Definition: The greenhouse effect theory states that carbon dioxide (and other greenhouse gases) trap heat in the atmosphere similar to how glass traps heat within a greenhouse. Heat can enter, but cant escape.
From Christine & Scott Gable, for About.com
Stay safe and save time by following these tips before driving a used car. More >
Discover the hottest cars for the 2010 calendar year. More >
©2009 About.com, a part of The New York Times Company.
All rights reserved.