- The planet is earth, a body of considerable size with enough gravitational attraction to hold an atmosphere.

The atmosphere contains invisible gases, essential for life on the planet, and under certain conditions.

One of these gases leaves the atmosphere and comes to the surface.

Water is a natural resource of immense value to life.

It affects the earth itself and ultimately the human community.

The tons of water, the billions of gallons that fill our lakes, streams, rivers, and oceans periodically fluctuate at any one point on the earth's surface.

At times, the reservoirs are overflowing, and it seems we have far more water than is ever needed.

While this is part of a natural cycle, when too much water appears too quickly, the human community is often affected.

Flooding is normally a temporary problem to humans when too much water is unable to drain away fast enough.

In some locations, flooding is expected at certain times of the year.

It's part of the typical cycle.

There are a number of conditions that affect the amount of water that may be available at any one moment to a specific place.

One factor is the amount of solar energy that evaporates water from our lakes and other bodies where it may be stored.

Another consideration is the use of water by man.

When a sequence of hot, dry weather couples with relatively excessive water use by humans, the stage is set for a shortage.

In the course of one year, about 100,000 cubic miles of water evaporates from the earth's continents and seas.

That moisture will eventually return back to the earth, but not necessarily immediately back to where it evaporated.

In one instance, a car wash may be an ordinary event, but during a water shortage, it may be a luxury.

A shortage of drinking water is heavily influenced by the increasing number of ways that humans consume water.

And of course, when we waste it, the problem is only complicated.

Under normal conditions, a lot of water may seem wasted to us because it evaporates when we wish it would remain.

This reminds us that natural forces and cycles are at work, which affect the amount of water available.

We cannot afford to waste that usable water which is accessible to us.

So a set of conditions exist that make a certain amount of usable water available to humans, and if the balance of human use far exceeds that which is being provided, we suddenly become concerned over every drop of water.

During prolonged droughts, we become concerned for our lawns.

We become concerned for water in which we can bathe or drink.

We become concerned for the land, our crops, the food supply.

A severe water shortage affects our way of life and can even threaten large numbers of jobs.

A prolonged drought cracks the earth itself.

The mud pulls apart breaking into sections.

A water shortage as with flooding, is usually temporary.

The majority of the earth is covered with water, with tempered use by humans and greater imagination.

Perhaps this type of shortage can be eliminated in the future.

Another shortage involves the amount of space available.

A simple illustration.

New York City, Manhattan Island is a good example of a shortage of space in the slightly more than 30 square miles of Manhattan.

There are approximately one in one half million residences with countless others, daily migrating in and out of this congested borough.

The space shortage on the street level is alleviated partly by the buildings that reach upwards, sometimes more than 100 stories or levels.

The Empire State Building has put one of the thousands of tall buildings they extend across the Manhattan skyline.

In endless configurations, people are stacked up vertically because at the ground level, there are more than 60,000 people per square mile.

So a different type of life exists for those on the rooftops.

Should the human population continue to grow, we may have to continue to reach upwards, more densely packing people together.

The competition for space is far above the city streets.

Humans require a certain amount of space in order to be comfortable.

There are those that project space available to each human will continue to shrink if the population continues to expand.

What we see in a heavily populated city serves as a reminder of the need for space.

Another shortage.

Consideration involves a lack of food, a complex problem on a worldwide level.

- Hungry.

They're hungry.

They're hungry.

Some - The earth has an abundant but limited supply of resources.

If the human community plans well, there will be fewer shortages in the future.

Let us hope.

They are always temporary.