Rising sea levels are not moot debates. People are already abandoning land that is now underwater. Typically, they are poor which means their situation is overlooked; but, the inland migration and loss of arable land has begun. Houses on stilts don’t help crops. Dikes are expensive and temporary. The only pragmatic response is to get out of the way of Nature.
“Seas Gobble Land So Pakistan’s Coastal Villagers Retreat” – Scientific American
Pretending Not To Panic 