"Carbon dioxide is an atmospheric gas comprised of one carbon and two oxygen atoms. A very widely known chemical compound, it is frequently known by its formula CO2. In its solid state, it is commonly called dry ice.

Atmospheric carbon dioxide derives from multiple natural sources including volcanic outgassing, the combustion of organic matter, and the respiration processes of living aerobic organisms; man-made sources of carbon dioxide come mainly from the burning of various fossil fuels for power generation and transport use. It is also produced by various microorganisms from fermentation and cellular respiration. Plants utilize carbon dioxide during photosynthesis, using both the carbon and the oxygen to construct carbohydrates. In addition, plants also release oxygen to the atmosphere, which is subsequently used for respiration by heterotrophic organisms, forming a cycle. It is present in the Earth's atmosphere at a low concentration and acts as a greenhouse gas. It is a major component of the carbon cycle."

Copyright 2006 Wikipedia

What is Dry Ice?

"Dry ice is pure, solid carbon dioxide (CO2). As a gas, CO2 exists naturally in our environment. To make dry ice, gaseous CO2 is first pressurized and refrigerated to form liquid CO2, and then liquid CO2 is allowed to expand in an atmospheric chamber where it yields snow-like CO2 and vapor CO2. The “snow” is then hydraulically pressed into dry ice blocks and dry ice pellets."

Copyright 2006 Continental Carbonic Products, Inc.