Hey, it's not the end of the world if all the Greenland and Antarctic ice shelves melt and raise sea level by a couple hundred feet: The world will get along just fine. It's done it before and it's also had ice ages during which sea level was much lower.

Of course, the human race might not like it much at either of those extremes. But as long as we can hold off killing ourselves en masse for a couple hundred years, we should have lots of other places to live. Then we can just visit earth for vacations. Like sun & surf on the North Slope of the Brooks Range. Or maybe a ski weekend on Haleakala, if the climate tips back the other way once the thermo-haline circulation stops.