Assessing and Mitigating Municipal Climate Risks and ...

AssessingandMitigatingMunicipalClimateRisksandVulnerabilitiesinYorkRegion,Ontario

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AssessingandMitigatingMunicipalClimate

RisksandVulnerabilitiesinYorkRegion,Ontario

Edmundo Fausto, Project Manager, Climate Information and Adaptation, Ontario Climate Consortium Secretariat, Toronto and Region Conservation Authority

Ontario, Canada

Vladimir Nikolic, Climate Vulnerability Researcher, Ontario Climate Consortium Secretariat, Toronto and Region Conservation Authority

Ontario, Canada

Glenn Milner, Climate Information and Adaptation Specialist, Ontario Climate Consortium Secretariat, Toronto and Region Conservation Authority

Ontario, Canada

Teresa Cline, Senior Planner, Regional Municipality of York Ontario, Canada

Kevin Behan, Deputy Director, Clean Air Partnership

Ontario, Canada

Laura Briley, Climatologist, Great Lakes Integrated Science + Assessments Michigan, United States

This project was funded by the Great Lakes Integrated Sciences + Assessments Center

through a 2014 Great Lakes Climate Assessment Grant.

Recommended Citation:

Fausto E., Nikolic V., Milner, G., Cline T., Behan K., Briley L., (2016). Assessing and Mitigating Municipal Climate Risks and Vulnerabilities in York Region, Ontario. Ontario Climate Consortium, Clean Air Partnership and Great Lakes Integrated Sciences + Assessments: Toronto, ON. In: Project Reports. D. Brown, W. Baule, L. Briley, E. Gibbons, and I. Robinson, eds. Available from the Great Lakes Integrated Sciences and Assessments (GLISA) Center.

For further questions, please contact [email protected]

ASSESSINGANDMITIGATINGMUNICIPALCLIMATERISKSANDVULNERABILITIESINYORKREGION,ONTARIO

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ContentsProjectContextandObjectives.................................................................................................................................................................3BuildingOnExistingAdaptationFrameworksandRiskandVulnerabilityAssessments..............................................4AdoptingaProcess-BasedAdaptationFramework.........................................................................................................................5TailoringtheRiskandVulnerabilityAssessmentFrameworkandTools..............................................................................6HistoricalandFutureClimateInformationforYorkRegion.......................................................................................................7EngagingMunicipalStaffinRiskandVulnerabilityAssessmentandAdaptationPlanning..........................................8ACaseStudyonCityofVaughanStormwaterMunicipalInfrastructure............................................................................10SummaryofProjectOutputs...................................................................................................................................................................11LessonsLearned...........................................................................................................................................................................................11NextStepsandKnowledgeTransfer...................................................................................................................................................12References......................................................................................................................................................................................................12AppendixA.....................................................................................................................................................................................................14AppendixB.....................................................................................................................................................................................................15


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ProjectContextandObjectivesOverthelastseveraldecades,variationsinglobalclimatehaveexposedmanynationstoanincreasedrangeofrisks,forcingthemtoadapttoemergingconditions.Manylocalcommunitieshaveexperiencedmorefrequentandintenseweatherevents,suchasextremetemperatures,rainstorms,snowstorms,prolongedheatwavesanddroughts,shiftsinseasonality,andotheranomalousclimateconditions.Inaddition,duetosignificantsocial,economic,andinfrastructuraldevelopment,communitiesareexposedtonumerouscascadingimpactsinitiatedbyachanginginclimate.

Figure1:YorkRegionLower-TierMunicipalitiesWithinYorkRegion,Ontario,thereareninemunicipalitiesactivelyadaptingtoclimatechange(Figure1).Atthemunicipallevel,climateadaptationisbeingaddressedthroughavarietyofmechanisms,includingsustainabilityplans,communityenergyplans,andenhanceddevelopmentstandards.ThedevelopmentofanadaptationframeworkassistsYorkRegionanditsninemunicipalitiestomovetowardscreatingactionplanstospecificallyaddressclimateadaptation.Withthisinmind,theproject“AssessingandMitigatingMunicipalClimateRisksandVulnerabilitiesinYorkRegion,Ontario,”whichwascooperativelyinitiatedbyYorkRegion,theOntarioClimateConsortium(OCC),andCleanAir

Partnership(CAP),hasthemainobjectiveofadvancingclimatechangeadaptationactionplanningintheregionandthusenhancingtheresilienceoflocalcommunities,naturalsystems.andmunicipalassets.AcomprehensivereviewofexistingclimateriskassessmenttoolswaspreviouslyconductedaspartoftheGreatLakesIntegratedSciencesandAssessments(GLISA)-fundedworkwiththeRegionofPeelandOCC.Theanalysisrecognizedthateachofthereviewedtools,someofwhichwerefoundtobeusedbyassessmentsacrosstheGreaterTorontoArea(GTA),sharedthefollowingfundamentalsteps:

1. Settingthecontext2. Identifyingthehazard(s)andsystems3. Estimatingandcharacterizingthe

“probability”and“consequence”4. Treatingrisks.

Thesestepsshapedtheprojectactivities,whereeachstepwascomprisedofseveralmorespecifictasks.Allphasesofworkaimedatproducingthenecessaryoutputs,whilemakinguseofexistingtoolsandinformation.Duetotheiterativenatureofcertainactivities,suchasstakeholderengagementandtherefinementofriskinformation,multipleactivitiesfedintoeachstepwithintheframeworkandtoolsdevelopment.TheProjectTeamcollaboratedwiththeJointMunicipalClimateChangeWorkingGroupinYorkRegiontorefinetheinitialtermsofreferenceandscopetheset-upofaRegion-wideriskandvulnerabilityframework.TheProjectTeamalsodevelopedbackgroundnarrativesandstatisticsonsignificantsectorsofYorkRegion’seconomy,environmentandcommunitiestodescribethecontextofthisproject.Thecoreobjectivehasbeenreachedbyestablishingtheprocesses,tailoringthetoolsandtemplates,compilingthenecessaryinformation,andenhancingstaffcapacitytoconductriskandvulnerabilityassessmentsandresiliency-basedadaptationplanning.Thekeyprojectoutcomesare:

1. Thedevelopmentofgreaterawarenessandrecognitionoftheimportanceandnatureofclimatechangerisks,


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vulnerabilities,andneedforadaptationamongmunicipalstaffanddecisionmakersinYorkRegion

2. Increasedcapacityatthestaffleveltoconductriskandvulnerabilityassessmentsandadaptation-planningacrossmunicipalmanagementandserviceareasinYorkRegion

3. Morestreamlinedprocessesandsystemsfortheexecutionofriskandvulnerabilityassessmentsandhavingthecapabilitytoupdateinformationovertimeandtrackprogressonadaptationinitiativestargetedatincreasingmunicipalresilience

Asaresultofjointefforts,theprojectisexpectedtodeliverthefollowingitems:

