> Airburst nuclear weapons produce basically 0 fallout. The bomb has to burst on the surface to pick up particles of earth and debris to create fallout.

Air bursts produce minimal localized fallout, but they have long-term global consequences, especially detonating many powerful fusion bombs. The fallout produces atmospheric carbon-14 and strontium-90, among other dangerous isotopes, that can have consequences for many future generations. This is part of the reason why the nuclear test ban treaty was created.