Scientists have just released evidence that confirms what they already suspected: Sea level has been rising faster over the past century than during the previous 2,000 years, and it's definitely down to warming associated with climate change.
Seas are about eight inches higher now than they were a century ago, which is a lot when it’s in your basement but doesn’t sound like that much in the context of an entire ocean. It's the rate of change that matters, though, not the absolute increase. The seas have been rising more than two millimeters per year, which is four times as fast as they rose during the “Medieval climate anomaly” in the 11th to 15th centuries.
We could be seeing between 30 and 75 inches of sea level rise by the end of the century. Because of how it increases the impact of storm surges, that's enough to warrant, for example, a gigantic multi billion-dollar river Thames-style flood barrier between Brooklyn and Staten Island, to protect New York City.