Nuclear winter is a climate cooling effect which is arises by the use of nuclear weapons in war. The cooling and darkening effect are produced by smoke blocking the sunlight which feels cold and dust entering in the atmosphere. Carl Sagan is an American astronomer who was first described the nuclear winter with an article which was published in 1983. This article described the effect and damage by the use of nuclear weapons in the war.
During the nuclear war, nuclear weapons would produce enormous fires and results a severe damage of cities, forests and killed thousands of people. As per research, the smoke produced by the nuclear weapons block the radiation coming from the sun which affect the darkness and reduces the temperature and feeling cool. The smoke and dust particles increase due to their high temperature and travel to the Northern Hemisphere which blocking sunshine from some weeks.
According to research, when the radiation from the sun was block by the smoke then it increases the darkness, cold and also destroyed the plants and animal life. This spread to hunger and diseases which severe threat for the human life. In this situation, the temperature of the upper troposphere increases due to the smoke and dust particles which absorb the sun rays and heat up, produce a temperature inversion. This creates smog at the lower level. The other expected result is that nuclear blasts would generate nitrogen oxides and destroyed the protective ozone layer in the stratosphere and resulting ultraviolet radiations coming to the surface of Earth which is threats for whole human population.
A nuclear summer is an imagined situation in which when the nuclear winter was reduced, a greenhouse effect takes place because the carbon dioxide released by combustion and methane released from the decaying organic matter that froze in the nuclear winter.
In the discussions it gives details about the drastic affect or damage by the use of nuclear weapons. The solution of the problem is that all the countries have decided for not use the nuclear weapons and make a situation for peace otherwise it will destroy the whole world and threats for whole human life.