Created: 12/1/1984

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The Soviet Approach to Nuclear Winter

Intelligence Assessment








The Scientific



Key Variables, Assumptions, and

Confidence in

Soviet Views on Nuclear


Current Soviet




Military Side

The Base


Annex A: The Soviet Nuclear Winter

Annex D: Selected Chronology of Nuclear Winter Discussions in




This Assessment looks al Soviet research on Nuclear Winter to determine what the Soviet leaders think of the hypothesis, the extent to which they are exploiting the subject for propaganda purposes, and the most likely implications from Moscow's perspective. It does not reach judgments about the scientific validity of the Nuclear WinterMost of the information on which this analysis is based is derived from the international scientific and diplomatic communities. This information is supplemented by foreign media reports. We also haveoviet scientist who recently defected from the USSR and was knowledgeable of the capabilities of individuals and organizations involved in Soviet research in this field. From these sources, we believe that weelatively good understanding of Soviet Nuclear Winter research. We also know what Soviet leaders say publicly about Nuclear Winter. Their private, personal perceptions, however, are not known. We identify some possible military and political dilemmas, should Soviel leaders come to believe Nuclear Wintererious danger, and note some possible indicators of increasing concern over possible adverse climatic consequences of nuclear war.

(vole: Thii AuroralDlwrdhe luipsee*(he National Intelligence Officer feec Program. Ii -a, coordinatedhe working level bv lhe Central In.elligcnce Agency, lh. Defense Intelligence Agency, aod the Intelligence component of the Derailment of Energy.


Wc do not anticipate any changes lo Soviet nuclear weapons policies oi programs solelyesult of Nuclear Winter research. Senior Soviet leaders arc informed about Nuclear Winter. Reportedly. Foreign Minislcr Gromyko has been briefed on lhe subject. But the scientific evidence is not yet convincing, and, more important. Soviet leaders do not see any apparent response in US strategic programs to Nuclear Winter concerns. Lacking both of these conditions, we believe Moscow will continue totrategic force posture that supports their war-fighting strategy and depends primarily on missiles with large throw weights and large numbers of warheads. Consequently, we believe that there is little chance for major reductions in their nuclear arsenalirect result of published or ongoing research on Nuclear Winter.

We believe that thereide difference in what Soviet officials say publicly about Nuclear Winter and what they believe privately. The official Soviet party line is that Nuclear Winter is real and the effects are certain and severe, but Soviet scientists have privatelythat substantial uncertainties remain. Despite these uncertainties, Soviet Nuclear Winlcr research remains concentratedmall group of Computer Center scientists with little background inThe research program does not appear to be well coordinated among other individuals and institutions in the Soviet Union that could make important contributions. Nor do we have any evidence that the research program is coordinated with the nuclear weapons design organizations al this time.

Soviel Nuclear Winter research beganew scientists moved quickly to conduct investigations and enter into the growing debate on the subject Thelt findings were widely reported as independent confirmation of the hypothesis that nuclear war would lead to widespread and devastating climatic changes On closerhowever, Soviet research on Nuclear Winter is not convincing. Neither is it well documented. It Is derived almost entirely from US ideas, data, and models. Early US climate models were greatlyand run wilh inpul data thai grossly exaggerated lhe effects of smoke from burning cities, the key variable in the Nuclear Winter equation. Not surprisingly, Soviet scientists have consistently reported more severe rlimatic chansjes than are usually found in similar research in the West Kurt her more, Soviel reporting tends to stretch conclusions


well beyond what the research supports, often concludingar of any dimension will signify cither the disappearance of the human race or its degradationevel lower thanhile Soviel scientists privately acknowledge errors in their work that produce more severe outcomes, they publicly continue to voice the party tine. Western scientists have been amazed at this kind of intellectual dishonesty.

The location, nature, and findings of Soviet research suggest that the primary interest in Nuclear Winter thus far is for external politicalarge, well-coordinated propaganda campaign has been organized with the international scientific community as the primary target audience. The objective is to use these scientists to convince Western publics, and ultimately their political leaders, that arms reductions are necessary, lhat the US arsenal is already too large, and lhat new weapons are not needed. The themes usually emphasized at international scientific forums and widely reported in the media include:

Nuclear war would have disastrous consequences for all mankind.

There is no effective defense againsi nuclear attack.

There is increasing danger of nuclear war due to the "arms race."

US actions are the main cause of the "arms race."

The efforts have met wilh some success. In certain cases, Soviel scientists gain direct access to political leaders in the West. For example, Vladimir Alcksandrov, the leading Soviet writer on Nuclear Winter, has testified before the US Congress. In other cases, Soviet participation in international organizations has served to keep the horrors of nuclear war before the public. The UN World Health Organization, for example, has placed the study of Nuclear Winter on its agenda.

In addition to the potential for political influence, Sovietin Nuclear Winter research also contributes lo continued Soviet access to US scientists, research, and computers. It also provides opportunities for Soviet scientists to develop new modeling techniques and improve global circulation models.

For all of these reasons, we cxprcl Soviel research on Nuclear Winter will continue, but no substantial contributions are anticipated. Experimental research on large-scale fires, which could provide useful inpul data, has not been approved. Also, analysis will be limited bv Soviet computers that lack thr capacily lo use advanced climate models. There will be continued Soviet interest in scientific exchanges wilh US


scientists, but Soviet agreement to joint research is unlikely because Moscow's public position is that the Nuclear Winter hypothesis has been adequately proved. Furthermore, it is important to Moscow that Soviet Nuclear Winter research be perceived as independent and original. In any event, unclassified Soviet research probably will be carefully circumscribed so thai il does not casl any serious doubts on (he Nuclear Winter hypothesis.

Classified analysis of Nuclear Winter is likely to be undertaken outside of the Computer Center.inimum, military planners would want to know to what extent their strike plans and US retaliatory strikes would cause adverse climatic conditions in the USSR. Another major issue is the possibility of asymmetrical damage in which the Soviet Union could experience somewhat more severeuclear war than the United States because prevailing winds could move smoke from the United States and Europe to the Soviet Union more quickly than smoke from the Soviet cities would arrive over the United States.

Regardless of the climatic consequences of nuclear war, Nuclear Winter research has pointed out some additional problems that may have been insufficiently considered by Soviet military planners, ir.cliniirii'.

Persistent smoke and dust could obscure targets from overhead reconnaissance and interfere with aircraft engines.

Cold and darkness could further stress personnel operating command and control systems.

High-frequency communications links and satellite groundstations could be affected by increased dust and water vapor in the atmosphere.

The Nuclear Winter hypothesis could pose potential dilemmas for the Soviet leadership and it could lead to contradictions between these new considerations, on the one hand, and Soviet doctrine and weapons employment policies on the other. Such contradictions would probably cause Soviel officials lo demand exceptionally high standards ofproof for the Nuclear Winter hypothesis, standards that probably cannot be met.

Efforts to leduce the climatic consequences of nuclear war would run counter to Soviet war-fighting slialcgy. which emphasizesand massive strikes Responses to this dilemma would be difficult for Soviet strategic planners; they apparently are highly skeptical of concepts of escalation control and small-scale strike options. Nuclear Winter considerations also could result in more empliasis onforces, biological weapons such as those achieved by geneticand direeled-eiicrnv weapons.

