Page|11.NitrousOxide:TheThirdLargestGreenhouseGasinTheWorldEmissionsofnitrousoxide(N₂O),amajorGHG,aregainingincreasedattention.DatafromtheGlobalAtmosphericResearchEmissionsDatabase(EDGAR)indicatesthatglobalN₂Oemissionsin2023reachedapproximately2.5billiontonsofcarbondioxideequivalent(CO2e),accountingfor5%ofglobalGHGemissions.ThismakesN₂OthethirdlargestGHGaftercarbondioxideandmethane.1AlthoughN₂Oemissionsarerelativelylowercomparedtocarbondioxide,ithasastrongwarmingeffect,withawarmingpotentialofabout273timesgreaterthancarbondioxideovera100-yearperiod—andlongatmosphericlifespanofaround120years.2The2024globalN₂ObudgetalsorevealsthatN₂Oemissionsfromhumanactivitieshaveincreasedby40%between1980and2020.3Inaddition,researchshowsthat,withoutadditionalmeasures,N₂Oemissionsareexpectedtorisebyapproximately30%by2050comparedto2020.4Therefore,takingearlyactiontoreduceN₂Oemissionsisessentialtomitigateclimatechange.Inadditiontocontributingtoglobalwarming,N₂Oemissionssignificantlydepletetheozonelayer,increasinghumanexposuretoharmfulradiation.WhiletheMontrealProtocolhasmadesubstantialprogressinrestoringtheozonelayerbyregulatingmajorozone-depletingsubstances,N₂Oemissionsremainoutsideitsscope.Asaresult,N₂Ohasbecometheprimarygasesdepletingtheozonelayer.5TheUnitedNationsEnvironmentProgramme(UNEP)highlightedthisissueinits2022scientificassessmentofozonedepletion.ThereportfoundthatN₂Oemissions(usingCFC-11equivalent)fromhumanactivitiesbetween2016and2020weretwiceashighasglobalemissionsofCFCsin2020.6Furthermore,theseN₂Oemissionsareexpectedtodelaytheozonelayer’srecovery,underscoringtheneedfortargetedmitigationefforts.1Crippa,M.,Guizzardi,D.,Pagani,F.,Banja,M.,Muntean,M.,Schaaf,E.,Monforti-Ferrario,F.,Becker,W.E.,Quadrelli,R.,RisquezMartin,A.,Taghavi-Moharamli,P.,Köykkä,J.,Grassi,G.,Rossi,S.,Melo,J.,Oom,D.,Branco,A.,San-Miguel,J.,Manca,G.,Pisoni,E.,Vignati,E.,&Pekar,F.(2024).GHGemissionsofallworldcountries.PublicationsOfficeoftheEuropeanUnion.https://doi.org/10.2760/40028972TheGWPvaluesusedintheIPCCSixthAssessmentReportareusedhere3Tian,H.,Pan,N.,Thompson,R.L.,Canadell,J.G.,Suntharalingam,P.,Regnier,P.,...&Zhu,Q.(2023).Globalnitrousoxidebudget1980–2020.EarthSystemScienceDataDiscussions,2023,1-98.4ValerieVolcovici.(October31,2024).WorldwillmissParisclimatetargetasnitrousoxiderises,reportsays.Reuters.https://www.reuters.com/business/environment/world-will-miss-paris-climate-target-nitrous-oxide-rises-report-says-2024-10-31/5Alcamo,J.,&Bouwman,L.(2013).DrawingdownN₂Otoprotectclimateandtheozonelayer.UnitedNationsEnvironmentProgramme.6UNEP.(2023).ScientificAssessmentoftheOzoneLayerDepletion:2022.https://ozone.unep.org/system/files/documents/Scientific-Assessment-of-Ozone-Depletion-2022.pdfPage|2ReducingN₂Oemissionscanalsoofferadditionalenvironmentalbenefits,asnitrogenoxides(NOx),acommonairpollutantfromstationarysources,containsmallamountsofN₂O.LoweringN₂Oemissionsnotonlyhelpswithclimatemitigationbutalsocontributestoimprovingairqualitybyreducingphotochemicalsmogandminimizingsoilacidification.2.CurrentStatusandTrendsofN₂OEmissions2.1.GlobalN₂OEmissions:HumanActivitiesDrivetheIncreaseWhilenaturalsourcessuchassoil,oceans,andtheatmospherecontributetoglobalN₂Oemissions,thesedonotresultinsignificantatmosphericaccumulation,asnaturalsystemscangraduallybalancethemovertime.7ThecurrentriseinN₂O...
