Steve Cohen begins his lecture on sustainable cities by discussing what defines a city and what defines a sustainable city. He goes through the technical challenges including: land use and materials, transportation, energy, water, waste, air quality, economic systems, and cultural, educational, recreational, health and entertainment institutions. Following the technical challenges, Cohen presents the financial, organizational and management obstacles to creating sustainable cities and concludes with public policies that can advance sustainability on the city-level. Content in this video is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License. http://creativecommons.org/licenses/by-nc-nd/3.0/