Thrawn Rickle 22

Greenhouse Effect

© 1993 Williscroft

The greenhouse effect is a very real atmospheric phenomenon that plays a significant role in everyday weather.

Our atmosphere is quite transparent to sunlight, except for ultraviolet which is absorbed in the upper atmosphere to form the ozone layer. Light reaching the surface generally is reflected or reradiated as infrared energy—what you feel radiating from warm pavement. The atmosphere is less transparent to infrared than to visible light, so it retains much of this reflected energy.

Two atmospheric gases are especially opaque to infrared: carbon dioxide and water vapor. Their presence in significant quantities dramatically affects global temperature.

Carbon dioxide is the end result of combustion. This is true whether you burn leaves, run an engine, or simply live and breathe. Wild fires are the largest natural source of carbon dioxide, although volcanoes and forests contribute measurably. Generating electricity by burning coal, oil, or gas is the largest man-made source of this gas, with automobiles a distant second. Water vapor in the atmosphere is always present, the amount dependent upon air temperature—the higher the temperature, the more water vapor.

Carbon dioxide in our atmosphere has increased due to man’s activities from as far back as scientists can measure. In recent times the increase has reached multiple exponential rates.

Researchers have created several mathematical models of our atmosphere. None of these is entirely accurate, but all allow relatively accurate predictions for specific phenomena. All clearly predict global temperature increases from increased atmospheric carbon dioxide, although each gives somewhat different results.

One thing is very clear. As the atmosphere warms, it will hold more water vapor, which directly contributes to the warming process. Each of the models predicts a point where global warming increases uncontrollably—like a snowball rolling downhill. Increasing water vapor causes global temperature to increase dramatically and rapidly, once the trigger point is passed. Since none of the models accurately predicts this trigger point, we cannot know how much carbon dioxide and water vapor will trigger this effect. It is clear, nevertheless, that once the effect is triggered, once global temperature begins to spiral upward uncontrollably, there is nothing humankind can do to stop it—at least nothing we know about today.

Oceanic models predict sufficient melting of polar ice when this happens to raise world-wide sea levels by as much as twenty feet. A glance at any globe will make it clear what kind of disaster would result from this.

Fortunately, we can do something about the upward spiral of carbon dioxide—the primary cause of the greenhouse effect. Since the principle source of this gas is the production of electricity by burning fossil fuel, we must cut down drastically on this method of producing electricity.

From the mid-fifties to the mid-sixties, new power plants world-wide were mostly nuclear power. During this period, the global increase of carbon dioxide was nearly halted. With the onset of world-wide movements (except for France and the Soviet Union) to limit nuclear power plants, carbon dioxide production resumed dramatically.

The solution is obvious. Until we develop efficient solar and fusion energy sources, we have no choice but to rely upon tried and tested nuclear power.