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The Medical Implications of Nuclear War, Institute of Medicine. @) 1986 by the National Academy of Sciences. National Academy Press, Washington, D.C. LONG-TERM CONSEQUENCES OF AND PROSPECTS FOR RECOVERY FROM NUCLEAR WAR: TWO VIEWS view ~ CARL SAGAN, PH.D. Cornell University, Ithaca, New York I have tried to read all the papers presented in this remarkable volume and have been impressed with the diversity of topics covered: targeting and prompt effects of nuclear explosions, atmospheric physics and chem- istry, biological consequences, and the wide range of medical effects, which is the central orientation of the book. I believe that this is the first interdisciplinary examination of the consequences of nuclear war that gives significant attention to the psychological and psychiatric aspects, which surely are a major part of the problem both pre- and postwar. It is striking to see how many new results have been announced on subjects that everyone thought were well-understood. The immediate and especially the long-term consequences of nuclear war seem to hold an enormous number of surprises, almost all of which are unpleasant. It is as if we live in a field of stones that no one has ever looked under. When finally we succumb to our curiosity and turn the stones over, we find a nest of vipers under many of them. There is a kind of deadly embrace between the United States and the Soviet Union their military establishments depend on each other that goes back at least to 1945 and that has led to the construction of a kind of global doomsday machine, which has been almost entirely ignored until lately. The population of the planet has, by and large, been sleepwalking through the last 40 years. The consequences of nuclear war, even as they were known 20 or 30 years ago, did not permeate the public consciousness. And that is still the case, although less so, as a kind of race transpires between how fast new and disquieting discoveries are made about the 555

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556 LONG-TERM CONSEQUENCES ID PROSPECTS FOR RECOVERY nature of nuclear war and how fast these discoveries are absorbed, often with great reluctance, into the consciousness of the public and the gov- ernment. In this summary I proceed in rough serial order through some of the topics presented in this volume and give a few impressions. On the nuclear winter issue itself, there now seems to be a fairly broad consensus after the original TRAPS study that it is something worth worrying about, something probably very grave. Even the most conservative and carefully phrased reports on this subject make that apparent. The National Research Council's reports states that nuclear winter is a "clear possibility" and that the probability that the severity of nuclear winter would be worse than in the "baseline case" is roughly the same as the probability that it would be better. Despite uncertainties, "the committee believes that long- term climatic effects with severe implications for the biosphere could occur. " Much stronger statements were made in early 1985 in a report by the Royal Society of Canada3 (it called nuclear winter a "formidable threat"), in various Soviet publications,4 and in September 1985 in the SCOPE/ ENUWAR (Scientific Committee on Problems of the Environment/En- vironmental Effects of Nuclear War) report by the International Council of Scientific Unions,5 a real tour de force involving hundreds of scientists from some 20 or so nations over a period of 3 years. They conclude that "the risks of unprecedented [climatic] consequences are great for non- combatant and combatant countries alike." I recommend that everyone take a close look at the first volume on the physical effects of nuclear war. It is an excellent summary of what we currently know. And the second volume on the biological effects in many places plows important new ground, which is especially useful because there is a curious reluct- ance on the part of the U.S. government to fund work on the biological consequences of nuclear winter. I will return to this question. The issue of the reliability of nuclear winter must of course be raised. The subject is not readily amenable to direct experimental verification- at least not more than once, and very few people wish to perform the experiment, as important as it is to know the answer. The issue of reliability has been described6 as analogous to what in the United States, perhaps unfortunately, is called Russian roulette. You have a revolver that has six chambers. It is filled with an unknown number of cartridges, but probably more than zero. The chambers are spun; you put the revolver to your temple and are about to pull the trigger. How relevant is it that you have some doubt about how many of the chambers are filled? Would you do something very different if only one chamber were filled or if five or six were filled?

