[1]Y blynyddoedd sylfaen ar gyfer allyriadau nwyon tŷ gwydr yw: 1990 ar gyfer carbon deuocsid, methan ac ocsid nitrus; 1995 ar gyfer y nwyon wedi’u fflworeiddio.
[1]Base years for UK greenhouse gas emissions are: 1990 for carbon dioxide, methane and nitrous oxide; 1995 for the fluorinated gases.