• Aframework(comprisingofasetofprocesses,tools,andtemplates)forongoingriskandvulnerabilityassessmentandadaptivemanagement/resiliencybasedplanninginYorkRegion

• Workshopsandsurveystoengagestaffinriskandvulnerabilityassessmentsandadaptation-planningmorebroadly

• InventoryofmunicipalmanagementandservicearearisksinYorkRegion(climatehazards,impacts,andsystem/components)

• Ariskandadaptation(andriskmitigation)databaseCityofToronto(COT)ToolandresearchtemplatedevelopedfortheRegionofPeel(P-CRAFT))populatedwithbasicinformationonthemanagementandservicearearisksidentifiedintheinventoryandtrendsonclimatehazardsspecificforYorkRegionbasedonriskinformationcompiledfromotherapplicableassessmentsintheGreaterTorontoAreaandtheGreatLakesBasin

• ClimatetrendsforvariablesrepresentingweatherhazardsinYorkRegion

• DetailedcharacterizationofrisksinmunicipalstormwatermanagementsystemsusingestablishedmethodsandlocaldatasetsforaCityofVaughancasestudy

• Discussionontheopportunitytoincorporatetheframeworkguidance

documentsintotheadaptationstrategyofYorkRegion.

YorkRegionandthelocalmunicipalitieshavebeenenvisionedtoutilizethedevelopedassessmentframeworkandtoolsinordertoundertakefuturevulnerabilityassessmentsandadaptationplanningwithintheirrespectivejurisdictions.Therefore,YorkRegion’smunicipalitiesweredirectlyengagedthroughtheJointMunicipalWorkingGroupandSteeringCommitteethatincludedrepresentativesfromtheJointMunicipalWorkingGroup.AProjectTeamwasestablishedtoensureprojectdeliverablesmeetabroadrangeoflocalmunicipalneeds.

BuildingOnExistingAdaptationFrameworksandRiskandVulnerabilityAssessmentsInordertodeliverthefirstitemanddefineastreamlinedframeworkforongoingriskandvulnerabilityassessmentandadaptivemanagement/resiliency-basedplanninginYorkRegion,allprojectactivitieswerebuiltonworkthathadbeenpreviouslycompletedintheareaofmunicipalclimateriskandvulnerabilityassessmentinGTA.Emphasiswasplacedonpreviouslyappliedtools,information,andlessonslearnedfromriskandvulnerabilityassessmentsconductedintheRegionofPeel,DurhamRegion,CityofToronto,andtheLakeSimcoewatershed(AppendixA).WithinthesuiteofreviewedGTA-basedriskassessments,arangeofmunicipalsystemsandassetclasseshaveundergonedetailedanalysis,andthisprojecttooktheopportunitytolearnfromtheseefforts.Morespecifically,theseassessmentshelpedidentifytoolsused,selectclimateindicators,delineateimpactsofgreatestconcern,establishmethodstodifferentiateasystemintocomponents,andproposeadaptationmeasures.Table1presentsanoverviewofthereviewedriskassessments(AppendixAcontainsadditionalinfooneach).


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Table1:ExistingGTAAssessmentsJurisdiction/Proponent AssessmentTheme

RegionofPeel

• Publichealth• Naturalsystems• Hydrology• Economy• Municipalcriticalinfrastructure/services(roadways,electricaldistribution,shoreline,privateproperty,publichealth)

GreaterTorontoAirportsAuthority • Stormwaterinfrastructure

RegionofDurham

• Municipalserviceareas(publichealth,transportation,flooding,electricalgrid,agriculture/food)

CityofToronto • TransportationservicesCityofHamilton&ConservationHamilton • Hydrologyandstormwater

CreditValleyConservation • HydrologyandstormwaterOntarioMinistryofNaturalResourcesandForestry

• Terrestrialandaquaticecosystems

WeatherWisePartnership• Electricaltransmissionanddistributioninfrastructurecasestudies

Initially,theinformationpulledfromtheseassessmentswasusedtoinformtheassemblyofaframeworkthatcouldbeusedacrossmultiplethemesandforsystem-specificassessments.Thisincludedthefollowingcorecomponents:

• ICLEIFramework(ICLEI,2010);• CityofTorontoClimateChangeRisk

AssessmentDatabase(COT)(CityofTorontoandDeloitteLLP,2011);and,

• ThePeelClimateRiskAnalysisFrameworkandTemplates(P-CRAFT)(Switzman&Hazen,2015).

Thegapsidentifiedthroughstakeholderengagementwerefilledthroughtheamalgamationandtailoringprocessoftheframeworkandtools.TheProjectTeamanalyzedhowtoleverageitsstrengthsandhowtointegratetheminamannerthatwasmostusefulforthestakeholders.Forinstance,theP-CRAFTtemplateswereincorporatedintotheCOTdatabase.TheProjectTeamliaisedwithCOTstaffandthesoftwaredeveloper(DeloitteLLP)toobtainrequiredlicensesandaone-day“trainthetrainer”sessionontheCOTdatabase,whichhelpeddetermineanoptimalapproachforintegratingtheP-CRAFTtool.

AdoptingaProcess-BasedAdaptationFrameworkProcess-basedframeworksforriskandvulnerabilityassessmentsareintendedtoguidelocalpractitionersthroughaprocessofinitiation,research,planning,implementation,andmonitoring.Basedontheexperienceleveragedfrompreviousassessments,thisprojectestablishedaframeworktailoredtothespecificneedsofYorkRegionthatareessentialforeffectivelong-termadaptationplanning.Therefore,thisprojectadoptedthestepspresentedinICLEI–LocalGovernmentsforSustainability,Canada2010documenttitled“ChangingClimate,ChangingCommunities:GuideandWorkbookforMunicipalClimateChangeAdaptation”asthebasisforadaptationplanningandimplementationinYorkRegion.Thisframeworkprovidesamilestonebasedapproachtoassistlocalgovernmentsinthecreationofadaptationplanstoaddresstherelevantclimatechangeimpactsassociatedwiththeircommunities.Itdrawsfromclimatechangeadaptationplanningmethodologiesadoptedbyspecificsectorsordepartments,municipaloperations,communitiesandspecializedadaptationteamsthroughoutCanadaandtheUS.Eachmilestonerepresentsastepintheadaptationplanningprocessthatiscompletedinsequenceandthenreviewedandupdated:

• Milestone1:Takesafirstlookatclimatechangeimpactsandexistingadaptationactionsinaregionormunicipality;

• Milestone2:Supportsandprioritizesclimatechangevulnerabilityandriskassessments;

• Milestone3:Establishestheadaptationvisionwithgoalsandobjectivestoachievethevision.Potentialadaptationoptionsareidentified,assessedforapplicabilityandincorporatedintoanadaptationplanwheresuitable;

• Milestone4:Implementsthisplan;• Milestone5:Dealswithmonitoring,

evaluationandreviewoftheadaptationactionsdetailedintheplan,andproposesupdatestotheactionswherenecessary.

