Our world's getting warmer, wetter, and more underwater.
1. St. Mark's Square in Venice, Italy
In Venice, the sea has always been close. After all, this is the city famed for its lovely canals and singing gondoliers paddling locals and tourists about. But after years of rising global temperatures, the water is rising, and engineers are finding it harder and harder to keep their beloved city above it. St. Mark's Square regularly finds itself calf-deep in seawater when high tides and full moons combine. Having floating seawalls and pumping groundwater out of city foundations helps hold back the rise — for now. But the city is sinking and sea levels are rising, and eventually one will prevail.
Here's what this public plaza looked like in 1955: