Nuclear Winter

Nuclear winter is a severe and prolonged global climactic cooling that occurs after widespread firestorms following a nuclear war. The firestorms caused by the nuclear blasts throw large amounts of soot into the stratosphere, blocking sunlight from entering the Earth.

The world has only ever experienced a nuclear winter once; one which lasted nearly 20 years following the Nuclear War of 1993.

Climate Effects
During a nuclear winter, the lack of sunlight entering the Earth's atmosphere causes plant life to die. Similarly, the lack of heat causes the global temperature to fall greatly for a long period of time until the soot settles. This can take decades, as it did following the Nuclear War of 1993.