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VIEW 1: SAGAN 557 Perhaps the greatest uncertainty at present has to do with the duration of the effects of nuclear winter, whether the atmosphere would cleanse itself in, say, weeks or months or whether it would take considerably longer. This is a real issue, especially considering the self-lofting of soot, which has been demonstrated in recent fully interactive general circulation models, such as those of Malone and colleagues7 at Los Alamos National Laboratory. Also, the earth's atmosphere is restructured by the heating that occurs at high altitudes to produce a vast region of thermal inversion. Working in the other direction is the fact that some soot but not dust would be chemically attacked in the upper atmosphere, and so the chemical properties, the absorption coefficients of the fine particles, may to some extent decay with time. There is a school of thought that says that as long as the effects of nuclear winter are uncertain, they should not be seriously considered- or at least they should not be taken into account in discussions of public policy.8 It is a curious position because, among other reasons, the standard military posture in thinking about He Soviet Union is the worst case analysis. The argument is always that we must plan not on what the Soviet Union is likely to do but what is the worst that they can possibly do. But somehow that approach does not carry over, even a little bit, in the minds of these people into assessments of the consequences of nuclear war. Here it is argued just the other way around; that is, the best possible case should be adopted as the basis for strategic policy and doctrine until it is un- ambiguously demonstrated that a worse case is probable. The issues of exactly how much the temperatures would fall and exactly how much sunlight would be attenuated are, of course, uncertain. "Un- certain" does not mean that we know nothing. Uncertain means simply that we are not certain.* But even for relatively small nuclear wars, involving roughly 1 percent of the 20,000 or so strategic warheads in the U.S. and Soviet nuclear arsenals, the effects appear to be devastating- especially if cities are targeted. What is especially relevant is the vul- nerability of biological systems, including the webs of ecological inter- dependence of which humans are a part, to even small temperature decl~nes *Most estimates of nuclear winter continental temperature declines from ambient for a midsummer central strategic exchange have remained around-10 to-25C, beginning with the original MAPS paper. Anspaugh (this volume) takes us to task for presenting one-dimensional calculations for land and sea separately, although we explicitly indicated that allowance for the thermal inertia of the oceans was likely to make "temperature decreases in continental interiors . . . roughly 30% smaller than predicted here, and along coastlines 70% smaller."

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558 LONG-TE~ CONSEQUENCES ID PROSPECTS FOR RECOVERY declines smaller than many recent models, as well as the earlier TRAPS models, suggest may be the case. Food arrives on the table, or at least in the kitchen, and I often eat it. Sometimes I go so far as to visit the grocery store or supermarket. But I rarely trace back the sequence of events that begins in a furrowed field or a water-covered paddy. Harwell presents in this volume a paper on the ecological consequences of nuclear war. It is good to remember that crops are tremendously vulnerable to temperature declines, because much of the food we eat has arisen by a process of artificial selection over thousands of years from plants that were originally tropical or semitropical varieties. Their sensitivity to temperature is marked. The Royal Society of Canada reports and the SCOPE/ENUWAR reports both describe how a temperature decline of two or three centigrade degrees in Canada does very little to harm the wheat and barley crops. But one additional degree a temper- ature decline in the growing season that is very modest compared with those that occur in many nuclear winter scenarios causes the crops to fail altogether. Global agriculture also requires many subsidies: pesticides, fertilizers, seed stocks, fuel for tractors, and many other things. Those subsidies to nations that are not engaged in the nuclear war, that are not in the northern mid-latitude combat zone, would, of course, be cut off since they come mainly from the industrialized, nuclear-capable targeted nations. Therefore, for such distant countries, the implications for food are serious even if no nuclear weapons fall on their territory. And this is not just true in places where subsistence is marginal. A nation like Japan imports more than 50 percent of its food supply. So in the unlikely case that in a major nuclear war no targets in Japan were hit, and no significant radioactive fallout arrived from China, and no nuclear winter effects oc- curred in Japan itself, then the principal effects would be on food, fuel, and other imports. But that in itself would be sufficient to induce starvation on an unprecedented scale in Japan. More generally, nations that have no part in the quarrel between the United States and the Soviet Union (if there are any) and nations that are far removed from the northern mid-latitude combat zone could nevertheless be utterly destroyed in a nuclear war.9 This is part of the answer to the question that I am sometimes asked: "What is new about nuclear winter? We all knew we were going to die anyway." Those of us in the United States and the Soviet Union perhaps imagined that we were going to die anyway in a major nuclear war. But people elsewhere in the world imag- ined that their fate would be quite different. Now it appears that we are all at risk. The SCOPE/ENUWAR report stresses that the carrying capacity of the planetary environment is limited. The report does not guarantee that this

