I've heard a suggestion that we aggressively harvest geothermal power from a volcano in order to cool it. But geothermal power can itself trigger earthquakes, and I'm not sure it's realistic we could harvest power at a rate to move the needle on cooling a volcano.
Oddly the eruption might help mitigate the resulting fallout.
Did not know this and it took me down a rabbit hole, starting at this article from the Scientific American: https://news.ycombinator.com/item?id=35561206
says a magnitude 9 earthquake is equivalent to 189 MT-tnt, so the largest atomic bomb detonated by mankind would be the energetic equivalent of an 8.6 magnitude earthquake.
But it's not really a fair comparison, since the atomic bomb is fast and probably wouldn't couple its energy into the earth particularly well compared to an earthquake.