When discussing the topic of climate change, it is essential to begin with a brief definition of climate change to know exactly what it is; globalissues.org defines climate change as “an increase in average global temperatures caused by the increase in greenhouse gasses such as Carbon Dioxide, or CO2”. This process, of course, is global warming which, in turn, leads to climate change. Although, climate change is considered one of the most significant threats facing the world today, there are many groups doing what they can to assist in slowing the climate change process or potentially halt it all together.
Even the carbon dioxide theory is not new; the basic idea was first precisely stated in 1861 by the noted British physicist John Tyndall. He attributed climatic temperature changes to variations in the amount of carbon dioxide in the atmosphere. According to the theory, carbon dioxide controls temperature because the carbon dioxide molecules in the air absorb infrared radiation. The carbon dioxide and other gases in the atmosphere are virtually transparent to the visible radiation that delivers the sun’s energy to the earth. But the earth in turn reradiates much of the energy in the invisible infrared region of the spectrum. This radiation is most intense at wavelengths very close to the principal absorption band of the carbon dioxide spectrum. When the carbon dioxide concentration is sufficiently high, even its weaker absorption bands become effective, and a greater amount of infrared radiation is absorbed. Because the carbon dioxide blanket prevents its escape into space, the trapped radiation warms up the atmosphere.
A familiar instance of this “greenhouse” effect is the heating-up of a closed automobile when it stands for a while in the summer sun. Like the atmosphere, the car’s windows are transparent to the sun’s visible radiation, which warms the upholstery and metal inside the car; these materials in turn re-emit some of their heat as infrared radiation. Glass, like carbon dioxide, absorbs some of this radiation and thus traps the heat, and the temperature inside the car rises.
Water vapor and ozone, as well as carbon dioxide, have this effect because they too absorb energy in the infrared region. But the climatic effects due to carbon dioxide are almost entirely independent of the amount of these other two gases. For the most part their absorption bands occur in different regions of the spectrum. In addition, nearly all water vapor remains close to the ground, while carbon dioxide diffuses more evenly through the atmosphere. Thus throughout most of the atmosphere carbon dioxide is the main factor determining changes in the radiation flux.
Meanwhile, the carbon dioxide content of the oceans will have doubled. This raises an incidental question about the welfare of sea organisms. We know that an increase in carbon dioxide concentration increases the acidity of water, and that many marine animals are extremely sensitive to changes in acidity. But if carbon dioxide is the most important factor, long-term temperature records will rise continuously as long as man consumes the earth’s reserves of fossil fuels.