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VIEW I: SAGAN i! 559 s the consequence of nuclear war, but the following numbers they adduce seem well worth pondering: If every nation were reduced to subsistence on local agriculture, without the kinds of major subsidies from without that I mentioned above, then the carrying capacity of the planet would be a population only 10 percent that at present, some hundreds of millions of people. If humans were to be reduced to living off natural ecosystems, as our hunter-gatherer ancestors did, then another factor of 10 reduction in the human population would immediately follow, so that 50 million or so humans would be all that the planet could support. And this assumes that there are no effects other than those from the destruction of agriculture, that no one dies from blast, prompt ionizing radiation, fires, fallout, disease, cold, dark, pyrotoxins, or an enhanced surface flux of solar ultraviolet radiation. Clearly, the agricultural consequences of nuclear war through starvation are much more serious than had been suggested only a few years ago. I was struck by a number of new findings presented in this volume: for example, the analysis by Rotblat that the acute mean lethal dose for humans (LDso) may be considerably less than was previously thought, provided the other wartime stresses (but no ecological factors) are considered. I was also struck by the findings of Greer and Rifkin on the vulnerability of human T cells, and therefore of the human immune system, to the various stresses, mainly radiation stresses, of nuclear war. This raises another set of issues. Let me mention two of them. First, if the dose required for radiation sickness and death goes down, does the dose required to compromise the immune system also go down? The answer seems to be that it does. The amount of prompt radioactive fallout that is in the range, for example, in which the human immune system would be compromised corresponds to what fraction of the area of the northern mid-latitude combat zone? Some very quick and rough estimates suggest that as much as one-third to one-half of the northern mid-latitude land area might suffer radiation doses approaching 100 reds. In the vivid phrase of Greer and Rifl`in, nuclear war carries with it a kind of global case of acquired immune deficiency syndrome (AIDS). The second issue is that of synergism, where the overall consequences of several different environmental stresses can be more than the sum of their parts. Let me give an example. Birds are differentially vulnerable to temperature declines, low light levels, and high-radiation environments. Insects are relatively invulnerable to those same environmental stresses. Birds are one class of predators on insects. After a nuclear war, birds would die but the insects would just close up shop for the winter. When the fine particles producing nuclear winter fall out or are carried out of the atmosphere and the conditions return more or less to normal, the insects rub their eyes and go about their business, reproducing at an increased

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560 LONG-TERM CONSEQUENCES ID PROSPECTS FOR RECOVERY rate. But insects are disease vectors. At the same time, human immune systems would be compromised and sanitary systems and medical and hospital systems would be severely attenuated. It seems likely that, under these conditions, epidemics and pandemics would rage. There are many other examples. Synergisms have not at all been ex- amined in detail. This is generally difficult to do because ecosystems are complicated. In virtually every case, but not in all cases, the synergisms work to decrease, not increase, the likelihood of long-term survival of the populations exposed to them. I was asked to say something about the issue of extinction. It is hard, of course, to be in any sense certain about it. The paper by Ehrlichi and 19 others mainly biologists and ecologists that was published in De- cember 1983, following publication of the TTAPS paper, stressed that at least under some circumstances, the extinction of plants, animals, and microorganisms might be expected. They went on to make a statement that was properly cautious, that is, that the extinction of the human species could not be excluded under these circumstances; however, they did not say that it was guaranteed. But extinction is the rule, not the exception, for life on Earth. By far, most species that have ever existed are extinct today. There have been massive species extinctions, including the extinctions at the Cretaceous- Tertiary boundary 65 million years ago, in which most of the species of life on Earth died out. It is at least a good Beth that the K-T extinctions were produced by something like nuclear winter, caused by the impact on the Earth of a 10-kilometer-diameter object, an asteroid or cometary nucleus, that sprayed fine particles up into the atmosphere that took 1 or 2 years to fall out. There is one major difference: the dinosaurs were not responsible for their own demise. Now, there is an announced American plan the so-called national program to study nuclear winter and its consequences. It was originally advertised to be funded at $50 million for 5 years. The first year of funding, however, turns out to be at a rate of $5.5 million, and much of that turns out to be for programs that are not very different from those already authorized before the discovery of nuclear winter. The research is very highly concentrated in the Department of Defense and the national weapons laboratories. Only $500,000 is allocated to the National Science Foun- dation. There is an uncomfortable tendency for this very small amount of money to go to institutions that may, more so than others, be captives of what passes for the prevailing wisdom. In addition, it is a matter of policy that virtually none of this money goes for biological studies on the grounds that you have to be "sure" of the post-war physical environment before you can trace the biological