Should Soviet leaders become convinced that stepsaken to reduce iho possibility of Nuclear Winter, these measures could affect Soviet research and development programs. This could reinforcetrends toward lower yields and better accuracy. Nonnuclear warheads also could be rotisidcrcd for strategic targets. In addition, targeting planners might consider target combustibility along with other factors to reduce the amount of smoke and dust. Nuclear Winter considerations also could complicate Soviet ballistic missile defense (BMD} efforts. Should Moscow become concerned with using BMD both to protect military capabilities and to prevent an attack from triggering Nuclear Winter,uch more extensive defense capability would be required.

Finally. Nuclear Winter also could influence Soviet thinking about civil defense. Because of the potential damage to food production, Soviet civil defense officials could be forced to extend their planning time frames for basic survival toear. Thus, substantial increases in civil defense food stockpiles might be an early indicator that Nuclear Winter was beginning to influence Soviet thinking at high levels.




Scientific Debafe pedogrwad

L The concept of "Nuclear Winter" couldchange the way we think aboul nuclear war. The term refer* to the possibility of catastrophic changes in cllniule due to nuclear war. This concept was first raised2 and.aught the attention of the scientific community with theof thetudy. The study ccaKfadcd that nuckai war could trigger severe and widespread changes In climate that could have devastaline global consequences Other scientists have concluded lhat these climatic changes could lead lo lhe extinction ol human life on earth.'

2 Nuclear Winter studies raise the possibility that the longer term, global-scale, aftereffects of nuclear war may be even more serious lhan the Immediate effects Previous studies were primarily concerned wilh immediate effects, including blast, heat, and short-term radiation. Studies ol longer term effect* concenlratcd on fallout, residual radiation, and ozone

'-VL. and Carl Sana "Nuclear Winter Clobal Coiueduenrn ul Multiple NoHearthesaaly ratatred to ai tbe "TTAPS" asdV nthe irBtsab ofbulea IcchatMal arWelt earast taj Carl Satan aopearad laS and iNwtvcd widespread atleorlnn Tbe TTAPS study Ctew out of anab/Ui of dun storm on Mais in coanrcilon wstb the US Marinni ipice riploralion project in lhe. Mariner data Irons Mart indicated thai tbe widespread and pmlstem dull storms ahsoibrd. cooaadarablc solar radialioa and mulled in tetn-

iriL'ei much tn*ser than normal atpollutedhttadn and much lower temperatures oo tb*hai wete mjiled lioas solar ladiaiioa Siffulaiwych mialhi arale it" teea aaaed on earthesult of nin voWnnae enantsoai lhat iniectcd later owanlilm ofi.-le. I'M the atnvost&ne- Ii

Itomp of Ameocan aelentiili decided to apply what had been learned ibnul ibe eflecti of lax* miinlKiei ol dust in ihr atmosphere to llie nurlrar war ronteat. in wlial eventually became the TTAVSeparate study1 by Crutien and Birds

pooled out tlie potential illniGcance of iirasa* from burrunc raties

and in bawerinc surfaceuclear altaet Wuh UMs Jural iit. asssaac dau were added to the TTAPS remeh

tarn astaard lhat ansae weald ns* tohitudn laeiuar sipuacaat. widaag-ead chraiaie rfera

faul Ehrlteh. Tbe nioloaxal Cotiseaaeneet of Nadeernd ihr fAtil9

;.ir ihemounis of smoke and dust were overlooked until recently, therefore lhe Nuclear Winter hypothesis has attracted considerable interest Many scientists,do not agree that the effects would be as severe and widespread as indicated in early discussions, andcientific debate has opened. Thb debate represents (lie latest In the long series of scientific concerns about nuclear war,

Nutlet* Winter Hypo the si I

The Kacseer Winter bvpotherti caeeoliaOy arguesuclear war would produce large quantities of sroole and duti that would absorb solar radiation.


Darkness for several weeks or longer.

Cooling temperatures lor several months or longer

Circulation pattern changes that wouldn. bul less severe, elunalic changes lo the Southern Hemlsolterc.

The Process

lthough smoke and dust were found to be the maior contributors to Nuclear Winter, the TTAPS sludy considered four main physical effects ofnuclear explosions: ttnoke In the tropcesphere. dust in the strateaphere. jetlovt of radioactive debris, and depletion of the oioneegaton (Ml) weapon detonated at ground level canons of fine dust lhal is propelled into the uppoi ttopwphere and sfratoiphcre. In the TTAPS base-rate scenario,0 million tons of fine dust was produced, aboutercent of which reached lhe stratosphere These particles wouldin the tfiaicapoere forear, scattering sunlight. Air bursts over cities would likely startfires thai could generate large quantities of smoke Smoke particles could remain In the upperlor weeks to months. In the TTAPS sludy, one scenarioeapon attack

kiloton (kt) warheads against an urban area equivalent loities This scenario produced anitlitxi torn ol* imoke in lhe troposphere In addition lo dun and smoke, radioactive particles abo are produced and carried aloft in the fireball or Ihe updraft Particles injocted into lhe lower troposphere settle back lo earth oi are rained oulaltar o( weeks. Those injected at higher altitudes, into live stratosphere, remain there lorear, by which time nsost of the fission products have decayed to safer levels The fourth effect, oroneul Is from nitrogen oiide* produced by hish-yield npWrn and amounted topercent maximum reduction in oionc in the TTAPS base case. This would producewofold increase In ultraviolet radiation in lhe first yearuclear exchange, according lo the TTAPS analysis- Other effects, including theof toxic gases. dvorins, and other dangrrous products were noted but not evaluated.

Climole Changes

These physical effects couldajor Impact on the global climate, due primarily tounlight by thick clouds of smoke from burning cities. Local weather and precipitation could be seriously disturbed for upear. The senrerity of changes in climate would vary from recson to region and depend on the season during which the attack occurred, but, even In the most eitrcme case considered In the TTAPS study, Ihe climatic changes did not suggestong-term ice age would be triggered by nuclear war This is primarily because of the tremendous quantities of heat stored in lhe oceans lhat would drive lhe climate back to normal ranges within, alew years Nevertheless, the combination ol darkness and cooling (or even one year could have disastrous confluences.

he normal temperature gradient could bechanged by large quantities ol smoke in the troposphere and dust in the stratosphere (figure I) Al the surface, when heated by the sun, the earth has an average annual temperature ofNuclear effects (smoke and dust) in the atmosphere could nthiee surface temperatures to aboutwell below fleering, withinaysuclear attack At the tame time, temperature changes in thecould be even larger, possibly rising hv ai muchC as the smoke particles absorb solar energy Tlie impact of such lemperalute chances could be severe An abrupt onset oi nold may be damaging or lata) to plants, particularly if exposed during (he glowing season. Crop harvests could be destroyed or


' rrAPS. SMt> fMxio- ttdciia.



severely reduced in much of the NorthernIn addition, the superheating of thecould affect circulation patterns, bringing the effects lo the Southern Hemisphere rather quicklyhe tropics are even more susceptible to damage from minor changes in climatic conditions

Furthermore, these conditions could persistong period of timehe TTAPS base-case scenario produced subfroczing temperatures for about three months, andear was required before temperatures began to return to normal levels. The effects would be less severe in coastal areas, which are warmed bv the oceans Even there, however, severe storms would be common and in some aieas further inland. there could be continuous snowfall lor tnonlhs. Water supplies could be frozen, and agriculture might be impossible lor upear in many aieai

Darkness is llie second ma'or consequence of injecting large quantities ol smoke and dmt In the atmosphere Virtually all life on earth depend* on sunlight II light levels were reducedercent. 2

Nuclear Winter: Range and Duration of Temperature Change*

11cure 3

Nuclear Winter Darkness*

Suited linil I'



Amount lemptmou


Timeant, snoo -

f mnli!hi

raeeaiag irawae!



