Assessment:ClimateChangepostquiz, graphicorganizers.
Extensions:This couldbedevelopedintoa fullresearchpaperwherestudents furtherinvestigatetheeffectsofclimatechangeandhowtocombatthem.
Homework:None.
Resources:
IsGlobalWarmingDrowningAfrica? /
ALastWarningonGlobal
Warming /
TheDireFateofForestsina
WarmerWorld /
WhyGlobalWarmingPortends
aFoodCrisis /
AllergiesGettingWorse?
BlameGlobalWarming /
CouldRisingSeasSwallow
California’sCoast? /
IsGlobalWarmingWorsening
Hurricanes? /
CanClimateChangeMakeUs
Sicker? /
HowClimateChangeWill
ImpactAnimals? /
WhyGlobalWarmingMayBe
FuelingAustralia’sFires /
ClimateChangeQuiz
Foreachofthefollowingstatementscirclewhetheryouthinkitistrueorfalse.Afterreadingarticlesonclimatechangeyouwillreviewthesestatementsagainandseeif youranswershavechanged.
Pre-quizPost-quiz
1. / Warmertemperatureswillleadtoincreasedfoodsuppliesduetolongergrowingseasons. / T / f / T / F2. / WarmertemperaturesareNOTresponsiblefortherecentincreasedseverityofhurricanes. / T / F / T / F
3. / WarmertemperaturesarecausingArcticseaicetomelt,whichisincreasingsealevels. / T / F / T / F
4. / Climatechangeisexpectedtoberesponsiblefortheextinctionof30%ofcurrentanimalspecies. / T / F / T / F
5. / Forestswillnotbeaffectedbyclimatechangebecausetreesareveryhardyspecies. / T / F / T / F
6. / PeopleintheUnitedStatesmaybeatriskformalariaiftemperaturescontinuetorise. / T / F / T / F
7. / Allergiesandasthmawillgetbetterbecauseofthedecreaseinhumidityassociatedwithclimatechange. / T / F / T / F
8. / Wildfireswillbemoreintenseandmorefrequentinthefuture. / T / F / T / F
9. / Climatechangewillonlycauseasmallincreaseintemperatures. / T / F / T / F
10. / Climatechangeissomethingthatwillaffectfuturegenerations,itisNOThappeningnow. / T / F / T / F
AllergiesGettingWorse?BlameGlobalWarming?
Oneofthefewpotentiallypositiveeffectsofclimatechange,atleastintheshortterm,isthatincreasedconcen-trationsofcarbondioxideintheatmospheremayenhancethegrowthofplants.Thatcouldbegoodforagriculture—thoughwarmingtemperaturesandchangingrainpatternsinawarmerworldmightwipeoutthatadvantage.Butthereare
nounalloyedgiftsfromclimatechange.Recentresearchsuggeststhatglobalwarming
willalsoexacerbaterespiratoryallergies,ashigherCO2concentrationsleadtovastincreasesinragweedpollenproduction."There'snodenyingthere'sachange,"saysPaulRatner,animmunologistwiththeAmericanCollegeofAllergies."It'sdefinitelybadnewsforpeoplewhohaveallergies."
Asthmaandotherrespiratoryailmentsarealreadyontheriseinmuchoftheworld.TheWorldHealthOrganizationestimatesthat300millionpeoplegloballyhaveasthma,with250,000dyingfromthediseaseeachyear.Thatrateisupconsiderablyoverthepastfewdecades,andscientistssayanumberoffactorscouldbeatwork.Oneclearreasonisrisinglevelsofragweedpollen—whichcanbeconnecteddirectlytorisinglevelsofCO2.ResearchershaveshownrepeatedlythatelevatedlevelsofCO2stimu-lateweedstoproducepollenoutofproportionwiththeirgrowthrates—meaningyougetmorepollenperplant,whichmeansmoreallergies.Evenworse,itseemsthattheweediestspeciesseemtothrivedisproportionatelyinhighCO2environments.The waveofurbanizationinAmericaandmuchoftheworlddoesn'thelp—theurbanenvi-ronment,oftenhotterandwithmoreCO2thanruralareas,isragweedheaven."Urbanplaces,becauseofthebakingeffectofthatincreasedconcrete,definitelypollinatemore,"saysRatner.Itdoesn'thelpthatwarmingwillalsoincreasethe productionofground-levelozone,arespiratoryirritantthatworsensasthma.
Longergrowingseasonsinawarmerworldmayfurtherworsenallergies.AstudyinSeptember'sJournalofAllergyandClinicalImmunologyreporteddatafrom1982to2001showingthat,forexample,increasinglyearlypollinationoftheEuropeanoliveinSpainledtohigheroverallpollencounts,similartowhatisfoundinwarmerpartsof theMediterranean;comparableoutcomescanbeexpectedinothertemperatepartsoftheworldasclimatechangekicksin.Asimilareffectwillalsobefeltinthenorthwardshiftofwhatisknownasthehardinesszones—meaningthatnortherncountries whereallergieswereonceraremaynolongerbeassafe."Thoseborderlinenorthernregionswilldefinitelyfeelchanges,"saysRatner.
Thecausesofallergiesandrespiratorydisordersarecomplex,andscientistscannotpredictexactlyhowmuchimpactclimatechangewillhaveontheirglobalrates.Buttherecentdata—recordsonpollencountsrarelygobackmorethan20years—certainlywouldindicatethatwarmingwillonlymakethingsworse.So,whatcanbedonetohelpmillionsofsneezing,watery-eyedpatients?Asallergysufferersalreadyknow,notawholelot.ButanyactiontakentocontrolrisingCO2levelsmightatleasthelpstemtheincreaseinglobalallergyrates.Sofar,theglobalasthmaepidemicshowsnosignsofabating,andinawarmerworld,effectivetreatmentsforallergieswilllikelybecomeevenmoreimportant.OneoptionforallergysuffersmightbetostartagitatingforactiontoreduceCO2emissions—afterall,theonlythingyouhavetoloseisyourbreath.
Source:TimeMagazine,BryanWalsh,September15,2008.
AllergiesandClimateChange
1.Howmanypeoplecurrentlyhaveasthma?
2.Howmanypeoplediefromasthmaeachyear?
3.Whatisonereasonfortherecentincreaseofpeoplewithasthma?
4.Whataretwocausesmentionedinthearticlefortheriseinragweedpollen?
5.Whatisasecondreasonthatasthmawillbeworseifaveragetemperaturescontinuetoincrease?
6.Whatwillwarmertemperaturesdotogrowingseasons?Howwillthisaffectallergies?
7.Whatsolutionisofferedtocombatthisissue?Howwillthishelp?
