For a story I’m writing that’s set in the future, I needed to research this sea level rise I’ve been hearing about. With the temperature rise from global warming, the sea levels will also rise, for two different reasons. For one thing, it’s basic physics that water expands as its temperature rises. As the temperature of the earth rises, the temperature of the oceans and all other water on the earth will also rise. As they rise, the water will expand, and the sea levels will rise.

The second reason is water from melting glaciers. This one is a lot less predictable. There could be only a little glacier melt running off into the oceans in the next hundred years, or large parts of major glaciers like the ones covering Antarctica and Greenland could not only melt but break off and float into the seas. If that happened, the rise of the sea level would be quite large.

What does all this mean for my story? Well, I originally set it in a seaside town, and now I need to see whether it might be underwater a hundred years from now. Not to mention checking on the other weather changes that global warming will bring, from more extreme temperatures (particularly heat waves) to stronger storms and more erratic weather patterns overall.

For the world, it means that people living in low-lying areas, including several island nations, will be displaced. New Orleans is the classic example – if sea levels rise a few feet or more, the city will have to be abandoned. Three feet (1 meter) is what I saw quoted as a fairly reasonable estimate of the sea level rise between now and 2100. New Orleans isn’t the only city that will be affected, though. Millions of people around the world live on coastlines that will be underwater if the sea level rises as predicted.