Yeah, I've thought about a climate battery but most of the ones you see are done in dry climates at elevation. Never seen one for a humid climate. Water table matters too for that, I've seen videos of peoples flooded tubes. Some claim mold can be a problem as well in the tube. Check this place out, no earth tubes put passive solar design dug down.
https://youtu.be/xrNsn9-wN1s