UNEPEEAP
AlkisBaisAristotleUniversityofThessaloniki,Greece
ChristosZerefosAcademyofAthens,Greece
JanetBornmanCurtinUniversity,Agri-FoodSecurity,Australia
onbehalfoftheEnvironmentalEffectsAssessmentPanelofUNEP
EnvironmentalEffectsAssessmentPanelEEAPSolarUV-Bradiationandtheenvironmental
effectsofozonedepletion
UNEPEEAP
• IncreaseofdamagingsolarUV-Bradiation,witheffectson:• Humanhealth• Terrestrialandaquaticecosystems• Troposphericair-quality• Biogeochemicalcycles• Materials
• EffectsofclimatechangeonstratosphericozoneandUV-B
• EffectsofclimatechangeonUV-Bradiation(directly)
Stratosphericozonedepletion&UVradiation
UNEPEEAP
• MeasurementsofUV-Bradiationweresparseinthe1980s
• SpectralUV-Bradiationmeasurementsstartedafter1990
Blumthaler&Ambach 1990,Science
Jungfraujoch1981-1989
IncreasesinErythemalirradiancewithrespecttototalSWirradiance
UNEPEEAP
• Totalozoneisthedominantfactorin“long-term”changesofsurfacesolarirradiancebelow320nm.
• Similar“long-term”variabilitywasfoundforThessaloniki,Brussels,Garmisch-PandReykjavikforall-skyconditions.
• Calculatedfractionalchangesinsolarirradiancecriticallydependonthelengthoftheperiodofstudy.Afewyearsarenotenoughforanyreliableconclusions.
Zerefosetal.,1997,GRL
FirstproofoftheinverserelationbetweenTotalOzoneandspectralUV-Bradiation
90 91 92 93 94 95 96 97YEARS
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Ozone
90 91 92 93 94 95 96 97YEARS
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325 nm
Ozone
UV-B
UV-A
O3 à
O3 à
UNEPEEAP
20yearslater… Thessaloniki(40o N);SZA=64°
307.5nmStrongozoneabsorption
UpdatefromFountoulakisetal2016,ACP
UNEPEEAP
20yearslater… Thessaloniki(40o N);SZA=64°
324nmweakozoneabsorption
UpdatefromFountoulakisetal2016,ACP
UNEPEEAP
• UV-Birradiance(307.5nm)isincreasingduemainlytodecreasingaerosols.Ozoneaffectstheshort-termvariations.
• Totalozonehasstabilizedsince~1990toabout3%belowitsvaluesintheearly1980s.
• IncreasesinUV-A(350nm)aresmaller.Negligibleeffectofozone,smallereffectofaerosols
• Theaerosolopticaldepthdecreasessteadilywithhigherratesafter~2000.
UpdatefromFountoulakisetal2016,ACP
Thessaloniki(40o N);SZA=64°;Clearskies 1992– 2017
UNEPEEAP
ThenoontimeUVIndexmeasuredatSouthPoleduringtheozoneholeperiod(October- November)is:20– 80%higher thaninsummeratcomparablesolarzenithanglesupto2timeshigher thaninthepre-ozoneholeperiod
Bernhardetal.,2010
NSFUVSpectralIrradianceMonitoringNetwork
Station Lat. max UVI
Palmer 64°S 14.8
Ushuaia 54°S 11.5
SanDiego 32°N 12.0
TheozonedepletioneffectonUV-BisclearlydetectedinAntarctica
(1991-2007)
UNEPEEAP
ChangesinUVirradianceat305nmin30years(1979-2008)estimatedfromsatellitedata
• Greatestincreaseswerefoundatmid-latitudesinthesouthernhemisphere
• Smalldecreasesorincreasesinthetropicsdependingonseason
• Forerythemalirradiance(UVIndex)changesarelessthanhalf
HermanJ.2010,JGRMissinghighlatitudes>55°
UNEPEEAP
The ozone trend in % per decade for different latitudes for 1984–1997 (left) and 1997-2016 (right). Shaded areas show regions where trends are statistically different from zeroat the 95% level.(Sofieva, V. F. et al.: Merged SAGE II, Ozone_cci and OMPS ozone profiles dataset andevaluation of ozone trends in the stratosphere, Atmos. Chem. Phys. Discuss.,https://doi.org/10.5194/acp-2017-598, in review, 2017.)
