Climatechangecouldaffectfoodsupplies,waterresources,humanhealthandhomes.

Ifgreenhousegasemissionskeepincreasingatthecurrentrate,globaltemperatureisexpectedtorisebetween2°Cand6°Cby2100.Thisdoesn’tsoundmuch,buta5°Cchangeisthedifferencebetweenthecurrentwarmperiodandaniceage.

Globalwarmingleadstootherchangesintheclimate:meltingice,moreevaporation(蒸发),changesingeographicalpatternsofrainfall,heavierdownpoursseparatedbylongerdryspells,morefrequentheatwaves,moreintensehurricanes,andsealevelrise.

Thesechangescouldaffectcropgrowthasdrought,increasedevaporationandshrinkingglaciers（冰川）disruptwatersupply.Somecropscouldsufferheatstress.Whiletheremaybebenefitsinsomeregions,overallclimatechangeislikelytohaveanegativeimpactonglobalfoodsupplies.Theimpactsofclimatechangeonagriculturewillvarywidelyaroundtheworld.Aglobaltemperatureriseof1–2°Cisexpectedtoincreasefoodproductioninsomeregions,particularlymid-latitudeareas.Butintropicalregionsevenasmallamountofwarmingcouldreducecropyields.Atemperatureriseof3°Cormorecouldthreatenglobalfoodresources,asallregionsarelikelytoexperiencenegativeimpactsoverall.

Freshwaterresourcescouldalsodiminish,especiallyintropicalregions,asrainpatternschangeandevaporationspeedsup.Somecommunitiescouldloseessentialmeltwaterasglaciersdisappear,whilemoreintenserainfallandhurricanescouldcausemoreflooding,leadingtowaterpollutionandbacterialdiseasessuchascholera（霍乱）becomingmorewidespread.

Climatechangecouldleadtoavarietyofhealthimpacts–bothpositiveandnegative.Onthenegativeside,scientistsanticipatemorecasesofmalnutrition,heatstrokeandwaterbornediseasessuchascholera.Althoughsomepopulationswillbenefitfromareducedriskofcold-relatedillnessessuchashypothermia,overallawarmingworldislikelytohavenegativeeffectsonhumanhealth.

Scientistsalsoexpectdamagetohomesandbuildingsfrommoreintensehurricanes,heavierrainfallandrisingsealevels.Climatechangeislikelytoaffectinfrastructurebyincreasingtheriskofbothcoastalandinlandfl