GLOBAL AIR POLLUTION M...1 GLOBAL AIR POLLUTION MAP: RANKING THE WORLD’S WORST SO 2 AND NO2...

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GLOBALAIRPOLLUTIONMAP:RANKINGTHEWORLD’SWORSTSO2ANDNO2EMISSIONHOTSPOTS

LauriMyllyvirta,leadanalyst,GreenpeaceGlobalAirPollutionUnit19March2019

SUMMARYGreenpeace’s updated analysis of a full year of TROPOMI NO2 satellite data and other scientific datasetsconfirmsthatthecoal-firedpowerplantandindustrialclusterinMpumalangaistheworld’sworsthotspotforpowerplantNO2andSO2emissions,andoverallranks4thforNO2and3rdforSO2emissionsintheworld.It is theonlyplace in theworld that ranksamong the top five forbothof thesedangerouspollutants.ThefindingiscorroboratedbyanalysesbyNASA,Netherlandsmeteorological instituteKNMIandEskom’sownpublishedemissionsdata.

Thesatellite-basedidentificationofhotspotsisaproxyforemissionsratherthanlocalground-levelpollutantconcentrations.ThevastvolumeofSO2andNOxemissionsfromMpumalangaaffectshealthoveralargearea,includingtheneighboringGautengCityRegion.SO2andNOxareconvertedthroughchemicalprocessesintoPM2.5,theairpollutantwiththelargestpublichealthimpact.

With PM2.5 air pollution causing the premature deaths of over 20,000 South Africans every year, it isessentialforthecountry’sdecision-makerstorequireEskom,Sasolandothermajorpollutersintheareatocomplywiththecountry’sMinimumEmissionStandards(MES).

INTRODUCTIONItisestimatedthatambientPM2.5airpollutioncaused3.4milliondeathsworldwidein2017andover20,000inSAeveryyear1.SO2andNOxemissionsfromtheburningofcoalandoilarethekeysourcesofthispollution.

ThelargestconcentrationofemittersinAfricaistheHighveld/MpumalangaregioninSouthAfrica(SA),just100-200km fromtheGautengCityRegion, the largestpopulationcenter inSA, implying theriskofmajorpublichealthdamage.

AGreenpeacerankingbasedonthreemonthsofdata,fromJunetoAugust2018,hadfoundthatMpumalangahadthehighestatmosphericNO2levelintheworldoverthisperiod,makingitoneoftheworsthotspotsofNOxemissionsintheworld.Afterthepublicationofthisranking,afullyearofNO2data,fromFebruary2018onwards,hasbecomeavailable,asESAhasprocessedandreleaseddataretrievedbeforeJune.

Based on a similar approach Greenpeace has for the first time also identified and ranked SO2 hotspotsglobally.

1 Stanaway JD et al., 2018. Global, regional, and national comparative risk assessment of 84 behavioural,environmental and occupational, andmetabolic risks or clusters of risks for 195countries and territories,1990–2017: a systematicanalysis for theGlobalBurden ofDisease Study2017. Lancet 392(10159):1923-1994.https://doi.org/10.1016/S0140-6736(18)32225-6

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UPDATEDMETHODOLOGYWithafullyearofdata,fromFeb2018toJan2019,moresystematicvalidationispossible.

WehavevalidatedthecomparisonofNOxemissionssourcesagainstmonthlyNO2emissionsdataforalllargepointsourcesintheU.S.A–thisistheonlysetofemittersforwhichhigh-qualitymonthlyemissionsdataisavailableinnear-realtime.Webuiltaregressionmodelthattakesintoaccountaveragemonthlywindspeeds,temperaturesandbackgroundNO2 concentrationsaround the emission source to quantifyemissions. TheemissionsdatasetstretchesthecontinentandtheperiodFeb-Dec2018,coveringawiderangeoftemperatureandwindconditions.

Afterapplying theregressionmodel to theglobalgriddeddataset togetpredictedNOxemissions foreachpointinthegrid,weidentifythelargestemissionhotspotsintheworldusingadiameterof50km.Choosingaspecificradiusisinevitablyarbitrarytoanextent,butatthesametimethisapproachismoreconsistentandobjective than ranking based on country or provincial boundaries. The group of the ‘top 10’ of largestpolluters presented here is largely unchanged using any diameter from 25 to 100km, with the orderingchanging.

