I absolutely believe that if there was a project where every nuclear weapon was systematically used for the purpose of making humans extinct, it would be successful.
>After one half-life of 5.27 years, only half of the cobalt-60 will have decayed, and the dose rate in the affected area would be 5 Sv/hour. At this dose rate, a person exposed to the radiation would receive a lethal dose in 1 hour.
>After 10 half-lives (about 53 years), the dose rate would have decayed to around 10 mSv/hour. At this point, a healthy person could spend up to 4 days exposed to the fallout with no immediate effects.
People can't stay in bunkers for 20 years at a time, just to emerge into a radiated hellscape.
https://en.wikipedia.org/wiki/Cobalt_bomb
>After one half-life of 5.27 years, only half of the cobalt-60 will have decayed, and the dose rate in the affected area would be 5 Sv/hour. At this dose rate, a person exposed to the radiation would receive a lethal dose in 1 hour.
>After 10 half-lives (about 53 years), the dose rate would have decayed to around 10 mSv/hour. At this point, a healthy person could spend up to 4 days exposed to the fallout with no immediate effects.
People can't stay in bunkers for 20 years at a time, just to emerge into a radiated hellscape.