UNEPEEAP
HowhastheMontrealProtocolaffectedtheUV-BradiationatEarth’ssurface?
UNEPEEAP
UVI>11
UVI>11
UVI>11
Newmanetal.,2011,PPS
WorldavoidedduetoMontrealprotocolSOLARUV-BRADIATION
UNEPEEAP
EXCESSSKINCANCER
WorldavoidedduetoMontrealprotocol
VanDijketal.,2011,P&P
Projectednumberofavoidednewcasesofskincancerpermillionpeopleperyearfor2030
UNEPEEAP
UV-Bradiationinthefuture
UNEPEEAP
• AsconcentrationsofODSsdecreaseoverthenextdecades,GHGswillbecomethedominantdriverofstratosphericozonechanges.
• UVradiationwilldecreaseinthemiddleandhighlatitudesrelativetothehistoricalperiod1955–1975.
• Inthetropics,thesignofchangedependsontheemissionscenario.
• OutsideAntarcticaotherfactors(aerosols,clouds,albedo,airpollution)dominatethevariabilityofUV-Bradiation,maskingeffectsofchangesinstratosphericozone.
• ThesefactorsareinfluencedstronglybyincreasingGHGs.
UV-BRadiation,OzoneandClimateChange
UNEPEEAP
PercentagechangeinUVIndexfrom PASTto PRESENT(1965-1655)to(2010-2020)
TOTA
LOZO
NE
AERO
SOLS(O
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CLOUDS
SURFAC
EAL
BEDO
Baisetal.,2015,PPS
UNEPEEAP
PercentagechangeinUVIndexfromPRESENTto FUTURE(2010-2020)to(2085-2095)
TOTA
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Baisetal.,2015,PPS
UNEPEEAP
TheUNEP’sEnvironmentalEffectsAssessmentPanel
EEAPprogressmeetingStratford-upon-Avon,UK,11-18Sept.2017
Stratosphericozonedepletion
Stratosphericchemistry ScienceAssessmentPanel
Climate
O3depletingsubstances
Howthe3PanelscomplementeachotherincontributingtotheMontrealProtocol
ODSuse&applications
Technology&EconomicsAssessmentPanel
ODSsubstitutes
EnvironmentalEffectsAssessmentPanel
UV-Bradiation
Humanhealth Ecosystem
healthandservices
Materials
AirQuality
UNEPEEAP
KEYQUESTIONS:PAST,PRESENTANDFUTURE
• WhatarethedirectandindirectbeneficialeffectsoftheMontrealProtocol?
• HavetheeffectsoftheMontrealProtocolbeenreflectedinmeasurementsofUV-Bradiation?
• WhenandwhereshouldweexpectdamagingorbeneficialeffectsofUV-B?
• HowincreasingGHGsmodifythewaysstratosphericozonechanges(depletionorrecovery)affectUV-Bradiation?
• Howhasstratosphericozonedepletionbeenaffectingclimateinthesouthernhemisphere?Willtheeffectsbereversedwhenozonerecovers?
UNEPEnvironmentalEffectsAssessmentPanel
UNEPEEAP
• DespiteindicationsofozonerecoveryinAntarcticainspring,noeffectsonUV-Bradiationareyetdetectable,dueto:
NOTE: DelayedozonerecoveryinlatespringandsummerisimportantforUV-Bradiationasthesungetshigherinthisperiod
RecoveryofAntarcticOzone
ü StrongvariationofUVattenuationbyozone,clouds,albedo
ü WeakUV-Bintensityinearlyspring
UNEPEEAP
Humanhealth– keyfindings
• EffectsonhumanhealthfromchangesinstratosphericozonearethroughchangesinexposuretosolarUV-Bradiation.
• Exposure ofhumanstoUV-Bradiationdependsonmultiplefactors,includingindividualchoices(e.g.relatingtosunbehaviour,clothing,useofsunprotection).
