Mexico City, Tokyo, and Shanghai—megacities with populations of more than 20 million and with unique infrastructures—have in recent years all made pledges toward total sustainability. Experts discuss how Los Angeles can learn from the triumphs and struggles of these mega metropolises. Dana Cuff is an architect and urban planning professor at UCLA who directs the global urban analysis think tank CityLAB and leads the Urban Humanities Initiative—a cross-disciplinary research project that examines these megacities and their resiliency. Matt Petersen is the former chief sustainability officer of Los Angeles, appointed by Mayor Eric Garcetti. He helped represent L.A. at C40 and currently serves as the president and chief executive officer of the Los Angeles Cleantech Incubator. Moderated by Mark Gold, UCLA associate vice chancellor of environment and sustainability.