The IPCC considers it likely that climate change will increase hurricane intensity, and New York may be particularly vulnerable to flooding from hurricanes and other storms, as Climate Progress reports:
Sea level may rise faster near New York than at most other densely populated ports due to local effects of gravity, water density and ocean currents, according to four new forecasts of melting ice sheets. The forecasts are the work of international research teams that included the University of Toronto, the National Center for Atmospheric Research in Boulder, Colo., Florida State University and the University of Bristol in the U.K., among others.
[S]ome university-based marine researchers and civil engineers are debating whether New York ought to protect its low-lying financial district, port, power grid and subways with storm surge barriers like the mobile bulwarks that safeguard London, Rotterdam, Netherlands, and St. Petersburg, Russia. Engineering concepts for multibillion-dollar barriers around New York harbor were discussed here this week during the H209 Water Forum, an international conference on coastal cities and climate change, held by the Henry Hudson 400 Foundation at the Liberty Science Center.
Saving New York seems like a no-brainer even for the most hard-nosed economist — but the price tag might be awfully high.