2020 environmental science written examination
TRANSCRIPT
ENVIRONMENTAL SCIENCEWritten examination
Thursday 26 November 2020 Reading time: 11.45 am to 12.00 noon (15 minutes) Writing time: 12.00 noon to 2.00 pm (2 hours)
QUESTION AND ANSWER BOOK
Structure of bookSection Number of
questionsNumber of questions
to be answeredNumber of
marksA 30 30 30B 9 9 90
Total 120
• Studentsarepermittedtobringintotheexaminationroom:pens,pencils,highlighters,erasers,sharpeners,rulersandonescientificcalculator.
• StudentsareNOTpermittedtobringintotheexaminationroom:blanksheetsofpaperand/orcorrectionfluid/tape.
Materials supplied• Questionandanswerbookof33 pages• Answersheetformultiple-choicequestions
Instructions• Writeyourstudent numberinthespaceprovidedaboveonthispage.• Checkthatyourname andstudent numberasprintedonyouranswersheetformultiple-choice
questionsarecorrect,andsignyournameinthespaceprovidedtoverifythis.• Unlessotherwiseindicated,thediagramsinthisbookarenot drawntoscale.• AllwrittenresponsesmustbeinEnglish.
At the end of the examination• Placetheanswersheetformultiple-choicequestionsinsidethefrontcoverofthisbook.
Students are NOT permitted to bring mobile phones and/or any other unauthorised electronic devices into the examination room.
©VICTORIANCURRICULUMANDASSESSMENTAUTHORITY2020
SUPERVISOR TO ATTACH PROCESSING LABEL HEREVictorian Certificate of Education 2020
STUDENT NUMBER
Letter
2020ENVSCEXAM 2
SECTION A – continued
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eaQuestion 1
WhichoneofthefollowingisthebestmeasureofEarth’secosystemdiversity?A. thevarietyofecosystemsinthebiosphereB. theabundanceofforestsinthelithosphereC. thegeneticdiversityofspeciesintheatmosphereD. therelativeabundanceofspeciesinthehydrosphere
Question 2ThecreationofaseedbankisintendedtoA. provideseedsforsaleatmarketprices.B. storegeneticdiversityforoneplantspecies.C. storegeneticmaterialforfuturegeneticmanipulation.D. storeseedstosupportthemaintenanceofspeciesdiversity.
Use the following information to answer Questions 3–6.LordHoweIslandinNewSouthWalesisanareaprotectedunderinternationalagreement.Theislandishometoseveralrareandendemicspecies,includingtheLordHoweIslandsilvereye,asmallbirdspecies.Ratswereintroducedtotheislandwhenasteamshipranagroundin1918.Sincethattimetherehavebeenconcernsthatthesmallbirdwillbecomeextinctduetocompetitionwithandpredationfromtherats.
Question 3WhichinternationalagreementprotectstheenvironmentofLordHoweIsland?A. WorldHeritagelistingB. Flora and Fauna Guarantee Act (Vic)C. ConventiononInternationalTradeinEndangeredSpeciesD. Environment Protection and Biodiversity Conservation Act 1999
Question 4TheintroducedratsareanexampleofA. anexoticspecies.B. aprotectedspecies.C. asymbiontspecies.D. anendemicspecies.
SECTION A – Multiple-choice questions
Instructions for Section AAnswerallquestionsinpencilontheanswersheetprovidedformultiple-choicequestions.Choosetheresponsethatiscorrectorthatbest answersthequestion.Acorrectanswerscores1;anincorrectanswerscores0.Markswillnotbedeductedforincorrectanswers.Nomarkswillbegivenifmorethanoneansweriscompletedforanyquestion.Unlessotherwiseindicated,thediagramsinthisbookarenotdrawntoscale.
3 2020ENVSCEXAM
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Question 5ThepopulationoftheLordHoweIslandsilvereyeisstableandhasbeenestimatedatabout5000breedingbirds.However,theInternationalUnionforConservationofNaturestillclassifiesthespeciesas‘vulnerable’.WhichoneofthefollowingisthebestreasonwhytheLordHoweIslandsilvereyeisstillclassifiedas‘vulnerable’?A. Thebirdsareatriskofinbreeding.B. Thegeographicrangeofthebirdsisrestricted.C. Thebirdsareatriskofgeneticswamping.D. Thespeciesislikelytobecomeextinctintheimmediatefuture.
