What are greenhouse gases (GHGs)?

15 January 2020

The most important GHGs are water vapour (H2O) and carbon dioxide (CO2). Other greenhouse gases include chlorofluorocarbons (CFCs), methane (CH4), nitrous oxide (N2O) and ozone (O3). While all GHGs are only present in the atmosphere as trace amounts, their effect is enormous: without the natural greenhouse effect, the earth’s average surface temperature would be only -18˚C instead of the current 15˚C.