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VIEW 1: SAGAN 561 implications. Well, that is a prescription for never studying the biological consequences at all. In contrast, a wide range of biological studies can be done in which possible nuclear war effects are parameterized for example, studies in which communities of organisms, biomes, are sub- jected to a wide range of environmental stresses that would simulate nuclear winter along with its collateral effects such as radioactivity, pyro- toxins, and, later, enhanced UV-B flux. Such experiments would also be of general ecological utility quite apart from the nuclear winter issue. Another aspect of some of the papers presented in this volume that struck me was the explicit or implicit seriousness of nuclear wars that fall significantly short of engaging the full strategic arsenals. In the original TTAPS nuclear winter study, ~ a heuristic calculation was performed for a nuclear war scenario in which 100 downtowns were burned and nothing else was destroyed. It would have required some 0.S percept of the strategic arsenals and was shown to be enough to produce a very major nuclear winter effect. Here, Daugherty, Levi, and von Hippel also talked about the destruction of 100 cities and found a trail of death and destruction resulting from prompt effects alone to be much worse than had been discussed previously. Abrams showed in many different ways the enormous disparity be- tween the medical facilities that would be available after a nuclear war and the urgent human needs that would actually exist. While there were different proportional disparities, some of them-intensive care units and especially burn beds- represented very large disparity factors: a factor of 100 or more for the Federal Emergency Management Agency (FEMA) 6,500-megaton attack scenario. So, if there is, say, a factor of 100 disparity between what is available and what would be needed for the survivors of a 6,500-megaton attack, it is again possible to see that the consequences would be extremely serious for something far less than a full exchange. Thus, it has been shown in three different ways that the strategic arsenals are vastly- I would say obscenely-in excess of what is necessary to produce unparalleled death and destruction. This has a range of policy implications, including policy implications for Star Wars, the Strategic Defense Initiative (SDI). Even under very optimistic assessments, SDI leaks. These are not im- permeable systems, and not even the most fervent technically competent advocates of Star Wars foresee impermeable systems in the next two or three decades. A system that is, for example, 10 percent permeable in a contemporary full strategic nuclear exchange might let through as many as a thousand and certainly a few hundred Soviet strategic warheads. This is in the same ballpark as or in excess of the kinds of numbers mentioned above. The U.S. and Soviet arsenals could be reduced by a factor of 10

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562 LONG-TERM CONSEQUENCES AND PROSPECTS FOR RECOVERY to 100 and still retain for each nation an invulnerable and devastating retaliatory capability, maintaining, if we think it desirable, the posture of strategic deterrence. The possible failures of human and technological systems, especially under stress, also have been discussed in this volume. There is currently a field of technology that is subject to a great deal of public scrutiny, in which an enormous amount of national pride has been invested, in which the best minds work, and for which the major nuclear nations have pow- erfu] incentives not to have embarrassing failures: the civilian space pro- gram. Nevertheless, there have always been and there remain major unexpected failures at every level in the civilian space program. Just recently there was the spectacle of French President Francis Mitterand visiting French Guiana to witness a launch of an Ariane booster, which promptly blew up on the pad. An even more famous case is when Soviet Premier Nikita Khrushchev was at the United Nations in New York and a spectacular launch was planned from Tyuratum. Instead there was a spectacular explosion, which killed Field Marshal Nedelin and other mem- bers of the upper echelons of Soviet rocketry senior management. The explosion is easy to understand; that it killed a marshal is more difficult to understand. And the space shuttle itself has had many failures: in the deployment of satellites, in its computers, and so on.* These examples are just re- minders that technical failures are unavoidable, especially in a situation in which there is insufficient opportunity for testing because, as has been stated repeatedly, there can only be one nuclear war. There will not be much opportunity to learn from experience. I would like to make a few remarks about the section of this volume on the psychosocial perspectives of images and risks of the nuclear arms race. I thought that this was extraordinarily useful and is perhaps the central topic of the nuclear war issue, namely, the human heart and mind. In the late winter and early spring of 1902, on the island of Martinique, there were a set of unmistakable premonitions of Me forthcoming volcanic *Note added in proof, May 9, 1986: Since I gave this presentation on September 22, 1985, my point has been tragically reinforced by the Challenger disaster and several sub- sequent NASA and DoD launch failures and, in the Soviet Union, by the Chernobyl disaster (for which the probability of meltdown was authoritatively stated by Soviet experts in 1985 as O.0001/yr). With these sobering recent experiences before us, how sure are we of the improbability of accidental nuclear war or, if nuclear war happens, that the long-term consequences will fall short of the worst case? And if we are unsure, how should decisions on policy and doctrine be skewed? Also, what do these experiences tell us about the ultimate reliability of the proposed and vastly more complicated SDI systems?

