>t you'd rather blame some river hacking for literally submerging Louisiana
Yes, because in this case you don't know what you're talking about. Flordia is built on rock (limestone in fact), when it see rises it stays the same level. Louisiana is not. The LA flood plain, if we allowed the natural flow of the river would take far longer than all the other land around it to be submerged by sea level rise. You should learn how river deltas work, and the fact they naturally compress over time.