• Warmertemperaturesasaresultofclimatechangewillalterhowmuchtimepeoplespendoutdoorsandthustheirexposuretosolarradiationacrossallwavelengths.
• WhilefocusremainsonexposuretoUV-Bradiationforrisksorbenefitstohumanhealth,longerwavelengthsofsolarradiationshouldalsobeconsidered.
UNEPEEAP
ExposuretoUVradiationhasbothrisksandbenefits
AdverseeffectsfromUVexposure:• Skin cancers,includingcutaneousmalignantmelanomaandkeratinocytecancers(previously:non-melanomaskincancers)
• Eyediseases,includingcataract• Immunesuppression,causingreactivationoflatentviruses
PossiblebenefitsfromUV-VISexposure:• ImprovedvitaminDstatus (knowntobeprimarilyfromUV-B)• Reducedriskofmyopia (shortsightedness)• Immunesuppression (reducingriskofautoimmunediseases)• Benefitsforcardio-metabolichealth
Humanhealth – keyfindings
UNEPEEAP
• Despitestrongpublic-healthprogramsforeffectivesunprotectionriskysunexposurebehaviourresultinginsunburn(andultimatelyskincancer)remainscommoninmanycountries.
• SuchbehaviourwillcontinuetoinfluencethehealtheffectsfromfuturechangesinUVexposureduetochangesinozoneandotherfactors.
• Benefits ofexposureofboththeskinand eyes tosolarradiation(UV-Bandlongerwavelengths)arestillbeinginvestigated,andcouldbeofconsiderableimportance.
• VitaminDdeficiencyduetoreducedUV-Bexposureiscommon,particularlyathigh-latitudelocations.ReliabledataforvitaminDlevelsremainverylimitedformanyregionsoftheworld.
Humanhealth- Remarks
UNEPEEAP
Modeledmeanmonthlyeffectivedoseforpre-vitaminD3synthesis
(2003–2012)
JUNE
DECEMBER
vit-Ddose(Jm−2)
• LowvitaminDstatusiscommoninEurope
O’Neilletal.,2016,Nutrients
• Dark-skinnedethnicgroupsinEuropehavegreaterriskofvitaminDdeficiencythantheirwhitecounterparts.
O’Neilletal.,2016,J.Ster.Biochem.
Deficiencylimit:1000Jm-2
UNEPEEAP
• UVradiationeffectsdependoninteractingenvironmentalfactors
IncreasesthechallengeofreliablypredictingoverallimpactofchangesbyUV-Bradiationonnaturaloragriculturalecosystems
Ecosystemhealthandservices• TerrestrialsystemsareaffectedbyUVradiationandconstraintsfromclimatechange(wateravailability,highertemperatures,CO2)o Ozone-depletiondrivenclimatechangeshaveaffectedgrowthanddistributionpatternsofplantsinnaturalecosystemsinsomepartsoftheSouthernHemisphere.
o Potentialchangesincropyieldandfoodqualityinagriculturalsystems(e.g.fasterripeningofsomecropsbyCO2,andchangesinnutrientstatus)
UNEPEEAP
• Dissolvedorganicmatter(DOM)selectivelyabsorbspotentiallydamagingUVradiationinaquaticecosystems
Ecosystemhealthandservices
UNEPEEAP
StrongevidencethatDOMisincreasing inmanyaquaticecosystems(“browning”):• Increasesasmuchastwo-foldinsomeinlandwaters• DOMisrelatedtoclimatechange(increasesinprecipitation,
extremerainevents)andotherfactors(e.g.,recoveryfromanthropogenicacidification,changesinlanduse)
Ecosystemhealthandservices
RupertBay,Quebec LakeMichigan
Ecosystemhealthandservices
UNEPEEAP
ConsequencesofreducedpenetrationofUVradiationintoaquaticecosystemsdueto“browning”• Increasedsurvival ofwater-bornehumanpathogensthatwould
otherwisebeinactivatedbyexposuretosolarUVradiation
• Increasedsurvivalofpathogensinsurfacewatersincreasestheriskofinfectiousdiseaseinhumansandwildlife
• Alteredbehaviour ofaquaticorganismsaffectswaterquality,aquaticfoodwebs andfisheryproductivity.
