Question

what are the sources of the following:

carbon dioxide CO2
chlorofluorocarbons CFC's
ground level ozone

Answer 1

http://en.wikipedia.org/wiki/Carbon_dioxide_in_Earth%27s_atmosphere#Sources_of_carbon_dioxide

http://www.pollutionissues.com/Br-Co/CFCs-Chlorofluorocarbons.html#b

http://www.airqualityontario.com/science/pollutants/ozone.php