The greenhouse effect is a term used to describe a developing condition that is being brought about through the releasing of carbon dioxide and several other natural and man made gases into the Earth's atmosphere. As the term suggests, these gases are in effect building a "greenhouse window" around the Earth. The result of this is very much the same as building a greenhouse over your garden. The visible light that passes through the greenhouse windows is absorbed by "dark objects" and then re–radiated as "long wavelengths" of heat, which cannot readily pass out through the greenhouse windows.

A window is, in general, a substance that will pass some wavelengths of energy while absorbing or reflecting others. Wood and plastic act as a window for radio waves, which are essentially low frequency light energy. If this were not true, a radio or TV would not work inside your house without an outside antenna. So, even though you cannot see through a substance, it still could be a window for some part of the energy spectrum.

The term "greenhouse gases" has been given to a group of gases that function very similarly to the glass in a greenhouse. They allow visible light to pass through, but reflect back the longer wavelengths of heat energy. The result is the Earth is heating up. It doesn't take a very large change in temperature, only two or three degrees, to have a major effect on the Earth's atmospheric weather. Changes in rainfall patterns will be the first and perhaps the most noticeable result of the early stages of global warming that will occur in our lifetime.

We must remember that at one time in the Earth's history, there was NO OXYGEN in the Earth's atmosphere. It was only after millions of years of plant growth that the high levels of carbon in the atmosphere were replaced by oxygen. That "excess" carbon was buried in the earth by geological changes and is today trapped in coal, peat and oil deposits. Theoretically, if we were to find and burn all these deposits, we would use up all the oxygen in the atmosphere. But we don't have to worry about that, because we'll all be dead long before that could happen. When the level of carbon dioxide reaches about 0.3% in the atmosphere, all animal life will die on the planet.

It is just possible, however, that we won't need to worry about the carbon dioxide level reaching 0.3%. Another atmospheric problem may result in the death of all life on the land masses in the next few years. The Earth's radiation shield is being destroyed by another group of man made gases.

There is a very thin yet extremely effective layer of Ozone, a molecule made up of three atoms of oxygen, that exists at a very high altitude above the Earth's surface. This thin, fragile layer of gas acts as our only defense from the high energy particles sent our way from the sun. We must remember that our sun is, for all practical purposes, a sustained atomic explosion. X–rays, atomic particles, high energy ultraviolet radiation and other high energy particle forms capable of tearing apart organic molecules, are constantly being showered on our Earth. Life was possible on land only after millions of years of sea plant growth had released enough oxygen for this layer of ozone to form.

Today, our industry is producing a number of gases that are destroying our fragile "radiation shield". Some of these gases have already been banned, or their use restricted in this country. However, American–owned or controlled companies are still producing these gases for use in other countries. This is a global problem, and unless we think and act in a global manner, the death of this planet is assured. It is not enough to ban the use of a product in this country. We must ban the manufacture of any product destined for release into the atmosphere that shows a potential for disrupting our critical radiation shield, even if studies are not 100% complete.

We CURRENTLY have technology and methods perfected that would allow us to greatly reduce the impact of our lifestyle on the environment. Something as simple as using light–colored roofing material, when multiplied by billions of homes, will significantly reduce global warming by reflecting light energy back into space before it is converted to heat. Using the "waste heat" from refrigeration to heat water would cut our energy use by many millions of barrels of oil each year. The "simple silly" things will ultimately make the most difference. Improving traffic lights, light colored roads, planting trees, radial tires, better planned shopping trips, are all things that when repeated by billions of people will make a big difference. If we want this planet to be friendly toward us, we must make every BTU count and count every BTU.

The picture of the Earth below is about 5.75 inches in diameter. At this scale, each inch represents about 1,400 miles. The Earth's atmosphere is less than 70 miles thick, about 0.05 inch on our scale. However, man can only survive without special breathing equipment a scant four miles up. Above that, the air is too thin to sustain us. On the scale of our globe, that results in a usable layer of air about two thirds the thickness of this sheet of paper. Our atmosphere, indeed, is a very thin and precious asset. Our asset, once despoiled, possibly could require centuries to repair.

In conclusion, the main reason there is life on Earth and not on the moon is that Earth has a large enough gravitational field to hold an atmosphere. A very thin and fragile atmosphere. The moon's soil is very fertile, but without the protection the atmosphere provides and the weather it manufactures, life is impossible there. Our atmosphere then, is the only thing between us and extinction. We'd better love and respect it!