Question 6In2019,conservationistsintroducedchemicallybaitedtrapstoeradicatetherats.Someoftheisland’sresidentswereconcernedabouttheeffectofbaitingonendemicspeciesthatmightfeedondeadratsoverthecourseoftheeradicationprogram.Whichoneofthefollowingexplainstheresidents’concerns?A. lossofpreyfortheratsB. overexploitationoftheratsC. overpopulationofendemicspeciesD. bioaccumulationinthetissuesofendemicspecies
Use the following information to answer Questions 7 and 8.Thebare-nosedwombatisanAustraliannativeanimalfoundinTasmania,theBassStraitislandsandmainlandAustralia.TheBassStraitislands’populationissmallandisolatedfromtheotherpopulations.Althoughtheirappearanceisdifferentfromthatoftheirmainlandrelatives,geneticstudieshavefoundthattheBassStraitislands’wombatshaveclosegeneticsimilaritytowombatsfoundonthemainlandandinTasmania.
Question 7Inthecaseofthebare-nosedwombat,shouldvariationsinmorphologyalonebeusedasconclusiveevidenceofahighlevelofgeneticdiversity?A. No,asthewombatsshownophysicaldifferencesfromtheirmainlandrelatives.B. Yes,asthewombatsaredifferentinphysicalappearance,despitetheirlowpopulationnumbers.C. No,asgeneticstudiescanprovidefurtherevidenceofthelevelofgeneticdiversityinthepopulation.D. Yes,asvariationsinmorphologyareconclusiveevidenceofahighlevelofgeneticdiversityinapopulation.
Question 8WhendecidingwhethertoimplementprotectionmeasuresfortheTasmanianpopulationsofthebare-nosedwombat,whichoneofthefollowingconsiderationsisoftheleastimportancefromanecocentricviewpoint?A. humanbenefitB. fundingofselectedspeciesC. theprecautionaryprincipleD. maintainingspeciesrichness
2020ENVSCEXAM 4
SECTION A – continued
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Question 9Coalisformedovertimefromdecayingplantmatterundergreatpressure.Whichoneofthefollowingisthebestapproximationofthetimetakenforcoaltobeformed?A. 1billionyearsB. 100millionyearsC. 2–3millionyearsD. 100000years
Question 10Whichoneofthefollowingisnotafossilfuel?A. oilB. coalC. naturalgasD. hydro-electricity
Question 11Whichoneofthefollowingisastatementofthefirstlawofthermodynamics?A. Thetemperatureoftheworldissteadilyrising.B. Thetotalenergyofanisolatedsystemisconstant.C. Thetemperatureofanisolatedsystemsteadilyrises.D. Thetotalenergyofanisolatedsystemsteadilydecreases.
Question 12Whichoneofthefollowingcorrectlydescribesnaturalgasasanenergysource?A. renewable,fossilsourceB. renewable,non-fossilsourceC. non-renewable,fossilsourceD. non-renewable,non-fossilsource
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Use the following information to answer Questions 13–15.
Emissions of carbon dioxide from various fuel types
Fuel type Carbon content (kgC/kg fuel )
Energy content (kWh/kg fuel)
Carbon dioxide emission relative to energy content
(kgCO2/kWh)
Carbon dioxide emission relative to amount of fuel
(kgCO2/kg fuel)
methane(naturalgas) 0.75 15.4 0.18 2.8
diesel 0.86 12.7 0.25 3.2
blackcoal(bituminous)
0.65 8.4 0.28 2.4
browncoal(lignite) 0.30 3.9 0.28 1.1
wood 0.50 4.5 0.41 1.8
Data:EngineeringToolBox(2009),‘CombustionofFuels–CarbonDioxideEmission’,online, <www.engineeringtoolbox.com/co2-emission-fuels-d_1085.html>
Note: kg–kilograms,kWh–kilowatthours
Question 13Whichoneofthefollowingstatementsiscorrect?A. Woodhasthelowestenergycontent.B. Methanefuelcontainstheleastamountofcarbonperkilogram.C. Whencombusted,dieselproducesmorecarbondioxideperkilogramthananyoftheotherfueltypeslisted.D. Whencombusted,onekilogramofblackcoalproducesthesameamountofenergyasonekilogramofbrown
coal.
