A sea level rise of a meter, what we can probably expect over the next century or so, will mean more frequent flooding of coastal communities, more devastating storms, etc, but Florida will not disappear, or Manhattan become an archipelago of skyscraper rooftops.

It will also be gradual, taking generations, so we will be able to adjust. The kind of flooding you can expect from Greenland and Antarctica being ice-free would be devastating, but the violent climate excursions we would experience prior to that would probably wipe out our mechanized agriculture and much of our industrial base long before we had to move to higher ground.

The figure I've read for a total meltdown would raise sea levels several hundred feet. I don't believe in runaway warming, it's never happened before, why should it happen now? I suspect the Earth's natural regulating and buffering systems would kick in and prevent that. But I don't believe just because the worst-case scenario is highly unlikely doesn't mean we don't have a very serious problem.

My house is 7 feet above mean high tide, and I live 8 miles from the Atlantic.