Kicker

(You may pay an additional

as you cast this spell.)
Canopy Surge deals 1 damage to each creature with flying and each player. If this spell was kicked, it deals 4 damage to each creature with flying and each player instead.
To determine a spell's total cost, start with the mana cost (or an alternative cost if another card's effect allows you to pay one instead), add any cost increases (such as kicker), then apply any cost reductions. The spell's mana value remains unchanged, no matter what the total cost to cast it was.