Venice, by virtue of its geographic situation will always be sinking as a course of nature. A research team from the Scripps Institution of Oceanography at the UCSD has recently concluded that Venice is sinking 2 millimeters per year...not catastrophic on a single year basis, but threatens the long-term viability and sustainability of the location.
Urban ecology: what economic forces created the rationale for building Venice? What environmental factors are currently threatening it? Will economic or environmental forces win out? Location: do the economic advantages of a location outweigh the environmental liabilities of the location? How do these competing factors influence the development of a city? For additional information on this story see: http://www.physorg.com/news/2012-03-venice-hasnt.html
Via Seth Dixon