Apocalypse Now: Credibility and Implications

APOCALYPSE NOW: CREDIBILITY AND IMPLICATIONS JANE M. ORIENT* Doomsday differs from mere disaster in several ways. In expectation of disaster, one can prepare to mitigate the consequences. If the Apocalypse is at hand, one can only repent. Instead of inspiring a study ofhistory and science, apocalyptic prophecies have a tendency to lead to magical thinking. Some groups, such as Creative Initiative, propose that by collective efforts to change our mode of thinking we could advance beyond warfare. Dr. Edsall [1] is more realistic. He calls for strengthening our conventional armaments, despite the position of Physicians for Social Responsibility that military expenditures should be reduced and the fact that conventional weapons are more costly than nuclear ones [2]. Furthermore, he is willing to acknowledge and to accept the implications of his belief that nuclear weapons are qualitatively different. Is the "nuclear winter" (TTAPS) report [3] the ultimate refutation of those who claim that nuclear weapons are only quantitatively worse than previous types? Consider the volcanic eruption cited by Dr. Edsall for comparison. Mount Tambora released about 20,200 megatons ofenergy [4] and ejected about 100 km3 (2 x 1011 tons) of debris [5]. Worldwide temperatures dropped about Io for approximately 1 year. The baseline 5,000-megaton case ofthe TTAPS report was assumed to result in about 1.2 x 109 tons ofsmoke and dust. Yet the temperature drops calculated for the nuclear winter resemble those thought to have occurred after a 10-km asteroid collided with the earth, possibly causing the massive extinctions at the end of the Cretaceous period [6—compare fig. 2 with fig. 1 of the TTAPS report]. The debris resulting from that impact should have been at least equal to the volume of the asteroid, about 523 The author is grateful to scientists in the fields of meterology, geophysics, physics, and mathematics for helpful discussions and criticisms, especially Hugh Willoughby, Howard L. Davidson, and Charles D. Roten. ?Address: Suite 9, 1601 North Tucson Boulevard, Tucson, Arizona 85716. F 1984 by The University of Chicago. All rights reserved. 003 1-5982/85/2802-0425J01 .00 218 J Jane M. Orient ¦ Apocalypse Now km3. Assuming a minimum velocity at impact of 11.2 km/sec (escape velocity), at least 2 x 107 megatons of kinetic energy would have been transferred. Obviously, the total amount of debris and the megatonnage are less important than the distribution of particle size and the consequences of the energy delivery. The results of the TTAPS report are critically dependent on assumptions about targeting strategy, because the most severe effects result from firestorms. The 100-megaton "threshold" involves the detonation of 1,000 warheads of 0.1 megatons each over central urban areas. The report is vague about which cities are chosen but cites a scenario from AMBIO which includes cities throughout the world, even in China, Japan, and India [7]. Whether firestorms would produce a high enough temperature to raise smoke to stratospheric altitudes, and whether modern cities even have a high enough density of combustible materials to permit firestorms [8], are matters for speculation . Additionally, the TTAPS model assumes, without comment, that 50 percent of the urban area in the 2-5-lb psi overpressure zone would burn, in contrast to the 10 percent or less estimated by the Office of Technology Assessment [8]. Many other questionable assumptions underlie the nuclear winter report [9]. The one-dimensional radiative convertive model for estimating temperatures neglects horizontal transport of energy, which is most important for predicting climate. Thus, the model cannot adequately account for the thermal inertia of the oceans. Even the general circulation model, which is usually applied, is not very accurate [10, 11] and depends on retrospective manipulation of constants. Since the behavior of the atmosphere is described by nonlinear systems, extrapolating from normal to markedly perturbed behavior is extremely problematic. An acknowledgment of some of these difficulties is relegated to footnote 19 in [3]. The nuclear winter is a hypothesis based on a number of worst-case assumptions. None of its authors is expert in dynamic climatology. The conclusions disagree with those presented by the National Academy of Science in 1975. Though we often hear about an independent Soviet review, Dr...