tion. (Elrod, 1999) A third major greenhouse gas is nitrous oxide. Its main sources are biomass burning, and combustion of fossil fuel. Nitrous oxide is not as much of havoc to our atmosphere as carbon dioxide and methane, but still plays an important role in the warming of the earth. Other greenhouse gases that aren't nearly as present in our atmosphere but play a major role in the warming effect are chlorofluorocarbons (CFCs). Industrial processes also generate these gases when byproducts of foam production, refrigeration, and air conditioning are released. What makes the chlorofluorocarbons important is their strength and longetivity. These gases can be thousands times stronger than carbon dioxide, and stay within the atmosphere before being chemically broken down for over a hundred years. There are no sinks for these greenhouse gases, so chemical reactions are the only way for them to disappear. The steps below show how they are broken down, and the destruction of ozone (O3) along with it. This also is a negative effect of CFCs when they destruct our ozone layer. Step 1 "Photolysis" (splitting by sunlight) of CFCs in the stratosphere Cl2CF2 + UV light --* ClCF2 + Cl Step 2 Catalytic destruction of ozone Cl + O3 --* ClO + O2 ClO + O3 --* Cl + 2O2 Bibliography REFERENCES: Website: http://www.biospherics.org Website: http://www.agu.org/sci_soc/policy/climate_change.html Website: http://www.epa.gov/ghginfo/questions.htm Website: http://www-personal.umich.edu/~ssandhu/clarkghg.html International Journal of Life support & Biosphere Sciences (1997) 4, (RAS Collection) Word Count: 1148 ...
