I suspect 1 meter wouldn’t take care of supernova radiation.
As far as I understand the issue, the danger is mainly from the temporary ozone layer depletion, with the resulting solar UV rays doing most of the damage, and not from any kind of direct supernova radiation. And UV is not hard to shield from.
Hm, so you’re right: http://en.wikipedia.org/wiki/Near-Earth_supernova#Effects_on_Earth In that case, it doesn’t sound like that much of a direct threat at all: we can use cheap underground or UV-glass-filtering greenhouses to grow our food. A disaster, but not really an existential threat.
As far as I understand the issue, the danger is mainly from the temporary ozone layer depletion, with the resulting solar UV rays doing most of the damage, and not from any kind of direct supernova radiation. And UV is not hard to shield from.
Hm, so you’re right: http://en.wikipedia.org/wiki/Near-Earth_supernova#Effects_on_Earth In that case, it doesn’t sound like that much of a direct threat at all: we can use cheap underground or UV-glass-filtering greenhouses to grow our food. A disaster, but not really an existential threat.