29 years may seem like a good record, but by the Doomsday Argument[0] we shouldn't necessarily assume that this lull will last more than another 29 years.
Also, I think your choice of time frame is a little strange. It's true that the last US nuclear test was 1992, but North Korea as recently as 2017 tested a hydrogen bomb[1]. I don't know if by "on the planet" you mean "above ground", but the 1992 US test occurred in a tunnel.[2]
Anyway, when the stakes are "billions of people are killed by radiation and famine", I think it's fair to want greater guarantees than "no nuclear detonation in the past 4 years". Similarly, "nuclear weapons haven't been used to kill people in the past 76 years" isn't much more comforting.
Also, I think your choice of time frame is a little strange. It's true that the last US nuclear test was 1992, but North Korea as recently as 2017 tested a hydrogen bomb[1]. I don't know if by "on the planet" you mean "above ground", but the 1992 US test occurred in a tunnel.[2]
Anyway, when the stakes are "billions of people are killed by radiation and famine", I think it's fair to want greater guarantees than "no nuclear detonation in the past 4 years". Similarly, "nuclear weapons haven't been used to kill people in the past 76 years" isn't much more comforting.
[0] https://en.wikipedia.org/wiki/Doomsday_argument
[1] https://en.wikipedia.org/wiki/2017_North_Korean_nuclear_test
[2] https://en.wikipedia.org/wiki/Operation_Julin