For centuries, bloodletting was an accepted medical procedure administered by physicians to treat patients for most illnesses. In today's world, we find it almost inconceivable that such a practice was condoned by entire populations.
Similarly, the claim that increased carbon dioxide (CO2) in the atmosphere is causing "global warming" has been accepted as "fact" in many countries worldwide. This belief has no more scientific foundation than the bloodletting of past generations.
Atmospheric carbon dioxide may be gradually rising, but there is no compelling evidence that such a modest rise in CO2, which still comprises significantly less than 1 percent of the Earth's atmosphere, will have any substantial negative effect on the Earth's environment.
Scientists Ignored
Activists have successfully pressured governments to declare CO2 a pollutant and to take drastic measures to reduce the amount entering the atmosphere. By contrast, little publicity is given to the large number of qualified scientists who strongly contest the claims of the advocacy groups. These scientists contend that if CO2 plays any part in global warming, it is so insignificant that it can barely be measured, let alone be the major cause.
One rationale given for claims that Earth's recent, moderate warming is being caused by increases in atmospheric CO2 is the high surface temperature of Venus, which stands at approximately 472° C. Venus is an Earth-size planet that has a predominantly CO2 atmosphere.
| If the Earth’s Atmosphere Were a Football Stadium | ||
|---|---|---|
| Atmospheric Gas | Percent in Atmosphere | People in the Stadium |
| Nitrogen (N2) | 78% | 7,800 |
| Oxygen (O2) | 21% | 2,100 |
| Argon (A) | 1% | 100 |
| Carbon Dioxide (CO2) | 0.038% | 4 |
However, a comparison between Venus and the Earth's recent moderate increase in atmospheric CO2 is misleading, because there is 25,000 times as much CO2 in Venus's atmosphere as there is in the atmosphere of Earth.
CO2 Rare in Atmosphere
Earth's atmosphere is made up of several major gases. For simplicity, let us picture a football stadium with about 10,000 people in the stands. Assume each person represents a small volume of one type of gas. The approximate numbers of people representing the various types of gas are set out in the accompanying table.
Not included in the table is "water vapor," the amount of which varies in the atmosphere but probably averages about 2 percent at any point in time. Water vapor is the principal greenhouse gas and has more impact on global temperature than all other greenhouse gases combined.
Carbon dioxide is represented as only about 4 parts in 10,000, the smallest volume of any major atmospheric gas.
Moreover, those who name CO2 as a pollutant are not concerned with the 4 parts, but only with 1 part--the portion added during the past 150 years by the burning of fossil fuels. This 1/10,000 increase is the target of the Kyoto Protocol.
Oxygen More Important
After nitrogen, the second most common gas in the atmosphere is oxygen (O2), which is derived from CO2 through photosynthesis. In simple terms, photosynthesis is the process by which the leaves of trees and other plants take in CO2 from the atmosphere, retaining the carbon (C) for food while releasing the O2 back into the atmosphere. Some organisms in water also release free oxygen through this same process.
There was no free oxygen in the Earth's early atmosphere. Relatively late in the geologic history of the Earth, photosynthesizing organisms began to release oxygen. This has continued to the present, gradually changing the composition of the air to 21 percent free oxygen at the expense of CO2.
CO2 Now Historically Low
A thin veneer of sedimentary rocks blankets the Earth's surface and, along with ice cores from glaciers, can provide a reasonable geologic history of the Earth's past atmosphere. Scientific study of these rocks suggests the Earth's atmosphere in ancient times had considerably more CO2 than today.
Many experiments have demonstrated that the rate of plant growth is largely governed by the amount of CO2 in the atmosphere. As atmospheric CO2 increases, the growth rate of plants increases dramatically. Similarly, the plant growth rate decreases as atmospheric CO2 decreases.
Atmospheric carbon dioxide is the basic food for plants, and since plants provide the food for animal life (including humans), CO2 is the base of the food chain for all advanced life forms on Earth.
The present level of CO2 in the atmosphere is extremely low by historical standards. If atmospheric CO2 is significantly reduced, it is more likely that slower plant growth could affect world food supplies while having little effect on global warming. The life of all plants and animals on Earth is dependent on CO2 for food and oxygen.
Carbon dioxide is not a pollutant. It is the staff of life for our planet.
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