A pair of students at the University of Pennsylvania have an audacious suggestion should rising sea levels make their presence felt in Manhattan, New York. Their scheme would see the installation of waterproof canopies to the lower stories of skyscrapers. Tingwei Xu and Xie Zhang say their idea has an "irreducible integrity," thanks to the canopies' various functions which, the students say, are each of equal importance. So in addition to keeping water out, these canopies provide additional structural support against lateral forces, provide green or agricultural space, and, judging by the visualizations, provide living and working areas in their own right.
Though the choice of New York might affords the students the opportunity to include iconic architecture in their visualizations, it's not without foundation in respect of climate science. A 2009 study carried out at Florida State University by climate modeler Jianjun Yin suggested the New York sea level could rise by up to 21 cm (8.3 in) depending on future greenhouse gas emission levels. Such a rise would not permanently submerge Manhattan, but would dramatically increase the threat of flooding in the event of hurricanes and storm surges. It is thought that the North Atlantic Ocean will experience a greater rise than the global mean due to thermal expansion, and the possible slowing of the North Atlantic Gyre.
In this scenario, a scheme that protects the city center from intermittent flooding begins to look sensible. Indeed, for the more multi-functional aspects of the student's scheme to work seem to incorporate this idea of infrequent submersion. But it's not merely the direct penetration of water into buildings that must be considered. Sea water is particularly corrosive, and poses a particular threat to essential services and infrastructure. Flood defenses located around buildings (perhaps less dramatic than those envisaged here) might therefore be adopted as an additional precaution, rather than as an alternative to more traditional defenses such as dikes that aim to prevent flooding outright.
The pair's scheme is merely a concept. There are no details as to proposed materials, construction methods, or the precise nature of water-proofing. The lattice form certainly doesn't appear all that watertight at the outer layers. What is interesting is the purely architectural response to flooding - a response not without optimism. It's a grim prospect that North Atlantic cities may face a future of increased flooding, but that flood defenses can be put to work as vibrant living and working spaces is commendably imaginative. Consider it the start of a conversation, then. And if you can, try to overlook the radiation suits and, er, Imperial Stormtroopers in the visualizations.
Sources: Evolo, Nature Geoscience