MostofMilestone1wasalreadycompletedthroughthedraftYorkRegionClimateChangeAdaptationplan,anditwasreviewedandupdated


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attheoutsetoftheproject.Therefore,thisprojectaimedatestablishingaframeworkandtoolstoconductMilestone2inaconsistentmanneracrossYorkRegion.Milestone3wasaddressedonlyaspartoftheCityofVaughan’smunicipalstormwaterinfrastructurecasestudy.TailoringtheRiskandVulnerabilityAssessmentFrameworkandToolsAsmentionedpreviously,twotoolswereselectedforcustomizationtofacilitatetheundertakingofanalysisonclimatevulnerabilityandriskinYorkRegion.ThefirsttoolwasaclimatechangeriskassessmentdatabasedevelopedbyCOT.Thesecondtool,P-CRAFT,wasaframeworkandtooldevelopedfortheRegionofPeel(Switzman&Hazen,2015).TheMunicipalSteeringCommitteeandexternalexpertsprovidedinputonhowtheselectedframeworksandtoolscouldbeamalgamatedinaneffective,user-friendlymanner.ComputationalresourceswereusedtoconductthecustomizationnecessarytoprovideYorkRegionwithaconsistentframeworkforthevulnerabilityandriskassessmentprocess.TheCOTtoolrepresentsanautomatedMicrosoftAccessdatabasethatstoresinformationandfacilitatestheevaluationofriskondifferentmunicipalassets,management,andserviceareas.COTwasusedtoprovideaconsistent,auditableapproachtovulnerabilityandriskassessment.Thetoolpromptsuserstodefinetheexposure,measureprobabilities,delineateconsequencesusinguniformandconsistentscales,documentjustifications,andscorerisk.Theinternalstructurewasupdatedwithnewinformationasmoredetailedriskassessmentswerecompleted,whenriskmanagementmeasureswereimplemented,andwhenrisklevelsneededtoberefined.However,oneoftheCOTtoollimitationswastheabsenceofastructuredmethodtoguidethegatheringofevidenceleadingtothedefinitionofvulnerabilitiesandindicators,aswellasthedocumentationof:a)keyassumptionsabouthowvulnerabilitiesandrisksaredefined;b)thesourcesofinformationusedtocharacterizerisksandvulnerabilities;and,c)definitionsofquantitativeindicatorsandcomplexinteractions

withinthepathwaysthatcauseimpacts–allofwhichwereidentifiedasvaluableinriskanalysisandrisk-basedplanningbythestakeholders.WorkwasconductedincollaborationwiththedevelopersoftheCOTdatabasetoaddressthisgapusingP-CRAFTtemplates.P-CRAFTtemplatesareessentiallyaseriesofstructuredExcelspreadsheetsthatguideusersonhowtoextractinformationfromliteratureandconductempiricalanalysestoderiveindicatorsofvulnerabilityinatransparent,efficientmanner.Furthermore,P-CRAFTtemplatescanbeusedbytheriskassessmentteamtorecordanddocumentallobservations,assumptions,andconclusionsthroughoutthevulnerabilityinvestigation.TheP-CRAFTtemplatedocumentationwasincorporatedtothecomprehensiveCOTmanualtoguidetheuserthroughtheproposedframeworkanduseoftheamalgamatedtools.ThroughtheprocessofevaluationofexistingriskandvulnerabilityassessmentsconductedacrossGTA(seeTable2),theinformationwascompiledandpopulatedinthedatabaseandP-CRAFTtemplates.Morespecifically,populatingthedatabaseandtemplateswithexistingriskinformationrequiredreviewingriskassessmentsalreadyfinalizedintheTorontoregionandotherGreatLakesBasinmunicipalities.ItalsorequiredextractinggenericdatathatisrelevanttothesystemsinYorkRegion,suchasassetcategories,climateindicatordefinitions,andclimatechangeadaptationmeasures(e.g.,fromliterature).Furthermore,climateinformationwasobtainedfromanarrayofclimatedatasets,includingCanadianGriddedHistoricalObserveddatafromNaturalResourcesCanada(McKenneyetal.2011),andafive-modeldynamicallydownscaledensembleproducedfromtheOntarioMinistryofEnvironmentandClimateChange(Wangetal.2015).Thesetwodatabaseswereusedtopopulateclimateindicatorsofhistoricalandfuturefrequencyintheamalgamatedtool.Otherclimatedatasetswerealsousedbutonlyforsimplecomparisonandforcontext.Theotherdatasetsincluded41-modelstatisticallydownscaledensembleproducedbyYorkUniversity(LAMPS2014),twodynamicallydownscaledmodelscoupledwithalake-basedmodeltoexaminetheinfluenceoftheGreatLakes(Notaroetal.2015a,2015b),andclimate


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indicatorsproducedatstationsfromastudyconductedfortheCOTinaFutureClimateDriverstudy(SENES,2011).Afterpopulatingthedatabaseandtemplates,internalcapacity-buildingforconductingriskassessmentsinYorkRegionwasneeded.Tofacilitatetrainingandunderstandingoftheprocessanddatabase,aworkshopwasheldwheremunicipalstaffwereprovidedthesummaryinformationfromthesurvey,climatedataanalysis,andbackgroundresearchandwereaskedtodiscussthepossibleinputsthatwouldbeinputtedintheriskassessmenttoolfortheirspecificservicearea.Thiswasdonetotheextentpossibleusingtheirprofessionaljudgment.Thisactionprovidedasolidsourceofinformationforusers,whichtheycouldtailorandadjustasnecessaryintheirassessments.Furthermore,thisensuresamoreconsistentapproachtoriskandvulnerabilityanalysisand,thus,resiliency-basedplanningacrosstheGTA.

HistoricalandFutureClimateInformationforYorkRegionTheProjectTeamsoughttocharacterizeclimatetrendsofperceivedimportancetoawiderangeofsystemsinYorkRegion.Initially,aliteraturereviewleadbyCAPofhistoricclimateeventsinSouthernOntario(intheperiodbetween1985and2015)andthestakeholdersillustratedthatthisregionhasobservedclimateeventsthatmayreflectshiftsinthetiming,magnitude,andfrequencyofextremeprecipitationevents,aswellassignificanttemperaturevariations.Insomecases,theseeventshavealsobeenidentifiedtooccursimultaneously.Theobservedchangesinclimateconditionshavebeenshowntobeharmfultohuman-builtsystemsandlocalcommunitywellbeing.Morebroadly,theclimateeventsobservedinSouthernOntariocanbecategorizedastemperaturefluctuations(observedinyears2003,2005,2007,2009,2010,2012,2013),extremeheatevents(years1999,2001,2003,2005,2006,2010,2011,2012,2013),extremecoldandicestormevents(2003,2013,2015),extremeprecipitationevents(1999,2000,2004,2007,2008,2009,2010,2013,2014),extremewinds(2006,2009,2011,2013,2014),anddroughtevents(2001,2002,2007).

