National Geographic has a good, but disturbing, interactive map showing what 216 feet of sea level rise will do to coastlines around the world.
The maps here show the world as it is now, with only one difference: All the ice on land has melted and drained into the sea, raising it 216 feet and creating new shorelines for our continents and inland seas.
There are more than five million cubic miles of ice on Earth, and some scientists say it would take more than 5,000 years to melt it all. If we continue adding carbon to the atmosphere, we’ll very likely create an ice-free planet, with an average temperature of perhaps 80 degrees Fahrenheit instead of the current 58.
Of course, it's not necessary for all of the ice to melt for us to experience devastating effects of sea level rise. Just from the current sea level rise caused by melting ice and thermal expansion, we're already seeing destruction from higher water. Right now, Alaskan villages are worrying about what to do as melting ice threatens to erode their village out from underneath their feet. In the Pacific, low-lying islands face existential questions such as if a country is underwater, is it still a nation-state?
With Arctic temperatures at their highest in 44,000 years, ice cover has hit record lows and scientists report that sea level is rising 60% faster than anticipated. Just six feet of sea level rise would be enough to ruin South Florida and experts warn that we've already "baked in" approximately 70 feet of sea level rise.
This shouldn't be taken to mean it's too late to act, but illustrations like this can serve as a useful reality check that unless we act now to stop greenhouse gas emissions, we're going to see worse and worse effects as time goes on.
This add some context, this is all the water on Earth if it was in the same place. On the scale of the planet, the oceans aren't that deep, so it doesn't take that much of a change to affect coastlines.
For more info on the image above, see: If You Put All Earth's Water In One Place, It'd Look Like This.