Abstract
It is only recently that studies have indicated that the indirect effects of a nuclear war are just as important as the direct consequences, but reach areas far removed from those targeted. The research reviewed in this paper has aimed to quantify the climatic influence of massive smoke emissions resulting from post-nuclear fires. The smoke yields and their physicochemical properties and the numerical models used to predict the climatic effects are discussed and their results compared. All studies show a large potential for major climatic changes as a result of the smoke injected by extensive post-nuclear fires. An assessment is made of the main uncertainties involved in the nuclear winter calculations.