Akademik

greenhouse effect
  the name for the system by which the earth retains some insolation. One of the fundamental preconditions for the development of life. Without it temperatures would be too low for water to be anything other than ice, and organisms could not function. Insolation arrives at the atmosphere. A portion of it is reflected back to space or absorbed by water and solids in the atmosphere. About half reaches the surface and again a portion is simply reflected back to space. The rest is absorbed by vegetation or the surface. The energy that is absorbed by the surface is then radiated to the air and is held by the greenhouse gases
  carbon dioxide, methane, di-nitrogen oxide, CFCs and water vapour.
  http://www.ucar.edu/learn/1_3_1.htm

Geography Dictionary & Glossary for Students \\ ITS Tutorial School (ITS) - Hong Kong.