HowClimateChangeWillImpactAnimals
ThethreatstowildlifeontheAfricanislandofMadagascararemanifold:rampantdeforestationthathasstrippedmostoftheislandofitsoriginalforestcover,leavingawasteland;ahumanpopulationthatisgrowingat3%ayear,straining naturalresourcesandhuntinganimalsforfood,especiallyMadagascar'semblematiclemurs;extractiveindustry,includ-inganickelminenotfarfromanationalparkthatcouldbecometheworld'sbiggest.
There'sanotherdangerthat'sinvisible,butmaybemoredangerousthantheothersputtogether:climatechange.Globalwarmingwilldotowildlifewhatitmaydotohumans. Astheclimatechanges,animalsmaybeforcedtomoveoutofthehabitatsthey'reac-customedto—likehumanrefugees."Globalwarmingissomethingthatallconservation-istsareworriedabout,"saysRussellMittermeier,thepresidentofConservationInter-national."Ithasthepossibilitytoundoalotoftheworkwe'vedone."
Whiletheimpactofclimatechangeonhumanpopulationsislikelytobedire,we're prettygoodatadaptingtochangeoverall.Animals,however,arenot.Whentheirhabitatschangeirrevocably—whentherainforestdriesuporcoolmountainsintropicalzonesheatup—animalsmaysimplygoextinct.ArecentstudyinSciencedemonstrateshowthatcanhappen.RobertColwell,anevolutionarybiologistattheUniversityofConnecticut,analyzeddatafromnearly2,000speciesofplants,insectsandfungiinthetropics,whereorganismsoftenlacktheabilitytoescapewarmingtemperaturesbygoingnorthorsouth;instead,theyhavetogoupinelevationtofindcoolertemperatures.Colwellfoundthataspopulationsinlowlandareasmoveup,theytendnottobereplaced.Thatmeansthatwemayseeareductioninoverallbiodiversityandwhatscientistscall"speciesrichness."Meanwhile,speciesthatalreadyliveatthehighestelevationshave noplacetogo,exceptperhapstoextinction.Caseinpoint:theGoldenToad,whichlivedinthehigh-altitudecloudforestsofCostaRicaandsuddenlywentextinct.Itsdisap-pearancemaybedueinparttowarming,whichmadeitshabitatunlivable.
Thetoadmaybethefirstanimalwhoseextinctionscientistswilllinktoglobalwarming,butitcertainlywon'tbethelast.Lastyear,theU.N.'sIntergovernmentalPanelonClimateChangeestimatedthatifglobaltemperaturesincreasemorethantwotothreedegreesFarenheitabovecurrentlevels—whichseemsquitepossible,givencurrenttrendsincarbonemissions—uptoone-thirdofthespeciesonEarthcouldbeatrisk forextinction."We'realreadyseeingnaturereactbadlytoclimatechange,"saysLarrySchweiger,thepresidentoftheNationalWildlifeFederation."We'rechangingtherulesofthegame."
Foronething,thegranddesignofconservationismistocreatereserves,protectedareaslikenationalparkswherewildlifecanlivefreefromtheimpactofhumanpopula-tions.Thatstrategyhasbeenoverwhelminglysuccessful,butconservationistsnow fearthatglobalwarmingcouldmakethosereservesmeaningless,ifanimalsthatareaccustomedtoadifferentclimatecan'tsurviveinthem."We'reusedtofocusingonprotectingrealestate,"saysSchweiger."Nowwehavetobeabletomakesureanimalscanmovetosafeareas."
First,conservationistssay,weneedtodoeverythingwecantoslowcarbonemissionsandreducetheimpactofclimatechange."That'sprioritynumberone,"saysMitter-meier.Butsomedegreeofwarmingisinevitable,soconservationistshavetoprepare.Thatmeanscreatingnotjustreserves,butsafenaturecorridorsthatwouldallowwild-lifetomigrateinthefaceofrisingtemperatures.Anothermethodistotrytocon-nectexistingreservesthroughreforestation—atechniquealreadyunderwayinMada-gascar,wherethegovernmentislookingtovastlyincreasethetotalamountofpro-tectedland.What'scertainisthatweneedtoact.Ifwedon't,saysSchweiger,"Climatechangecouldunderminetheconservationworkofwholegenerations."
Source:TimeMagazine,BryanWalsh,October13,2008.
ClimateChangeandAnimals
1.Whatwillclimatechangeforceanimalstodo?Howwillclimatechangeimpactanimals?
2.Whataretwoexamplesofhabitatschangingbeyondrepair?
3.Whatarethetwopossibilitiesforanimalsiftheirhabitatchanges?
4.Whatistheconcernaboutanimalsmovinghabitats?
5.Whathappenstotheanimalsatthehighestelevations?
6.Whatdoscientistspredictwillhappeniftemperaturescontinuetorise?
7.Whatchallengesdoesclimatechangeofferconservationists?
8.Whatsolutionsareofferedtocombatthisissue?Howwilleachofthesehelp?
CanClimateChangeMakeUsSicker?
Whatdowetalkaboutwhenwetalkaboutglobalwarming?It'llgethotter,that'sasafebet;polaricecapswillbemelting,andwildlifethatcan'tadapttowarmertempera-turescouldbeonthewayout.Butwhatdoesitreallymeanforthehealthofus,thehumanrace?It'saquestionthatremainssurprisinglydifficulttoanswer—researchintoclimatechange'simpactsonhumanhealthhavelagged
behindotherareasofclimatescience.Butwhatwedoknowhasscientistsanddoctors
increasinglyworried—arisingriskofdeathfromheatwaves,thespreadoftropicaldiseaseslikemalariaintopreviouslyuntouchedareas,worsenedwater-bornediseases."Whenwethinkaboutclimatechange,wethinkabouticecapsandbiodiversity,butweforgetabouthumanhealth,"saysDr.JonathanPatz,aprofessorofenvironmentalstudiesandpopulationhealthsciencesattheUniversityofWisconsin-Madison."Thereareahugenumberofhealthoutcomesthatareclimatesensitive."
TheWorldHealthOrganization(WHO)andotherglobalhealthbodiesareworkingtoremindusofthatfact.OnMarch31theAmericanPublicHealthAssociation(APHA)launcheditsfirstblueprintforcombatingthehealthimpactsofclimatechange,andonApril7,WHOwilldedicateitsannualWorldHealthDaytotheintersectionbetweendiseaseandglobalwarming.Themessageisthatsevereclimatechangecouldfunda-mentallyweakenglobalpublichealth,thatdoctorsneedtobereadytodealwiththeconsequences—andthatthereisamoralcasetobemadeforreducingcarbonemis-sionstosavefuturelives."Ifyoulookatclimatechangeoverthelongterm,itwillprofoundlyaffectthepillarsofpublichealth:water,sanitation,airqualityandsuffi-cientfood,"saysDr.DavidHeymann,AssistantDirector-GeneralforHealthSecurityandEnvironmentatWHO."Thefactisthathumanhealthshouldbeatthecenterofthepoliticaldebateonclimatechange,butrightnowthat'snotthecase."