I Mllll lfNll

mo-ih [ ,

w*<* nonthi

(log nilii

moil planti would be unable to maintain net growth In (he TTAPS bate case, smoke from urban fires and forest fires reduced the amount of sunlight reaching the earth's surface by overercent for moreeek in the northern midlatitudes (figuret couldear or more for sunlight to reach normal levels (figureWidespread disruption of photosynthesit combined with radiation damage, severe cold, and other effects, coulderious danger to plants and ultimately to the animals and humans which depend on them.

Key Voriobles. Assumptions, ond Uncertointios

8 Smoke Is the key variable that determines the nlent lo which climatic change would occur, over the shorler term, while dust largely determines whether Ihe effect will be long lasting. In particular, the amount of smoke produced, the altitude to which it roae. and lhe duration that it persisted are crucial factors in aucuing resulting dtarages in the global climate For ciample. in the TTAPS base

'nOS-megaton iicaano

ImimSf- tl iKr Indian o* li|ti ikv in ii^gimii uawiii Ihih ti tiuaiiilj|lu

-eenwou the iiimHibbixwal> tuaanni idCihit n

million ions of smoke were injected into lheand accounted for up toercent of (he reductions in the solar energy reaching the earth's surface and corresponding reductions in temperatures that in some cases amounted toegrees centigrade For such conditions to occur, however, there would have to be large numbers of urban fires generating interne beat that would carry some ol the smoke Into Use slraloipherc. where il would persist for much longer periods than commonly occurs at lowerThe fireball of large-yield weapons, tn the megaton range, also could inject smoke and dust into the stratosphere Thus, the main smoke parameters-how much, how high, and howon several Important assumptions. For ciample. the amount of smoke Generated depends mainly upon the kind of fuel, the amount of oiygen available, weather

Nuclear Winlcr: Attenuation of Solar Energy

Solar 'ntrethc cround IWam ncr squire meter)


Cltim Wa Iran point

KiRurc S

Nuclear Winter: Scenario Variations


Time (diyii


.-onditions. and lhe rale of bum. The total injected smoteuclear war scenario may varyd or ofr more

Variations in the assumed properties of smoke and dust generateduclear war could change the climatological results significantly. For trample,variations in estimates of dust and smoke particle parameters could vary the optical depth of resulting dust clouds2ange in opacity would result in conditions that range from negligible haze to near-total darkness Furthermore, the TTAPS study assumed Iristanlaneous, uniform inkcctioci of smoke, whereas actual smoke and dust injections obviously would vary cotusderabiy from place to place and over lime, so there would be corresponding variations in local temperatures In some rates, surface temperatures would be una fleeted, in othersise in temperatures li possible.

The assumed nuclear war scenarios also slgnifi-canlly aHoct research findings. The critical scenario variable is the catcnt of uiban industrial targeting.

Time tdayil



although the number ol weapons used, (heir yield, height of burst, and timing also are important The TTAPS Use-case scenariootal yieldO0 Ml from lO.eOO weapons ranging0 Ml each. Aboutercent of the yield was devoted lo urtjan-itsduslrial targets This scenario is similar to those used by other researchers Several other HM-nnrlos also were used in the TTAPS research to lesl the sensitivity of the outcome to variations In the postulated attacks. One of Ihe major findings was thatelatively small nuclearMl on urbanproduce relatively large di malic effects. This scenario, however, used different smoke parameters from the base case.l counlerforce exchange, where cities were avoided, the climatic con too, unices were less severe (figure 5)

II. Another unccrlainty Is the extent to which smoke and dust will reach the Southern Hemisphere and cause substantial cooling. Research using various climate models suggests thai typical circulation(Hadlevhat would normally inhibit lhe

transport u( smoke and dial to ihc Southernmay he interrupted. This i> due lo warming ol* lhe stratosphere lhal could reduce precipitation in lhe tropical convergence zone lhal would be eipeded lo prevent the spread ol aerosols lo the SouthernBut Ihe research is very preliminary at this point.

the key assumption! abouland scenariosseful manner presentsproblem In particular, translating; theof burnableities and forests intosmoke clouds that can be used in globalis lhe greatest source of uncertainly inresearch Until mote accurate dala canlinm actual large-scale fires, there willto be serious questions aboul the likelihoodand poislitent climatic changes followingwar

Confidence in Findings

Nuclear Winter hypothesis initiallycoruarlerable support in lhe scientificEarly independent research using more commodels yielded similar resultsWinter research has net been withoutFor cample, one argument challengeswould ittbstanlially reduce lhe amountIn lhe atmosphere within Iwo weeks.eflecti. such as local winds andcould further reduce the effects of smokein the season selected foe analysisa fleet the outcome For eiample.hat indicated relatively minormightuclear eichangein lhe wlntei.emit of these factorsaboul the iniiial amount andsmoke generated, average tempcratuiebe far less than those suggested in theFurthermore, the areas adversely jHcctedmore restiicied than suggested In theHowever, even if lhe early Nuclearu in erroractorhechanges may still producedamage in certain areas *

n ihcuoh local temperature changci may frequently be largerapid tin eieouCatter ol boun orhe global climate, consideredemirlabty Millie. For rumple lvenge ittruiil temperature! have viried byver the last hundred vein The itibiliit of ihu huge, complei iviirm iiduc

to ocramai iiiie cneegt eeser-oirs and tunycomplei

Iiiieiartlve processes lhal itnrc ind rediiliibule solar energy.'I lhe inherent nib*f thrt lyitem. it (ilei global-scilr

fidence in the Nuclear Winter hypothesis probably will huve to await actual measurement of particles produced by large (ires. This could Involve monitoring forest 6rcs. experimental fires, or quick-response measurement of actual large fires Other important areas ol sludy Include the dynamics of smoke plumes, regional rather than global-scaleand calculations aboul the probability of black smoke reaching high altitudes. Even when the physical phenomenon are fairly well ursderstood,there will continue to be substantial uncertainty aboul lhe biological consequences of climate changes.

Soviet Views on Nudear Winter leadership Per re pi ions

do not know how seriously theand military leadership takes theissue, all hough many senior Sovietarc aware of the hypothesis ForVehkhov, the main force behindresearch tn Ihe USSR has

.{that he personally has briefed Foreign Minister Giomyko. (miner Chief of the Ceneral Slaff Ogarkov. and Defense Minister Ustinov on the subject of Nuclear Winter However, we base net yet noted any significant Soviet military inlcrest in Nucleai Winter.

the Soviet leaders have been briefedWinter, and we believe ihoy have, then Iessentially the same scientific basis forthe problem as do US leaders. Thus, atSoviet leaders are likely to believe lhatwould cause varying degrees of increased coldin some regions, but the effects wouldthe end of life on earth This view generallywith what (hey have been sayingears, thai is. nuclear war wouldisaster of

evenu to causend even relati>el> smill rhentra lo global averages ran eauw diamine local ooiuequrnora Kor euro pie, raatoi volcanic eiiiplntu inHWt large quantities of dust and ash Into the atmosphere- ihii ipraadi oxer much of the earth The eruption of