BasedonthereviewofhistoricalclimateeventsandimpactsinSouthernOntario,alistofclimatevariableswasputforwardtotheMunicipalSteeringCommittee.Onlytheclimateindicatorsidentifiedtoberelevanttostakeholderswereincludedintheanalysis(Figure2andTable2).Itisanticipatedthatfutureassessmentswillexpandonthislistbyincludingmoredetailedindicatorsandanalysis.Inlightoftheobservedeventsandtrends,historicalclimatedataandprojectedclimatemodeloutputsrelevanttoYorkRegionwereutilizedtoestimatetheprojectedtrendsforeachclimatecategoryforthefuturetimeperiodreferredtoasthe“2050’sclimatenormal.”Specificclimateindicatorsweredefinedtorepresenttheeventsofconcernidentifiedbythestakeholdersandtheliteraturereview.ClimatetrendinformationwasgeneratedinpartnershipwithGLISA.TherawmodeloutputsoftwomodelensemblesfundedbytheMinistryofEnvironmentandClimateChange(i.e.,Wangetal.2015,LAMPS2014)wereusedforthehistoricalandfutureperiodsforasetofprecipitationandtemperatureindicators,althoughthefive-modelensemblecreatedbyWangetal.wasusedtopopulatetheriskassessmenttool.Figure2:YorkRegionMunicipalBoundarieswithSpatialAveragingBoxUsedinClimateTrendAnalyses

Table2SummaryofselectedclimatevariablesClimateDriver Variable

Temperature

AverageMaximumAverageMinimumAverageTemperatureMaximumMaximumMaximumMinimumMinimumMaximumMinimumMinimumDiurnalTemperatureRange

Precipitation TotalPrecipitation


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NumberofWetDaysConsecutiveWetDays

ExtremePrecipitation

1-DayMaximumPrecipitation5-DayMaximumPrecipitationSimpleDailyIntensityIndexHeavyPrecipitationDaysVeryHeavyPrecipitationDays

IceStorms IceDaysIcePotential

ExtremeCold

NumberofDayswithMinimumTemperature<-50CNumberofDayswithMinimumTemperature<-150CNumberofDayswithMinimumTemperature<-200CNumberofDayswithMinimumTemperature<-250CColdDays(%ofDaysTmax<5-day10thPercentilevalue)ColdDays(%ofDaysTmax<5-day10thPercentilevalue)

ExtremeHeat

NumberofDayswithMaximumTemperature>250CNumberofDayswithMaximum>30oCNumberofDayswithMaximum>35oCNumberofDayswithMaximum>38oCNumberofDayswithMaximum>40oC

Furthermore,GLISAassistedwiththegenerationofindicatorsobtainedfromallotherclimatedatasetsexamined,includingtheSENESandNotarodatasets.Aspreviouslymentioned,theseotherclimatedatasetswereonlyusedforsimplecomparisonandcontext.Morespecifically,twodynamicallydownscaledclimatemodelsfromNotaroetal.(2015a,2015b)wereanalyzedforcontextsincethesetwodownscaledmodelsincludedacoupledlake-basedmodeltoincorporatetheinfluenceoftheGreatLakes.However,giventhatonlytwomodelswereobtainedfromthisdataset,itwasexcludedfromthetool’sensembleapproach.Similarly,theSENESdatasetwasonlyincludedforcontextbecauseofstakeholderfamiliaritywiththisstudyanditsuseinriskassessments,butitwasnotusedwithintheriskframeworktoolbecausetheclimatenormaldefinedis10yearsasopposedtotherecommended30years(WMO2007).Forall

climatedatasetsexamined,aclimatetrendsreportpreparedforYorkRegionaspartofthisprocessdescribeseachdatasetanditsprojectedchangesinmoredetail(Faustoetal.2015).Ingeneral,stakeholderperspectivesonlocalrisksandtheirinformationneedswerecriticalinputstothistailoringprocess.Forthatreason,regularstakeholderinteractionswereincorporatedinallprojectactivities.Inthiscase,theengagedstakeholdersincludedtheJointMunicipalClimateChangeWorkingGroupaswellasstaffanddecisionmakersthatwereinvolvedinthedevelopmentoftheoriginalYorkRegionadaptationactionplan.

EngagingMunicipalStaffinRiskandVulnerabilityAssessmentandAdaptationPlanningAsurveywasdevelopedanddistributedtotheJointMunicipalClimateChangeWorkingGroup.ThissurveyguidedstakeholdersthroughasetofquestionsthataidedgatheringinformationonexperiencedandexpectedimpactsonvarioussystemsduetoclimateandYorkRegion’stheinteractions,perceivedimportanceandoverallrisktolerance.Approximately24percentofallstakeholderscompletedthesurvey.TheProjectTeamusedthesurveytofacilitateafocusgroupworkshopdiscussionwithmembersoftheJointMunicipalClimateChangeWorkingGroupandotherstakeholdersinYorkRegion.Atthisworkshop,participantsexploredtopicscoveredbythesurveyinmoredetail.Moreover,participantshadanopportunitytoelucidatemoreinformationontheimpactsandassociatedvulnerabilitiesidentifiedandcharacterizeperceivedimportanceofrisks.Priortotheworkshop,stakeholderswereprovidedwiththe

ClimateChangeImpactsofHighestPriority

SystemsPremises/Infrastructure/Assets

Cost/Time(Includingreputation)

EnvironmentLogistics(Supplychain)

People CorporateProcesses

Infrastructurefailurecausingflooding x x x x x x

Poweroutages x x x x x xSewerbackupsandsurcharging x x x x x x

Humanhealthimpacts Conditional x x x x xInterruptiontopublictransportation Dependsonscale x x x x x

Interruptiontotelecommunicationservices

x x Conditional x X x

Basementflooding x x x Conditional X Conditional

Table3:SystemsAffected


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resultsofthesurveyandasummaryofhistoricalandfutureclimatetrendsproducedbyCAP,GLISA,andOCC.Usingfocuseddiscussiontechniques,theProjectTeamguidedstakeholderstoaconsensusontheclimatechangeimpactsofgreatestconcerntoarangeofmanagementandserviceareasinYorkRegion.Furthermore,thestakeholdergroupdiscussedsysteminteractionsassociatedwiththeimpactsandperceivedconsequences(Table3).Finally,theworkshopallowedforadiscussionaroundclimatechangepreparednesswithinYorkRegion.Asaresult,thegroupidentifiedthefollowingsevenimpactsasbeingassociatedwithgreatlevelsofconcern:

