Why depleted carrier air groups cannot simply reinforce Europe

Could heavy aircraft attrition in Europe force carrier air groups to reinforce the land campaign?

Only in an extreme emergency, because stripping the carriers would sacrifice the forward naval barrier that helps protect the convoys.

Carrier air groups are part of the layered naval geometry, not a spare pool of fighters. Their aircraft defend the carriers while contesting Soviet bombers and maintaining pressure on the northern bases and bastions. Removing them from the Norwegian Sea would expose the ships and effectively abandon Norway. It would also collapse the forward barrier that keeps more Soviet aircraft and submarines away from the convoys, so a short-term reinforcement of Europe could make the transatlantic logistics problem substantially worse.