

So although one thousand years seems like a long time, compared to millions and billions of years, it is a relatively short period of time.As a result, soil is considered a renewable resource—one that is replaced in a short period of time.On the other hand, minerals in rocks and fossil fuels would be considereda. renewable resourcesb. nonrenewable resources

About 1 thousand years to make one inch

So what are the natural resources that can be replaced in a relatively short amount of time ?

And what are the ones that cannot be replaced in a relatively short amount of time or at all?

About 1,000 years to make one inch

Notice that the renewable resources are all renewed through a cycle:

•plant life cycle•animal life cycle•water cycle•carbon-dioxide oxygen cycle•rock to soil back to rock cycle

Life cycle of an animalLife cycle of a plant

Carbon dioxide to oxygen back to carbon dioxide

Carbon dioxide and oxygen are part of the carbon cycle in which• plants take in carbon dioxide and give off oxygen and• animals take in oxygen and give off carbon dioxide

Rock to soil Soil to rock

Rock can be weathered and changed to soil.

Sometimes soil that is deposited in water can be changed into sedimentary rock.

Water cycle

Water in the oceans and lakes evaporates, condenses as clouds and falls back to Earth as rain, snow or sleet.

This is one way nature cleans our water.

library.thinkquest.org

So all of the renewable resources occur in cycles that allow them to be renewed in a relatively short amount of time—plants, animals, oxygen in the air, water and soil.

Place the resources in the correct category:coal, beans, copper, gold, cattle, naturalgas, soil, water, crude oil, oxygen.Renewable Resources Nonrenewable Resources

coalbeanscoppergold

cattle

natural gassoilwateroxygen crude oil

In conclusion, which of these is a true statement:

a. Everything we use comes from natural resources.

b. A few things we use come from natural resources.

c. Many things we use come from natural resources.

d. None of the things we use comes from natural resources.