this is a very good source for the science of climate change
http://www.realclimate.org/index.php/archives/2007/05/start-here/
This is a good illustration of the various mechanisms in play
http://www.windows2universe.org/earth/Atmosphere/images/earth_rad_budget_kiehl_trenberth_1997_big.gif
Fossil carbon emissions has altered the radiative balance so it's getting warmer until it reaches a new balance point in t a warmer world....because carbon dioxide is so persistent in the atmospher ....the effect is cumulative.