Timbora in Indonesia5 produced ani tnil'mr

sons of aerosol particles that iibsrouenrlr eawadrdurtacaa-ceag* global teigaiaieie Tat, thts aeoalagt* seaal change peodueed 'the yearaan ISIS Severe and peetiueM fieem caused mdoiiiead lou if hfc and crop Insure thaougliiiul the United Stales and Kurope Volcanic dust paitectei. because ol thru large lire, are, InetHelcnl in

blocaini iiiallght AnilHon torn of unci* anil dusl

irwltieigiuchnr mi muldora savin* impact than

empe'aluc chinf*

unprecedented proportions From this pri timet ive, colli and datkness would furthet complicate thodifficult problem of survivaluclcai war.

e beheve Soviet leaders will remain inlet est ed in lhe subsect because Nudear Winter could have profound implications, if, as suggested in the TTAPS study, theieeyond which lhe use ol nuclear weapons would be sell-destructive. Inoncept of deterrence lhat depended on lhe credibility ofetaliatory strikearge number of nuclear weapons would beThe attractivenessisarming first strike also would be reduced because, evenirst strike were iiiccessful in totally destroying the retaliatoryof the adversaries, it could exceed lheriggering Nuclear Winter, (bus bringing about self-destruction Furthermore, the nuclear Inventories of France, the United Kingdom, and China also could independentlyore significant minimum deterrent capability. Despite these considerations,scientists have not expressed an Inleresl In the mililaiy scenarios' or live threshold concept, except to comment in line with their propaganda lhat the threshold is very low andimited nuclear war piobably would trigger Nuclear Winter

he threshold that could trigger Nuclear Winuite low according to the TTAPS study. Car) Sagan has suggested that, depending on yields and largeiing. it may be somewhereuclear warheads Soviet scientbts claim that their calculations indicate-imes less than Ihe TTAPS base-case

'The use ol ihe irnri "thivsliold" in connection with Nuclear Winter has become conlrovnslil. mainly because it import thai there Is some simple met tin* ofot yields that will Inner ad.cue global cb'maleore proper uie of the term

would be to indicate the man of ui-ikt irUnrtnil into the atmosphere

that would create (InUillytemperature decreases. Smoke

nutancticn of the number of wraponi. their yield, and. mrnt

in;"iim. the eomt-iOhtlii. nl whan arm tiriered Abo the local weather, Ihe leaten.triable? can affect the eUtat ef riinatw effect! etpeeted fromrwcirai war Another rarobtet* mrn the tent 'threshaaeT ariwi at menct icaeMsfte teese aicasa ati raaeatein ocean, such asbodst. Bach use. nhtelear

wmsd occurornl whet* 'he addilttfiingle weapon wtaoU

nme (iaballvenir dram More realist leaTly. therenremuum ol worwmng -He, n

' In flint scientific ric-hanmonti<ti have urged Wen-em scientists to use rilreme nerniiot. un the orderedMl. By

comparison ihr TTAPS tiaieease tcenirmOO

Mr Kmino also was leited. bul onnaily is ennudned lo be

mrrilisiieallt largp

coulduclear Winter. Not all scientists agree, however, thaielf destructive threshold exists. Nevertheless, such un idea has important implications for perceptions of liut Kast-Wcst military balance. From the Nuclear Winterimited war in Europe conceivably could exceed the threshold. Thus perceptionsow threshold could undermine the credibility of NATO's flexible response policy and place additional importance on lhe conventions' force balance

e believe that Soviet military planners are interested in the possible dangers of Nuclear Winter.inimum, they would want lo know to what extent theii strike plans and US retaliatory Strikes would lead to adverse consequences in the USSR To answer this kind of question, lhe basic relationship between nuclear weapons and Nuclear Winter will need lo be better understood. In particular, how do variations In numbcis, yields, and targets affect the extent and severity of cold and darkness?

Current Soviet Research

he logical place for Soviet climate research is the Slate Committee for Hvdiometrorceogy andControl (usually called HydrornetX theorgannalron generally responsible for dirnate research and forecasting Instead. Soviet research on Nuclear Winter until recently has been concentrated in the Academy of Sciences Vladimirs the leading Soviet scientist working on Nuclear Winter and appears lo head an ad hoc group of aboutcientbts.ork In (his field grew out of Soviel interest in US high-speedathematician speciallring in computer science,was directed ino shift hb research from gas dynamics and plasma mechanics to dimaiology. He was sent to the United States8 to study computer-based general weather circulation models andomputer program compatible with

Vladimir Aleksandrov

Leading Sooiet scientist on Nuclear Winter

relatively ilow-speed Soviet cornpuleis He returned to the United States (ot futthei iiudy aad research02 Dunne his visits he requested and was granted accessomputer at the National Center for Atmospheric Research Ho travel to the United States has been under scientific exchange agreements on climate research signedeH before Nuclear Winter became an issue.

lokwtidrov was directed to work on Nuclear Winter, probably by Yevgerriyice president of the Academy of Sciences Among his several duties. Velikhov is secretary of the Depaitrnent of Information Science. Computer Technology, and Automation. This department, createdthe Computer Center where Ihe main Nuclear Winter research is conductednterest in Nuclear Winter stems from his participation inscientific forums and his responsibilities as director of tbe Soviet effort to developHe probably learned of Nuclear Winter at one of the numerous internallonal conferences he attended and recognised its potential lo contribute both to Soviet knowledge of computer science and lointernational public opinion on the nuclear "armselikhov is politically influentialrime candidate to head the Soviet Academy of Sciences He is heavily involved in all areas of nuclearconcentrating particularly on lhe issues of mili-tariiotion of outer space and the US Strategic Defense Initiative Velikhov will continue to be Ihe key person in shaping Soviel Nuclear Winter research, and. under his direction, it will continue to serve Soviet political purposes.

Ycvgeniy Velikhov

Rev promoter of Soviet Nuclear Winter research

elikhov took the lead on Nuclear Winter and tasked the Computer Center, which quickly produced lhe first Soviet research report on the subject The speed with which Ihe report was producedighly unusual accomplishment in Soviel science. Inhe basic input information was probablyat the TTArS 'Peer Review" in Boil on Byeport was completed, printed in English,

ami delivered al lhe International Seminar on Nuclear War held annually al Ertee. Italy. Such work would normally take years in the Soviet Union because of inherent difficulties in thecomputers, lack of computer paper, and so forth. In ihb case. Velikhov was able to bring together the necessary resources and get Ihe job done. This was possible mainly because Aleksandrov obtained two versionseneral circulation model 1CCM) during his earlier visits to the UnitedHydromet had been unable to do

o date. Soviet Nuclear Winter research has primarilyimplified CCM. derivedS model, and runomputer.3 preprint describing his work, Aleksandrovhour modeling run on thehis wasingle calculation, one year inlo the future, on his highly simplified model. He also noted that similar calculationsomputer would require only about eight minutes. In addition to threeomputer has been installed at the Academy's Moscow Computer Center, bul operational difficulties with theave thus far prevented successful useore advanced CCM.Aleksandrov and Stenchikov continue to rely on the more sunplificd CCM using the BESM-6

The Computer Center facilities impose severe limilattons on their abililles lo do realistic Nuclear Winter climate modeling State-of-the-art calculations require hours of time on Oay-dass supercomputers.ingle modeling run in lhe Wcr.illion anthmetic operations arc performed, at acomputational rale of aboulillion floating' point operations per second (Mflop* Thes capable ofBop for high-precisionmodeling problems Even the fastest Sovietcomputer, thes still lea than one-tenth the effective speedray.

