The burning of fossil fuels has brought about many harmful substances in the atmosphere. Global concerns over this particular problem are having some positive effects. Air quality has greatly improved in several parts of the world. CO and sulfur oxide levels are down in most cities. But the level of carbon dioxide and water vapor has been overlooked. Since about 90% of our energy comes from fossil fuels, a tremendous amount of carbon dioxide and water vapor being released in the air. These two compounds are natural components of our environment. Scientists are becoming alarmed over the possible long-term effects of their buildup in the atmosphere.
Both carbon dioxide and water vapor absorb infrared radiation (heat) given off by the earth. Similar to the function of glass or filter, allowing the sun's rays to enter the atmosphere but preventing the longer wavelength infrared radiation from leaving is called the "greenhouse effect." Water vapor plays less of a role in the greenhouse effect since water vapor quickly falls back to earth as rain. Carbon dioxide is practically absorbed by the oceans. Some is consumed in photosynthesis but about 50% remains in the atmosphere to affect the earth's climate. Some scientists predict that the doubling of carbon dioxide in the atmosphere will raise the average global temperature from 30 to 80 degrees Fahrenheit by the middle of next century.
Source: Phoenix Science Series - Chemistry by Estrella Elona Mendoza
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