• Infrastructurefailurecausingflooding• Poweroutages• Sewerbackupsandsurcharging• Humanhealthimpacts• Interruptiontopublictransportation• Interruptiontotelecommunication

services• Basementflooding

ThesurveyandworkshopindicatedastronglevelofagreementthatYorkRegionisalreadyexperiencingextremeprecipitationevents,changesintimingoffreeze/thawcycles,changesinaveragetemperature,extremeheat,extremehotdays,andchangesinlakewaterlevels.Noteworthyagreementshowedthatchangesintypesofprecipitation,extremecolddays,changesingrowingseason,andsnow/icestormsarealsopresentintheregion.Theresultsalsoshowedthatthefollowingclimateeventimpactsareperceivedasmorefrequent:increasederosionandsedimentation,sewerbackupsandsurcharging,coastalandriverineflooding,infrastructurefailurecausingflooding,deterioratedwaterquality,impactsonhumanhealth,andinterruptiontopublictransportation.Participantsalsoindicatedanincreasedfrequencyinthenumberofcombinedseweroverflows,basementflooding,severewatershortages,reducedagriculturalyield,andpoweroutages.AlevelofunfamiliarityinYorkRegionwaspresentedwiththeimpactsofdecliningwatersupplies,increasedwildfires,andinterruptiontotelecommunicationservices.Thesurveyalsoindicatedalevelofconsensusaroundtheideaofchangesthatwereidentifiedas“mostlikely”totakeplaceunderchangingregionalclimate

conditions.Morespecifically,changesinaveragetemperaturesandfrequencyofextremeprecipitationeventswereidentified.Accordingtothesurvey,climateeventsperceivedas“verylikely”tooccurinthisregionincluded:extremeheat,increasednumberofhotdays,changesintypeofprecipitation,changesintimingoffreeze/thawcycles,changesingrowingseason,historicalclimateloads,lakewaterlevels,extremecolddays,snow/icestorms,anddrought.Furthermore,thisworkshopinitiatedadiscussionaroundpreparednesswithinYorkRegion.ParticipantsrecognizedthatthefollowingactionswereplannedorongoinginYorkRegionandwithinitspartnermunicipalitiesthatarerelevanttoclimatechangeadaptation(includingbutnotlimitedto):

• YorkRegionPublicHealthprograms:o Extremeheatmonitoring

programo Beachwatersamplingo Vector-bornediseases(WestNile

virus,Lymedisease,EasternEquineEncephalitis)

• UrbanheatislandstudyinYorkRegion• UpdatestotheOntarioPublicHealth

StandardsandProtocols• UpdatingYorkRegionGreeningStrategy• SustainableDevelopmentinitiatives(e.g.

LEEDstandards,LowImpactDevelopment(LID),andupdatedguidelines)

• GreenlandsStrategy• Monitoringprogramsreporting;• Treeplantingprograms• SupporttobusinessthroughTheClimate

WiseNetwork(SustainabilityCoLABframework)

• GreenParkingguidelines• Updatingofdesignstandardsforwater,

stormwater,andwastewater• InclusionofLIDstandardsintodesign

standards• Electricvehiclechargingstations

deployment• LEDstreetlightreplacements• Incorporationofsustainabilitymetrics• Districtenergyinitiatives• Adaptationandmitigationinclusive

sustainabilitymasterplans• Eco-homes(LEEDHomesPlatinum)


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ACaseStudyonCityofVaughanStormwaterMunicipalInfrastructureThestormwatersystemoftheCityofVaughanwasselectedasacasestudytoutilizethetailoredtoolsandframeworksanddelveintoMilestone3oftheICLEIframeworkinmoredetail.Thiscitywasselectedduetoongoingeffortsofthestormwaterandsustainabilitymunicipalstafftocharacterizevulnerabilitiesandrisksinlightofclimatechange.Thegoalsofthiscasestudyweretosupportthecharacterizationofvulnerabilitiestoclimatechange,furtherdevelopthecapacityofstafftoconductriskandvulnerabilityassessments,andsupporttheongoingadaptationplanningeffortsintheCityofVaughanbyincorporatingtheadaptationtoolsdeveloped.Inordertoclearlydefinethesystemundergoingdetailedanalysis,thecasestudyteamselectedthreestormwaterinfrastructureassetcategories:

• Stormwatermanagementponds(wetanddry)

• Stormwatermains• Ditches,catchbasins,andculverts

Acombinationofdesktopreviewofacademicandgreyliterature,combinedwithstructuredinterviewsanddiscussionswithselectedstormwaterexpertshelpedrecognizetheimpactsofinterestandsupportedthedefinitionofvulnerabilityfactorsforeachoftheassetcategories.Vulnerabilityfactorsrefertothespecificassetattributesthatmakeitmoreorless“vulnerable”totheimpactinquestion.Thedefinitionsofthesefactorssupportthefurtherunderstandingofthesensitivitytoclimatechangeandtheoveralladaptivecapacityofthesystem.Theliteraturereviewaccountedforaccreditedresearchonthecurrentstateofknowledgeregardingstormwaterinfrastructurevulnerabilitytoclimatechange,whiletheexpertengagementsaimedtovalidateandexpandontheinformationrelevanttotheCity’ssystem.ThedocumentationoftheinformationfoundwasorganizedandguidedbytheP-CRAFTtemplates,whichwerethenincorporatedintotheCOTdatabase.Theliteraturereviewandstakeholderengagement

providedthescientificbackgroundtodefinevulnerabilityindicatorsandperformtheanalysis/mappingofstormwatersystemvulnerabilitiesintheCityofVaughan.Theapproachtakenthroughthisframeworkfocusedontheconceptsofvulnerabilityandadaptivecapacitytounderstandhowthesystemrespondstoaclimatedriverandhowtodefineriskandpossibleadaptationmeasures.Theassumptionisthatalthoughfutureclimateinformationislimitedandoflowerresolutionatthelocalscale,evaluatingthesystem’sadaptivecapacityiscrucialtocharacterizepotentialriskinlightofuncertaintyassociatedwithfutureclimate.Stormwater-specificclimaticindicatorsandtrendsweredevelopedthroughseriesofinterviewsandexpertconsultationswithmunicipalstormwaterpractitionersandbasedonthereviewedofliterature,includingpaststormwaterriskassessments.GLISAandtheOCCanalyzedtheclimatedatatoinformtheprobabilityofexposuretoextremeclimateeventsinthecasestudyarea(Table4).Table4:SampleClimateIndicatorsRelevanttoStormwaterClimateIndicators ThresholdsExtremeHeavy1-dayTotalRainfall Dayswithrainfall>100mm

Heavy1-dayTotalRainfall Dayswithrainfall>50mmHeavy5-dayTotalRainfall 5-dayperiodwith>100mmof

rainfallRainFrequency Numberofdayswith>10mmof

rainWinterRain/Rain-onSnow Numberofdayswith>25mmof

rainduringJanuarytoMarchTheCOTtoolandP-CRAFTtemplatesallowedtheworkinggrouptocollectandanalyzeinformationforderivingvulnerabilityfactorsandindicatorsinatransparentway.Thisapproachtodeterminingriskencouragesgreatertransparencyandabetterunderstandingofpathwaysbywhichclimatedriverscanresultinimpacts,whichposeriskstotheassetsundergoinganalysis.Toimprovetheimpactofthecapacity-buildingexercise,thecasestudyteamincludedthefollowing:aprocessleadwithinacentraldepartment,whowasfocusedontheuseoftheframeworksandtoolstoguidetheprocessandanexpertlead,whoguidedthetechnicalteamthroughtheanalysis,ensuringthework’sadherencetothediscipline’sprinciplesandbestpractices.Itisexpectedthatthisstructurewill


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allowfortheprocessleadtoparticipateinseveralassessmentswithinthemunicipality,bringinglessonslearnedandexperiencetothemultipleexpertteamsconductingvulnerabilityandriskassessments.