Thefirststeptomakingthatcaseisunderstandingexactlywhatwarmertempera-tureswilldotousandourdiseases—andfewscientistsknowmoreaboutthetopicthanPatz,amemberoftheUN'sNobelPrize–winningIntergovernmentalPanelonClimateChange(IPCC).Astemperaturesincrease,andhotter,driersummersbecomethenorminregionsthatwereoncetemperate,powerfulheatwaves—liketheoneinEuropein2003,whichkilledanestimated35,000people—willtakeatoll.Atthe sametime,climatemodelssuggestthatraincouldbecomelessfrequentoverallbutmoreintensewhenitdoesfall,leadingtoadoublewhammy.Longerandfiercerdroughtsinsomeareaswillworsenhunger,butsevererainstormscarryanincreasedriskofwater-bornediseaseslikecholera."It'snotjustwarming,it'sclimatechange,"saysPatz."It'schangingtheaircycle,creatingmoreextremeflooding,moreextremedroughts."
Forsomediseases,climatechangewillbeboon.Takemalaria—rightnow,theinsect-bornediseaseismostlyconfinedtohottropicalareas,whichiswhyyoudon'tneedtotakequininewhenyou'rehikingthroughCentralPark.Butiftemperaturesincrease,themosquitoesthatcarrythemalariaparasitewillbeabletoexpandtheirrange,whilemoreintenserainstormswillgivethemmoreplacestobreed.AreportthisyearbyAustralia'sCenterforEpidemiologyandPublicHealthestimatedthatbetween20to80millionmorepeoplewillbelivinginmalarialregionsby2080,astheparasiteexpandsitsrange;anotherstudyreleasedonApril3byBritishdoctorsraisedthepossibilitythatinsect-bornediseases—virtuallyunknowninthecoolU.K.—couldhittheBritishislesthanksto climatechange."There'srealworryaboutmalaria,"saysHeymann."Malariabecomesamorethreateningdiseaseasitspreadstonewareaswherepeoplelackimmunitybecausetheyhaven'thaditbefore."
WHOandotherbodiesarepushingtostrengthentheglobalpublichealthsysteminpreparationforthechangesthatglobalwarmingmightbring.Thatmeansreadyingsocie-tiestodealwithheatwaves—ensuringthatthemostvulnerableelderlyaren'tleftontheirown—andimprovingdefensesagainstvector-bornediseases,withanti-malarianetsandmedicineslikeartemisinin.Suchpreparationswillbeespeciallyneededinthosepartsofthedevelopingworld—sub-SaharanAfrica,southAsia—thatwillbearthebruntofclimatechange.ButPatzwouldalsoliketoseepublichealthtacklecarbonemissionsdirectly,cuttingoffglobalwarmingatthesource.Forhim,carbondioxideshouldbetreatedasapollutantthatdamageshumanhealth,albeitindirectly,andit'sinourmedicalintereststoreduceit."Energypolicybecomesoneandthesameaspublichealthpolicy,"saysPatz.
Policiesthatcutcarbonemissionscanhaveadirectpositiveimpactonhumanhealthnow aswell.Imaginehowmuchbetteroffourenvironmentandourcholesterollevelsmightbeifmoreofusbikedtoworkratherthandrove—orifcityplannersputgreateremphasisondesigningmorewalkablecommunitiesandensuringsustainablepublictransportation. Buttherealityisthatclimatechangeishappeningtoday,andwillbeworsetomorrow,evenifwemanagetopulltogetheraglobalefforttoreducecarbonemissions,whichseemslesslikelyandmoredifficulteveryday.(AcommentaryintheApril3editionofNaturear-guedthatthetechnologicalchangesneededtodecarbonizeenergycouldbemuchharderthanwethought;meanwhile,overinBangkok,diplomatsattheU.N.climateconference lastweekmadelittleprogressonhammeringoutthesuccessortoKyoto.)Ifthereismoneytobespentonpreparingtheworldforthehealthimpactsofclimatechange,thepriorityshouldbeadaptingourpublichealthsystemtoawarmerworld,versusspendingoncarbonmitigation.Globalwarmingtosomedegreewillbeinevitable—buthumansufferingneedn'tbe,ifwe'resmartenoughtoprepare.
Source:TimeMagazine,BryanWalsh,April4,2008.
ClimateChangeandDisease
1.Whatarethethreeareasofconcernthatdoctorsandscientistshaveabout humanhealthasaresultofclimatechange?
2.Whatarethepillarsofpublichealth?
3.Howwilleachofthepillarsbeaffectedbyclimatechange?
4.Howdoesclimatechangecauseheatwaves?Whatwillbetheeffectoftheseheatwaves?
5.Howwillrainfallaffecthumanhealth?
6.Explainhowclimatechangewillaffectmalaria.
7.Whatsolutionsareofferedtothisissue?Howwilleachofthesehelp?
WhyGlobalWarmingMayBeFuelingAustralia’sFires
Theraginginfernosthathaveleftmorethan160peopledeadinsouthernAustraliaburnedwithsuchspeedthattheyresembledlessawildfirethanamassiveaerialbombing.Manyvictimscaughtintheblazeshadnotimetoescape;theirhousesdisintegratedaroundthem,andtheyburnedtodeath.Asfirefightersbattletheflamesandpolicebegintoinvestigatepossiblecasesofarson
aroundsomeofthefires,therewillsurelybedebatesoverthewisdomofAustralia'sstandardpolicyofadvisingresidentstoeitherfleeafireearlyorstayintheirhomesand
waititout.JohnBrumby,thepremierofthefire-hitAustralianstateofVictoria,toldalocalradiostationonMondaythat"peoplewillwanttoreviewthat...Thereisnoquestionthattherewerepeoplewhodideverythingright,putinplacetheirfireplan,andit[didn't]matter—theirhousewasjustincinerated."
Althoughthewildfirescaughtsomanyvictimsbysurpriselastweekend,therehasbeennoshortageofdistantearly-warningsigns.The11thchapterofthesecondworkinggroupofthe2007IntergovernmentalPanelonClimateChange,forexample,warnedthatfiresinAustraliawere"virtuallycertaintoincreaseinintensityandfrequency"becauseofsteadilywarmingtemperaturesoverthenextseveraldecades.Researchpublishedin2007bytheAustraliangovernment'sownCommonwealthScientificandIndustrialResearchOrganizationreportedthatby2020,therecouldbeupto65%more"extreme"fire-dangerdayscom-paredwith1990,andthatby2050,underthemostseverewarmingscenarios,therecould bea300%increaseinsuchdays."[Thefires]areasoberingreminderoftheneedfor thisnationandthewholeworldtoactandputataprioritytheneedtotackleclimatechange,"AustralianGreenPartyleaderBobBrowntoldtheSkyNews.
