Thehumanracehasexperiencedaconsistentincreaseinpopulationsincethebeginningofitshistory.Famineanddiseasehavedonelittletooffset(抵消)thissteadyincrease.Toomanypeopleareaddedannuallytothepopulationoftheworld.Soboththecausesofpopulationincreaseandtheresultsofhavingmorepeopleareworthcarefulstudy.
Cultureevolutionisthemajorfactorresponsibleforpopulationincrease.Earlyinhumandevelopment,peopleinventedtoolstohuntanimals.Latertheybuiltshelterstoprotectthemselves.Stepbystep,theymadelifeeasier.Asaresult,fewerdiedfromnaturalforces,suchasharshclimateanddisease.
Inthepast,whenpopulationgrew,therewasunexploredterritorytoinhabit.Butnow,almostallthehabitablelandhasbeenexplored.
Theworld'spopulationmayreach8.7billionin2033.Itisclearthatworldpopulationisaseriousissuethatneedscarefulattention.Humanbeingsareuniquetosolveproblemsthroughculturalevolution.(发展)Facingtheworldpopulationexplosioninthenearfuture.Wemustcarryoutthebirthcontrolprograminordertosavethemankindandsavetheworld.