The Effort Sharing Regulation (ESR) is the European effort sharing for the years 2021-2030. It covers the European Union, Norway, Iceland and Liechtenstein and the following greenhouse gases: carbon dioxide, methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons, sulphur hexafluoride and nitrogen trifluoride. Emission quantities under the ESR are calculated using global warming potentials from the Fifth IPCC Assessment Report.