DestructivewildfiresarealreadycommoninAustralia,andit'snothardtoseewhyclimatechangewouldincreasetheirfrequency.Thedriestinhabitedcontinentontheplanet,Aus-traliahaswarmed0.9°Csince1950,andclimatemodelspredictthecountrycouldwarmfur-therby2070,upto5°Cover1990temperatures,ifglobalgreenhouse-gasemissionsgoun-checked.Beyondasimpleriseinaveragetemperatures,climatechangewillalsoleadtoanincreaseinAustralia'sextremeheatwavesanddroughts.SouthwesternAustraliaisalreadyinthegripofaprolongeddroughtthathasdecimatedagricultureandledtowidespreadwaterrationing;theregionisexpectedtoseelongerandmoreextremedryperiodsinthefutureasaresultofsteadywarming.It'simportanttoacknowledgethatnosingleweathereventcanbedefinitivelycausedbyclimatechange—andit'spossiblethatthecurrentinfernoinAustraliamighthavebeenasintenseanddeadlyevenwithoutthewarmingofthepastseveraldecades.Policearebeginningtosuspectthatmanyofthefiresmayhavebeendeliberatelyset,andthesheerincreaseinthenumberofhomesbuiltinfire-dangerzonesinsouthernAustraliatodayputsmorepeopleinharm'sway,raisingthepotentialdeathtoll.
Still,heatwavesanddroughtsetthetableforwildfires,andtemperaturesintheworst-hitareashavebeenover110°F(43°C)whilehumidityhasbottomedoutnearzero.Climatechangewillcontinuetobeathreatmultiplierforforestfires.
That'sonemorereasonwhytheworldmustworktogethertoreduceglobalcarbonemissionstominimizetheimpactofclimatechange.Thetroubleis,though,CO2cutswon'tbeenough.AsarecentpaperintheProceedingsoftheNationalAcademyofSciencepointsout,evenifwearesuccessfulincuttingcarbonemissionsrapidly—hardlyaneasytask—themomentumofclimatechangewillcontinueforcenturies. Thatmeansourabilitytoadapttotheimpactsofwarming,includingmoreaggressiveresponsestowildfireslikethoseinAustralia,willbecomeallthemorecritical,lestnaturaldisastersturnintohumancatastrophes.Butitalsomeansthattheworldwe'vebecomeaccustomedtowillchange,perhapsirrevocably.ThewildfiresinsouthernAustraliaarealreadytheworstinthenation'shistory—buttheysurelywon'tbe
thelast.
Source:TimeMagazine,BryanWalsh,February9,2009.
ClimateChangeandFires
1.Whywillfiresincreaseinfrequencyandintensity?
2.Whatdoesthefutureholdforthenumberoffire“extremedanger”days?
3.Explainhowrisingtemperaturesleadtomorefiresworldwide.
4.Whatsolutionsareofferedtocombatthisissue?Howwillthesehelp?
5.HowcanthisinformationbeappliedtoSouthernCalifornia?
WhyGlobalWarmingPortendsaFoodCrisis
Itcanbedifficultinthemiddleofwinter—especiallyifyouliveinthefrigidNortheasternU.S.,asIdo—toremainconvincedthatglobalwarmingwillbesuchabadthing.Beyondthefactthatpeoplepreferwarmthtocold,there'sareasontheworld'spopulationisclusteredintheTropicsandsubtropics:warmerclimatesusuallymeanlongerandrichergrowingseasons.Soit'seasytoimaginethatona
warmerglobe,thedamageinflictedbymorefrequentandsevereheatwaveswould
bebalancedbytheagriculturalbenefitsofwarmertemperatures.
Acomfortingthought,exceptforonething:it'snottrue.AstudypublishedintheJan.9issueofScienceshowsthatfarfromcompensatingforthedamagesassociatedwithclimatechange(heavierandmorefrequentstorms,increasingdesertification,sea-levelrise),hottertemperatureswillseriouslydiminishtheworld'sabilitytofeeditself.DavidBattisti,anatmosphericscientistattheUniversityofWashington,andRosamondNaylor,directoroftheProgramforFoodSecurityandtheEnvironmentatStanfordUniversity,analyzeddatafrom23climatemodelsandfoundamorethan90%chancethatbytheendofthecentury,averagegrowing-seasontemperatureswouldbehotterthanthemostextremelevelsrecordedinthepast.
Thatmeansthatbarringaswiftandsuddenreductioningreenhouse-gasemissions,bytheendofthecenturyanaverageJulydaywillalmostcertainlybehotterthanthehottestheatwavesweexperiencenow.Andtheextremeheatwillwiltourcrops.BattistiandNaylorlookedattheeffectthatmajorheatwaveshavehadonagricul-tureinthepast—liketheruthlessheatinWesternEuropeduringthesummerof2003—andfoundthatcropyieldshavesuffereddeeply.InItaly,maizeyieldsfell36%in2003,comparedwiththepreviousyear,andinFrancetheyfell30%.Similareffectswereseenduringamajorheatwavein1972,whichdecimatedfarmsintheformerSovietUnion,helpingpushgrainpricestoworryinglyhighlevels.Ifthosetrendsholdinthefuture,theresearchersestimatethathalftheworld'spopulationcouldfaceaclimate-inducedfoodcrisisby2100."I'mveryconcerned,"saysNaylor."How arewegoingtofeedaworldof8or9billionwiththeeffectsofclimatechange?"
It'struethatastemperatureswarm,thereislikelytobeatemporarybeneficialeffectonagriculture.Likepeople,plantsgenerallypreferwarmthtocold,andtheymayflourishwithrisinglevelsofCO2.ButresearchfromWolframSchlenkeratColumbiaUniversityshowsthat,asaveragetemperaturescontinuetowarm,thosebenefitsdwindleandeventuallyreverse,andcropyieldsbegintodecline."Itsimplybecomestoohotforthegrowingplants,"saysNaylor."Theheatdamagesthecrops'abilitytoproduceenoughyield."
What'smore,intheirstudy,BattistiandNaylorlookedonlyattheeffectofhighertemperatures—notatthepossibleeffectofchangingprecipitationpatterns.Yetmanyclimatologistsbelievethatglobalwarmingwillmakedryareasdryerandfurtherdamagefarming,whichisespeciallydirenewsforsub-SaharanAfrica,aregionthatalreadystruggleswithheatwaves,droughtsandfaminesevenaspopulationcontinuestogrow."ClimatechangeisgoingtobeamajorconcernforAfrica,"saysNteranyaSanginga,directoroftheTropicalSoilBiologyandFertilityInstituteoftheInterna-tionalCenterforTropicalAgricultureinNairobi."Wecouldlosewholegrowingseasons."
