temperatureofearth'satmospherehasgoneup1Fahrenheit.Theweatherhasnotchangedexactlythe
samewayineveryareaoftheplanet.Butscientiststhinkthattheriseinaveragetemperatureisalready
affectingtheearth'sclimate.
Manyscientistsnowbelievethatglobalwarmingiscausedbycuttingdowntrees,producingmore
trash,andpollutingtheenvironmentwhicharesomeofthereasonswhythetemperaturehasgoneup.
Manyscientistsbelievethatthebiggestcausesofglobalwarmingarenewhumantechnologiesthat
releasegreenhousegasesintotheatmosphere.
Thegreenhouseeffectisnotnew.Certaingasesintheatmosphere,likecarbondioxide,nitrousoxide
andmethane,makingithardforheatenergytogointospace.Inthepast,theclimatedidn'tchangemuch
becausenatureproducedjusttherightamountofgreenhousegasestodealwithit.
Today,mostscientistsareprettysurethattherisingtemperaturecan'tbeblamedonnature.Eversince
theindustrialrevolutioninthe1700s,humanshavereliedonmachinesfordailylife.Andmanyofthose
machinesgiveoffalotofgreenhousegases.Anincreaseinthereleaseofgreenhousegasesfromhuman
activitiesisthrowingnatureoffbalance.
Theclimateisaverycomplicatedthing,butmanyscientistsagreethattherisingatmospheric
temperaturehasalreadydamagedtheenvironment.Sheetsofice,calledglaciers,aremeltinginAntarcticaandotherpartsoftheglobe.Asglaciersbreakoffandmeltintotheoceans,theyareaddingwarmwater
totheoceansandcausingthesealeveltorise.
Overthepast100years,thesealevelhasrisen6-8inchesaroundtheworld.Thatmeanslandalong
thecoastsisbeginningtodisappearunderwater.Biggerandwarmeroceansarealsoaddingtoother
weatherproblemscausedbypollutionintheatmosphere.Someplaceshavereceivedmorerain,others
havehadbiggerstormsandafewareasintheworldhaveexperiencedunusualdrou
