I think hydrogen bombs tend to be cleaner. Or at least, they have a higher ratio of heat/kinetic energy versus radioactive fallout. The long-term environmenta

I think hydrogen bombs tend to be cleaner. Or at least, they have a higher ratio of heat/kinetic energy versus radioactive fallout. The long-term environmental contamination of a few large hydrogen bombs probably wouldn't be as bad as a lot of smaller fission bombs. (I'm not an expert though. And either way you'd probably want to hide in a hole in the ground for awhile at least if you aren't and can't get far upwind.)