2019-2020年高中英语 Unit 20 New Frontiers教案 北师大版选修7

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1、2019-2020年高中英语Unit20NewFrontiers教案北师大版选修7【美文阅读】　Ourworldin2050尽管人类在改造大自然方面已取得了不少成绩，但是人类频繁的活动已使今日的地球失去了原有的艳丽姿色。Whenscientistsscantheglobalhorizon，over－fishing，lossofspecieshabitat，watershortage，climatechange，andinvasive(侵害的)specieslooktobethebiggestthreats

2、totheearth.Whatwillourworldbelikein2050?PopulationdecreaseandincreaseTherearetwofeaturesinthegrowthofworldpopulation.First，theannualincreaseinpopulationin15Europeancountries，inthepastfewyears，hasbeenonly300,000.TheUnitedNationsestimatesthatby2050，thepopul

3、ationofEuropeancountrieswilldecreasefromthecurrent0.72billionto0.63billion.Second，thepopulationindevelopingcountriesisgrowingrapidly.Overthepast50years，therateofincreaseinpopulationhasbeenfastestintheleastdevelopedcountries.By2050，thepopulationofAfricaise

4、xpectedtoreach1.8billion,0.9billionmorethanitscurrentpopulation.GlobalwarmingArecentresearchreportindicatesthatitisquitepossiblethattheEarth'stemperatureisrisingwellabovethepreviousestimate.Sucharesultwouldhavesevereconsequences(后果)．AresearchteamfromtheUn

5、iversityofColoradousedsatellitedatatoestimatethattheicesheetwillloseupto48cubicmilesby2050.IceshelvesintheAntarcticwillhavedecreasedbymorethan7,200squaremilesinthenextfourdecades.WatershortageAfrica'sriversfacedramatic(戏剧性的)changethatwillleaveaquarterofth

6、econtinentseverelyshortofwaterbythemiddleofthecentury.“Inthoseareaswherethereisalreadyawatershortage，it'sgoingtohaveadevastating(毁灭性的)effect，”thestudysays.“Ifyou'renowwalking5kmtotheneareststreamtogetwater，by2050，it'sgoingtomeanwalking30kmormovingyourwhol

7、ehouseholdclosertothewatersource.”Fourwheelsgood，fourwheelsbadThecarhastransformedthelivesofpeople，buttheplanetispayingtoohighaprice.Todaythereare620millionprivatecarsworldwide，tosaynothingofbuses，vansandlorries.Withcurrentgrowthtrends，thatnumberisexpecte

8、dtoreachastaggering(难以置信的)threebillioncarsworldwideby2050.Ifwecontinuetoburnfossilfuelsatcurrentrates，levelsofcarbondioxideintheatmospherewillreach550ppm(partspermillion)byaround2050.Thiswillincreaseglobaltemperatur