Withthesefrighteningpredictionsinmind,weneedtotrytoheat-proofouragricul-ture.Thatcanbeaccomplishedbyusingcropsthathave provedresistanttoextremeheat—likesorghumormillet—tobreedhybrid-cropvarietiesthataremorecapableofwithstandinghighertemperatures.We'llneedtodropanysqueamishnessaboutconsuminggeneticallymodifiedcrops.Unlesswecantapthepowerofgenetics,we'llneverfeedourselvesinawarmerworld.Butwe'llneedtoactquickly.Itcantakeyearstobreedmoreheat-resistantspecies,andinvestmentinagriculturalresearchhasshriveledinrecentyears.
WealsoneedtofocusonimprovingtheagriculturalproductivityofthosepartsoftheworldthathavebeenleftbehindbytheGreenRevolution—likeAfrica,whereaveragecropyieldsperacreremainwellbelowthoseinAsiaortheWest.OnesimplewayistoincreasetheamountoffertilizeravailabletoAfricanfarmers.Sanginganotesthatabout440lbs.(200kg)ofnitrogenfertilizerisgenerallyneededtogrowfivetons(5,000kg)ofmaize,buttheaverageAfricanfarmercanaffordonly8lbs.offertil-izer.WecanalsoworkonsafeguardingthedegradedsoilsofAfrica,wherealmost55%ofthelandisunsuitableforanykindofcultivatedagriculture.Helpisonthe way:theAfricanSoilInformationServiceislaunchingareal-timedigitalmapofsub-SaharanAfrica'ssoils,whichshouldallowfarmersandpolicymakerstomakebetter useofthecontinent'sagriculturalresources."Farmersneedtoknowwhentoinvestandwhentoholdback,"saysSanginga,whoisinvolvedwiththemappingproject.
There'salimit,however,toourabilitytoadapttoclimatechange.Weneedtoreducecarbonemissionssharplyandsoon.Ifwefail,awarmerfuturewon'tjustbeuncom-fortable;itwillbedownrightfrightening."Weneedtowakeupandtakecareofthis,"saysNaylor."Wewon'thaveenoughfoodtofeedtheworldtoday,letalonetomor-row."
Source:TimeMagazine,BryanWalsh,January13,2009.
ClimateChangeandFoodSupply
1.Whatdoeswarmerweathernormallymean?
2.Howisglobalwarmingdifferentfromwarmerweather?
3.Whateffecthavemajorheatwaveshadonagricultureinthepast?Giveanexample.
4.Whatwillhappentofoodprices?Why?
5.WhatistheoutlookforagricultureinAfricaiftemperaturescontinuetorise?
6.Whatsolutionsareofferedinthearticle?Howwilleachofthesehelp?
TheDireFateofForestsinaWarmerWorld
It'snoteasytokillafull-growntree—especiallyonelikethepiñonpine.Thehardyevergreenisadaptedtolifeinthehot,parchedAmericanSouthwest,soittakesmorethanalittle dryspelltoaffectit.Infact,itrequiresaonce-in-a-centuryeventliketheextendeddroughtofthe1950s,whichscientists
nowbelieveledtowidespreadtreemortalityintheFourCornersareaofUtah,Colorado,NewMexicoandArizona.
So,whenanotherdroughthittheareaaround2002,researchersweresurprisedtoseeupto10%ofthepiñonpinesdieoff,eventhoughthatdryspellwasmuchmilderthantheonebefore.Thedifferencein2002wasthefivedecadesofglobalwarmingthathadtranspiredsincethedroughtinthe1950s.ThatledterrestrialecologistsattheUniversityofArizona(UA)toposethequestion,withtemperaturessettorisesharplyoverthecomingcenturyifclimatechangegoesunchecked,whatimpactwillithaveonthepiñonpine?
Unsurprisingly,theoutcomedoesn'tlookgood.InanewstudypublishedApril13in theProceedingsoftheNationalAcademyofSciences(PNAS),scientistsatUAfoundthatwater-deprivedpiñonpinesraisedintemperaturesabout7°Fahrenheit(4°Cel-sius)abovecurrentaveragesdied28%fasterthanpinesraisedintoday'sclimate. It'sthefirststudytoisolatethespecificimpactoftemperatureontreemortalityduringdrought—anditindicatesthatinawarmerworldtreesarelikelytobesignifi-cantlymorevulnerabletothethreatofdroughtthantheyaretoday."Thisraisessomefundamentalquestionsabouthowclimatechangeisgoingtoaffectforests,"saysDavidBreshears,aprofessoratUA'sSchoolofNaturalResourcesandaco-authorofthePNASpaper."Thepotentialforlotsofforestdie-offisreallythere."
ThePNASstudy,ledbyHenryAdams,adoctoralstudentatUA'secologyandevolu-tionarybiologydepartment,alsoconfirmsthathottertemperaturesactuallysuffocatetreesindrytimes.Piñonpinesrespondtodroughtbyclosingtheporesintheirneedle-likeleavestostopwaterloss.Thatkeepsthemfromgoingthirsty,butitalsopreventsthemfrombreathinginthecarbondioxidetheyneedtolive—andeventually,thedrought-stressedtreessimplysuffocate.
ThehigherlevelsofatmosphericCO2thatwouldlikelybeseeninawarmerfuturewon'tmakemuchofadifferenceeither—ifthepineneedles'poresareclosedtopreventwaterloss,CO2simplywon'tgetin.Evenmoreworrisome,thePNASstudydoesn'ttakeintoaccountpossiblechangesinprecipitationpatternsinawarmerfuture,whichmanyclimatemodelssaycouldbedrier,exacerbatingtheimpactsofhighertemperatures."Wecanenvisionthelandscapegettinghammeredoverandoveragain,"saysBreshears.
Thestudytookadvantageoftheuniversity'suniqueBiosphere2researchfacility. The7.2million–cubic-footdome—famousforanexperimentintheearly1990swheneightpeoplelivedinsideitfortwoyears—allowsscientiststorecreatealmostanyclimateonEarth.AdamsandhiscollaboratorskepttwogroupsofpiñontreesinsideBiosphere2innearlyidenticalconditions.Onekeydifference:fortheexperimentalgroup,researchersrampedupthetemperature7°Fahrenheit(4°Celsius),theroughmidpointoftheIntergovernmentalPanelonClimateChange'sbusiness-as-usualpredic-tionsforwarminginthiscentury."Wethoughttemperaturemightplayabigrole,butthatwasspeculationuntilwecouldconductanexperiment,"saysAdams."ThegreatthingaboutBiosphere2isthatitallowedustotestthisout."