Question 14Whichunitisusedtomeasuretheamountofcarbondioxideproducedbyeachfueltypeduringcombustion,accordingtohowmuchenergyeachtypecontains?A. kilogramsofcarbondioxideB. kilowatthoursperkilogramoffuelC. kilogramsofcarbondioxideperkilogramoffuelD. kilogramsofcarbondioxideperkilowatthour
Question 15Inordertogeneratethedatainthetable,scientistsrepeatedthemeasurementofenergycontentineachofthefuelssixtimesusingthesameprocedureandequipment.Theresultstheyobtainedwereallwithin0.2%ofeachfigurelistedinthetable.Astherewasacloseagreementwithineachsetofresults,itcanbesaidthatthereisaA. highlevelofaccuracy.B. highdegreeofprecision.C. lackofbiasduringtheexperimentalprocedure.D. lackofquantitativedatawithineachofthesets.
2020ENVSCEXAM 6
SECTION A – continued
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Question 16Urbanenvironmentscontainmanysurfaces,suchasroadsandroofs,thatstoprainwaterfromsoakingintothegroundandcauseahigheramountofrun-offtoflowintodrains,creeksandrivers.Run-offfromthesesurfacesoftencarriesrubbish,chemicalsorpollutants.Thisrun-offcanhaveadirectharmfulimpactonboththeA. biosphereandlithosphere.B. atmosphereandlithosphere.C. atmosphereandhydrosphere.D. hydrosphereandbiosphere.
Question 17Water-sensitiveurbandesignisanapproachtoplanninganddesigningnewurbandevelopmentsthatmakesbetteruseofrun-offandmanagesimpactsoncreeks,riversandotherwaterbodies.Discussionswithlocalgovernmentagenciesandenvironmentalinterestgroupsaboutaspecificwater-sensitiveurbandesignwouldberegardedasA. partoftheuser-paysprinciple.B. usefulstakeholderinvolvement.C. aminorstepintheplanningprocess.D. importantwhenthedevelopmentiscompleted.
Question 18Insteadofallowingrun-offtoflowdirectlyintoalocalcreek,plannersdevelopastrategytostorethewaterinanearbypondecosystem.Thiswillhelptocleanthewaterandfilteroutanypollutants,andthendivertitforusebylocalstrawberryfarms.ThisstrategywouldberegardedasA. designingforresourceuseefficiency.B. havinganegativeimpactonthestrawberryfarms.C. awayofsequesteringcarbonintheenvironment.D. decreasingtheecologicalsustainabilityofthelocalcreek.
7 2020ENVSCEXAM
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Question 19Aspartofwater-sensitiveurbandesign,somedevelopmentsincludestrategiestotreatwastewater,suchassewage,andrecycleit.InVictoria,theEnvironmentProtectionAuthority(EPA)setsguidelinesforthequalityofrecycledwaterandworkswiththeDepartmentofHealthandHumanServicestoassessandmonitorwaterquality.TheworkoftheseagenciesA. involvesenforcingaregulatoryframework.B. includesmakingregulationsthatwillresultinadecreaseinwaterquality.C. isunnecessarybecausesewageshouldnotberecycledforhumanuse.D. isimportantsothatthewaterqualitystandardssetbydevelopersareevaluated.
Use the following information to answer Questions 20 and 21.Thegraphbelowshowsapproximateglobalaveragesurfacetemperatureversusyearsbeforepresenttime.
400000 300000 200000 100000years before present time
presentglobal averagesurfacetemperature
2 °C
0 °C
–2 °C
–4 °C
–6 °C
–8 °C
–10 °C
–12 °C
–14 °C
global averagesurfacetemperature
Data:adaptedfromClimateDataInformation, <www.climatedata.info/proxies/ice-cores>
Thegraphshowsglacialandinterglacialperiods.Glacialperiods(oriceages)arecolder,drierperiodsduringwhichlargeicesheetscoversignificantpartsofEarth’ssurface.Interglacialperiodsarewarmerperiodswhereglaciersandicesheetsmeltandreduceinsize.