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VIEW l: SAGAN 563 explosion of Mt. Pelee. There were rumblings heard all over the island. There were ash deposits and a number of people on the island, including scientists, spoke out and urged prompt evacuation. But civil authorities reassured everyone that there was nothing to worry about and vigorously opposed the idea of taking any precautions what- soever. On May 8, 1902, the famous volcanic explosion occurred, which killed the entire population of the port of St. Pierre (some 26,000 people), except for a handful of prisoners in subterranean cells, and the like. This is a dramatic illustration of denial: denial by public officials, denial in the face of the clear public interest. I give this as an existence theorem of what can happen, not hypothetically, but in the real world. The psychiatric mechanisms that were discussed today denial, dis- placement, and projection are not part of the lexicon of political debate in this country or, indeed, as far as I know, anywhere else. And yet they are central issues of our time, especially, but by no means exclusively, for the nuclear war problem. Better education of national leaders and the world public on the existence and force of such unconscious motivations should have a high priority. One of the principal difficulties of the nuclear war issue is a kind of failure of the imagination; that is, most of us have not experienced a nuclear war, and therefore it is hard to imagine. It has an abstract quality. It seems unreal. The principal, most effective means of transcending that failure of the imagination is to portray it in the news media, and especially on television. We have heard about The Day After, but The Day After was, of course, a very bowdlerized version of nuclear war. The American Broadcasting Company (ABC) executives thought that even a bowdlerized version was too much for the American people and were unusually skittish and nenous about showing it. A television program much closer to the realities of a nuclear war for example, the British Broadcasting Corporation (BBC) program Threads was widely considered to be too difficult for Ameri- cans to see and was not shown by the commercial networks or even by the Public Broadcasting System. Only Ted Turner and WTBS had the courage to show it. There is, here, an important tension between public education about these unpleasant possibilities and the understandable wish to avoid feeling rotten all the time. But it is essential that we understand what the stakes are if there is to be any likelihood that we can reduce the prospects of nuclear war. It is noteworthy and surprising and distressing how infrequently tele- vision or films portray a hopeful future for the human species. Most television attempts to prognosticate what the future holds involve either

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564 LONG-TERM CONSEQUENCES AND PROSPECTS FOR RECOVERY a very unimaginative extrapolation from where we are today and/or some kind of global, usually nuclear, catastrophe. As a result, youngsters grow up expecting the worst, without any knowledge that major departures from the prevailing wisdom, in a benign direction, have occurred many times before in human history. They can happen again. There was a time when the divine right of kings was powerfully ad- vocated, in which national leaders and the clergy argued, to take an American example, that it was the specific intention of God Almighty that Americans should live under the yoke of King George III. Well, we now laugh at that. How could anyone have been so foolish as to believe that George III was divinely foisted upon us? But there was a time when the remark I have just made was treasonable. The same is true of slavery, at least chattel slavery, in which people were bought and sold like cattle. That was also considered divinely or- dained. Aristotle