Adams'paperisthelatestinanumberofrecentstudiesthatpaintagrimfatefor theworld'sforestsifwarmingisn'tslowed.AmajorSciencestudypublishedinJanuaryfoundwidespreadincreaseintreemortalityratesinthewesternU.S.,thanksinpart toregionalwarmingtrendsandgrowingwaterscarcity.Anotherstudypublishedlastmonth,alsoinScience,foundthateventheseeminglylimitlessAmazonrainforest couldbehighlyvulnerabletodrought.AndsincelivingtreessuckupCO2fromtheat-mosphere,massivetreemortalityduetowarmingcouldproduceafeedbackeffect,furtherintensifyingclimatechange.Intheend,wemightneedabiggerBiosphere2,becausewe'reontracktoscrewupBiosphere1—otherwiseknownastheEarth.
Source:TimeMagazine,BryanWalsh,April14,2009.
GlobalWarmingandForests
1.Whatwasthedifferencebetweenthedroughtsinthe1950sandthedroughtin2002 thatthepiñontreeswereexposedto?
2.Howdidthisaffectthepiñontreepopulation?
3.Whateffectdoesanincreaseintemperaturehaveontreemortalitywhenexposedtodrought-likeconditions?
4.Whatistheimplicationforforeststhatcanbederivedfromthestudyonpiñontrees?
5.Howdopiñontreesrespondtodrought?
6.Howdoesthisresponserelatetocarbondioxidelevels?
7.Nametwosolutionsthatcanbeimpliedfromthisarticle.Howwilleachofthesehelp?
IsGlobalWarmingWorseningHurricanes?
Itcouldbeasignofjusthowtraumatic2005'sHurricaneKatrinawasthatwhenHurricaneGustavfailedlastweektofullypulverizeNewOrleans,itwasnews.ThefalloutfromGustavwasrelativelylimited,butitwasstillamajorstorm,withmaximumsustainedwindsof110m.p.h.whenitmadeland-fallinLouisiana—strongenoughtocauseanestimated$20
billionindamages.AndGustavwon'tbethelastthisseason.HurricaneHannagath-eredstrengthintheAtlanticlastweek,andIkeisswirlingnotfarbehind,headednow
fortheU.S.That'sjustintheAtlantic,thismonth.LastMayinthePacific,themas-siveCycloneNargiskilledanestimated100,000peopleintheSoutheastAsiannationofBurma.
Allthesehurricanesinsuchashortperiodoftimebegsthequestion:arestormsgettingstronger,andifso,what'scausingit?AccordingtoanewpaperinNature,theanswerisyes—andglobalwarmingseemstobetheculprit.ResearchersledbyJamesElsner,ameteorologistatFloridaStateUniversity,analyzedsatellite-deriveddataoftropicalstormssince1981andfoundthatthemaximumwindspeedsofthestrongeststormshaveincreasedsignificantlyintheyearssince,withthemostnotableincreasesfoundintheNorthAtlanticandthenorthernIndianoceans.Theybelievethatrisingoceantemperatures—duetoglobalwarming—areoneofthemaincausesbehindthatchange."Thereisarobustsignalbehindtheshifttomoreintensehurricanes,"saysJudithCurry,chairoftheschoolofearthandatmosphericsciencesattheGeorgiaInstituteofTechnology.
Stormstendtorunonmulti-decadalcycles,soit'sdifficulttotellfromyeartoyearwhetherthenumberofhurricanesisreallyontherise.Sofar thatdoesn'tseemto bethecase,withtheoverallnumberofstormsworldwideholdingaboutsteady—infact,somescientistsarguethatwarmingmightactuallybringaboutareductionintheoverallfrequencyofstorms.ButtheNaturepaperarguesthatwarmersea-surfacetemperatureswillresultinstrongerstorms,becausehotteroceansmeanthedevelop-ingstormscandrawmorewarmair,whichpowersthestorm."Hurricanesaredrivenbythetransferofenergyfromtheoceantotheatmosphere,"saysKerryEmanuel,ameteorologistattheMassachusettsInstituteofTechnology."Aswaterwarms,theabilityofwatertoevaporategoesup,andagreaterevaporationratewillproduceamoreintensehurricane."
Sofar,tropicaloceantemperatureshaverisenbyabout0.5degreeCsince1970,whichcouldexplainthemorepowerfulstorms.TheNatureresearchersestimatethatevery 1degreeCincreaseinsea-surfacetemperaturewouldresultina31%increaseintheglobalfrequencyofcategory4and5storms.Giventhatcomputermodelsindicatethatoceantemperaturescouldrisebyupto2degreesCby2100,thosearescarycalcula-tions.It'sespeciallyworryingbecausethemostintensestormsdothemostdamagebyfar—severalminorstormscanequalthedamageofasingleseverehurricane."Thecategory1or2stormsdon'tdothatmuch,"saysEmanuel."It'sthe3and4stormsthatreallydothedamage,andwecouldseemoreofthem."
Noteveryoneagrees.Recordsofpasthurricanestrengtharelessthanperfect,soit'sdifficultforscientiststobesurethattherecentincreaseinstormintensityhasn'toccurredbefore,intheyearsbeforetheEarthstartedwarming.Andtheweather—asweallknow—iscomplicated,whichmeansthatit'sdifficulttomodelpreciselyhowfuturewarmingmightaffecttheformationofstorms.Climatemodelsworkwellonagloballevel,buttheycanrarelybeappliedaccuratelytoareassmallerthan200squaremiles—whichhappenstobelarger thanmanystorms."It'snotjustasimplerelation-shipwithsea-surfacetemperatures,"saysCurry."It'smorecomplicatedthanthat. Weneedthemodelstogetalotbetter."
Modelswillimprove,andovertime,weshouldhaveabetterideaofjusthowmuchwarm-ingmightintensifystorms,andhowthatprocessworks.Butthat'sasecondaryissue.Whetherornotwarmingwillcreatemoresuperstorms,weknowthathurricaneswillhappen,andweknowthattheywillstrikehumanpopulations.Thedifference,asmycolleagueAmandaRipleyrecentlypointedoutiswhetherornotwe'repreparedfor them.AspopulationnumbersandpropertydevelopmentgrowinvulnerableareasliketheGulfCoast,naturaldisasterswillgetworseevenwithouttheeffectofwarming.Think ofthedamagethathurricaneshavecausedevenwithoutthepossibleeffectofwarming:HurricaneCamillein1969,whichcausedover$9billionindamages,andHurricane Andrewin1992,whichcaused$38billionindamages.Nowimaginethosestormspoten-tiallyamplifiedbytheunpredictableeffectofglobalwarming.Weneedtobeprepared.GustavcausedfarlessdamagethanKatrinabecauseitwasaweakerstorm,yes,butalsobecausewewerereadythistime.Butwealsoneedtoreducecarbonemissionsandbluntclimatechange—orwemayexperiencestormsforwhichthereisnopreparation.
Source:TimeMagazine,BryanWalsh,September8,2008.
ClimateChangeandHurricanes
1.Arestormsgettingstronger?Ifso,whatiscausingthis?
2.Wherearetheincreasesinstormstrengthbeingseen?