SummaryofProjectOutputsAsaresultofthiscollaborativeeffort,theProjectTeamfocusedondevelopingtoolsandprojectdeliverablesthatsupportthedevelopmentofanadaptation,risk,andvulnerabilityframeworktoassistsYorkRegionandeachoftheninemunicipalities.Tosupporttheseefforts,theProjectTeamdevelopedthefollowingresources:

• Adetailedandpeer-reviewedtechnicalmanualoutliningthestepsinvolvedintheproposedframework,focusingontheCOTandP-CRAFTamalgamatedtool(comprisingofasetofprocesses,toolsandtemplates)

• A‘primed’tool(COT–P-CRAFT)tofacilitatefutureriskandvulnerabilityassessmentsofavarietyofsystemswithinYorkRegion.Thistemplatewaspopulatedwithinformationonclimatehazards,managementandserviceareasrelevanttoYorkRegion,andadaptationmeasuresfrompreviousvulnerabilityassessmentswithintheGTA

• Adetailedpeer-reviewedreportonclimatetrends,includinghistoricalandfutureclimatologicalinformation,focusedonvariablesrepresentingweatherhazardsinYorkRegion

• Workshopsandsurveystoengagestaffinriskandvulnerabilityassessmentandadaptationplanningmorebroadly

• Theresultofanannotatedliteraturereviewofover100publicationsfocusedonmunicipalstormwatermanagementsystemsusingtheP-CRAFTtemplatesforselectedassetcategoriesoftheCityofVaughan’sstormwatersystem

• Apopulatedriskandadaptationtool(COT–P-CRAFT)includingtheresultsoftheprocessstepsfollowedtoconductavulnerabilityandriskassessmentoncasestudy(stormwatersystemoftheCityofVaughan).

LessonsLearnedThisprojecthasbroughtnumerousbenefitstoYorkRegionanditsmunicipalities.First,stakeholderswereinitiallyintimidatedbythecomplexityofclimatedata,models,andinformation:- Localmunicipalitiesperceivelackofclimate

scienceandinformationasabarriertoinitiatingriskassessmentandadaptationplanninginformation.

- However,participantswereverycomfortablediscussingextremeweathereventsthathadalreadyimpactedtheirareasofexpertise.Manyalsohadinsightsonwhatfutureimpactswerelikely.

- Startingvulnerabilityandadaptationdiscussionsatthisverypracticallevelledtogreaterunderstandingandacceptanceoftheregionalclimatemodelinformation.

Second,third-partyassistancewasalsobeneficial:- Havinganoutsideorganization(e.g.GLISA)

helpedallparticipatingmunicipalitiesdevelopacommonassessmentandplanningframework.

- Workshopparticipantshadgreatercomfortthatmethodologybeingdevelopedwouldmeettheneedsandbeapplicabletoallorganizations.

- Projectstakeholderswereabletoleveragetheircollaborativeeffortstoengageclimateexpertsthattheymightnothavehadaccesstoindividually.

- Stakeholderswerealsomorecomfortablethatdecisionsbasedonclimateinformationanduseofacommontoolwouldbemoredefensiblegiventheexpertisethatleveragedinthisproject.Therewassomediscussionthatthiswouldpotentiallymaketheresultsoftheseassessmentsmorereadilyacceptedbymunicipalcouncils.

- Dedicatedoutsideresourcesensuredthattheprojectstayedontrackanddidn’tcompetewithconflictingpriorities(corebusiness)ofprojectstakeholders.

Finally,useoflocaltoolsledtogreateracceptance:


12

- Utilizingtoolsthathadbeendevelopedbylocalmunicipaljurisdictionswasbeneficialtothisproject.

- Therewasgreatercertaintythatthesetoolsworkedwithintheexistingadministrative,geographical,andlegislativecontextrelevanttoprojectstakeholders.

- Utilizingexistingtoolsalsocreatedasenseofurgency,wherebyprojectstakeholderswereencouragedtorespondefficientlyandbeengagedthroughouttheprocess.

NextStepsandKnowledgeTransferNextstepsforthisprojectincludecompletingtheoutstandingstepsforthecasestudyvulnerabilityanalysisandacapacity-buildingexercisetodevelopstormwater-specificadaptationrecommendations.Thisportionoftheprocessincludes:

• Validationofthevulnerabilityfactorsandindicatormappingforthestudyarea

• Identificationofprioritieswithintherisksidentified

• Integrationofthe‘lessonslearned’andadaptationmeasuresproposedbyexistingassessmentsintheadaptationmeasuresdiscussions

FurthereffortsareongoingtomaximizetheimpactofthedeliverablesandlessonslearnedfromthisprojectinYorkRegion.Theseeffortsandnextstepsinclude:

• DiscussionsontheopportunitytoincorporatetheframeworkguidancedocumentsintotheadaptationstrategyofYorkRegion

• ConsultationstodefinedatasharingprocessesforthisframeworkthatareinlinewithcurrentprocesseswithinYorkRegion

• OngoingefforttoformalizeandstrengthenmunicipalitiesthroughtheJointMunicipalClimateChangeWorkingGroup,asaplacetoshareandleveragelessonslearnedfromadaptationandmitigationeffortsacrosstheregion

• EffortstoincreasetheexposureofthemunicipalitiesacrosstheYorkRegiontothisproject’sdeliverables

• Supportinguidingthetrainingofprocessexpertsinlocalmunicipalities

• Effortstoleverageopportunitiestoaddresscompoundingrisksthroughcollaborationattheregionandmunicipallevel

References

Auld,H.,Switzman,H.,Comer,N.,Eng,S.,Hazen,S.,

andMilner,G.(2016).ClimateTrendsandFutureProjectionsintheRegionofPeel.OntarioClimateConsortium:Toronto,ON.

CityofTorontoandDeloitteLLP.(2011).EnvironmentalRiskAssessment:Userand

TechnicalManual.Version1.6.Toronto,ON:pp.93.

Fausto,E.,Milner,G.,Nikolic,V.,Briley,L.,Basile,S.,Behan,K.,andTrainor,E.2015.HistoricalandFutureClimateTrendsinYorkRegion.