There has not been any significant Sovieton Nuclear Winter beyond the two reports by Aleksandrov and Stenchikov delivered at Ence34 and frequently repeated elsewhere-other Soviet studies related to nuclear effects have recently been presented at internallonal conferences because tliey generally support the possibility of sort-out climatic changes due to multiple nuclear eaplo-sions For the most part, these additional reports represent earlier rneaich. completed before (he idea ol Nuclear Winter became popular. These additional leiwrts also represent some internal competition among various institutes in the USSR al they atti-rti|it

lo (Miu additional recognition. One report' Ity Hydro-met scientists, concluded lhal gaseous byproducts of nudear esiMOsions, especially oxone in the Iroposphcre and nitrogen oxides in lhe stratosphere, would produce lower surface temperatures lhat would persist because these pollutants would remain in the atmosphere much longer than smoke and dust AnotherSovietoted that the altisoipheric injee-lion of nitrogen oxides from nudear testing duringime frame may have contributed lo about adiop in average temperature. Data fromtesting in theere scaled upMl nuclear exchange, and it wat estimated that there couldC temperature drop without considering the effects of smoke and dust

e expect further bureaucratic com petition wilhin Ihe USSR on Nuclear Winter research, latheroordinated approach to improveof the phenomenon. Research funds and personal prestige are at stake, including cleclion to theof Sciencesromotion from corresponding lo full momhip. The ire in compelftion Involves the Academy of Sciences'nter and. as director of Hydromet, mayarger role in Nuclear Winter research, using scicn-lists with more experience in climate research than those found at the Computer Center. luad' heads bilateral exchanges with the United State* onscience, including Nuclear Winler. and could insert more of his scientists into the exchanges or attempt lo block Alcksandrov. or others from the Computer Center, from future meetings. Among the possible scientists lo look for outside of the Computer Center ii Igor Karol. at the Main Ceophystcalol Hydromet. who has done climate research thai includes nuclear dfects. Within the Academy of Sciences but not yet associated withroup at the Computer Center, there are otherwho may become involved in Nuclear Winter research Cotilratev, wilh the Chemical Physicshas been mentioned to possibly head up some fire experiments in lhe USSR But. if present relationships continue, man of ihr research will be orsnducled at the Computer Center and it will not be well coordinated wilh otheihe USSR. Increasing involvement of Hydromet would be an important indicator that

Moscow was becoming mote seriously interested in Nuclear Winter.

hove not identified any secret researchWinler In tlie USSR, but we believein the wenpons development structure, alare following the Nuclear Winterdone by the Academy of Sciences Thesewould most likely include planners In theDirectorate of the Ministry of Defenserequirements for nuclear weapons Inwe would expect scientists at the twoweapons design centers al Sarova andIo be closely following Nuclear Winlerdesign centers lall under the management ofof Medium Machine Building. To date,no evidence of contacts between theseand Soviel scientists involved in theWinler reseaich

Soviet Contributioni

Soviel Nuclear Winter research is derivedentirely fiom US Ideas, data, and modelsof pressure to produce results quickly, and given limited computer capabilities. Soviet research often is inaccurate and does not iigril6cantly advance the understanding of the Nuclear Winter phenomenon.

To date, there have been two main Soviet cuntrlbuHorn to Nuclear Winter basic Nuclear Winter findings were testedhreeniiroenskinal CCM for tbe first lime, whereas the original TTAPS studvr>edimensional model'he eUects of moving smoke were added lo the Soviet CCM. whereas previous research hadsmokeialic, uniform rrurtner. Thesearc considered modest conceptual advances from the original TTAPS research. However, somepiomineni scientists who have conductedon Nudear Winter have characterized lhe work as weak, crude, and seriously flawed. Nevertheless, it is currently the only national Nuclear Winler research program outside (he United Slates. Regardless of the quality of the work, the USSR has effectively ioincd the scientific debate on Nuclear Winter.

"Atmceoheric Composition and Thermal Regime Model Chinaes After the Possible Nuclearyarol. Klsclev. and Kosanov of lhe Mlin Cnophyiical Observatory. Goskoeneidio-nsei. presented al Ericr.

1 "Observational Evidence of the Impair of Nuclear Eirfejtoe* in Iheoodrat'iev. presenied in bilateral meei.ns

American wicnlisti in4

* The oneltitude The model used in the TTAPS siudvingle poinl on lheepresenting the average, year-round global temper at uieThe temperature ai various levels nl altitude alwe ihiihen calculated (or various (hinge* in solar ndiation cerrrsosodlng lo scallcrmg and

ibtorplioii ol imolie indhree-dimensional model include* longitude mil lililiufcltitude.

Soviet Nueloai Winlei roscaich consistently produces mote severe results (Kin similai research done in the West. For example, 'he original TTAPS studyemperature decline of upew weekil exchange. As would be expected, subsequent two- and three-dimensional studies that accounted for the moderating effects of the oceans noted less severe temperature declines ofut Soviet research,hree-dimensional model,emperature drop of aboutover the United States (figurehe addition of moving smote to lhe Soviet CCM (figureesulted in even mote severe temperature drops than noted in the earlier Soviet research These findings result from the unrcalistically high Input of smoke into the CCM. Soviet scientists have privately admitted their conceptual errors, but the results are nevertheless widely reported in the West without reservation or qualification.

Soviet scientists abo tend lo argue againstthat would moderate the effects of Nuclear Winter. For example, ralnout may remove substantial

quantities ol smoke, but Soviet scientists argue that heating of the atmosphere would decrease Its relative humidity and reduce turbulent convection that creates precipitation In additioniscounting rnoderating effects, Soviet scientists note the relatively rapidof smoke into the Southern Hemisphere, thus bringing Nuclear Winter lo Africa, Australia, and Soulh America

oviet reporting on Nuclear Winter research often stretches conclusions well beyond what can be supported bv research, mosl likely to further their propaganda effort. Fot example, the centralof3 Alektandrov-Slcnchlkov Report wasuclear war would probably produce conditions under which man would not be likely to survive. (See inset) Such conclusions have even been criticized within the Soviet scientific community. Dr. Budyko. with Hydrornet, noted lhat small differences inwithin various models can produce targe differences in outcomes In particular, he has pointed cut lhat there has been too much duplication in Nuclear Winter research He and others have called

Soviet Scientists' Drama tk Portroyol ol Nuclear Winter

ur ihrcc-dimcnvonal liydt adynamic model of the clirnaie (hows that the Nucleii Winter will entail an avatinche of pernicioushis will feneiare severe noron* the roasts, causingaraounU of snowfall en land TUtvtdeWrv destroy life on the coeval tone On tbe other hand, the ehangei In the itraasiierr trill completely change ihe hydrologies! cycle, and aevere drought will break on! over lhe night -enveloped, frod-bouradIn other words, everything living which hadn't been incinerated during the files will fleece out And if it survives in conditions ol low temperatures, it will nevertheless die ol llilrit. But the earth's Bora will nothe (oresli of all middle latitudes willhe planct'i entire climatic system will patsew statenew glacial period,he temperatures over Tibet and thr (Cordilleras will be heated to such an extent that tlie giant masses of snow and glaciers will melt and precipitate inconceivable streams of water on the continentseluge in cond'liom of severe cold (Aleksandrov.n Moscow News in Fnglnhj