Question 20Whichoneofthefollowinggivestheaveragetimeintervalbetweenwarmperiods?A. 1000000yearsB. 500000yearsC. 100000yearsD. 10000years
Question 21Therateofglobaltemperatureincreasebetweeniceages(glacialperiods)andwarmpeaks(interglacials)comparedtotherateoftemperaturedecreasebetweeninterglacialsandiceagesA. isfaster.B. ismuchslower.C. isapproximatelythesame.D. cannotbedeterminedfromthedata.
2020ENVSCEXAM 8
SECTION A – continued
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Use the following information to answer Questions 22 and 23.Fouridenticalclear-sidedcontainersarefilledwithdifferentgasesatthesamepressure,allat22°C:onecontainspureoxygen,onecontainspurecarbondioxide,onecontainsaircollectedintheyear2020andonecontainsairfromtheyear1800.ThecontainersarerandomlylabelledE,F,GandH.Thecontainersareexposedequallytoinfra-redlampsforonehour.Athermometerinsideeachcontainerrecordsthetemperature.Thetablebelowsummarisestheresultsoftheexperiment.
Container E Container F Container G Container H
Temperature after one hour 25°C 23°C 22.5°C 22°C
Question 22Whichcontainerholdspurecarbondioxide?A. EB. FC. GD. H
Question 23Whichcontainerholdsaircollectedintheyear2020?A. EB. FC. GD. H
9 2020ENVSCEXAM
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Question 24Thediagrambelowshowsthesun,EarthandpartsofEarth’satmosphere.ThelinesandarrowsA–Eindicatedifferentformsofradiation.
sun
deep space
upper limit ofEarth’s atmosphere
(stratosphere)
Earth’s surface
A
D
E
B C
(troposphere)
indicates not absorbedindicates beinggradually absorbed
Key
Whichlinesandarrowsindicateinfra-redradiation?A. DonlyB. AandDC. AandBD. CandE
2020ENVSCEXAM 10
SECTION A – continued
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Use the following information to answer Questions 25 and 26.In2019scientistspublishedclimatechangeprojectionsforaVictoriancity.Thetablebelowshowsthetemperatureprojectionsfortwopossiblesetsoffuturegreenhousegasemissionsintotheatmosphere:mediumemissionsandhighemissions.Foreachoftheyears2030,2050and2090,themediantemperatureriseisgiven,withthelikelytemperatureriserangeinbrackets.
Average daily maximum
temperature, 1986–2005
Greenhouse gas emissions
scenario
Projected changes (°C)
2030 2050 2090
20.4°C medium 0.9(0.8–1.3) 1.6(1.0–2.0) 2.2(1.8–3.4)
high 1.2(1.0–1.6) 1.9(1.5–2.7) 4.0(2.8–5.3)
Data:JMClarke,MGrose,MThatcher,VRoundandCHeady,‘GreaterMelbourneClimateProjections2019’, CSIRO,Melbourne,Australia,2019,<https://publications.csiro.au/rpr/pub?pid=csiro:EP195032>
Question 25Thebaselinefortemperatureprojectionsistheaveragedailymaximumtemperaturebetween1986and2005,ratherthanthepreviousyear’saveragedailymaximumtemperature.ThisisbecauseA. Earth’salbedoisrising.B. climatevariesfromyeartoyear.C. greenhousegasesareincreasingintheatmosphere.D. thepreviousyear’saveragedailymaximumtemperatureislikelytobehigherthanthe1986to2005average.
Question 26ClimateprojectionsforeachscenarioarepresentedwitharangeoflikelytemperatureincreasesbecauseA. citiesarehotterthanthesurroundingcountryside.B. projectionsarebasedontheexactfuturesequenceofevents.C. projectionsarebasedonpasttemperaturetrendsthathavebeenextendedintothefuture.D. climatemodelsvaryandtheresponseofclimatetorisinggreenhousegaslevelsisnotperfectlyunderstood.
Question 27ThenaturalgreenhouseeffectistheprocesswherebyatmosphericgreenhousegasesA. causethealbedoeffect.B. createnaturalvariabilityinclimate.C. increaseinconcentrationduetohumanactivities.D. maintainEarth’ssurfacetemperatureatahigherlevelthanitwouldbewithoutthem.
