What might happen if North Korea tries to launch a hydrogen bomb

Dave Mosher reports at Business Insider that nearly all nations now ban nuclear testing.

...The problem with nuclear test explosions is that they create radioactive fallout. Space detonations come with their own risks, including a more widespread electromagnetic pulse.

Only a fraction of a nuclear weapon's core is turned into energy during an explosion; the rest is irradiated, melted, and turned into fine particles. This creates a small amount of fallout that can be lofted into the atmosphere and spread around.

But the risk of fallout vastly increases close to the ground or water.

There, a nuclear explosion can suck up dirt, debris, water, and other materials, creating many tons of radioactive fallout - and this material rises high into the atmosphere, where it drifts for hundreds of miles.

This kind of Cold War-era fallout killed scores of innocent people in the Pacific, including Japanese fishermen, and is still causing cancer and health problems around the world today.

Read more here.