OntarioClimateConsortium:Toronto,ON:pp.48.

LocalGovernmentsforSustainability(ICLEI).(2010).ChangingClimate,ChangingCommunities:GuideandWorkbookfor

MunicipalClimateAdaptation.AvailableOnline:http://www.icleicanada.org/images/icleicanada/pdfs/GuideWorkbookInfoAnnexes_WebsiteCombo.pdf

IPCC(2012).SummaryforPolicymakers.In:ManagingtheRisksofExtremeEventsandDisasterstoAdvanceClimateChangeAdaptation[Field,C.B.,V.Barros,T.F.Stocker,D.Qin,D.J.Dokken,K.L.Ebi,M.D.Mastrandrea,K.J.Mach,G.-K.Plattner,S.K.Allen,M.Tignor,andP.M.Midgley(eds.)].ASpecialReportofWorkingGroupsIandIIoftheIntergovernmentalPanelonClimateChange.CambridgeUniversityPress,Cambridge,UK,andNewYork,NY,USA,pp.1-19.

IPCC(2013).ClimateChange2013:ThePhysicalScienceBasis.ContributionofWorkingGroupItotheFifthAssessmentReportoftheIntergovernmentalPanelonClimateChange[Stocker,T.F.,D.Qin,G.-K.Plattner,M.Tignor,S.K.Allen,J.Boschung,A.Nauels,Y.Xia,V.BexandP.M.Midgley(eds.)].CambridgeUniversityPress,Cambridge,UnitedKingdomandNewYork,NY,USA,1535pp.

IPCC-TGICA(2007).GeneralGuidelinesontheUseofScenarioDataforClimateImpactand

AdaptationAssessment.Version2.Preparedby


13

T.R.CarteronbehalfoftheIntergovernmentalPanelonClimateChange,TaskGrouponDataandScenarioSupportforImpactandClimateAssessment,66pp.

LaboratoryofMathematicParallelSystems(LAMPS)(2014).DevelopingHigh-Resolution(45kmx45km)ProbabilisticClimateProjectionsoverOntariofromMultipleGlobalandRegionalClimateModels.Downloadedfromhttp://haze.hprn.yorku.ca/moe/on26/06/14.

McKenney,D.W.,Hutchinson,M.F.,Papadopol,P.,Lawrence,K.,Pedlar,J.,Campbell,K.,Milewska,E.,Hopkinson,R.,Price,D.,Owen,T.(2011).CustomizedspatialclimatemodelsforNorthAmerica.BulletinofAmericanMeteorologicalSociety-BAMSDecember:1612-1622.

Meehl,G.,Zwiers,F.,Evans,J.,Knutson,T.,Mearns,L.,&Whetton,P.(2000).TrendsinExtremeWeatherandClimateEvents:IssuesRelatedto

ModelingExtremesinProjectionsofFuture

ClimateChange.BulletinoftheAmericanMeteorologicalSociety,81(3),427-436.

Notaro,M.,BenningtonV.,andVavrusS.(2015).Dynamicallydownscaledprojectionsoflake-

effectsnowintheGreatLakesBasin.JournalofClimate,28,1661-1684.

Notaro,M.,BenningtonV.,andLofgrenB.(2015).Dynamicaldownscaling-basedprojectionsof

GreatLakes’waterlevels.J.Climate,inrevision.

SENESConsultantsLimited.(2011).Toronto'sFutureWeatherandClimateDriverStudy:

Volume1-Overview.Toronto,Canada.Sillmann,J.,Kharin,V.V.,Zhang,X.,Zwiers,W.;

Bronaugh,D.(2013a).ClimateextremeindicesintheCMIP5multimodelensemble:Part1.

Modelevaluationinthepresentclimate.JournalofGeophysicalResearch:Atmospheres,118,1716-1733.

Sillmann,J.,Kharin,V.V.,Zhang,X.,Zwiers,W.,Bronaugh,D.(2013b).ClimateextremeindicesintheCMIP5multimodelensemble:Part2.

Futureclimateprojections.JournalofGeophysicalResearch:Atmospheres,118,2473-2493.

Switzman,H.,andHazen,S.2015.ThePeelClimateRiskAnalysisFrameworkTool(P-CRAFT):

TechnicalReportandGuidanceDocument

(DRAFT).OntarioClimateConsortium,Toronto,ON:pp.47.

Tebaldi,C.andKnuttiR.(2007).Theuseofthemultimodelensembleinprobabilisticclimate

projections.PhilosophicalTransactionsoftheRoyalSociety(specialissueonProbabilisticClimateChangeProjections),Vol.365,pp.2053-2075.

Wang,XiuquanandGordonHuang(2013).OntarioClimateChangeDataPortal.AvailableOnline:http://www.ontarioccdp.ca

Wang,Xiuquan,etal.(2015).EnsembleprojectionsofregionalclimaticchangesoverOntario,

Canada.JournalofClimate.DOI:http://dx.doi.org/10.1175/JCLI-D-15-0185.1.>>Download

WorldMeteorologicalOrganization(WMO).2007.TheRoleofclimatologicalnormalina

ChangingClimate.WorldClimateDataandMonitoringProgramme-No.61.WMO-TDNo.1377.

Zhu, H., Deng, Z., Switzman, H., Hazen, S., andFausto,E.(2015).IdentificationandValidationofExtremeWeatherIndicatorsforAgricultural

Production and Rural Resilience in Ontario.Ontario Climate Consortium & Laboratory ofMathematical Parallel Systems (Lamps):Toronto,ON.


14

AppendixA

TableA-1:ReviewedExistingGTAAssessmentsJurisdiction /

Proponent Assessment Theme Geography Year Completed Climate Information Adaptation Policy /

Framework Assessment Protocol /

Tools Assessment Tier*

Region of Peel

Public Health Peel 2013 None ICLEI WHO (2003) II

Agriculture Caledon, Brampton 2015 (ongoing) Auld et al. (2015) ICLEI P-CRAFT** II

Natural Heritage Peel 2015 (ongoing) Auld et al. (2015) ICLEI P-CRAFT & Gleeson et al. (2011) II

Hydrology Credit Valley Watershed 2015 (ongoing) TBD ICLEI PIEVC*** III

Economy Mississauga 2015 (ongoing) Auld et al. (2015) ICLEI - II Municipal critical infrastructure /

services(roadways, electrical distribution, shoreline, private

property, public health)

Port Credit 2015 (ongoing) Auld et al. (2015) ICLEI P-CRAFT II

Greater Toronto Airports Authority Stormwater Infrastructure

Pearson International

Airport 2014

CCCSN 2007a, CCCSN 2007b, AR4 2007(TRCA

2009)

Internal risk management PIEVC III

Region of Durham All municipal service areas (Public Health, Transportation, Flooding,

Electrical Grid, Agriculture/food, ) Durham 2014 Senes (2011) Senes (2014) ICLEI - I

City of Toronto Transportation services City of Toronto 2014 Senes (2011) Resiliency strategy Deloitte Tool III City of Hamilton & Conservation Hamilton

Hydrology and stormwater Spencer Creek watershed 2015 (ongoing) TBD TBD TBD III

Credit Valley Conservation Hydrology and stormwater Cooksville Creek

watershed 2015 (ongoing) Auld et al. (2015) - PIEVC III

Ontario Ministry of Natural Resources and Forestry

Terrestrial and Aquatic Ecosystems Lake Simcoe watershed 2012 McKenney et al. (2011) Gleeson et al.