11 2020ENVSCEXAM
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END OF SECTION ATURN OVER
Question 28CarbonsequestrationisenhancedbyA. theburningofbiofuels.B. theintroductionofwaterpurificationsystems.C. areductioninthesaleofsingle-useplasticbottles.D. theplantingofnativetreeswithinremnantvegetation.
Question 29Whichoneofthefollowingcontributesto‘scientificuncertainty’?A. theexperienceoftheresearcherB. whethertheexperimentmeasureswhatisintendedC. variationduetolimitationsofthemeasuringequipmentD. thedifferencebetweenthehypothesisandtheexperimentalresults
Question 30Theconceptsofsustainabilityandecologicallysustainabledevelopment(ESD)aredifferentbecauseA. sustainabilityisthegoalandESDisaprocesstoachievethegoal.B. sustainabilityvaluesanthropocentrismandESDvaluesbiocentrism.C. sustainabilityconsidersonlysocialfactors,whereasESDconsiderssocial,environmentalandeconomicfactors.D. ESDemphasisesintragenerationalequity,whereassustainabilityemphasisesintergenerationalequity.
2020ENVSCEXAM 12
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SECTION B – Question 1 – continued
Question 1 (16marks)Thepresenceofahealthynumberofinsectsiscrucialtomaintainingbalancedecosystems.Intermsofabundance,insectsarethedominantformofanimallifeonEarth.Closetoonemillioninsectspecieshavebeendescribedtodate,whereasaround5416mammalspecieshavebeenidentified.ScientistssoughttomeasurehowthediversityofinsectlifeatalocationinruralVictoriahaschangedovertime.Theytookmeasurementsfromthesamelocationduringthesametwoweeksoftheyearin1995,2005and2015.ThescientistscalculatedSimpson’sIndexofspeciesdiversity(D)tocomparethediversityofinsectsoverthetimeperiod.Theindex(D)canbecalculatedusingthefollowingformula.
Simpson’sIndexofspeciesdiversity:Dn n – 1
N N – 1 i i1
Note:∑ referstothe‘sumof’ ni meansthetotalnumberoforganismsofeachindividualspecies N meansthetotalnumberoforganismsofallspecies
Thisformulashouldproduceavaluebetween0and1.Ahigherindexvalue(thatis,anumbercloserto1)indicateshigherspeciesdiversity.
SECTION B
Instructions for Section BAnswerall questionsinthespacesprovided.Unlessotherwiseindicated,thediagramsinthisbookarenot drawntoscale.
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SECTION B – Question 1 – continuedTURN OVER
a. CalculateSimpson’sIndexofspeciesdiversity(D)forthesitein2005intheblankspacesprovidedinthetablebelow.Theindexvaluesfor1995and2015havealreadybeencalculated. 3marks
1995 2005 2015
Insect type ni ni − 1 ni (ni − 1) ni ni − 1 ni (ni − 1) ni ni − 1 ni (ni − 1)
leafhopper 4 3 12 1 2 1 2
slater 17 16 272 11 6 5 30
honeybee 20 19 380 21 18 17 306
Christmas beetle
4 3 12 1 2 1 2
cicada 4 3 12 3 1 0 0
bogongmoth
30 29 870 20 2 1 2
dragonfly 7 6 42 2 1 0 0
butterfly (allspecies)
22 21 462 16 7 6 42
cricket 4 3 12 2 2 1 2
∑[ni(ni−1)] =2074
∑[ni(ni−1)]=
∑[ni(ni−1)] =386
N=112
N(N−1) 112 × 111 =12432
N= N(N−1) N=41
N(N−1) 41×40 =1640
D=1 207412432
−D= D=
1 3861640
−
D= 0.833 D= D= 0.765
b. Describethetrendinspeciesdiversityovertimeatthesamplesite.Usedatatosupportyouranswer. 2marks
2020ENVSCEXAM 14
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SECTION B – Question 1 –continued
c. Suggesttwoimprovementstothestudythatmayincreasetheaccuracyofitsresults.Makethemeaningoftheterm‘accuracy’clearinyouranswer. 3marks
d. i. Thesamerurallocationmaybehometoarangeofmammalspecies.