Irrespective of ihe season of lherotractednlet will begin In the runtr-tland of eeeah-nenti tainfalh will be a'masl mo. agricultural crops will perish, and domestic anlmatl.if Ihey survive the eold. will die of ihirt) beeauae Iresh water lor: pari will only be availablerttien

The tropical fotests. which are the main bearers ef organic llie on earth and the chiel touice of tuygen. will be killedhe biosphere will be left without its main source of oxyien. Theentioned will arise -practically in any nuclear war teen*no Even with an etpknion of lOJi dear war ol any dimensions will signify either the disappearance of the human race or tls degradationevel lower than prehistoric (Alektandrov.n Sower Pan coma.ovosti Press Agency Bulletin)

The impenetrable black cover would spread from Ihe northern hemisphere to the southern, andenclose the entire planet All sources of Iresh water would frees* over, al! ogaggajojl balances would be upset, aad all harvests would fait The total terrestrial biota, thai is. Ihe total population of vinous Species of animals, plants, and microorginttmt. would completelyonclusions drawn Irom out calculations indicated thaio ISO megatons of nuclear fuel ilhat is. SO limes leu than in the Sagan scenario) were useduiirsi richatige, the marar cities of Europe. Asia, and North Anient'a would be deitiuyed. and the Nuclear Winter would beginut even this wouldnsure the end of life on earthrticle "Sdenliiti Warn The World in lhe Aftermathuclear Strike:ovoHi and Sovetskaya Kiri{iiiva]


Figure 7

Soviet Nuclear Winter Research:

Three-Dimensional Global-Circulation4

more independent research methods and more complete documentation of studies prior to theirat scientific meetings. Kirilloviet specialist in atmospheric particles, has suggested that Aleksandrov and other "Tike-minded" scientists had reached conclusions far beyond what was justified bv ihelr limited work Indeed, this frequently happens at international conferences, when Soviet scientists seem to stretch inferences. The tendency lo oveislate Nuclear Winter conclusions, however, is not limited to Soviel scientist'

oviet research on Nuclear Winler does not Stand up well lo close ciamirution. As noted,input data produced more severe climatic eortsc quences Soviet research, for ciampie. used smoke parameters lhat were roughly equivalent loillion tons of smoke in thecomparedillion torn estimated in the

TTAPSeven these figures may be too highonsnleiable margin. Although the Sovietinitially claimed that they were using datawith the TTAPS worst case scenario, they made some erroneous assumptions Thev essentially treated dus! and smoke equally, even though dust tends to scatter sunlight whereasore absorbent Furlhermore. ihey assumed thai tlse combined smoke and dusl absorbed all the sunlighl, ratherore reasonable estimate ofoercent. Also, general hemispheric circulation patterns appear to bein Soviel teporls.

uch basic errors are surprising for scientists of the caliber of Aleksandrov arrdStenchiko.

{docs not believe the results 'if Ins large computer models because of lhe simplistic BMumplions necessarily Incorpoiaied Into the model ^

J ihey

publicly continue to voice the parly line thai Nudear Winter it real and the elloctl are certain and tevere Western scientist* have been amazed at this kind o( intellectual dishonesty

n additiononceptual errors. Soviet research findings in many cases ate not logically sound. These logical inconsistencies piobably result from the limited data points used in the greatly simplified CCM. alone with the limited knowledge of dimatology among Soviet scientists at the Computer Center.

Research findings are quickly repotted and not subiected lo sensitivity tests Soviet research onWinter has not been documented in sufficient detail to understand clearly exactly what was done. Proposals to compare directly Soviet and US CCMs bv using the same input dala have not been favorably considered in the USSR While these and olher shortcomings become apparent to experts who take Ihc time lo import Soviet findings and Question thehe averageal international conferences is only aware of the results oi the Soviet research And. in each case, ihc reported results amountevere Nuclear Winter.

While Sovset research has been citedf the Nuclear Winterit falls far short of normal scientific standards for such dairtu. ll represents more replication thanbecause it lacks original Soviet data or models When asked at scientific exchanges lo provide data from Soviet atmospheric nuclear testing prior to3 ban. Soviet scientists have not been able to respond Early interns! by Soviet scientists in ibint experiments also apparently has been vetoed at higher political levels In tho Soviet Union. Using data and models of US origin, It Is not surprising lhat Soviet findings are similar lo early studies in the United

Technology Irons for

understanding of advancedTechniques probably has benefitedcooperation wilh US scientists. Forhas been able lo use Cray computersUnited Stale* and ha* demorisJraledm adapting complex modeltide langeAt the same lime. Aleksandrov hasadvanced climatoiogieal models Irom theStates thai could benefit Soviet theoretical science

A lewtorntltts would disagree wild these judgmentsconirisd lhat Soviet Nuclear Winter inearch Is orHtiiul. Inde-imiiltiit ana cooiribuies lo (urihei iiml-mmidlni ulphenonw-non Ihc. *ould further disagree wilh characierinna Soviet Nu-elcii vVinici irscjich as ijuKl and careless.

and provide practical applicationsariety of impoitanl fields such as agriculture. Soviet inldlutence also could conceivably gain from contacts wlih US scientists

inimum, frequent scientific exchanges enable the Soviet leadership to keep informed on Ihe state of research in lhe West In particular, we would expect Moscow lo be interested in the prospects for asymmetricalwhich lhe USSR couldsomewhat more severe Nuclear Winter effects lhan the United Slates because the prevailing winds would move the smoke from the United Stales and Europe to the USSR more quickly than smoke from Soviet cities would arrive over the United Stales. To keep (rack of ihese and otheroviet scientists will want lo stay In dose touch wilh Western scientists

ImpBcotions PoititcJ Befits

In addition lo tedwetogy transfer. Moscow derives several political benefitsodestWinter research program. The Soviet imageesponsible superpower is furthered by taking the Nuclear Winter issue seriously al international forums. Soviel officials have an informed position on Nuclear Winler that Is not based soldv on research conducted In the United Stales. Of course, it I* no accident lhal Soviet Nuclear Winter research generally confirm* longstanding Soviet pronouncements on thenature ol nuclear war.

Soviet interest in Nuclear Winter research also has lhe potential to influence arms reductions in the United States Soviel leaders understand the American political process wdl. and by their active participation In conferences on nuclear war and arm* control, (hey can support political forces that seek arms reductions and disarmament. As noted, Soviet presenialiom on Nuclear Winler corisislenlly emphasize severe climatic consequences, and are widelyerllicalion of lhe TTAPS study. Ongoing Soviet Nuclear Wintet research ensures continued Soviet pjiticinaiion al international conlerersces {see figure

We can already see widespread Soviet use of lhe Nuclear Winter theme abroad The primary large! audience is (he internal social scientific community, because ol Us credibility and the "power ol reason, with the ultimate goal of influencing Western political leaders Direct face-lc-facc communication isIsecause it is Ihc most persuasive media Thus, we note extensive Sovielnietruillonal scirntllic foiums. These meetings also are widely


publicized in the press, on radio, and on television The theme* lhat are generally emphasized In the Soviet media and often repeated in the West include.

Nuclear war would have disastrous consequence* for all mankind

There is no effective defenseuclear attack.