(2011) Gleeson et al. (2011) II

WeatherWise Partnership

Electrical transmission and distribution infrastructure case

studies

City of Toronto and Mississauga 2015 (TRCA 2009) - PIEVC III

Notes: *Assessment Tier definitions based on UKCIP risk assessment types in Willows and Connell (2003): I – screening assessment; II – semi-quantitative, sector/theme focused; III – full quantitative, sector/theme detailed analysis ** P-CRAFT = Peel Climate Risk Analysis Framework and Templates (for conducting systematic review of risk information) *** PIEVC = Public Infrastructure Engineering Vulnerability Committee’s risk assessment protocol (for detailed engineering assessments) References: Auld, H., N. Comer, H. Switzman, S. Eng, and G. Milner. “Climate Trends and Future Projections in the Region of Peel”. DRAFT REPORT. Ontario Climate Consortium: Toronto, ON. Gleeson, J., P. Gray, A. Douglas, C. J. Lemieux, and G. Nielson. 2011. “A Practitioner’s Guide to Climate Change Adaptation in Ontario's Ecosystems”. Sudbury, ON. Reclamation, 2013. “Downscaled CMIP3 and CMIP5 Climate and Hydrology Projections: Release of Downscaled CMIP5 Climate Projections, Comparison with preceding Information, and Summary of User

Needs”. U.S. Department of the Interior, Bureau of Reclamation, Technical Services Center: Denver, Colorado. 47pp. SENES Consultants Limited (Senes). 2011. "Toronto's Future Weather and Climate Driver Study." City of Toronto: Toronto, Canada. SENES Consultants Limited (Senes). 2014. "Durham Region’s Future Cliamte." Durham Region: Durham, Canada. National Engineering Vulnerability Assessment to Climate Change for Flood Control Dams, Toronto and Region Conservation Authority (TRCA), December, 2009. Willows, R.(ed) and R. Connell (ed) Connell. 2003. “Climate Adaptation: Risk , Uncertainty and Decision-Making.” edited by R.I Willows and R.K Connell.UKCIP: Oxford, UK. World Health Organization (WHO). 2013. “Protecting health from climate change: vulnerability and adaptation assessment.” World Health Organization: Geneva.

ASSESSINGANDMITIGATINGMUNICIPALCLIMATERISKSAND

VULNERABILITIESINYORKREGION,ONTARIO

15

AppendixBTheconfidence in climateprojections variesby climatedriver, aswell asbymodel given the inherentassumptionsembeddedwith

atmosphericprocessesbeingcaptured.Asaresult,thisreportadoptslanguageusedintheIPCC’smostrecentassessmentreportingas

the basis for describing confidence and uncertainty in a particular climate driver. Confidence wording in the IPCC documents is

characterizedbytheuseofspecifictermssuchas‘verylikely’or‘virtuallycertain’(seeTableB-1).Therehasbeenagradualincreasein

confidenceoftheprojectionsfromclimatemodelsovertime.WitheachIPCCreportthereareincreasingquantityandhigherquality

observationsof the changing climateand improvements in themodel equations, parameterizations, and their spatial and temporal

detail.TheIPCCreportscontinuetoprovidethebestscience-basedinformationonprojectedclimatechangeassembledfromthebest

climateresearchersworldwide.Generally,evidenceisconsideredtobemorerobustwhentherearemultiple,consistent,independent

sourcesofhighqualityinformation(IPCC2012)(seeTableB-2).

TableB-1: ConfidenceterminologyemployedbytheIPCCintheirofficialreports(AR5)(fromIPCC2013)

Term Likelihood of the Outcome

Virtually certain 99 – 100% probability

Very likely 90 – 100% probability

Likely 66 – 100% probability

About as likely as not 33 – 66% probability

Unlikely 0 – 33% probability

Very unlikely 0 – 10% probability

Exceptionally unlikely 0 – 1% probability

Ag

reem

ent

of In

form

atio

n

High agreement

Limited evidence

High agreement

Medium evidence

High agreement

Robust evidence

Medium agreement

Limited evidence

Medium agreement

Medium evidence

Medium agreement

Robust evidence

Low agreement

Limited evidence

Low agreement

Medium evidence

Low agreement

Robust evidence

Evidence Strength (type, amount, quality, consistency)

Confidence Scale

FigureB-1: Conceptualdepictionoftherelationshipbetweenevidenceandconfidence(adaptedfromIPCC2012).

Given that the quantification of uncertainty associated with future climate projections was a key element of the analyses in this

project,itwasfeltthatusingalargerange(fromthe10thtothe90

thpercentile)ofclimatemodelprojectionsinanensemblewasthe

most robust way of capturing the range of uncertainty associated with climate projections in York Region. Both statistical and

dynamicaldownscalingtechniquesrelyongeneralcirculationmodels(GCMs)todrivelocal-scalemodelingandanalysis,andideallythe

uncertaintyassociatedwiththeGCMsshouldbepropagatedthroughthedownscalingprocess.Historicalanddownscaledlocalclimate

estimatesofextremeeventshavebeenobservedinmanystudiestoliewithintheuncertaintyboundsofrawGCMensembles.

Analyses in this projectwere limited to data availability and particularly to those climate datasetswhich are reputable, commonly

known and/or robustly created. While a full climate model ensemble (i.e. CMIP5) was not independently run, other datasets do

capturetheseprojectionsinamorelocally-relevantformatforYorkRegion.Forexample,theYorkUniversityLAMPSdatasetaccessed

(LAMPS2014)producedclimatevariablesforthe2050susingthefullCMIP5ensemblestatisticallydownscaledformat.Whileitshould

be noted that statistical downscaling relies on historical relationships among climate variables of various scales, and there is

uncertaintyastowhethertheserelationshipswillholdunderevolvingconditionsassociatedwithclimatechange,theYorkUniversity

LAMPSdatasetprovidesavaluableinitial lookattheCMIP5modelensemble.Furtheranalysescouldderiveclimatevariablesusinga

dynamicaldownscalingapproachbasedontheCMIP5.Aclimatetrendsreportprepared forYorkRegiondescribesclimatedatasets,

theirprojectedchanges,anduncertaintiesinmoredetail(seeFaustoetal.2015).

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