07 57-L-RWC Ex)N RESEARCH AND ENGINEERING COMPANY CORPORATE RESEARCH P, O. Ao,( 45, Llnd.n. N. J. 07036 SCIENCE LABORATORIES OUANE G. LEV lN E, Dir.ctot BOGE B W,COHEN, Dlr.ctor Th.or.ticrl .nd M.thtn.tlc.l Scl.nc.. Llborltory September 2, 1982 H- N. WEINBERG Mr. A. M. Natkin Office of Science and TechnologY Exxon corporation 1251 Avenue of the Americas Nevr York, New York 10020 siP 2 198? Dear AI: I would like to sunnarize the findings of our resea rch in climate modeling and place our results in the context of the existing body of knowledge of the CO2 greenhouse effect. Although the lncrease of atmosPheric CO2 is well docunented. it has not yet resulted in a measurable change in the earthis clirnate. The concerns surrounding the possible effects of increased CO, have been based on the predictions of models which simulate Ehe earthrs climate. These nodels vary widely in the level of detail in which clirnate processes are treated and in the approxinations used to describe the complexities of these processes. Consequently the quantitative predictions derived f rorn the various nodels show considerable variation. However, over the past several years a clear scientific consensus has energed regarding the exPected glimatic effects of increased atmoipheric Co1. The consensus- is that a doubling of atnospheric CO, frofi its pre-industrial revolution value qoulil result global temperature rise of (3.0 t 1.5)oc. The in "n "u"f"gein this figure is a result of the inability of even uncertainty the most elaborate models to simulate clinate in a totally realistic nanner. The temperature rise is predicted to be distributed nonuniformly over the earth, with above-average temPerature elevations in the polar regions and relatively smalL increases near the equator. There is unanimous agreement in the scientific community that a temperature increase of this magnitude would bring about significant changes in the eart.hrs climate' including rainfall distribution and alterations in the biosphere. The time +NationaI Research Council Panel Reportt Carbon Dioxide Climate: A second Assessment, National AEE?emt-Press, and Mr. A. M. Natk i n -2- August 25, 1982 required for doubling of atmosPheric CO, depends on future world consumption of fossil fue1s. current piojections indicate that doubling will occur sonetime in the latter half of the 2lst changes centuryl The models predict that co2-inducedIt climate generally is doub1ing. should be observable well before believed that the first unambiguous CO2-induced temPerature increase wiIl not be observable until Eround the year 2000. It should be ernphasized that the consensus prediction scientists have of global warming is not unaninous. Several of the prevaLidity takln positions that openly guestion the which proposed mechanisms dictions of the nodels, and a few have of these most serious could mitigate a CO2 warming. One of the proposals has been fiade by Professor Reginald Newe11-of.MIT. ire*if f noted that geoJ-ogical evidence points to a relative constancy of the tenp;ratu;e of the equatorial waters over hundreds view of of miilions of yelrs. This constancy is remarkable inaturing this ihanges in other regions of the earth ni:o, Newell asciibed this anctloring of the temPerature of the p.iioa."fi."tic this Lquatorial waters to an evaporative buffering nechanisn. - In the of mos! equator, at the increases when heating mechanism, extra energy induces greater rates of evaporatlon rather than night raising tefr-peratures. Newe11 proposed that this effectatmospheric increased of effect global warming tieatfi redlce the coz' In our clinate research we have explored the 91oba1 effects of Newelfrs evaporative buffering mechanism using a simple mathematical climate model. Our findings indlicate- that Hewill's effect is indeed an imPortant factor in the earthrs does climate systen. As Newe11 predicted, evaporative bufferlng limit cor:induced tenperature changes in the equatorial regions.- However, we find a compensatingly Iarger temperature inirease in the polar regions, giving a global averaged temPerathe scientific ture increase thlt fa1ls well within the range ofpublished with the are consistent Our results Predicconsensus. in agreement are also They models. cl.imate conplex tions of more a with estinates of the global temperature distribution during than nuch warmer was period the earth when prehistoric certain tod a y. In summary, the results of our research are in accord with the scientific consensus on the effect of increased atnospheric co, on climate. our research appears to reconcile NewelI's 5bservations and proposed mechanisn r.tith the consensus opinion. we are now ready to present our research to the scientific community through the usual mechanisms of conference Presentations and publications in appropriate journals. I have enclosed a detailed plan for presenting our results. Mr. A. M. Natkin - 3 - August 25, 1982 As we discussed in the August 24 meeting, there is the potential for our research to attract the attention of the pop- ular news media because of the connection between Exxon's major business and the role of fossil fuel combustion in contributing to the increase of atmospheric CO . Despite the fact that our results are in accord with those of most researchers in the field and are subject to the same uncertainties, it was recognized that it is possible for these results to be distorted or blown out of proportion. Nevertheless the consensus position was that Exxon should continue to conduct scientific research in this area because of its potential importance in affecting future energy scenarios and to provide Exxon with the credentials required to speak with authority in this area. Furthermore our ethical responsibility is to permit the publication of our research in the scientific literature; indeed to do otherwise would be a breach of Exxon's public position and ethical credo on honesty and integrity. incerely ours, 1m ROGER W. COHEN RWC:tmc Enclosure cc: A. J. Callegari E. E. David, Jr. 8. P. Flannery M. B. Glaser D. G. Levine P. J. Lucchesi H. N. Weinberg r' ,0763-L-RWC COt Cl imate trlodel i ng Resea rch : Timetable-for Presentations and Publications I. Presentations (I) DOE Sponsored CO2-CLimate l'leeting Virginia) (a) Results pertaining to general aspects of the model to be presented in an informal session by our collaborator Prof essor l'1. I. Hof f ert of NYU- The COZ calculations wilI not be included. (b) Preprints of the PaPer t* (1) belowl to be distributed at this meeting to general Peer comments and discussion.* September 19-23,-L982 (West (2) Ewing Symposium (Lamont-Doherty/Exxon Foundation Supported) October 25-27, 1982 (a) Results concerning general aspects of the model and the COo calculations to be presented by B. P. Flannery (6n). II. Publications (1) l'lanuscript developing general aspects of the model to be submitted for publication to the Journal of Geophysical Research, September, 1982.* (2) tlanuscript on cor related model predictions to submitted in }atd 1982. be * provided formal publication clearance has been granted by this t ine.