There is Increasing danger of isucsear war due to the "arms race-

US actions are the main cause of the "arms race"

uclear Winter is appearing somewhat more Irequently In the Soviet media aimed at foreign audiences. In Ihe August to4 time frame, for example. Nuclear Winter was discussed on about a

weeklyoviet foreign broadcasts and press leJeascs. It also it appearingreater variety of Soviet media, including poelry and an article In the SoofeJ Uleraruuch of the reporting i* lepetitlvc. citing lorcign news sources, particularly from the United Stales and the United Kingdom. This lends credibility to Ihe Nuclear Winter hypothesis by Hiving the impression of widespread, independent vrnScatiort

udear Winter receive, some attention tndomestic media, largely In lhe context of the dangers of nuclear war. In such cases, the Soviet Union it characterized as leading the crusade for peace and disarmament. Contradictions between the Soviet con-cern with Nudear Winter and Moscow's opposition to arms control agreements with deep cuts In strategic forces are not discussed.

Figure 8

Soviet Nudear Winler Network


Computer Crnin




I nit <tOT



ol Soviel Scientist! in Defrntr ol Peace .no Ajumu hueld' Wir

ForumsInterna noml

Seminar on

lEncr. lut'i

ei(My. World




Sew-iAcCefauuc* o< Nk'ui

'We'd After


' Key inomouiuoipniraiioni are in tones A

n addition lo ihc public media. Soviet sclcntisls continually strew the responsibility of all to educate the public and the noatical Wadcrshrp on the dangers of nuclear war In funeral. In particulai, thev argue that scientists should all work fur peace by vailingalt to the "arms race" and opposing the development ol new weapons and the militarization ol outer space Clearly, Soviet leaders want US leaders to believe tho Nuclear Winler hypothesis. On at least two occasions Soviet scientists have met with USLeaders. On one of these occasions. Aleksandrov appearedongressional subcommittee. Such access to the US political system is highly valuable to Moscow.

s part of this propaganda effort, ad hochave been created to produce reports, grant interviews, and sponsor eichangesor example,3 the Committee of Soviet Scientists for Peace and Against Nuclear War was established with Vehkhov as Chairman. One of the purposes of this organisation is to;

"mobilize the scientists' efforts in lhe struggle foruclear holocaust, tocience-based and credible picture of the dangers ofalong the route of the 'armshich will lead mankind over the nuclear abyss, and to provide broad sections of the public and those who directly take political decisions with accurate scientific"

he propaganda eflort is well coordinated. In some cases, foreign attendees arrive al international conferences to find that the Soviet organizers have alreadyraft final report,tatement on the adverse conseQueiKcs of Nuclear Winter. The subject has been raisedariety of influential networks, such as the international medical piofession In this field. Soviet imitative* were in part responsible for the World Health Organization'sesolution in3 that "The role ol physicians and other health workers in theand promotion of peace is the most significant factor for the attainment of health forhe World Health Assembly endorsed the conclusion that ". l is impossible lo prepare health services to deal in any systematic wayatastrophe resulting from nuclear warlaie. and that nuclear weapons constitute tho greatest tminediale threat to the health andofhe Assembly recommended that the World Health Organiratioo. in cooperation with otl-er United Nations agencies, "continue the work of collecting, analysing, and regularly publishing ac-

count! of activltlea and further studies on the effects of nuclear war on health and health services'* Such efforts have met with considerable success in making the general public concerned about nuclear war.

Milllory Side Ellecls

uclear Winter research may raise some Issues lhat Soviet military planners would want to consider, regardless of the climaticor example, the smoke and dust generated by multiple nuclearmay obscure targets from overhead visualand could interfere with ground-to-satellite links Reconnaissance may be precluded over large areas for long periods. Infrared lensors also may be degraded by the heal-absorbing aerosol particles. Ra-dar imaging would be less affected exceptew hours and in area* where ground bursts produce very large quantities of dust. These considerations could affect the development of Soviet Imaging systems. For example, we would expect added incentive* to develop radar imaging systems for satellites, aircraft, and possibly the spaceplane.

ommand and control systems abo might be Stressed by the effects of Nuclear Winter. High-frequency communications links and satellite ground control stations could be affected by increased dull and water vapor in the atmosphere. In addition, dust could Interfere with aircraft engines, causing some degradation to Bight operations. Also, the personnel that operate command and control systems may have difficulty functioning well during prolonged periods of cold and darkness Thus Nuclear Winter concerns could reinforce existing efforts to Improve capabilities for ptuttJCtcd war that include testing and training with prolonged occupation of underground command posls.


Tho Base Cose

e do not atitleipale any changes to Soviet nuclear weapons policies or programs solelyesult of Nuclear Winter research The scientific evidence is not yet convincing and. more important, Soviet leaders do nol see any apparent response in US stralegic programs to Nucleai Winter concerns. Lacking bolh of these conditions, we believe Moscow will continue totrategic force posture that supports then war-fighting strategy and depends primarily onwilh large throw weights and on large numbeis of


warheads In addition, Soviet sirs teste planning will be (urthei complicated by Ihe prospective inodetnidation of US, British, and French nuclear forces. NATO deployments of cruise missiles and Pershiiuja lis; and expanding Chinese strategic forces.

n any event. Soviet research on Nuclear Winter will continue, thus guaranteeing Soviet participation in the debate But Soviet contributions are not likely to be significant Analysis will be limited by theSoviet computer capacity to handle advanced climate modeling for at least theseveral years. The prospects lor new or original Soviet data also are poor Individual Soviet scientists are interested in experimental research, but higher level approval will not be forthcoming, unless senior Soviet officialsmore seriously concerned about Nuclear Winter. For present purposes, it appears that Soviet leaders are content to rely on US data This will involve continued Soviet Interest in scientific exchanges with Ihe United States. Join! experimental research could provideto US measurement lechnolcgy, bul there may continue to be reluctance to approve such work at high levels because the results could reduce the credibility of earlier Soviet research and Soviet scientists might eventually be put in an embarrassing position of agreeing to lhe possimlity of much lesi severe elunatie consequences

he public presentation of Soviel views on Nuclear Winter has shifted from commentary on basic research lo publicizing the policy implicalions- Soviel officials have noted lhat the main Nuclear Winter Questions have been sufficiently resolved and thereeed to move on to dealing with the basic problem of superpower relations Such views have been expressed by Morseyev. Deputy Director of theey administrator in the chain between Velikhov and Aleksandrovants to shift the focus to the largei context of "man in thehe subreelorthcoming book he hopes lo publish in the United States and the USSH. In linking the perils of Nuclear Winter to other serious environmental problems Involving the superpowers. Moiseyev uses the analogy ol passengers riding togethermall boat Inituation, any serious differences must be resolved to "mutuale can expect to see ihls theme associated with futuie Soviet reporting on Niactear Winter

oviet scientists will seek to keep Nuclearin front of the public, particulatly in lhe United Sl.ites and Western Europe This will help keep pressure on Western governments to reduce their nuclear weapons inventories We cann see the

issue introducedide variety of forums,the various United Nations agencies Further-more, Soviet othcxab will attempt to raise concerns about Nuclear Winter with members of lhe peace movement in Europe. In addition to the Soviet media, television documentaries on Nuclear Winter already have been produced in the United Kingdom and Japan. In the Third World. Soviet officials will exploit Nuclear Winter because research suggests thai the consequences of nuclear war could extend lo the Southern Hemupheie. All of ihese efforts will be partarger Soviet strategy to blame (be United States for the "arms race" and get other countries to bring pressure on Washington to reduce the US strategic arms inventory.

believe it is unlikely that Soviet positionscontrol will change dramatically solely as aNuclear Winter research. Moscow will continuesubstantial reductions in their mediuminter continental ballistic missile force,alterations of iheir force structure, oron their weapons modern!rationtoorce large enough to carrymajor missions assigned to nuclear forces areoutweigh Nuclear Winter concerns

