1. San Francisco, USA
. Cause: Earthquake
Scientists from the University of California with a 75% probability of misleading that by 2086 in the San Francisco happens is an earthquake of seven points or more. San Francisco is one of the fastest changing cities in the United States. It's all part of the displacement of the expensive and geographically hazardous coastal areas inland. Big trouble could accelerate this trend.
2. Detroit, USA
. Reason: the Outflow of population
The population of Detroit has decreased by one third since 1950 to about 950 thousand people. Assume that its population will decline slowly but continuously, at least until 2030 – the unemployment rate in the city amounted to about 10%. (In turn, the population of the suburbs around Detroit is growing all the time). If these trends continue, Detroit will change beyond recognition by 2100.
3. Venice, Italy
. Reason: Lowering the level of the soil
The city of canals opuscles already approximately for millennia but in the last century the lowering speed is increased dramatically. Over the last hundred years Venice has sunk 24 cm. The government has plans to protect the city from rising to the level of the sea, but whether they work or not, nobody knows.