Nuclear winter is a term given to what would happen to Earth's environment following a large-scale nuclear war. In effect, the entire planet would be plunged into a very bitter winter that would last months or years. The most severe consequence would be that Earth's climate would become too cold to grow vital food crops, including rice, wheat, and corn. It would likely lead to the starvation of hundreds of millions of people who survived the initial nuclear blasts. In effect, it would likely be the end of civilization.

However, with the end of the Cold War and the breakup of the Soviet Union, the threat of a full-scale nuclear exchange between the United States and Russia has greatly diminished. Today, the term nuclear winter is also used to describe the aftermath of any event that sends huge amounts of particulate matter into the atmosphere, blocking...