The Medical Implications of Nuclear War (1986) / Chapter Skim
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3 Recent Assessments of the Environmental Consequences of Nuclear War
3 Recent Assessments of the Environmental Consequences of Nuclear War
Pages 96-116
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From page 96... ...
Rey, California NEW FINDINGS Since late 1984 a number of important scientific studies have considered the global-scale consequences of a major nuclear war. These studies look beyond the immediate and direct effects of nuclear explosions (blast, thermal radiation, and local radioactive fallout)
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From page 97... ...
Regardless of the resolution to this problem, wildland fire smoke remains a secondary contributor to a nuclear winter, with industrial and urban smoke being the primary contributor. The heights of deposition of smoke in large fire plumes have been studied by Cotton (1985)
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From page 98... ...
POTENTIAL CONTRIBUTION OF PLASTICS TO NUCLEAR WINTER Modern civilization is finding more uses for plastics in construction, durable goods, and packaging. When burned, plastics typically generate a sooty toxic smoke (and could therefore contribute to a nuclear winter)
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From page 99... ...
(The coefficient for phenolics is only estimated.) The extinction coefficient, when multiplied by the quantity of a particular type of plastic that may be burned, and divided by the area over which the smoke may be dispersed, provides an estimate of the extinction optical depth of the resulting smoke layer.
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From page 100... ...
, about 800 Tg could be in use in the NATO and Warsaw Pact alliances by the turn of the century, with the quantities in use in these countries continuing to grow well into the century. Greater amounts would have been produced and discarded, and much of this would be accessible at trash disposal sites.
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From page 101... ...
Under flaming conditions, the smoke is typically black and sooty, with a large optical absorption coefficient. Table 1 summarizes data on the specific extinction coefficient of the smoke generated by a variety of plastics during flaming combustion (the specific extinction coefficient is expressed in terms of the square meters of cross section produced by each gram of material burned)
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From page 102... ...
Fraction Activated by Firesa Equivalent Global Extinction Optical Depthb Global Absorption Optical DepthC TTAPS Baseline Urban Smoke Absorption Optical Depth (global) 1,000-2,000 750- 1 ,500 118-1/2 0.2-1.5 0.1-1.2 ~0.5 aThis factor assumes that one-fourth to two-thirds of all plastics in the warring nations could be burned in a major nuclear war and that one-fourth to one-half of the smoke would be removed immediately by precipitation (Pittock et al., 1986)
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From page 103... ...
1986. Nuclear winter: Three-dimensional simulations including interactive transport, scavenging and solar heating of smoke.
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From page 104... ...
1983. Nuclear winter: Global consequences of multiple nuclear explosions.
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From page 105... ...
1. DIRECT EFFECTS OF NUCLEAR EXPLOSIONS The two comparatively small detonations of nuclear weapons in Japan in 1945 and the subsequent higher yield atmospheric nuclear tests preceding the atmospheric test ban treaty of 1963 have provided some information on the direct effects of nuclear explosions.
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From page 106... ...
and about half of the radioactivity from surface bursts would be lofted on particles into the upper troposphere or stratosphere by the rising fireballs and contribute to longer term radioactive fallout on a global scale. · Nuclear explosions high in the atmosphere, or in space, would generate an intense electromagnetic pulse capable of inducing strong electric currents that could damage electronic equipment and communications networks over continent-size regions.
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From page 107... ...
This procedure may introduce considerable error in quantifying smoke emissions, especially in making estimates for intense fire situations. · About 70% of the populations of Europe, North America and the Soviet Union live in urban and suburban areas covering a few hundred thousand square kilometers and containing more than ten thousand million tonne of combustible wood and paper.
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From page 108... ...
4. THE EVOLUTION AND RADIATIVE EFFECTS OF THE SMOKE The sooty smoke particles rising in the hot plumes of large fires would consist of a mixture of amorphous elemental carbon, condensed hydrocarbons, debris particles, and other substances.
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From page 109... ...
If 30 million tonne of amorphous elemental carbon were produced by urban/industrial fires and spread over Northern Hemisphere mid-latitudes, the insolation at the ground would be reduced by at least 90%. The larger quantities of smoke that are possible in a major nuclear exchange could reduce light levels under dense patches to less than 1% of normal, and, on a daily average, to just several percent of normal, even after the smoke has spread widely.
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From page 110... ...
Nonetheless, these uncertainties probably do not affect the general character of the calculated atmospheric response. · For large smoke injections reaching altitudes of several kilometers or more and occurring from spring through early fall in the Northern Hemisphere, average land surface temperatures beneath dense smoke patches could decrease by 20-40°C below normal in continental areas within a few days, depending on the duration of the dense smoke pall and the particular meteorological state of the atmosphere.
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From page 111... ...
. Within one or two weeks, thin, extended smoke layers could appear in the low to mid-latitude regions of the Southern Hemisphere as a precursor to the development of a more uniform veil of smoke with a significant optical depth (although substantially smaller than in the Northern Hemisphere)
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From page 112... ...
· Much less analysis has been made of the atmospheric perturbations following the several week, acute climatic phase subsequent to a nuclear war involving large smoke injections. Significant uncertainties remain concerning processes governing the longer-term removal of smoke particles by precipitation scavenging, chemical oxidation, and other physical and chemical factors.
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From page 113... ...
The smoke, however, might also prolong and further augment the long-term ozone reduction as a result of smoke-induced lofting of soot and reactive chemicals, consequent heating of the stratosphere, and the occurrence of additional chemical reactions. · Large amounts of carbon monoxide, hydrocarbons, nitrogen and sulfur oxides, hydrochloric acid, pyrotoxins, heavy metals, asbestos, and other materials would be injected into the lower atmosphere near the surface by flaming and smoldering combustion of several thousand million tonne of cellulosic and fossil fuel products and wind-blown debris.
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From page 114... ...
However, because nuclear explosions create highly radioactive fission products and the emitted neutrons may also induce radioactivity in initially inert material near the detonation, radiological doses would be delivered to survivors both just downwind (local fallout) and out to hemispheric and global scales (global fallout)
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From page 115... ...
~ Laboratory and field experiments are needed to improve estimates of the amount and physical characteristics of the smoke particles that would be produced by large fires, particularly by the combustion of fossil fuels and fossil fuel-derived products present in urban and industrial regions.
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From page 116... ...
Closer attention should be paid to He possible effects in low latitudes and in the Southern Hemisphere, where the climatic effects are likely to be much more important than the direct effects of the nuclear detonations, which are expected to be confined largely to the Northern Hemisphere. ~ · Laboratory and theoretical studies are needed of the potential chemical alterations of the atmosphere on global and local scales, and of the extent that smoke particles could affect and might be removed by chemical reactions high in the atmosphere.
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