Nuclear fusion occurs naturally in the center of active stars such as our Sun in our solar system, and that process keeps the Sun active and providing energy to the planets around it, including Earth; in the process atoms in the nucleus of the star are combined and fused together creating other type of atoms, and this releases a lot of energy, it is that energy coming from the sun that keeps Earth as we know it.
Well, it will always be important but I suppose it's because it hasn't stopped and I personally doubt it will any time soon. The wrongful incarcerations are still an issue because it can ruin someone's career and life.
