Non-CO2 greenhouse gases in the atmosphere

Although global warming is generally Linked to increasing levels of carbon dioxide, there are many other gases produced from industrial, agricultural, and energy-generating sources that can also cause the Earth's temperature to rise. Individually these gases are not likely to make a significant contribution, but, taken together, it is believed that they can rival the effects of carbon dioxide. This paper reviews the current trends of the most abundant or the most effective of these non-CO2 greenhouse gases. Methane, nitrous oxide, and the major chlorofluorocarbons (F-11 and F-12) have been the most notable greenhouse gases other than CO2. Although these gases will continue to play a role in global warming, new compounds are likely to become increasingly important. These include the fluorocarbon replacement compounds in the hydrofluorocarbon and the hydrochlorofluorocarbon groups and gases that are nearly inert in the atmosphere, persisting for thousands of years, such as the perfluorocarbons and sulfur hexafluoride.