Describethemark-recapturesamplingmethodthatcouldbeusedtoestimatethepopulationsizeofamammalspecies. 2marks
ii. Explainwhetherthemark-recapturesamplingmethoddescribedinpart d.i.wouldbesuitableforsamplinginsects. 2marks
e. Explainonewayinwhichinsectsareanessentialpartofhealthyecosystems. 2marks
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SECTION B – continuedTURN OVER
f. Onestrategytomaintainthediversityofinsectsisimprovedtargetingofpesticidesinagriculturalareas.
Explainhowthisstrategycanhelpmaintainthediversityofinsects. 2marks
2020ENVSCEXAM 16
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SECTION B – Question 2 –continued
Question 2 (12marks)Aftersevereenvironmentalchanges,suchasthosecausedbyavolcaniceruption,conservationistsworktorehabilitateanimalsandplantsinanaffectedarea.Thisstrategyincludesactiveanimalrescue,whereinjurednativeanimalsareremovedfromthechangedhabitat.Theseanimalsarethenplacedinwildlifesanctuaries.
a. Intermsofmaintainingnativeanimalpopulations,suggestwhyonlyinjuredanimalsareremovedfromdamagedhabitats,ratherthanthehealthyanimals. 2marks
b. Outlineonetechniquethatisemployedbyconservationiststoensurethegeneticdiversityofaspeciesismaintainedaftertheremovalofindividualsfromapopulation.Explainhowthistechniqueeithermaintainsorincreasesgeneticdiversity. 3marks
c. Suggestanotherconservationtechniquethatcouldbeemployedafteravolcaniceruption.Explainhowthistechniquemaypromotebiodiversity. 3marks
17 2020ENVSCEXAM
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SECTION B – continuedTURN OVER
Theparadiseparrot,previouslyfoundinNewSouthWalesandQueensland,isthoughttohavebecomeextinctduetopredationinthe1920s.
d. Istheextinctionoftheparadiseparrotanexampleofamassextinction?Explainyouranswer. 2marks
e. Whatconservationcategorywouldtheparadiseparrothavebeenassignedtojustpriortotheextinction?Explainyourreasoning. 2marks
2020ENVSCEXAM 18
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SECTION B – Question 3 –continued
Question 3 (12marks)Themainbeachofacoastaltownisexperiencingongoingproblemswitherosion.Toprotectthecoastalenvironment,45yearsagothetowncouncilbuiltaone-metre-highstoneseawall.Betweentheseawallandthetownarevegetatedsanddunesthatareanimportanthabitatforanumberofthreatenedplantandreptilespecies.Thetownisbuiltonlow-lying,flatland.Thebeachareahasdecreasedduetoerosion,particularlyoverthelastthreeyears.Atthesouthernendofthebeachisarockypointthatispartofanoffshoremarinereserve.Manyrecreationalscubadiversandsnorkellersusethereserve.Lastwintertheseawallwastoppedbystormwaves,causingdamagetothewallandthelossofindigenousplantsonthesanddunes.Climatechangemodelsindicatehighersealevelsareexpectedinthefuture,withprojectedincreasesfortheyear2090beingbetween0.51m(intermediatewarmingscenario)and0.70m(highwarmingscenario).Risingsealevelscombinedwithwavesduringastormsurgearelikelytocauseacceleratedbeachandduneerosion,andincreasedriskoffloodingoflow-lyingareas.Thetowncouncilisdevelopingamanagementplanandconsideringanumberofproposalsregardingtheseawallanderosionofthebeachandsanddunes.Oneproposalistorepairtheseawallandincreaseitsheightbyhalfametre.Asecondproposalistodonothingbecauseseawallsareverycostly,andthenaturalprocessesandimpactsoferosionarenotfullyunderstoodlocally.Thegroupputtingforwardthissecondproposalbelievesthesealevelwillnotrisetothelevelspredictedineitherwarmingscenario.
a. Itissuggestedthattheproposaltorepairthedamagedseawallandincreaseitsheightbyhalfametreshouldberegardedasanecologicallysustainabledevelopment.