FULL-YEARRANKINGOFNO2HOTSPOTSTheupdatedfull-yeardataputsthepowerplantandindustrialclusterinMpumalanga,centeredonNkangala,at the fourth spot in theworld, after Tehran and Dubai, twoMiddle Eastern locationswith very high oilconsumptioninpowerplants,industriesandtransport,andSeoulinSouthKoreawithalargeconcentrationoftransportandindustrialemissions.TheselocationshadveryhighseasonalitywithhigherNO2levelsinthenorthern hemispherewinter, and consequently rank lower in the southern hemispherewinter, when theoriginalanalysiswasmade.

Mpumalanga remains the highest-emitting non-urban and the highest-emitting power plant hotspot in theworld,atparwiththeSonbhadracoalminingandpowerplantclusterinIndia,accordingtothefull-yeardata.

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PerformanceofTROPOMI-basedemissionsestimatesagainstU.S.EPA-reportedemissionsforlargepointsources,Feb-Dec2018.

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RANKINGSO2HOTSPOTSGreenpeace analysed the NASA MEaSUREs SO2 source emission catalogue data2 to identify countries andstates/provinceswiththelargestman-madeSO2emissions.

The NASA SO2 monitoring team has recently updated their annual emissions estimates for large SO2emissionssourcesfor2018,usingdatafromtheNASAOMIsatelliteinstrument.ThemethodologyisbasedoncomparingSO2levelsmeasuredbysatellitesupwindanddownwindofidentifiedpointsources,andhasbeenvalidatedagainstmeasuredSO2emissionsintheU.S.andtheEU.3

TheanalysisfindsthatMpumalangarankedthirdintheworldforSO2emissionsin2018forthesecondyear,after strict emissions standards brought emissions from highest-emitting Chinese provinces downdramatically.

The only places in the world with even higher emissions were Krasnoyarsk in Russia, with the Norilskindustrialclusterwithtremendouslypollutingsmelters,powerplantsandfactories,andtheSaudiregionofMakkah(Mecca)withoilrefineriesandoil-firedpowerplants.BothoftheseregionshavealargerlandareathanMpumalanga.

SouthAfricaalsoranksthirdintheworldforpowerplantSO2emissionsin2018,afterIndiaandChina,andfollowedbySaudiArabiaandtheUnitedStates.

2excludingvolcanicsources3Fioletov,V.,McLinden,C.A.,Kharol,S.K.,Krotkov,N.A.,Li,C.,Joiner,J.,Moran,M.D.,Vet,R.,Visschedijk,A.J.H.,andDeniervanderGon,H.A.C.(2017):Multi-sourceSO2emissionsretrievalsandconsistencyofsatelliteand surface measurements with reported emissions, Atmos. Chem. Phys., 17, 12597-12616, DOI:10.5194/acp-17-12597-2017.

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OTHERDATASETSTheGreenpeacefindingsarebynomeansanoutlier,but ratherwell in linewithearlier,publiclyavailabledata.BesidesusingtheNASASO2emissiondata,wecomparedourNO2estimatestotwoothersources:theDutchmeteorologicalagency’s(KNMI)monthlyNOxemissionsestimatesbasedonNASAOMIsatellitedata,andofficialemissionsstatisticsfromChinaandEskom.

KNMIDECSOALGORITHMFORNO2TheDutchRoyalMeteorologicalInstitute(KNMI)hasdevelopedasophisticatedapproachtoestimatingNOxemissions combining satellite-based NO2 measurements with a detailed atmospheric model to relateatmosphericlevelstoemissionsourcesandrates4.

DECSOdatawasavailableforeasternChinaandSouthKoreauntil2017,theMiddleEastuntil2014andSouthAfricauntil2011.EstimatesforIndiawereonlyavailablefor2008andwerediscardedastooold,giventherapidgrowthinthecountry’sfossilfueluseandemissionsinthepastdecade.

Within this limited dataset, thecoal power plant and industrial cluster inMpumalanga ranks as the thirdlargestNO2hotspot in theworld,after two locationsin theMiddleEastwithveryhighoilconsumption intransport,industriesandpowerplants.

4Ding,J.,vanderA,R.J.,Mijling,B.,Jalkanen,J.-P.,Johansson,L.andLevelt,P.F.,MaritimeNOxemissionsoverChineseseasderivedfromsatelliteobservations.GeophysicalResearchLetters,45.https://doi.org/10.1002/2017GL076788.Mijling,B.andR.vanderA(2012).Usingdailysatelliteobservationstoestimateemissionsofshort-livedairpollutantsonamesoscopicscale.J.Geophys.Res.117,D17,https://doi.org/10.1029/2012JD017817.

