Starting at 1st level, you are more effective with elemental magic than most. You can add your proficiency bonus to the damage rolls you make whenever you cast either an evocation spell, or a spell that does bludgeoning, fire, cold, or lightning damage.
This ability can extend to other spells that have elemental descriptors such as 'fire' and 'earth'. At your GM's discretion, you can use this ability on spells that fit this description.