Storage and disposal of the weapons is technically difficult but probably a manageable problem. However, it is a daunting political and social problem. It is a challenge to maintain these weapons, to significantly reduce their numbers, to clean up the waste, and to insure that these weapons never will be used again. Nuclear weapons are with us to this day and could be with us in the future. Even if all conflicts among nations end, some nuclear weapons might be retained.
Earth is vulnerable to impacts from comets and asteroids.
Some scientists have proposed that nuclear weapons could possibly be used to deflect them from hitting our planet.