4.12 understand that water vapour, carbon dioxide, nitrous oxide, methane and CFCs are greenhouse gases

A green house gas is one that absorbs heat reflected by the earth, this heat is then trapped in the earth's atmosphere warming the earth. In large quantities these gasses can change the climate by keeping in too much heat. Gasses that do this include: water vapour, carbon dioxide, nitrous oxide, methane and CFCs.

A CFC is a compound that contains only carbon, chlorine, hydrogen and fluorine.