Usetheprinciplesofintergenerationalequity,andconservationofbiodiversityandecologicalintegritytohelpjustifythissuggestion. 5marks
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SECTION B – continuedTURN OVER
b. Usingtheappropriatesustainabilityprinciple,explainwhythesecondproposal(thatis,todonothingtotheseawall)wouldberegardedasanincorrectapproach.Explainhowtheprincipleappliestothissituation. 3marks
c. Afirststepindevelopingamanagementplanistoidentifythepotentialrisksofeachproposalregardingtheseawall.
Oncethesepotentialrisksareidentified,whatelseshouldbedoneintermsoftheriskmanagementprocess? 2marks
d. LocalEnvironmentalSciencestudentshavebeenaskedtohelpcollectscientificdataaboutspecieslivingwithintheoffshoremarinereserve.
Identifyonehealthandsafetyconcernandoneethicalconcernthatthestudentsshouldmanagewhencollectingthisdatainthefield. 2marks
2020ENVSCEXAM 20
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SECTION B – continued
Question 4 (8marks)Aremoteislandusesa50MWnatural-gas-firedpowerstationforitselectricitysupply.Thisstationisjustabletomeettheisland’speakelectricitydemand.
a. Identifyanddescribeoneenvironmentaldisadvantageofusingthenatural-gas-firedpowerstationfortheisland’selectricitysupply. 2marks
b. Theisland’sgovernmentseekstoreplace,asfaraspossible,energyfromthepowerstationwithenergyfromawindfarm.Eachwindturbineiscapableofreliablyproviding500kWofpower.
Howmanyturbineswouldberequiredtoreplacethenatural-gas-firedpowerstation?Showyourworking. 2marks
c. Identifyanddescribetwodisadvantagesofthewindfarmproposal. 4marks
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SECTION B – continuedTURN OVER
Question 5 (6marks)AccordingtotheIntergovernmentalPanelonClimateChange’s‘FifthAssessmentReport’,oneunitofnitrousoxidehasaglobalwarmingpotentialof265andoneunitofsulfurhexafluoridehasaglobalwarmingpotentialof23500.
a. Explainwhattheterm‘warmingpotential’meansinrelationtoagreenhousegas. 2marks
b. Calculateandcomparetherelativewarmingpotentialofoneunitofsulfurhexafluoridetooneunitofnitrousoxide. 2marks
c. Suggestwhyclimatescientistsaremoreconcernedabouttheimpactofgreenhousegases,suchascarbondioxide,methaneandnitrousoxide,thanagaslikesulfurhexafluoride,whichhasahigherglobalwarmingpotential. 2marks
2020ENVSCEXAM 22
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SECTION B – continued
Question 6 (4marks)Twointernationalmodellingteamscreatedthefollowinggraph,whichshowstwodifferentpeakoilscenarios.
historical data2010 peak prediction2020 peak prediction
Key
World oil production (1855–2010) and two peak oil scenarios
35
30
25
20
15
10
5
0
oilproduction(Gb/year)
1850 1875 1900 1925 1950 1975 2000year
2025 2050 2075 2100 2125 2150
Source:adaptedfromGMaggioandGCacciola,‘Whenwilloil,naturalgas,andcoalpeak?’, inFuel,vol.98,August2012,pp.111–123,<https://doi.org/10.1016/j.fuel.2012.03.021>
a. Usingthegraphabove,explaintheconceptof‘peakoil’. 2marks
b. Theincreasingdemandforoilsincethe1800shasresultedinthedrillingofmanywellsandtheconstructionofoffshoreoilrigs.
Describeonenegativeenvironmentalimpactthatcanresultfromtheextractionandtransportofcrudeoilfromthesesources. 2marks
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SECTION B – continuedTURN OVER
CONTINUES OVER PAGE
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SECTION B – Question 7 –continued
Question 7 (10marks)Thetablebelowshowsannualaveragetemperaturessincetheyear2000globallyandasrecordedataweatherstationinanAustraliancity.