• CO2isreleasedbysolarUV-Bradiation-drivenbreak-downofDOM thatenterstheaquaticecosystems
• ReducedUV-BradiationinthefuturewouldresulttolessCO2releasedbyterrestrialandaquaticecosystems
Ecosystemhealthandservices
UNEPEEAP
• CO2isreleasedbysolarUV-Bradiation-drivenbreak-downofDOM thatenterstheaquaticecosystems
• FuturechangesinUV-BradiationwillaffectthereleasedCO2 by:
• Carbonenteringaquaticecosystemsdueto“browning”
• Photochemicalorbiologicaldegradationofdead-plantmaterialinterrestrialecosystems
• ReducedUV-BradiationinthefuturewouldresulttolessCO2releasedbyterrestrialandaquaticecosystems
Ecosystemhealthandservices
Stratosphericozonedepletion
Stratosphericchemistry
Ecosystemhealthandservices
Speciesdistribution
Land-usechange
CloudAerosols
Dissolvedorganicmatter
Wateravailability
Temperature
Carbondioxide
Climate
UV-Bradiation
EXPOSUREtoUV-Bradiation
BIOLOGICALRESPONSEtoUV-Bradiation
Concurrentmultipleenvironmental
changesincreasethechallengeofreliably
predictingoverallimpactof
changesinstratosphericozoneonnaturaloragricultural
ecosystems.
O3depletingsubstances
UNEPEEAP
AirqualityUVradiationdrivesthechemistryofthetroposphere
Examples:1.RemovalofODSandGHG(e.g.HCFCs,HFCs,CH4,tropospheric
ozone)byOHradicalso UVradiationisanimportantfactoraffectingthelifetimeofCH4
andtemporaltrendsinitsamountsintheglobalatmosphere
2. Formationanddestructionofground-levelozoneo DecreasingUVradiationresultingfromstratosphericozone
recoverywillleadtoslowerproductionandslowerdestructionoftroposphericozone:- smalldecreases inO3 incities- smallincreases inruralO3 regionally.
UNEPEEAP
Airquality
1. Formationofpersistentcompounds,e.g.TFAfromHFCs
Atpresent,amountsofTFAproducedfromHFCsandHCFCsaresmallrelativetoothersources,andthereforeunlikelytoposearisktohumansortheenvironment.
SubstitutesforODSmustbemonitoredforpotentialrisks:
2. Smallbutnon-zerocontributionstourbanpollution,forexamplethroughtheuseofvolatileorganiccompounds(hydrocarbons)asODSsubstitutes
UNEPEEAP
Materialsdamage
• ExposuretoUVradiationandambienttemperaturedeterminetheoutdoorservicelifetimesofplastics,woodandotherconstructionmaterials
• IncreasedUVradiationandtemperature canshortenreplacementtimeforproductsusedoutdoors.Thecontroltechnologiesinusetoday,ortheirimprovedversions,mitigateadditionaldamage,butaddtothecost oftheseproducts.
UV-shieldingpigmentsarepresentlyusedtostabilizePVCagainstUVradiation.
UVdamagetowoodisavoidedbysurfacecoatings(paints)orchemicalmodi-fication ofwood.
UNEPEEAP
Mainconclusionsandresearchneeds• ProjectingfuturechangesinUV-Bradiationandeffectsonhealth
andotherecosystems(includingfoodproduction)demandsthatresearchisnotlimitedsimplytochangesinstratosphericozone.
• ClimatechangewillinfluenceUV-Bexposurethroughchangesinozonebutalsoclouds,aerosols,andDOMand,forhumanhealth,changesinbehavior.
• BiologicaleffectsonecosystemsofalteredexposuretoUV-Bwillbefurthermodifiedbyinteractionswithotherfactors,e.g.intemperature,wateravailabilityandquality,CO2.
• Thescaleandscopeofthenecessaryresearchisincreasinglyunderthreatduetotheperceptionoffundersthatozonedepletion/UV-Barenolongermajorenvironmentalthreats.
