Nuclear winter

From Conservapedia

Nuclear winter is the theory that large-scale nuclear war would cause a global cooling effect, because soot and smoke would block out the sun for a prolonged period of time.

Fred Singer said:

• I always considered "nuclear winter" to be a hoax and scientifically incorrect—and have said so in my Nightline debate with Carl Sagan. The data from the Kuwait oil fires support this view. Actually, nuclear explosions would create a strong greenhouse effect and cause warming rather than cooling. Let's hope we never have to find out. [1]