Illinois Math and Science Academy
DigitalCommons@IMSA
Ecosystem Disruption & Climate Change
Biology
2016
The Greenhouse Effect: Does the Concentration of
Carbon Dioxide Affect the Air Temperature in a
Closed Environment?
Climate Science Investigations - NASA
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Mathematics Education Commons
Recommended Citation
Climate Science Investigations - NASA (2016). The Greenhouse Effect: Does the Concentration of Carbon Dioxide Affect the Air
Temperature in a Closed Environment?.
Retrieved from: http://digitalcommons.imsa.edu/eco_disrupt/9
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TheGreenhouseEffect:DoestheConcentrationofCarbonDioxideAffect
theAirTemperatureinaClosedEnvironment?
LessonType:
Experiment
EstimatedTime:
45-50minutes
Vocabulary
• amplified
greenhouseeffect
• natural
greenhouseeffect
Materials(perteam)
• 2emptyplasticor
glasswaterbottles
• 4Alka-Seltzer
tablets
• 2rubberbands
• 2thermometers
• 2sheetsofplastic
wrap
• 200mLofwater
(100mLforeach
bottle)
• lamp(with100wattbulb)
HS• clay
ESS2-4.
• timer
PURPOSE
Thepurposeofthislessonistoinvestigatetheeffectofcarbondioxide(CO2)concentration
onairtemperatureinaclosedenvironment.
LEARNINGOBJECTIVES
Bytheendofthelessonstudentswillbeableto
• Explainhowthegreenhouseeffectworks.
• DifferentiatebetweenEarth’snaturalgreenhouseeffectandanamplifiedgreenhouse
effect.
• CompareandcontrastamodelofthegreenhouseeffecttoEarth’sgreenhouseeffect.
SCIENCESTANDARDS
Climateand/orEnergyLiteracyPrinciples
(Seehttp://cleanet.org/clean/literacy/index.html)
• GreenhousegasesaffectenergyflowthroughtheEarthsystem.Greenhousegasesinthe
atmosphere,suchascarbondioxideandwatervapor,aretransparenttomuchofthe
incomingsunlightbutnottotheinfraredfromthewarmedsurfaceofEarth.Thesegases
playamajorroleindeterminingaverageglobalsurfacetemperatures.WhenEarthemits
thesameamountofenergyasitabsorbs,itsaveragetemperatureremainsstable.
(EnergyPrinciple2.6)
• TheamountofsolarenergyabsorbedorradiatedbyEarthismodulatedbythe
atmosphereanddependsonitscomposition.Greenhousegases–suchaswatervapor,
carbondioxide,andmethane–occurnaturallyinsmallamountsandabsorbandrelease
heatenergymoreefficientlythanabundantatmospheregaseslikenitrogenandoxygen.
Smallincreasesincarbondioxideconcentrationhavealargeeffectontheclimate
system.(ClimatePrinciple2.C)
NextGenerationScienceStandards
(Seehttp://www.nextgenscience.org/next-generation-science-standards)
• ThefoundationforEarth’sglobalclimatesystemsistheelectromagneticradiationfrom
thesun,aswellasitsreflection,absorption,storage,andredistributionamongthe
atmosphere,ocean,andlandsystems,andthisenergy’sre-radiationintospace.(HSESS2-2)(HS-ESS2-4)
• Changesintheatmosphereduetohumanactivityhaveincreasedcarbondioxide
concentrationsandthusaffectclimate.(HS-ESS2-6),(HS-ESS2-4)
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PREPARATION
• Priortoclass,gatherthematerialsforeachteamofstudents.
• Dividestudentsintosmallteamsof4(dependingonavailabilityofmaterials).Eachteamwillneeda
setofmaterials.
• Explainthepurposeandintroductorybackgroundofthelessonandpurposeoftheactivity.
• Askeachteamtoreadthroughtheprocedureandwriteahypothesisthatincludesboththe
independentanddependentvariables.
• Haveeachteamconducttheexperiment.
Foranexcellentreviewongraphing,directthemtoPaulAndersen’sBozemanScienceWebsite:
http://www.bozemanscience.com/beginners-guide-to-graphing-data
http://www.bozemanscience.com/graphing-data-by-hand
http://www.bozemanscience.com/graphing-data-by-spreadsheet
BACKGROUND
As1827,Frenchmathematicianandphysicist,JosephFourier,wonderedwhyEarth’saveragetemperatureis
approximately15°C(59°F)insteadof(−18°Cor0°F).HiscalculationsindicatedthatEarthshouldactuallybe
muchcolder.Tohaveanaveragetemperatureof15°C(59°F),Fourierknewthattherehadtobeanother
processoccurringintheatmosphere––somethingsimilartothewayagreenhouseretainsheat.A
greenhouse’sglassenclosureallowsvisiblelighttoenterandbeabsorbedbytheplantsandsoil.Theplants
andsoilthenemittheabsorbedheatenergyasinfraredradiation.Theglassofthegreenhousethenabsorbs
thatinfraredradiation,emittingsomeofitbackintothegreenhouseandthuskeepingthegreenhousewarm
evenwhenthetemperatureoutsideislower.