Poientiol DJeenrnen

The Nuclear Winter hypothesis is uncertain While the Soviets will continue lo exploit it for propaganda puiposes, we believe that there is little chance lor fundamental changes In Soviet nuclear weapons policies or major reductions in Iheir nuclear arsenalirect result of published or origoing research on this subject If the Soviet leadership eventually were lo accept Nuclear Winter effects as both credible and profound, il could lead to serious contradictions between these new considerations, on the one hand, and Soviet doctrine and weaponspolicies on the other. Such contradictions are obvious to the Soviets and would probably cause Soviet othcialt in demand exceptionally high standards of scientific proof for tbe Nuclear Winter hypothesis, standards lhat probably cannot be met

The Soviels could be laced with several dilem mas if ihey had to reconcile the potential implications of the Nuclear Winter hypothesis with Important tenets of their military doctrine. For example. Nuclear Winter would call into question those aspects of Soviet war-rjghtlrtg strategy that emphasize preemptive,nuclear strikes which, according to lhewould literally be suicidal for the Soviets even if US leiritory bote the brunl of the nuclear detonations


espouses to this dilemma would be di(Hcul( for Soviet strategic planners, ihey apparentlyhighly skeptical ol concepts of escalation control and small-scale slrike options. Ultimately, increasing doubts that nuclear weapons would be used could undermine Soviet beliefs in tbe political utility of nuclearTliis, in turn, could result in more emphasis on conventional forces, biological weapons such as those achieved by genetic enritseering, and diiected-eneiity sveapons

uclear Winter considerations also could pose dilemmas for Soviet research and development pro-strams- In some respects, this could reinforce existing trends toward developrnenl of lower yields and better -ocuracy lo reduce tlie climatic effects of strikes on (lilical targets. Nonnuclcar warheads also could be considered for strategic targets. Thn might beattractive in the European Theater lo reducethat effects from burning cities would

extend lo tbe USSR- In addition, targeting planners

might consider target combustibility along with yield.

height of bursts, liming, ond other factors lo reduce

lire amount of smoke and dust

uclear Winter considerations also couldSoviet ballistic missile defense (BMD) planning. Large Quantities of smoke, dust, and paniculatein tho atmosphere could degrade large! detection.

(racking, and intercept capabilities after the initial strikes Abo, more advanced BMD technologies may have tohe cHerts of inlcicrpts occurring in the boost phase, exoatmospherJc. at terminal phase of missile flight in light of Nuclear Winter Should Moscow become concerned with using BMD both lo protect military capabilities and to prevent an attack from triggering Nuclear Winter,uch more extensive defense capability would be required, including:

Increased eHectiveness to reduce leakage.

Extended protection for urban areas, to reduce smoke and particulate matter.

uclear Winter also could influence Soviet thinking about civil defense Soviet agriculture may be moie susceptible lo damage than US crops because of weather patterns, greater geographical concentration, ami less diversity of Soviet crops, llecausc ol lhe potential damage to food production, Soviel civil defense officials could be forced to extend iheir planning time frames for basic survival toeai, rather lhan aboutays when lallout woukl be the major long-term consideration. Tims, substantial increases in civil defense food stockpiles might be an early indicator that Nuclear Winter was beginning to influence Soviet thinking at high levels.


ail 'II

Annex B

Selected Chronology of Nuclear Winter Discussions in International Forums

April, Boston. TTAPS Peer Review. (Colitsyn)

av, Moscow. All-union Conference of Scicnlisls Against lhe Threat^(Vclikho,.

- *-

Votanrnfer, Second Vienna Dialogue for Disarmament and Detente

ovember. Tbilisi, Georgia. USSR. Session of the Commiltee of Soviet

^I'lfrPeacC.epresent^vt HZ

Fedcralion of Amencan Scientists attend. (Velikhov. Colitsyn)

svmpotiurn of Soviet and American scientists, lo discuss the effects of nuclear wflr (Vdikhov. Aleksandrov)

.*TI'C!"ne onexplosions on the atmosphere

ontifical Academy of Sciences. (Aleksandrov)

F-fnia-'Committee of Soviet Scientiststhe Defense of Peace and Asjainsl Nuclearelikhov)

Sovtet Scetmsts in Use Defense of Peace and Against Nuclear War. (Vclikhov)

ommittee of Soviet

Scientists in the Defense of Peace and Against Nuclear War and representative, 0fof American Scientists.,he



ninerad. mcclinc of the Scientific Community on Problems ofInternational Council of Scicntibc Unions. (Aleksandrov.

June, Geneva World Mctcorotocicalh seminar of Executive Committee. (Israel}

une Helsinki. Finland. International Physicians for the Prevention of Nuclear War. (Various Soviet scientists)

inerad. UN Rceional Conference on World Disarmament.August. Erlce. Italy, International Seminar on Nuclear War.Co^renee on Nuclear Deterrence.

iBSBOW" SCOl'and' CO"ICWt,hc cffcc"attack.

I. International Conference on (he -Conseouenccs or Nuclear War. (Skryabin)


ri" i

Annex C

Selected Bibliography

Soviet Reieorch on Nuclear Winter

Aleksandrov.tcochikov. C. L. The Proceedings on AppliedUSSR Academy of Sciences,

Aleksandrov.Update on the Climatic Impacts of Nuclearrice, Italy: International Seminar on Nuclear

Cinsberg. A. S. Colitsyn, C. S. Dcmchenko.Development of Highly Turbid Convective Boundaryoscow. Institute of AtmosphericSSR Academy of

Colitsyn,insberg, A. S, "Possible Climatic Consrxiuences of Nuclear ConDict and Some Naturaloscow, Committee of Soviet Scientists for Peace Against the Nuclear

Izrael'.iselev.osanov.Atmospheric Composition and Thermal Regime Model Charges After Possible Nuclearoscow.

Kondrafyev.Observational Evidence of the Impact of Nuclear Explosions on the Atmosphere andoscow. Lake Study Institute, USSR Academy of

Western Research on Nuclear Winter

US National Academy of Sciences. The Effects on the Atmosphereajor Nuclear Exchange. Washington: National Academy

Ehrlich.agan. Carl. Kennedy. Donald; Roberts. Walter Orr. The Cold and the Dark: The World After Nuclear War. New York: W. W.

Sagan. Carl, "Nuclear Winter and aimatic Catastrophe: Someoreign Affatrs. vol..

Crutzen, Paul f. and Birks.Tlse Atmosphereuclear War: Twilight atmbio vol. II,

Turco.oon.ckerman.ollack.nd Sagan. C. "Nuclear Winter: Global Consequences of Multiple Nuclearcience.

, "The Climatic Effects of Nuclearcientific


MacCracken, Michael. "Nuclear War: Preliminary Estimates of the Climatic Effectsuclearcrmore National Laboratory Report




cmnlC7eV' Scl,7idc'- and Thompson. "Global At.nospl.cfic Effects ofInborn

Other Articles

S SUWS'ebruary Anne. -'NuclearmVf'stAWmte SM to.. General Bockground on Nuclear Effects

wJl^fjTreTecbiHhVw. Assessment. TA,/ rVudcar War. Washington: US Government

WashmgtOD: US Government Printing

Wr of the Secretary General. Comprehensive Studv on

YO'h UN DePi",men,VoUl^

Original document.

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