What is left of the Earth after 100 nuclear warheads are detonated at the same time?

Historically, humans have witnessed the tremendous destructive power of atomic bombs in two Japanese cities thrown by the United States. The scene of death and desolation so far still haunts many people. So if 100 nuclear warheads were detonated, what disaster would await Earth?

1. What is left of the Earth if all the nuclear bombs in the world fire at the same time?
2. The Earth used to be purple and 8 secrets of little surprise

The video below will help us better understand that terrible disaster. Of course, everything is just a hypothesis of scientists, but it may be even more formidable. Hopefully, this terrible thing will never happen to our 'common home'.