PerspectiveNew Model Agrees with Old: Nuclear War Between U.S. and Russia Would Result in Nuclear Winter

Most people who lived through the nuclear age have heard of nuclear winter, in which global cooling would result from a major nuclear war. Early fears of such an outcome have been bolstered by sophisticated computer models that showed what would happen if a large number of nuclear bombs were detonated in large urban areas. The planet would grow colder due to the huge amount of smoke generated by fires ignited by the atomic blasts—the smoke would cover the entire planet for years, blocking the sun.

Bob Yirka writes in Phys.org that in this new effort, the researchers analyzed a large number of variables, such as estimated number of bombs, their strength, where they would blow up, and the amount of smoke that might be generated by each of them. In their analysis, they chose to look at the worst-case scenario, in which all of the atomic weapons held by both countries were used in an all-out nuclear war. In such a scenario, the researchers assumed that all of the bombs would land in either the U.S. or Russia.

The models the researchers used were not designed to provide predictions of what a major nuclear war would mean for the fate of humanity—past theories have suggested such a war would result in human extinction, along with most other species. More recent predictions suggest that might not be the case, however. The researchers with this new effort found, for example, that the amount of soot making its way into the atmosphere would be far less than that released when the Chicxulub asteroid struck the planet, wiping out the dinosaurs—but not all life on the planet.