3.Whatpowersstorms?
4.Howdoesglobalwarmingaffectthestrengthofthesestorms?
5.Whatsolutionsaresuggestedtocombatthisissue?Howwilleachofthesehelp?
CouldRisingSeasSwallowCalifornia'sCoast?
ImagineSanFranciscoAirportunderwater,orLongBeachHarborinLosAngeles,thesecondbusiestportinAmerica,washedaway.PictureOrangeCounty'sNewportBeachcom-pletelysubmergedundertheencroachingocean.
That'sthesoggyfuturethatcouldbeinplaceforCaliforniaattheendofthiscentury ifclimatechangecontinuesunabated.AccordingtothePacificInstitute,anenviron-mentalNGOthatspecializesinwater,uncheckedglobalwarmingmaycausetheworld'sseastorisemorethan4.6ft.(1.4m).TheCaliforniagovernmentcommissionedtheinstitute'sstudy,releasedonMarch11,oneofanumberofforthcomingreportsonhowclimatechangewillaffectthecoastalstateandoneofthemostdetailedanalysesyetonthelocalimpactofrisingseas.
ThePacificInstitutefoundthatby2100,anestimated480,000Californianswillbeatriskofincreasedflooding—almostdoublethenumbercurrentlylivingindisaster-proneareasofthestate—alongwithroads,schools,hospitalsandotherlow-lyingcoastalinfrastructure.Nearly$100billionworthofcoastalpropertycouldbeatrisk—andthecosttoprotectthatlandfromfloodingwilllikelybeinthebillions,evenifwedocontrolgreenhouse-gasemissions."Thischangeisinevitable,andit'sgoingtoalterthecharac-terofCalifornia'scoast,"saysHeatherCooley,aseniorresearchassociateatthe PacificInstituteandaco-authorofthestudy.
Thereport'swarningsaresostrikinginpartbecauseitassumesamuchhighersea-levelrisethanpreviousstudies.The1.4mfigureusedinthePacificInstitutereport—whichcomesfromresearchbytheScrippsInstituteofOceanography—isconsiderably higherthantheestimatesputforthintheU.N.IntergovernmentalPanelonClimateChange's(IPCC)mostrecentassessmentin2007,whichprojectedasea-levelriseof18to59cmby2100.ButtheIPCCnumberswerebasedonolderdataandtookinto accountonlythethermalexpansionoftheseas.(Waterexpandsasitheats,sowarmerseasrise.) TheIPCCdidnotfactorinthepotentiallyfargreaterimpactofmeltingicecapsinGreenlandandAntarctica—Greenlandalonehasenoughicetoraisesealevelsbymorethan20ft.AtthetimeoftheIPCCreport,thepolaricesheetswereclearlymelting,butitwasn'tclearhowfasttheyweregoingorhowtheywouldrespondtorisingtemperaturesinthefuture.
Newresearchisclarifyingtheice-capquestionandtheresultsaresobering.ScientistsattheClimateChangeCongressinCopenhagenthisweekpresentedastudyestimatingthatsealevelscouldrisegloballyby1mormorebytheendofthecentury,withlargeregionaldifferencesaroundtheworld.Atthelowerendoftheestimate,scientistssayit'sunlikelythatseaswillriselessthan50cmevenifwecangetagriponcarbonemis-sions.
TherevisedpredictionsareduetobetterdataonmeltinginGreenlandandAntarcticaandfromglaciersaroundtheworld,whicharepouringwaterintotheoceansandcaus-ingthemtorise.Upto600millionpeopleincoastalareasaroundtheworldcouldbeatincreasedriskforflooding."Unlesswetakeurgentandsignificantmitigationactions,theclimatecouldcrossathresholdduringthe21stcenturycommittingtheworldtoasea-levelriseofmeters,"saysJohnChurch,anoceanographerattheCentreforAus-tralianWeatherandClimateResearchandoneofthestudy'sco-authors.
ThePacificInstitutereporttakesthatabstractnumberandshowswhatitwillmeanforthecities,streets,bridges,beachesandpowerplantsinAmerica'smostpopulous
—andvulnerable—state.Nearlyhalfamillionpeoplewillbeatriskforwhat'scalled
a100-yearfloodevent.Thatdoesn'tmeanafloodthathappensonceacentury,but
ratheradisasterthathasa1%chanceofhappeningeveryyear—whichmeansithasa26%chanceofhappeningoverthelifeofanaverage30-yearmortgage.Thevulner-abilityisconcentratedalongthecoastlineoftheBayArea,wherelargepartsofbothSanFranciscoandOaklandcouldbethreatenedwithextremefloodingbytheendofthecentury.EvenpartsofthePacificcoastlinethatmaybeshieldedfromfloodingcouldbeatriskforincreasederosion.Worse,aswithHurricaneKatrina,itwillbethepoorandthosewithoutinsurancewhowilllikelybearthebruntofthefloodingdamage."There'sthisnotionthatthoselivingonthecoastareallrichwithinsurance,"saysCooley."Butinfactthesepopulationsareoftenpoor,andtheywillbeparticularlyvulnerable."
ThebestwaytoprotectCalifornia'scoastwouldbetosharplyreducecarbonemis-sionsnowandhopetoaverttheworstofthewarming.Butevenifwedocutcarbonsoon,we'velockedinsea-levelrise,andweneedtobeginprotectingsensitivecoast-linesbetterthanwedidinNewOrleans.ThePacificInstitutestudysuggeststhatsome1,100milesofimprovedcoastaldefenses—includingdunesandseawalls—wouldbeneededtoprotectagainsta1.4msearise.Itwon'tbecheap—thecostwillbeatleast$14billionupfront,accordingtothePacificInstitute,withanadditional$1.4billionayearinmaintenancecosts.Buteventhatmightnotbeenough."Eventuallyyoucouldseephasedabandonmentofcertainareasthatwouldexperiencefloodingalot,"saysCooley.We'reusedtocontrollingtheeffectsofnature,butifwefailtocontrolclimatechange,wemayhavetosurrender.
Source:TimeMagazine,BryanWalsh,March11,2009.
ClimateChangeandSeaLevels
1.Howmuchcoulduncheckedglobalwarmingcausetheseastorise?
2.Howmuchwillitcosttoprotectcoastallandsfromflooding?
3.Whattwofactorsleadtotherisingsealevels?
4.Howmanypeopleworldwidewillbeatriskforcoastalfloodingbytheyear2100?
5.WhatimpactswilloccurinCaliforniaifclimatechangecontinues?
6.Whatsolutionsaresuggestedbythearticle?Howwilleachofthesehelp?
