Fiction is a tool used by humans to elicit, experience and process feelings under (mostly) safe circumstances. The details (such as how much the sea level would have to rise for this to be accurate) are not quite relevant; the point is to make the reader think about how they would feel if this sort of concern was just a commonplace consideration in their daily life. Is it not shocking? Uncomfortable? Sorta nihilism-inducing?

In summary: doesn't it make you want to act towards preventing this from ever being close to happening?