Earthexperiencesasimilarphenomenon,knownasthegreenhouseeffect.Thesun’svisiblewavelengthsof
radiationpasseasilythroughtheatmosphereandreachEarth.Approximately51%ofthissunlightis
absorbedatEarth’ssurfacebytheland,water,andvegetation.Someofthisenergyisemittedbackfromthe
Earth’ssurfaceintheformofinfraredradiation.Watervapor,carbondioxide,methane,andothertrace
gasesinEarth’satmospherethenabsorbthelongerwavelengthsofinfraredradiationfromEarth’ssurface.
Thesegasesre-emittheinfraredradiationinalldirections,bothoutwardtowardspaceanddownward
towardEarth.Thisprocesscreatesasecondsourceofradiationtowarmtosurface(visibleradiationfrom
thesunandinfraredradiationfromtheatmosphere),whichcausesEarthtobewarmerthanitotherwise
wouldbe.ThisprocessisknownasthenaturalgreenhouseeffectandkeepsEarth’saverageglobal
temperatureatapproximately15°C(59°F).Fourier’scalculationsindicatedthatEarthshouldactuallybe
muchcolder(−18°Cor0°F)ifitdidnothaveanaturalgreenhouseeffect,butwhatifEarth’sgreenhouse
effectwereamplified?
EXPERIMENTALDESIGN
Inthisexperiment,studentswillconstructtwomodels(onewithanaturalgreenhouseeffectandanother
withanamplifiedgreenhouseeffecttoanswerthefollowingquestion:
DoestheConcentrationofCarbonDioxideAffecttheAirTemperatureinaClosedEnvironment?
Hypothesis
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Afterreadingthroughthemethodssectionbelow,writeahypothesisthatincludestheindependentand
dependentvariablesintheexperiment.
Hypothesis:TheairtemperatureinsidethebottlewiththeAlka-Seltzertabletswillincreasemorethan
theairtemperatureinsidethecontrol.
Methods
1. Filleachbottlewith100mLofwater.
2. Labelthebottlesas“control”and“CO2.”(ThebottlelabeledasCO2willhave4Alka-Seltzertabletsin
thewater).
3. Covertheopeningofthebottlewithaclumpofclay.Insertathermometerintoeachbottlethrough
theclay.Makesurethethermometerishangingintheairabovethewater.
4. Placethetwobottlesunderthelightatthesamedistanceandangle.
5. Tear2sheetsofplasticwrapandsetaside.
6. Drop4Alka-SeltzertabletsintothewaterbottlelabeledCO2.
7. Immediatelycoverthetopofeachbottle(includingthethermometerinsertedintheclay)looselywith
theplasticwrap.Usearubberbandtosecuretheplasticwraparoundthetopofthebottle.
8. Turnonthelightandtakeaninitialtemperaturereading.
9. RecordyourdataandconstructagraphintheResultssectionbelow.
Results
Recordtheairtemperature(˚C)ineachbottleat2-minuteintervalsfor20minutes.Writeyourresultsinthe
tableandincludeatitleforthetable.
Title:__________________________________________________________________________________
AirTemperature(˚C)
Control/
0Alka-Seltzers
Experimental/
4Alka-Seltzers
Initial
Temp
2
min
4
min
6
min
8
min
10
min
12
min
14
min
16
min
18
min
20
min
Studentsshouldobservethatthetemperatureoftheairinsidethecontrolled
environment(withoutanAlka-Seltzertablet)increasesslightlyby1or2˚C.Theyshould
observetheairtemperatureinthebottlewiththe4Alka-Seltzertabletsincreasesby
morethan2˚C.
GraphyourData
Constructalinegraphthatsummarizesyourresults.Includeatitle,labeltheaxesandincludealegend.
Title:_______________________________________________________________________________
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ExamplefromStudentExperiment
SummaryofResults
Writeasummaryofyourresults.
Answerswillvary.Studentsshouldobservethatthetemperatureoftheairinsidethe“control”(bottle
withoutAlka-Seltzertablets)increasedslightlyby1or2˚C.Studentsshouldhaveobservedanincrease
ofmorethan2˚Cfortheairtemperatureinthebottlewiththe4Alka-Seltzertablets.
