-4slnks for carbon dloxlde Dust be larger and aore efflclent than pre_
viously esthated. Thlg would reduce the levels to whlch carbon dl_
oxlde has been proJected- to r.nctease. ?hls posslblllty 1s veheoe'tly
denled by the oceanographers, who cla!.D thet the oceans cannot posslbiy
absorb nuch nore carbon dloxlde. Hovever, lt 16 Ey lmpreeslon that
the scleDce of oceaooglaphy has Dot a6 yet reached a slate of develop_
Eent lrhlch can Justl.fy such a posltlve claln.
The culaetrt atatus of gclentlflc opLnion regardlng the carbon
cycle ls sur@allzed ln Vugraph 7. First, curreut sctinttttc oplnlon
overwhelnlngly favore attrlbutlng at'ospheric carbon dloxlde lncrease
to fo6s11 fuel coobustlou. Holrever, Dost scientlats feel that r0ore
research 1e needed to Bupport an unquallfled concluelon. Flna11y, soue
aclentlats, partlculerly the blologlEts, clalm that part or all ti tne
co2 lncrease arlses fron the destructloo of folests and othe! land b1ota.
II.
Pledlctlons on the slgaiflcances of lncreases ln atmospheric
rust be based upon clLEete oodellng. Modellng cliDatlc effeits ls
currently haadlcapped by an 1nab1llty to hsndle all the coDpllcated lEteractlons whlch are lmportant to pledlctlng ghe cllEate. Soo! of these
are sholrn in Vugraph 8.
C02
One
iDteracrlon whlch ha6 not has yet been lncluded wlth
any
of sophlstlcatloo ln cll'ate nodels le the effect of eloudlness.
clouds can reflect lneoalng vlslble aad ultravlolet radlatlon back into
space lrlth greater efflclency than would occur at the glound. On the
other hand' at thelr bottom surface they absorb outgolng radiatl0u aod
the cloud tops also ealt lnftared radlatlor\ dependlng uton the teEpelature (that 1s altltude) at lrhlch the top 1s'located. fhe effect oi a
cloud n111 thelefore depeod upon its slze, 1ts shepe, and the altltude
at lrhlch lt ls loceted
degree
Another uncertalnty whlch has not, as yet, been handled ln any
gleat deta1I ls the atDosphere - oceau clrculatlon - aea Burface teDpelature lnteractlon. Eow should the heat capaclty of the oceans be handled
1n vlev of the turbulence at the surface aod to whet depths are the oceans
lnvolved ln lnteractlDg nlth the etooBphere? TheEe are laportant que6tlons because the etrtlre heat content of the atDosphere t"s equal to the
heet content of Just lhe fl:ist thlee Deters of the oceans. A third uncertalnty ln rnodellog ls the iotelactlon betweeE the seasons and longterE cllmate treods. Ia present oodele, the ehaages vhlch are predlcted for lncreaslng carbon dloxLde concentratlons are calculaled wlth
legpect to a constant clLDate, that is a perpetual epring or sumer
seaaotr. It ls quite posslble thet thls assl@ptlon 1s luadequate. lor
example, the best accepted explanatlon for the on-set of the Lce ages
ls that orbltal and other changes resulE in the earth euteling a plrlod