"As previous work has pointed out, the nuking of a sufficiently large city would be enough to generate a global-scale nuclear autumn. Take Los Angeles, for example, a city that extends for 500 square miles. The explosion and resulting fires would send an estimated 5.5 million tons of ash and soot into the stratosphere, causing sunlight, temperatures, and rainfall to temporarily decrease around the world. Globally, this would result in diminished growing seasons for the next half-decade, and temperatures would be the lowest in a thousand years. In some parts of the world, rainfall would be down by as much as 80 percent."