argued that chattel slavery is part of human nature, some humans (those in power) are "naturally" masters, others "naturally" slaves. And yet today, all over the world, with only a few exceptions, it is widely recognized that slavery is something monstrous; maybe our ancestors were comfortable with such an institution, but we in the en- lightened present recognize it for what it is. Similar remarks apply to cannibalism, smallpox, and many other social conventions and natural events that were once thought immutable. I sug- gest that our descendants if we are wise enough to avoid the worst- will look upon our tolerance of nuclear weapons, or willingness to "live" with them, as we look on those tolerant of absolute monarchy or chattel slavery. I suggest that the nuclear war issue, which seems to be such a difficult nut to crack, also is a soluble problem, but only if, as Einstein urged upon us, we are willing to change our way of thinking. A ~ ~ ., . . NOTES Marco, R. P., O. B. Toon, T. P. Ackerman, J. B. Pollack, and C. Sagan. 1983. Nuclear winter: Global consequences of multiple nuclear explosions. Science 222:1283-1292. [TTAPS] 2National Research Council. Committee on the Atmospheric Effects of Nuclear Explo- sions. 1985. The Effects on the Atmosphere of a Major Nuclear Exchange. Washington, D.C.: National Academy Press. 3Royal Society of Canada. 1985. Nuclear Winter and Associated Effects: A Canadian Appraisal of the Environmental Impact of Nuclear War. Ottawa: Royal Society of Canada. 4Alexandrov, V., Update of climatic impacts of nuclear exchange, International Seminar on Nuclear War, Fourth Session, EIice, Italy, August 19-24, 1984; The Night After: Climatic and Biological Consequences of a Nuclear War, 1985, Moscow: Mir; see also Ehrlich, P. R., C. Sagan, D. Kennedy, and W. O. Roberts, 1984, The Cold and The Dark: The World After Nuclear War, New York: W. W. Norton.

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VIEW 1: SAGAN 565 sPittock, A. B., T. P. Ackerman, P. J. Crutzen, M. C. MacCracken, C. S. Shapiro, and R. P. Turco, 1986, Environmental Consequences of Nuclear War, Vol. I: Physical and Atmospheric Effects, New York: John Wiley & Sons; Harwell, M. A., and T. C. Hutch- inson, 1986, Environmental Consequences of Nuclear War, Vol. II: Ecological and Ag- ricultural Effects, New York: John Wiley & Sons; see also Sagan, C., 1985, Nuclear winter: A report from the world scientific community, Environment 27(8):12-15,38-39. 6By S. Schneider in testimony, House Interior and Science and Technology Committees, March 14, 1985. (Proceedings in press, U.S. Government Printing Office, Washington, D.C.) 7Malone, R. L., L. H. Auer, G. A. Glatzmaier, M. C. Wood, and O. B. Toon. 1986. Nuclear winter: Three-dimensional simulations including interactive transport, scavenging, and solar heating of smoke. J. Geophys. Res., 91(D1):1059-1053; also see R. L. Malone, Atmospheric perturbations of large-scale nuclear war. This volume. 8See, e.g., Teller, E., 1984, Widespread after-effects of nuclear war, Nature 310:621- 624; and the rebuttal, Sagan, C., 1985, On minimizing the consequences of nuclear war, Nature 317:485-488. 9Sagan, C. Nuclear war and climatic catastrophe: Some policy implications. 1983/1984. Foreign Affairs 62(2):257-292. ~Ehrlich, P. R., et al. 1983. Long-term biological consequences of nuclear war. Science 222: 1293-1300. ~Sepkoski, J. John Jr. 1986. Phanerozoic overview of mass extinction, in Pattern and Process in the History of Life, D. M. Raup and D. Jablonski (eds.). Berlin: Springer- Verlag. i2Alvarez, L. W., W. Alvarez, F. Asaro, and H. V. Michel, 1980, Extraterrestrial cause for the cretaceous-tertiary extinction, Science 208: 1095; Pollack, J. B., O. B. Toon, T. P. Ackerman, C. P. McKay, and R. P. Turco, 1983, Environmental effects of an impact- generated dust cloud: Implications for the cretaceous-tertiary extinctions, Science 219:287.