In case of a full-scale atomic war, about 15,000 warheads could be fired. That’s enough to kill about three billion people, but it’s not nearly enough to cover the entire surface of the earth with detonations. Since there are people everywhere, that means that atomic bombs cannot kill every single person, but sadly the explosive force is only the first problem.

An atomic war would cause thousands of huge explosions. Each blast would throw particles from the Earth so high up into our atmosphere that they would take years to fall back down.

Some humans might survive

The particles would block out the sun and cool down the whole planet. Agriculture would practically stop causing billions to starve. This scenario is called a nuclear winter and that is how nuclear war could lead to human extinction.

What isn’t known is if every part of the world would be affected equally. Some humans might survive.

We don’t know if a nuclear war would kill all humans, but we can’t rule it out.