Year Annual average temperature (°C)
Global City
2000 14.38 16.27
2001 14.52 16.32
2002 14.61 15.91
2003 14.60 16.20
2004 14.52 15.89
2005 14.66 15.73
2006 14.62 16.14
2007 14.64 16.61
2008 14.53 16.05
2009 14.64 16.51
2010 14.71 15.99
2011 14.59 16.01
2012 14.63 15.66
2013 14.67 16.17
2014 14.73 16.08
2015 14.88 15.93
2016 15.00 16.40
2017 14.90 16.51
2018 14.83 16.22
Data(global):adaptedfromNASAGoddardInstitutefor SpaceStudies,<www.giss.nasa.gov>
a. List,inorderfromhighesttolowest,thethreewarmestyearsgloballysince2000. 1mark
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SECTION B – Question 7–continuedTURN OVER
b. Statetworeasonswhythewarmestyearsince2000recordedinthecitydidnotoccurinthesameyearasthewarmestyearglobally. 2marks
c. Charlottearguesthattheglobaltemperaturedatadoes notshowawarmingtrendas2018wascoolerthan2017.
Commentonthescientificmeritofherargument. 2marks
d. Whataretwomaincausesofsealevelrise? 2marks
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SECTION B – continued
e. Whichtwoofthefollowingarelikelytobeimpactsoftheenhancedgreenhouseeffect?• lossofspecies• globalpopulationgrowth• morefrequentandlongerheatwaves• reductionintheavailabilityoffossilfuels
Explainwhyeachimpactislikelytooccur. 3marks
Impact1
Impact2
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SECTION B – continuedTURN OVER
CONTINUES OVER PAGE
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Question 8 (8marks)Thegraphbelowshowsatmosphericmethaneconcentrations(inpartsperbillion)fromaroundtheyear1000totheyear2020.
1000 1200 1400 1600 1800 2000
2000
1750
1500
1250
1000
750
500
atmospheric methane
concentration(parts per
billion)
year
Source:MethaneLevels.org,<www.methanelevels.org>; 2°Institute,<www.2degreesinstitute.org>
a. Explainwhyatmosphericmethaneconcentrationsremainedrelativelysteadyfromaroundtheyear1000untiltheyear1800. 2marks
b. Calculatethechangeinmethaneconcentrationbetweentheyears1800and2020,expressingyouranswerasapercentage. 2marks
SECTION B – Question 8–continued
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SECTION B – continuedTURN OVER
c. Listtwosourcesofmethanethathavecontributedtotheincreaseintheatmosphericconcentrationofthegassincetheyear1800. 2marks
d. Whatimpacthastheincreaseinatmosphericconcentrationofmethanehadonglobaltemperatureandwhyhasithadthiseffect? 2marks
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SECTION B – Question 9–continued
Question 9 (14marks)Studentsconductanexperimenttostudyglobalwarmingbymodellingthegreenhouseeffect.Theexperimentconsistsoftwobeakers,AandB,eachwithalightsource(modellingthesun)andatemperatureprobe.ThebaseofeachbeakerisblacktorepresentEarth’ssurface.BeakerAcontainscarbondioxide.BeakerBisfilledwithair.Thelightsareswitchedonatthesametimeandthetemperatureineachbeakerisrecordedeverytwominutes.Theexperimentalset-upisshowninthediagrambelow.
CO2
temperatureprobe
temperatureprobe
air
light
Beaker A Beaker B
a. Writeahypothesisrelevanttotheexperiment. 2marks
b. ExplainthepurposeofBeakerB. 2marks
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SECTION B – Question 9–continuedTURN OVER
c. Listoneindependentvariable,onedependentvariableandonecontrolledvariableforthisexperiment. 3marks
Independentvariable
Dependentvariable
Controlledvariable
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SECTION B – Question 9–continued
Thefollowingdatawasrecorded.
Time (minutes)
Temperature in Beaker A (CO2) (°C)
Temperature in Beaker B (air) (°C)
0 24.0 24.0
2 26.5 25.5
4 29.0 27.0
6 30.5 28.0
8 31.5 28.5
10 32.0 29.0
d. Onthegridonpage33,plotagraphofthisdata.Include:• atitle• labellingandsuitablescalesonbothaxes• pointscorrectlyplottedwithcurvesofbestfit,andalegend. 5marks
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Title
Legend
e. Explainwhetherthedatasupportsthehypothesisgiveninpart a. 2marks
END OF QUESTION AND ANSWER BOOK