Stephen Cassell, principal architect at Architecture Research Office, discusses his firm's proposal to reshape the New York City harbor in response to global warming and rising water lines. ARO's proposal consists of two basic components that form an interconnected system: porous green streets and a graduated edge. Their new conception of what a “street” is will not only provide productive park space within the city, it creates a network of absorptive green surfaces. On the edge of the island, three interrelated high-performance systems are constructed to block higher sea levels and mitigate storm surge force and flooding: a productive park network, freshwater wetlands, and tidal salt marshes. The above- and below-ground performance of the city can be supported by a newly integrated and mutually beneficial infrastructure.