Stone Age settlement found under the sea in Denmark

> As today’s world faces rising sea levels driven by climate change, the researchers hope to shed light on how Stone Age societies adapted to shifting coastlines more than eight millennia ago.

Unfortunately I don't expect there is any particularly reusable solution to be uncovered. Ancient peoples facing rising tides almost certainly just walked a bit inland and built new huts there. They probably thought nothing of it. They were a far more physically mobile culture, without great dependence on immense, immovable infrastructure - nor on rigid land ownership rules.

Our culture's migration will be entirely different.

Rigid land ownership seems to be the source of a great deal of our troubles.

Now try non-rigid land ownership, where land and buildings can be expropriated in the name of nebulous greater good.

Been there, done that, it is worse than the alternative. People will stop cultivating anything, because why bother if a random officer can just take things from you at will.

Western regulations about land appropriation are strict for a reason, and they always require just compensation for a reason. That is the only way to prevent powerful people from just grabbing what they want, cloaking the thieving act in word bubbles about common prosperity.

The concept of borders is relatively new. Up until a few hundred years ago, countries simply didn't have them. Battles would start simply because "we saw those other guys again! Stop em!"