ALastWarningonGlobalWarming
Thelanguageofscience,likethatoftheUnitedNations,isbynaturecautiousandmeasured.Thatmakesthediretoneofthejust-releasedfinalreportfromthefourthassessmentoftheU.N.'sIntergovernmentalPanelonClimateChange(IPCC),anetworkofthousandsofinternationalscientists,allthemorestriking.Globalwarmingis“unequivocal”.Climatechangewillbring"abruptand
irreversiblechanges”.Thereport,asynthesisforpoliticiansculledfromthreeotherIPCCpanelsconvenedthroughouttheyear,readlikewhatitis:afinalwarningtohumanity.
"Todaytheworld'sscientistshavespokenclearly,andwithonevoice,"saidU.N.Secretary-GeneralBanKiMoon,whoattendedthepublicationofthereportinValencia,Spain. Climatechange"isthedefiningchallengeofourage”.
TheworkoftheIPCC,whichwasco-awardedtheNobelPeacePrizelastmonthwithAlGore,underscoresjusthowmomentousthatchallengewillbe.Thereportpredictedthatatawarmingtrendof3.6degreesFarenheit—nowconsideredalmostunavoidable,duetothegreenhousegasesalreadyemittedintotheatmosphere—couldputupto30%ofspeciesontheplanetatriskforextinction.Awarmingtrendof3°wouldputsmillionsofhumanbeingsatriskfromflooding,wetlandswouldbelostandtherewouldbeamassivedie-offofseacorals.Sealevelswouldriseby28to43cm,andmostfrighteningofall,thereportac-knowledgedthepossibilitythatthemeltingoftheGreenlandicesheet,whichwouldreleaseenoughfreshwatertoswampcoastalcities,couldoccurovercenturies,ratherthanmillen-nia."IfyouaddtothisthemeltingofsomeoftheicebodiesonEarth,thisgivesapictureofthekindsofissueswearelikelytoface,"saidRajendraPachauri,theIPCC'schairman.
Asifthepotentialconsequencesofclimatechangeweren'tscaryenough,theIPCCempha-sizedjusthowlittletimewehavelefttotrytochangethefuture.Thepanelreportedthattheworldwouldhavetoreversetherapidgrowthofgreenhousegasesby2015toaverttheworstconsequences.Theclockwasrunning."Whatwewilldointhenexttwo,threeyearswilldetermineourfuture,"saidPachauri."Thisisthedefiningchallenge."
Thatputsthepressureontheworld'sleaderstofinallydosomethingaboutglobalwarming.They'llhavetheirlast,bestchancenextmonth,whenenergyministersfromaroundtheworldtraveltoBali,Indonesia,fortheannualmeetingoftheU.N.'sFrameworkonClimateConvention.TherepolicymakerswillbeginattemptingtonegotiateasuccessortotheKyotoProtocol,whichexpiresin2012."ThebreakthroughneededinBaliisforacomprehensiveclimatedealthatallnationscanembrace,"saidBan.
Allthenationsintheworldwillplayaroleinthosenegotiations,buttheirsuccessandfailurewillcomedowntotwocountries:theU.S.andChina.Iftheworld'stwobiggestcarbonemitterscanagreetocaptheirgreenhousegasemissions—neithersignedonforlimitsunderKyoto—wemaystandachanceofavertingthegrimmestconsequencesofclimatechange.Iftheyfail,thentheIPCChasalreadywrittenourfuture.We'llfindoutinBali.
Source:TimeMagazine,BryanWalsh,November17,2007.
IsGlobalWarmingDrowningAfrica?
Africahasalwaysbeenpredictedtobethecontinentthatwillbeworsthitbyglobalwarmingandclimatechange.Couldthose pre-dictionsbecomingtrue?ExtremerainsandfloodshavemadeforaverywetsummerinAfricaandthereisnoendinsighttothedownpoursthatareswallowingtownsandforcingoveramillionto
fleetheirhomesinatleast20countries.SinceJune,Uganda,Sudan,EthiopiaandKenyahavehadhundredsofthousandsofpeopleuprootedfromtheirhomes.Scoreshavediedsince.WestAfricahasseenitsworstfloodsinyears,with300,000fleeingtheearth-coloredwatersofnorthernGhana.Meanwhile,forecastsbyAfricanmeteorologistssaytherainshaveyettopeak.Octobermaybetheworstmonthtocomeinthisverywetyear.
Thisweatheriswhatclimatologistspredicted,anditishappeningevenfasterthanexpected,"saysGraceAkumu,executivedirectoroftheKenya-basedClimateChangeNetwork."Weareoverwhelmed."TheimmediateconsequencesofclimatechangeinAfrica?Countrieswillexperienceeithertorrentialfloodsorseveredroughtduringaseason.AkumusaysthattheunpredictableclimatewillthreatenthefoodsupplyinAfricaandpotentiallyeliminatekeycrops.Africansareexpectedtofaceaseverelackoffoodanddrinkablewaterbytheendofthecentury.
ScientistsontheU.N.'sIntergovernmentalPanelonClimateChangewarnedthisweekthattheeffectsofglobalwarmingarealreadybeingfeltinAfrica.TheIPCC'smostrecentreportonAfricapredictedaminimum2.5degreecentigradeincreaseinthecontinent'stemperatureby2030.Growingseasonswillbecutshortandstretchesoflandmadeunsuitableforagriculture,withyieldsdecliningbyasmuchas50%insomecountries.Insub-SaharanAfrica,between25%and40%ofanimalsinnationalparksmaybecomeendangered.Africa'smajorbodiesofwater,includingtheNile,willsufferexcessivefloodingcausedbyrisingsealevels.
Africaisparticularlyvulnerablebecauseithasalowinstitutionalcapacitytocombatthechangingweather.Asaresult,saysUgandanclimatechangespecialistJamesMagezi-Akiiki,"inAfrica,adaptationtoclimatechangeismoreimportantthanmitigation."InresponsetothefloodsdevouringUganda,Magezi-Akiikisaysthatthegovernmentwillnowconsidertheeffectsofglobalwarming,suchasincreasedrainfall,initsplanningoffutureinfrastructureprojects.Ironically,Africaproducesfarlesscarbonthanothercontinents,leadingsomescientiststoblameindustrializedcountriesforAfrica'sclimateplight.Uganda'sPresidentYoweriMuseveniannouncedatanAfricanUnionsummitthisyearthatdevelopedcountrieswere"committingaggression"againstAfricabycausingglobalwarming.
"There'snotmuchAfricacando—unlessothercountriescuttheirgreenhouseemissions,oureffortswillbeundercut,"Akumusays.Inthemeantime,floods,droughts,earthquakes,landslidesandothernaturaldisastersareexpectedtobecomemorefrequent,alongwiththeoccurrenceofdiseasessuchastyphoid,choleraandmalaria.Akumuwarnsthatwithoutaidfromrichercountriesintheformofcashtopayformoredurableroadsandhospitals,Africawillbeunabletohandlemoredisasterslikethissummer's.
Source:TimeMagazine,BryanWalsh,