-2It seems 1lke1y that any general. tempetature increase would be acceutuated ln the polar reglons, possibly as much as trro- or threefoLd as Eentl'oned above. Any large temperature increase at hlgh latitudes would be assoclated wlth a reductj.on in sno\r cover and a of the floatlng lce-pack. Present thlnking suggests that theremelting would be llttle or no neltlng of the polar ice-caps it re"porrse to rf,armer temperatures on a tlme scale over which the Greenhouse Effect is predicted to apply. A nurnber of assrmrptions and uncertairlties are iuvolved, ia the predictlons of the Greenhouse Effect. The fLrst is the assunption that the observed Co2 lncrease can be attributed eati.rel-y to fossil. fuel coubustLon. At Presentr meteorol.ogists have no direct evldence that the incremental C02 tn the atmosphere comes from fossil carbon. The increase could be at least partly due to changes in the natural balance. There is eonsiderable uncertainty regarding what controls the exchange of atuospheric Co2 wlth the oceans and with carbonaceous uaterlals on the contlnents. Models whlch predict the climatic effects of a CO2 lncrease are in a prfurltlve stage of development. The atmosphere i.s a very comp]-icated system, particuLarry on a global- scaLe. rn existlng models, lmportant lnteractions are neglected, ei.ther because they ar! not completely understood or because thelr proper roathematical treatment is too cuobersome. Substantlal efforts are being expended to improve exlsting models. But there is no guarantee that better knowleage wfU lessen rather than auguent the severity of the predictions. The Greenhouse Effect has been the subject of a number of lnternatlonal sclentlflc conferences during the past two years. These neetlngs have identified the infonoation needed to definitely establish the source and ultlmate signiflcance of the C02 increase fn lne atmosphere. Present thlnklng holds that man has a tlne window of five to ten years before the need for hard decisions regarding changes in energy strategles might become critical. The DOE is presentiy Congreisional supPort for a research program whieh will produce""ekirrg the necessary inforrnatLon ln the required ti.ne. This proglam is deseribed.