Nuclear summer

Nuclear winter is the severe and prolonged global climatic cooling effect hypothesized to occur after widespread firestorms following a nuclear war. The hypothesis is based on the fact that such fires can inject soot into the stratosphere, where it can block some direct sunlight from reaching the surface of the Earth. Historically, firestorms have occurred in a number of forests and cities. In developing computer models of nuclear-winter scenarios, researchers use both Hamburg and the Hiroshima firestorms as example cases where soot might have been injected into the stratosphere, as well as modern observations of natural, large-area wildfires.

"Nuclear winter," and its progenitor, "nuclear twilight," refer to nuclear events. Nuclear winter began to be considered as a scientific concept in the 1980s, after it became clear that an earlier hypothesis, that fireball generated NOx emissions would devastate the ozone layer, was losing credibility. It was in this context that the climatic effects of soot from fires was "chanced upon" and soon became the new focus of the climatic effects of nuclear war. In these model scenarios, various soot clouds containing uncertain quantities of soot were assumed to form over cities, oil refineries, and more rural missile silos. Once the quantity of soot is decided upon by the researchers, the climate effects of these soot clouds are then modeled. The term "nuclear winter" was coined in 1983 by Richard P. Turco in reference to a 1-dimensional computer model created to examine the "nuclear twilight" idea, this 1-D model outputted the finding that massive quantities of soot and smoke would remain aloft in the air for on the order of years, causing a severe planet-wide drop in temperature. Turco would later distance himself from these extreme 1-D conclusions.

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