It’s Waterworld!
got gills?
The good news: With a big enough rise in sea level, we could get rid of New Orleans, New York City, Washington, DC, parts of California and the East Coast, and large sections of Europe and Russia. And have warmer winters, too.
The bad news: The British Museum would have to be relocated to somewhere in the Scottish Highlands.
All in all, quite a bit more than a fair trade, I'd say.