I'm not sure how much you need to raise the island. Just matching sea level rise isn't enough, because Tuvalu would really be better off being a couple meters

I'm not sure how much you need to raise the island. Just matching sea level rise isn't enough, because Tuvalu would really be better off being a couple meters higher to reduce storm damages before climate change started, and climate change both raises the seas and makes intense storms more common. But more importantly than the amount you need to raise the islands: 26 sq km * 1 meter probably doesn't raise the islands anywhere close to 1 meter, because of: * Early losses from erosion and compaction * The angle of repose around the islands (you can't just build the island straight up 1 meter).