10. Greenhouse gases carbon dioxide (CO 2 ) – burning coal, oil and gas for energy, transport and heat nitrous oxide (N 2 O) – waste disposal sites, agriculture and cattle methane (CH 4 ) hydrofluorocarbons (HFCs) perfluorocarbons (PFCs) sulphur hexafluoride (SF6) – used in fridges, air-conditioning and even shoes