Around the world, new "green" cities are being built from the ground up. What lessons do these ambitious projects have for the environmental retrofit of an existing city like New York—and vice versa? Moderator Eric Sanderson of the Wildlife Conservation Society and landscape ecologist behind the Mannahatta Project will lead a discussion on eco-cities with Hillary Brown of New Civic Works and founder of New York's Office of Sustainable Design; Kate Orff of SCAPE and the Columbia University Graduate School of Architecture, Planning, and Preservation; and Ashok Raiji of ARUP, engineer on the Songdo City project in South Korea. They will be joined by Gerard Evenden and Michael Wurzel of Foster + Partners, architects of the Masdar project in Abu Dhabi. Presented in collaboration with the Van Alen Institute, in conjunction with the exhibition Growing and Greening New York: PlaNYC and the Future of the City.