In the past decade, a new breed of urbanization, the eco-city, has been conceived to anticipate the effects of the built environment on climate change. Several models have been proposed in Asia and the Middle East, where large swaths of urban fabric are being woven almost overnight. Yet the question remains–how does one define and measure the sustainability of developing a new city?

This fall the Forum for Urban Design in conjunction with the Lincoln Institute of Land Policy convened four of the world’s leading urban designers and architects to discuss the development of eco-cities. Malcolm Smith, James Corner, Thomas Auer, and Byron Stigge explained their approaches to designing ecological urbanism and expressed their cautious optimism about carbon neutrality and the future of urbanization.