CONCLUSIONS:DEVELOPINGEXPLANATIONSFROMEVIDENCE
1. Wasyourhypothesissupportedbythedataorevidence?
Answerswillvary.Thedatashouldsupportthehypothesisthattheairtemperatureinthebottlewith
theAlka-Seltzertabletsincreasedmorethantheairtemperatureinthecontrol.Ifstudentsdidnot
obtaintheseresults,theymayneedtoconducttheexperimentlongerorconductrepeatedtrials.
2. Explainyourrationalefortheresults.
TheamountofAlka-SeltzertabletsinfluencestheamountofCO2thatisreleasedintothebottle’s
environment,whichaffectstheoveralltemperatureineachenvironment.Thebottlewithoutthe
tabletshasasmallertemperatureincreasethanthebottlewiththeAlka-Seltzertablets.Thisrisein
temperatureiscausedbytheabsorptionofheatbytheCO2gasmoleculesintheair.
3. Whatrecommendationsdoyouhaveforimprovingtheexperimentandforfurtherstudy?
Answerswillvary.Studentmayrecommendconductingtheexperimentoveralongerperiodoftime
orconductingrepeatedtrials.
4. CompareandcontrastthemodelofthegreenhouseeffecttoEarth’sgreenhouseeffect.
ThemodelofthegreenhouseeffectwithoutAlka-seltzertabletsrepresentsEarth’snaturalgreenhouse
effect.ThisbottlecontainedwatervaporandsomesmallamountofCO2,soitissimilartoEarth’s
naturalgreenhouseeffect.Thebottlewiththe4Alka-Seltzertabletsrepresentsanenvironmentwith
anincreasedconcentrationofCO2(oranamplifiedgreenhouseeffect).Thesimplemodelsconstructed
inthisexperimentaredifferentfromEarth’sactualgreenhouseeffectbecausetheyhavethephysical
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barrieroftheclayandplasticcover,whichalsopreventswarmerairfromflowingoutofthebottle.
(Thisisalsohowagreenhousefunctionstokeepplantswarmerduringwintermonths.)
5. WhatdoyoupredictwillhappentotheglobaltemperatureofEarthasmoreCO2isaddedtotheatmosphere?
AnincreasedconcentrationofatmosphericCO2willcausemoreinfraredradiationtobeabsorbed,resultingin
awarmingatmosphere.
6. Whatisthecurrent(pastmonth)concentrationofCO2inEarth’satmosphere?____ppm(partspermillion)
WhatwastheconcentrationofCO2theyearthatyouwereborn.
Youmayuse:http://co2now.org/.
Answerswillvary.StudentsshouldseetheincreaseinCO2concentrationoverthepastdecades
THESCIENTISTS’EXPLANATION
Thecontrolrepresentsanaturalgreenhouseeffect.Thisbottlecontainswatervaporandsomesmall
amountofCO2.Thebottlewiththe4Alka-Seltzertabletsrepresentsanenvironmentwithanincreased
concentrationofCO2.WhenAlka-Seltzerisdissolvedinwater,CO2isreleasedandcarriedtothesurfaceby
smallbubbles.Asbubblesreachthesurface,CO2isreleasedintotheairabovethewater’ssurface.This
equationexplainswhathappenswhenanAlka-Seltzertabletisdissolvedinwater.
C6H8O7(aq)+
3NaHCO3(aq)
→3H2O(l)+
3CO2(g)
+Na3C6H5O7(aq)
citricacid +sodiumbicarbonate→ water +carbondioxide+sodiumcitrate
Carbondioxideisthemajorgreenhousegasbecauseofit’srelativelylonglifetimeintheatmosphere
(approximately100years),and
abilitytoabosrbinfrared
radiation.Whenagitatedby
infraredradiation,theCO2
moleculevibratesandabsorbs
heat.Itthenre-radiatesoremit
heatinalldirections,including
backtowardEarth.Carbon
dioxideabsorbsinfraredradiation
emittedfromEarth’ssurface
beforere-emittingthesame
infraredradiationaswasabsorbed.
Iftheconcentrationofgreenhousegasesincreases,thenmoreinfraredradiationwillbeabsorbedand
emittedbacktowardEarth’ssurface,creatinganamplifiedgreenhouseeffect.
Whenaveragedoverthecourseofayear,theamountofincomingsolarradiationreceivedfromthesunhas
balancedtheamountofoutgoingenergyemittedfromEarth.Butrelativelysmallchangesintheamountsof
greenhousegasesinEarth’satmospherecangreatlyalterthatbalancebetweenincomingandoutgoing
radiation.Earththenwarmsorcoolsinordertorestoretheradiativebalanceatthetopoftheatmosphere.
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