Kyoto Protocol European Union-15, made up of 15 states at the time of the Kyoto negotiations) commit themselves to binding targets for GHG emissions. The targets apply to the four greenhouse gases carbon dioxide (), methane (), nitrous oxide (), sulphur hexafluoride (), and two groups of gases, hydrofluorocarbons (HFCs) and perfluorocarbons (PFCs). The six GHG are translated into CO equivalents in determining reductions in emissions. These reduction targets are in addition to the industrial gases, chlorofluorocarbons, or CFCs, which are dealt with under the 1987 Montreal Protocol on Substances that Deplete the Ozone Layer. Under the Protocol, only the Annex I
Nitrous oxide production of nitric acid and adipic acid are the largest sources of nitrous oxide emissions. The adipic acid emissions specifically arise from the degradation of the nitrolic acid intermediate derived from nitration of cyclohexanone. Natural processes that generate nitrous oxide may be classified as nitrification and denitrification. Specifically, they include: These processes are affected by soil chemical and physical properties such as the availability of mineral nitrogen and organic matter, acidity, and soil type; as well as climate-related factors such as soil temperature and water content. The emission of the gas to the atmosphere is limited greatly by its consumption