Read here. James Hansen, and his creepy friend A. Gore, have crisscrossed the world claiming sea levels will rise by some 20 meters due to global warming. It's a nice scary story designed to frighten the clueless, MSM reporters and Hollywood celebrities, but unfortunately it is told by two non-experts regarding sea levels. As a result of their non-expertise, it happens their scary story has zero connection with current reality or the ancient/historical past.
So, what do the real sea-level experts say? The latest peer-reviewed report from the world expert PALSEA team indicates a worst-case scenario of 0.59 meter to 1.4 meters by 2100. Hellooooo....the experts say it's not even going to be close to the 'teens' let alone a rise 20 meters.
And carefully note, that's the worst-case scenario. If the actual present trends of sea-level rise continue, it's highly likely that the sea-level rise might only be 0.2 meters by 2100. How scary is that? It's only a tiny fraction of the mythical scariness.