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KNMIDECSONOxemissionsforSouthAfrica(kt/yr)

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EMISSIONSTATISTICSAnotherapproachcorroboratingourresultsiscomparingannualemissionvolumesreportedbyEskomasapartofitsapplications5forsuspensionofcompliancewithSouthAfrica’sMinimumEmissionStandardswithprovince-levelstatisticsonindustrialemissionsinChina.

Eskom’sHighveldplantsemitmoreSO2andalmostasmuchNOxasalltheindustrialemittersinthelargestemittingprovinceinChina,Shandong.Shandong’sareaistwiceaslargeasMpumalanga’s.EasternChinaandShandonghavereducedNOxemissionsby24%and31%respectivelyfrom2012to2017.SO2emissionshavefallenbymorethan80%inChinaandmorethan90%inShandongfrom2012to2018.

5http://www.naledzi.co.za/public-documents-naledzi.php

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WHYCOALPOWEREMISSIONSINMPUMALANGAARETHEHIGHESTINTHEWORLDThereisaclearreasonwhyHighveldranksastheworld’slargestpowerplantSO2andNO2emissionhotspot–besideshavinga largeconcentrationofcoal-firedpowergeneratingand industrial capacity, theemissioncontrolperformanceofthecoal-firedboilersisdramaticallyworsethaninothercountries.Eskom’scoal-firedpowerplantsareallowedtoemitmorethan20timesasmuchSO2and15timesasmuchNOxasChineseandEuropeancoal-firedplants.

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HOWCHINAHASCUTEMISSIONSFROMCOAL-BURNING

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Afterpublic opinion reachedaboilingpointduringdisastroussmogepisodes inwinter2011-12,laterknownasChina’s“Airpocalypse”,thegovernmentreactedforcefullyandpublisheda“NationalAirPollutionPreventionActionPlan”,whichsetdetailedtargetsforimprovingairquality,reducingemissions and reducing coal consumption in the country’s key regionsby2017.The actionplanperiod also saw new emissions standards for coal-fired power plants enter into force in 2014,requiring steep reductions in SO2 and NOx emissions from the power sector, and a newenvironmental law become effective at the start of 2015, strengthening the enforcement ofemissionlimitsandincreasingfinesforviolators.

Overthefive-yearperiodfrom2012to2017,Chinaachieveddramaticreductionsinpowerplantandindustrialemissionsandequallydramaticimprovementsinairquality.

China retrofitted approximately 250 gigawatts of existing coal-fired capacity with Flue GasDesulphurisation(FGD)between2005and2011,bringingtheshareofcapacitywithSO2controlsfrom14.3%to89.1% in six years.These installationswere in response to thenational emissionstandards introduced in 2004. Similarly, after the emission standards were updated in 2011 tolevels that required selective catalytic NOx controls (SCR), these retrofits were carried out onapproximately480GWofcapacityby2015,raisingpenetrationfrom18.2%to84.5%infouryears.6

SubsequentlyChinahasbeenretrofittingexistingpowerplantstomeetso-calledultralowemissionstandards,which are100 timesas strictasSouthAfrica’sMinimumEmissionsStandards for SO2(26mg/Nm3inChinavs.3500mg/Nm3inSouthAfrica7).

Chinaremainstheworld’slargestemitterofNOx(andCO2)andoneofthelargestemittersofSO2,andairpollutionlevelsremainhazardousdespitedramaticimprovement.However,China’ssuccessinreducingemissionsandimprovingairqualityrapidlyoverthisdecadeshowshowmuchcanbeachievedwithacoordinatedactionplanthatrequiresmajorpolluterstocomply.

6DatasummarizedfromannualeditionsofChinaAssociationofEnvironmentalProtectionIndustry:AnnualReportonChinaDesulfurizationandDenitrificationIndustry.Seee.g.赵雪,程茜,侯俊先(2018):脱硫脱硝行业

2017年发展综述.中国环保产业,2018(07):10-24.http://kns.cnki.net/KCMS/detail/detail.aspx?dbcode=CJFQ&dbname=CJFDLAST2018&filename=ZHBY201807006&v=MTE2NThSOGVYMUx1eFlTN0RoMVQzcVRyV00xRnJDVVJMT2ZadVJtRkNybVdyM0lQeVhKZDdHNEg5bk1xSTlGWW8=7 The Chinese standard is 35mg/Nm3at 6% oxygenwhich converts to 26mg/Nm3 at the 10% referenceoxygenlevelusedinSouthAfricanstandards.

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